2015 Gout Classification Criteria: an American College of Rheumatology/European League Against Rheumatism collaborative initiative

Correlations of characteristics with tissue involvement in knee gouty arthritis: Magnetic resonance imaging analysis

Objective

This study investigates the MRI features of knee gouty arthritis (KGA), examines its relationship with the extent of tissue involvement, and assesses whether risk factors can predict KGA.

Materials and methods

Patients diagnosed with KGA underwent MRI examinations, and two independent observers retrospectively analyzed data from 44 patients (49 knees). These patients were divided into mild and severe groups based on tissue involvement observed during arthroscopy. MRI features were summarized, and the intraclass correlation coefficient evaluated interobserver reproducibility. Single-factor analysis compared clinical indicators and MRI features between groups, while Cramer's V coefficient assessed correlations. Multivariate logistic regression identified predictors of tissue involvement extent, and a ROC curve evaluated diagnostic performance.

Results

Among 49 knees, 18 had mild and 31 had severe tissue involvement. Key MRI features included ligament sketch-like changes, meniscal urate deposition, irregularly serrated cartilage changes, low-signal signs within joint effusion, synovial proliferation, Hoffa's fat pad synovitis, gouty tophi, bone erosion, and bone marrow edema. The interobserver reliability of the MRI features was good. Significant differences (P < 0.05) were observed between the groups for anterior cruciate ligament (ACL) sketch-like changes, Hoffa's fat pad synovitis, and gouty tophi. ACL sketch-like changes (r = 0.309), Hoffa's fat pad synovitis (r = 0.309), and gouty tophi (r = 0.408) were positively correlated with the extent of tissue involvement (P < 0.05). ACL sketch-like changes (OR = 9.019, 95 % CI: 1.364-61.880), Hoffa's fat pad synovitis (OR = 6.472, 95 % CI: 1.041-40.229), and gouty tophi (OR = 5.972, 95 % CI: 1.218-29.276) were identified as independent predictors of tissue involvement extent (P < 0.05). The area under the ROC curve was 0.862, with a sensitivity of 67.70 %, specificity of 94.40 %, and accuracy of 79.14 %.

Conclusion

This comprehensive analysis of MRI features identifies ligament sketch-like changes, meniscal urate deposition, and low-signal signs within joint effusion as characteristic MRI manifestations of KGA. Irregular cartilage changes are valuable for differential diagnosis in young and middle-aged patients. ACL sketch-like changes, Hoffa's fat pad synovitis, and gouty tophi correlate with tissue involvement severity and are critical in predicting and assessing the extent of tissue involvement in KGA.

2023 EULAR recommendations on imaging in diagnosis and management of crystal-induced arthropathies in clinical practice

OBJECTIVE

To formulate evidence-based recommendations and overarching principles on the use of imaging in the clinical management of crystal-induced arthropathies (CiAs).

METHODS

An international task force of 25 rheumatologists, radiologists, methodologists, healthcare professionals and patient research partners from 11 countries was formed according to the EULAR standard operating procedures. Fourteen key questions on the role of imaging in the most common forms of CiA were generated. The CiA assessed included gout, calcium pyrophosphate deposition disease and basic calcium phosphate deposition disease. Imaging modalities included conventional radiography, ultrasound, CT and MRI. Experts applied research evidence obtained from four systematic literature reviews using MEDLINE, EMBASE and CENTRAL. Task force members provided level of agreement (LoA) anonymously by using a Numerical Rating Scale from 0 to 10.

RESULTS

Five overarching principles and 10 recommendations were developed encompassing the role of imaging in various aspects of patient management: making a diagnosis of CiA, monitoring inflammation and damage, predicting outcome, response to treatment, guided interventions and patient education. Overall, the LoA for the recommendations was high (8.46-9.92).

CONCLUSIONS

These are the first recommendations that encompass the major forms of CiA and guide the use of common imaging modalities in this disease group in clinical practice.

Identification of SOCS3 and PTGS2 as new biomarkers for the diagnosis of gout by cross-species comprehensive analysis

Background

Gout is the most common inflammatory arthritis in adults. Gout is an arthritic disease caused by the deposition of monosodium urate crystal (MSU) in the joints, which can lead to acute inflammation and damage adjacent tissue. Hyperuricemia is the main risk factor for MSU crystal deposition and gout. With the increasing burden of gout disease, the identification of potential biomarkers and novel targets for diagnosis is urgently needed.

Methods

For the analysis of this subject paper, we downloaded the human gout data set GSE160170 and the gout mouse model data set GSE190138 from the GEO database. To obtain the differentially expressed genes (DEGs), we intersected the two data sets. Using the cytohubba algorithm, we identified the key genes and enriched them through GO and KEGG. The gene expression trends of three subgroups (normal control group, intermittent gout group and acute gout attack group) were analyzed by Series Test of Cluster (STC) analysis, and the key genes were screened out, and the diagnostic effect was verified by ROC curve. The expression of key genes in dorsal root nerve and spinal cord of gout mice was analyzed. Finally, the clinical samples of normal control group, hyperuricemia group, intermittent gout group and acute gout attack group were collected, and the expression of key genes at protein level was verified by ELISA.

Result

We obtained 59 co-upregulated and 28 co-downregulated genes by comparing the DEGs between gout mouse model data set and human gout data set. 7 hub DEGs(IL1B, IL10, NLRP3, SOCS3, PTGS2) were screened out via Cytohubba algorithm. The results of both GO and KEGG enrichment analyses indicate that 7 hub genes play a significant role in regulating the inflammatory response, cytokine production in immune response, and the TNF signaling pathway. The most representative hub genes SOCS3 and PTGS2 were screened out by Series Test of Cluster, and ROC analysis results showed the AUC values were both up to 1.000. In addition, we found that PTGS2 expression was significantly elevated in the dorsal root ganglia and spinal cord in monosodium urate(MSU)-induced gout mouse model. The ELISA results revealed that the expression of SOCS3 and PTGS2 was notably higher in the acute gout attack and intermittent gout groups compared to the normal control group. This difference was statistically significant, indicating a clear distinction between the groups.

Conclusion

Through cross-species comprehensive analysis and experimental verification, SOCS3 and PTGS2 were proved to be new biomarkers for diagnosing gout and predicting disease progression.

Systematic literature review to inform the EULAR recommendations for the use of imaging in crystal-induced arthropathies in clinical practice

OBJECTIVE

To summarise current data regarding the use of imaging in crystal-induced arthropathies (CiAs) informing a European Alliance of Associations for Rheumatology task force.

METHODS

We performed four systematic searches in Embase, Medline and Central on imaging for diagnosis, monitoring, prediction of disease severity/treatment response, guiding procedures and patient education in gout, calcium pyrophosphate dihydrate deposition (CPPD) and basic calcium phosphate deposition (BCPD). Records were screened, manuscripts reviewed and data of the included studies extracted. The risk of bias was assessed by validated instruments.

RESULTS

For gout, 88 studies were included. Diagnostic studies reported good to excellent sensitivity and specificity of dual-energy CT (DECT) and ultrasound (US), high specificity and lower sensitivity for conventional radiographs (CR) and CT. Longitudinal studies demonstrated sensitivity to change with regard to crystal deposition by US and DECT and inflammation by US and structural progression by CR and CT. For CPPD, 50 studies were included. Diagnostic studies on CR and US showed high specificity and variable sensitivity. There was a single study on monitoring, while nine assessed the prediction in CPPD. For BCPD, 56 studies were included. There were two diagnostic studies, while monitoring by CR and US was assessed in 43 studies, showing a reduction in crystal deposition. A total of 12 studies with inconsistent results assessed the prediction of treatment response. The search on patient education retrieved two studies, suggesting a potential role of DECT.

CONCLUSION

This SLR confirmed a relevant and increasing role of imaging in the field of CiAs.

The Tophus Impact Questionnaire (TIQ-20): responsiveness to change during urate-lowering therapy

OBJECTIVES

In 2015, the 20-item Tophus Impact Questionnaire (TIQ-20) was developed as a tophus-specific patient-reported outcome measure. The aim of this study was to determine whether TIQ-20 scores change during urate-lowering therapy.

METHODS

We analysed data from a 2-year clinical trial of allopurinol dose escalation using a treat-to-target serum urate approach. For participants with tophaceous gout, the longest diameter of up to three index tophi was measured, using Vernier calipers, and the TIQ-20 was recorded at study visits. Participants at the one site were invited to participate in a dual-energy CT (DECT) substudy. Participants were included in this analysis if they had tophaceous gout and TIQ-20 scores available at baseline, Year 1 and Year 2 (n = 58, 39 with DECT data). Data were analysed using a mixed-model approach to repeated measures.

RESULTS

Improvements were observed in all tophus measures over the 2-year period. The mean (s.d.) TIQ-20 scores reduced over 2 years from 3.59 (1.77) to 2.46 (1.73), P < 0.0001, and the mean (95% CI) TIQ-20 change over the 2 years was -1.13 (-1.54, -0.71). The effect size (Cohen's d) for the change in the sum of the index tophi diameter over 2 years was 0.68, for the DECT urate volume was 0.50, and for the TIQ-20 was 0.71.

CONCLUSION

For people with tophaceous gout treated with allopurinol using a treat-to-target serum urate approach, improvements in TIQ-20 occurred, as did improvements in physical and imaging tophus measures. These findings demonstrate that the TIQ-20 is a responsive patient-reported instrument of tophus impact.

Defining the key clinician skills and attributes for competency in managing patients with osteoporosis and fragility fractures

Osteoporosis and fragility fractures are managed by clinicians across many medical specialties. The key competencies of clinicians delivering bone health care have not been systematically established. We aimed to develop a decision rule to define the threshold of adequate skills and attributes associated with clinical competency in bone health for a clinician serving as a referral source for bone health care. Using a modified-Delphi method, we invited clinicians with expertise in treating osteoporosis and representatives of patient advocacy groups focused on bone health to create a list of desirable characteristics of a clinician with bone health competency. Characteristics were defined as "attributes" with "levels" within each attribute. Participants prioritized levels by perceived importance. To identify the cut points for defining adequate competency, participants next ranked 20 hypothetical clinicians defined by various levels of attributes from highest to lowest likelihood of having adequate bone health competency. Lastly, we conducted a discrete choice experiment (DCE) to generate a weighted score for each attribute/level. The threshold for competency was a priori determined as the total weighted score at which ≥70% of participants agreed a clinician had adequate bone health competency. Thirteen participants generated lists of desirable characteristics, and 30 participants ranked hypothetical scenarios and participated in the DCE. The modified-Delphi exercise generated 108 characteristics, which were reduced to 8 categories with 20 levels with associated points. The maximum possible score was 25 points. A summed threshold score of >12 points classified a clinician as having adequate bone health competency. We developed a numeric additive decision rule to define clinicians across multiple specialties as having adequate competency in managing bone health/osteoporosis. Our data provide a rigorously defined criteria for a clinician with competency in bone health and can be used to quantitate the skills of clinicians participating in bone health research and clinical care.

Association between low-density lipoprotein cholesterol levels and serum uric acid to serum creatinine ratio in Chinese male gout patients

This study aimed to evaluate the association between low-density lipoprotein cholesterol (LDL-C) and serum uric acid to serum creatinine (SUA/SCr) ratio in male gout patients at different BMIs. This real-world study included 956 male gout patients aged 18-83 years. We retrospectively analyzed the medical records of Chinese male gout patients from 2017 to 2019. The correlation between LDL-C and SUA/SCr was tested after adjusting for confounding factors. We found a nonlinear relationship between LDL-C and SUA/SCr in the whole study population. Stratification analysis showed that there was actually a nonlinear relationship between LDL-C and SUA/SCr in men with a BMI of 24-28, the inflection point of LDL-C was 1.8 mmol/L, when LDL-C was greater than 1.8 mmol/L, there was a positive correlation between LDL-C levels and SUA/SCr (β = 0.67, 95% CI 0.35-0.98, P < 0.001). Moreover, LDL-C showed a significant positive correlation with SUA/SCr with a BMI of 28 or greater (β = 0.30, 95% CI 0.05-0.55, P = 0.019). However, no association was found between LDL-C and SUA/SCr with a BMI of less than 24 (β = 0.42, 95% CI - 0.03-0.86, P = 0.070). LDL-C levels were associated with SUA/SCr in Chinese male gout patients, but this correlation appeared inconsistent among different BMIs. Our findings suggest that LDL-C levels may be more noteworthy in overweight and/or obese male gout patients.

Superiority of Low-Dose Benzbromarone Add-On to Low-Dose Febuxostat Compared With Febuxostat Monotherapy in Gout With Combined-Type Hyperuricemia

OBJECTIVE

There is an unmet need for simpler urate-lowering therapy (ULT) regimens that achieve the serum urate target and improve the overall quality of gout care. We report a comparative effectiveness trial of febuxostat monotherapy versus benzbromarone add-on to low-dose febuxostat in gout specifically with combined renal urate underexcretion and overload.

METHODS

A prospective randomized trial was conducted on patients with combined-type hyperuricemia and estimated glomerular filtration rate >60 mL/min/1.73 m2 1:1 randomly assigned to febuxostat and benzbromarone combination therapy (initially febuxostat at 20 mg/day, with benzbromarone at 25 mg/day added onto 20 mg/day of febuxostat if not at target) or febuxostat monotherapy (initially 20 mg/day, escalating to 40 mg/day if not at target). The primary end point at 12 weeks was the proportion achieving a serum urate (SU) level <360 μmol/L. Other outcomes included altered liver and kidney function, new-onset urolithiasis, and gout flares.

RESULTS

There were 250 participants randomized; 219 completed 12-week treatment. More patients in the febuxostat and benzbromarone combination group achieved the SU target compared to patients in the febuxostat monotherapy group (75.5% vs 47.7%; odds ratio 3.37 [95% confidence interval 1.90-5.98]). Safety profiles were comparable between the two groups.

CONCLUSION

Simply adding on low-dose benzbromarone (25 mg/day) to low-dose (20 mg/day) febuxostat showed superior urate lowering compared to febuxostat monotherapy in gout with a combined-type hyperuricemia. For selected patients, expedited achievement of the SU target in more than 75% of patients using one titration step and low xanthine oxidase inhibitor and uricosuric doses is a potential alternative to standard ULT regimens.

[First classification criteria for diseases caused by calcium pyrophosphate deposition (CPPD)-Translation, explanation and assessment]

AIM

For diseases caused by calcium pyrophosphate deposition (CPPD), validated classification criteria were previously lacking. In this article the recently developed and validated classification criteria are translated, explained, and assessed.

METHODS

In recent years a multinational research group developed classification criteria for CPPD disease with the support by the European Alliance of Associations for Rheumatology (EULAR) and the American College of Rheumatology (ACR), following an established method. The developed criteria were finally validated in an independent cohort. The translation and annotation of the new first classification criteria were carried out in an iterative procedure in consensus with the authors.

RESULTS

The presence of a crowned dens syndrome or calcium pyrophosphate crystals in the synovial fluid in patients with pain, swelling or sensitivity of the joints (entry criterion) is sufficient for the classification as CPPD disease, where the symptoms cannot be completely explained by another rheumatic disease (exclusion criterion). If these symptoms are not present, a count of more than 56 points based on weighted criteria comprised of clinical features and the results of laboratory and imaging investigations can be included for classification as a CPPD disease. These criteria had a sensitivity of 92.2% and a specificity of 87.9% in the derivation cohorts (190 CPPD cases and 148 mimics), whereas the sensitivity was 99.2% and the specificity 92.5% in the validation cohorts (251 CPPD cases and 162 mimics).

CONCLUSION

The ACR/EULAR classification criteria 2023 of a CPPD disease will facilitate clinical research in this field. The use in the clinical routine will show how practical the criteria are.

Tophi and carotid atherosclerosis in gout patients: Role of insulin resistance

BACKGROUND AND AIM

Gout and cardiovascular disease are closely related, but the mechanism linking them is still unknown. Gout may affect the insulin signaling pathway inducing insulin resistance (IR). The study aims to evaluate the association between tophi and carotid atherosclerosis, considering the potential role of IR.

METHODS AND RESULTS

A total of 595 patients with gout aged 18 to 80 were enrolled in this study. Carotid intima-media thickness, plaques and tophi were evaluated by B-mode ultrasonography. IR was assessed by the HOMA index (hepatic IR) and Gutt index (peripheral IR). Multivariable logistic regression and interaction analysis were used to examine the association between tophi and IR and its impact on carotid atherosclerosis. Among these participants, the average age was 55.4 (±12.54) years, and 94.6 % were male. Tophi were associated with increased odds of carotid atherosclerosis and burden after adjustment for confounders (P < 0.05). Tophi and IR synergically interacted for inducing carotid atherosclerosis. The interaction between peripheral IR with tophi was more pronounced than hepatic IR with tophi.

CONCLUSIONS

Tophi were independently associated with carotid atherosclerosis risk. IR mediated a significant amount of the effect of tophi on the development of carotid atherosclerosis. Peripheral IR probably plays a more important role than hepatic IR does.

Diagnostic Accuracy of Raman Spectroscopy Integrated With Polarized Light Microscopy for Calcium Pyrophosphate-Associated Arthritis

OBJECTIVE

We studied the performance of integrated Raman polarized light microscopy (iRPolM) for the identification of calcium pyrophosphate (CPP)-associated arthritis (CPPD).

METHODS

This is a diagnostic accuracy study including 400 consecutive synovial fluid samples from a single hospital in the Netherlands. Accuracy measures were calculated against polarized light microscopy (PLM) and the 2023 American College of Rheumatology (ACR)/EULAR criteria set for CPPD.

RESULTS

The interrater reliability between iRPolM and the 2023 ACR/EULAR criteria set for CPPD was strong (κ = 0.88). The diagnostic performance of iRPolM compared to the 2023 ACR/EULAR criteria set was sensitivity 86.0% (95% confidence interval [CI] 73.3-94.2), specificity 99.1% (95% CI 97.5-99.8), positive likelihood ratio 100.33 (95% CI 32.3-311.3), negative likelihood ratio 0.14 (95% CI 0.07-0.28), positive predictive value 93.5% (95% CI 82.2-97.8), negative predictive value 98.0% (95% CI 82.2-97.8), and accuracy 97.5% (95% CI 95.5-98.8). We allowed rheumatologists to rate the certainty of their microscopic identification of CPP and found a large correspondence between iRPolM and a certain identification (κ = 0.87), whereas only 10% of the uncertain CPP identifications could be confirmed with iRPolM. We identified several novel particle types in synovial fluid analysis, including calcium carbonate crystals, deposited carotenoids, microplastics, and three types of Maltese cross birefringent objects.

CONCLUSION

iRPolM can easily identify CPP crystals with a strong diagnostic performance. PLM alone is not specific enough to reliably resolve complicated cases, and the implementation of Raman spectroscopy in rheumatology practice can be of benefit to patients with suspected CPPD.

Upregulation of CD39 During Gout Attacks Promotes Spontaneous Remission of Acute Gouty Inflammation

Gout is a self-limiting form of inflammatory arthropathy caused by the formation of urate crystals due to hyperuricemia. The resolution of gout involves the transition of proinflammatory M1-type macrophages to anti-inflammatory M2-type macrophages, as well as neutrophil-mediated extracellular trap (NET) formation. However, the underlying mechanisms of these changes are not clear. Studies have confirmed that high expression of CD39 on macrophages and neutrophils can trigger the polarization of macrophages from a proinflammatory state to an anti-inflammatory state. Recent studies have shown that the pathogenesis of gout involves extracellular ATP (eATP), and the synergistic effect of MSU and extracellular ATP can cause gout. CD39 is a kind of ATP hydrolysis enzyme that can degrade eATP, suggesting that CD39 may inhibit the aggravation of inflammation in gout and participate in the remission mechanism of gout. To confirm this hypothesis, using data mining and flow cytometry, we first found that CD39 expression was significantly upregulated on CD14 + monocytes and neutrophils in gout patients during the acute phase. Inhibition of CD39 by lentivirus or a CD39 inhibitor in acute gout models aggravated gouty arthritis and delayed gout remission. Apyrase, a functional analog of CD39, can significantly reduce the inflammatory response and promote gout remission in acute gout model mice. Our findings confirm that the upregulation of CD39 during gout flare-ups promotes spontaneous remission of acute gouty inflammation.

Clinical characteristics and risk factors associated with bone erosion in patients with tophi

INTRODUCTION

If a large amount of urate crystals is deposited in a joint cavity for an extended period of time, bone erosion will occur and gradually cause skeletal muscle necrosis and joint deformity. The aim of this study was to describe the clinical characteristics and factors associated with bone erosion in gout patients with tophi.

METHODS

A total of 210 gout patients with tophi were enrolled and divided into a bone erosion group (n = 135) and a non-bone erosion group (n = 75). Digital radiography (DR) was performed to detect bone erosion in the elbow, wrist, knee, ankle joints, interphalangeal and metatarsophalangeal joints. The clinical characteristics were recorded and compared between the two groups. Multivariate logistic regression analysis was conducted to explore the factors associated with bone erosion.

RESULTS

Compared with the non-bone erosion group, the bone erosion group had an older age, longer disease duration of gout and tophi, higher level of serum creatinine (sCr), higher proportion of drinking history and ulceration, and a lower glomerular filtration rate (GFR). Univariate logistic regression analysis results showed that sex, age, body mass index (BMI), gout duration, tophi duration, GFR, white blood cell (WBC) count, sCr level, smoking history, drinking history, and presence of ulceration were associated with bone destruction. Multivariable logistic regression analysis results indicated that tophi duration, drinking history, ulceration and sCr were positively and independently related to bone erosion.

CONCLUSIONS

Tophi patients with bone erosion presented different clinical characteristics. Tophi duration, drinking history, ulceration and sCr were associated with bone erosion in gout patients with tophi.

Traditional Chinese Medicine is Associated with the Reduction in Endpoint Events in Patients with Gouty Arthritis: Cohort Study and Association Rule Analysis

Objective

This study aimed to evaluate the effect of traditional Chinese medicine (TCM) on endpoint events in patients with gouty arthritis (GA).

Methods and Materials

A total of 2091 hospitalized GA patients were followed up by telephone, and propensity score matching (PSM) was used to reduce potential bias in the study design. Cox proportional risk model and Kaplan-Meier survival curve were utilized to analyze the impact and time effect of factors on the readmission of GA patients. The differences of laboratory indexes before and after treatment between the low and high exposure groups were compared, and the types and frequencies of medicines in all patients were counted. Association rule analysis was performed to investigate the association between TCM and test indexes or endpoint events.

Results

After 1:1 PSM, 187 patients were enrolled in the TCM group and 187 patients in the non-TCM group. The incidence of readmission, new tophus, and all-cause death was lower in the TCM group than that in the non-TCM group (P < 0.05). Cox proportional risk regression analysis showed that TCM, NSAIDs and uric acid lowering drug were independent protective factors for GA readmission. The protective effect was enhanced by the prolongation of TCM treatment and the drug combinations. Kaplan-Meier survival curves indicated a significantly lower readmission rate in the high exposure group than in the low exposure group (P < 0.01). Compared with before treatment, NLR, hs-CRP, UA, TC and other laboratory indexes of the low and high exposure groups were improved after treatment (P < 0.01); The improvement of TG and TC in the high exposure group was more significant than the low exposure group (P < 0.01). The analysis of medicines used by all patients identified the top 20 Chinese herbal medicines and the top 2 Chinese patent medicines. The core drugs identified through association rule analysis that can improve test index and reduce the incidence of endpoint events include Yiyiren, Danshen, and HQC, among others. The network diagram of association rule analysis intuitively shows the relationship between core drugs and "improvement of indicators" and "the absence of endpoint events".

Conclusion

TCM is associated with a reduced incidence of endpoint events in patients with GA.

Analysis of the relationship of refractory gout between potential biomarkers and diet structure and lifestyle based on 1H-NMR

OBJECTIVE

We investigated the different life styles among the diet structures and exercise patterns of 100 patients with refractory gout and 79 healthy volunteers; of these, we selected 39 patients and 20 healthy volunteers for serum proton magnetic resonance (1H-NMR) metabolic network detection. We determined the potential biomarkers of refractory gout and attempted to explore the relation between potential biomarkers and diet structures and exercise patterns.

METHODS

The study employed a questionnaire survey to analyze diet structures and exercise patterns from 100 patients of refractory gout and 79 healthy volunteers. At the same time, using 1H-NMR metabolic technology to analyze the metabolites present in the serum samples obtained from 39 patients of refractory gout (group B) and 20 healthy subjects (group A). Employing MestReNova (Version 8.0.1) to analyze the metabolites maps, collecting the NMR results, further importing into SIMCA-P+ 14.0 software (Umetrics, Sweden) for principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), and orthogonal partial least squares discriminant analysis (OPLS-DA) statistical analysis. Combining patterns recognition and multivariate statistics, potential biomarkers were searched. Other experimental data, including creatinine and adiponectin, were counted by the SPSS21.0. The measurement data were expressed by X ± S and t test. The counting data were expressed in percent and performed by X2 test.

RESULTS

Our results revealed that patients with gout tended to be obese, and there were differences in their lifestyle with exercise, sleep, and smoking, as well as in their preference for fructose drinks, alcohol, and total and structural distribution of meat, milk, eggs, and so on when compared with the healthy volunteers. Importantly, we found the adiponectin in the gout group was lower as compared to the healthy group. Further, metabolomics in combination with KEGG analysis revealed that the biosynthesis of aminoacyl tRNA, biosynthesis of valine, leucine, and isoleucine, metabolism of alanine, aspartic, and glutamate, metabolism of glycine, serine, and threonine, phenylalanine, glycolysis/gluconeogenesis, ketone body synthesis and degradation, metabolism of D-glutamine, citric acid cycle (TCA cycle), triglyceride metabolism, and others could be used as specific biomarkers of this disease.

CONCLUSION

Recurrent refractory gout and formation of tophus may be related to the diet structures and lifestyles between the patients and the healthy people, and their abnormal metabolic network may be related to the disorder of mitochondrial energy metabolism, which further results in abnormal metabolism of glucose, lipids, amino acids, and deposition of uric acid in joints, peripheral connective tissue, and kidney, inducing an inflammatory response.

From skin to microscope, case report of a rare manifestation of tophaceous gout: Miliary gout

Joint symptoms associated with gout, mostly characterized by joint flare-ups, are well known. Tophi represent the main cutaneous manifestation of gout, most often associated with a chronic and inadequately controlled disease. On rare occasions, atypical skin manifestations may occur. We present the case of a miliary form of gout in a 36-year-old man known to have hyperuricemia. Microscopic direct analysis of the skin material revealed the presence of monosodium urate (MSU) crystals. Rash disappeared with corticosteroid therapy in parallel with joint symptoms recovery. Knowledge of this unusual gout-related skin disease is essential to diagnosing uncommon presentations of gout, which sometimes occur before joint symptoms. This case highlights the importance of sampling any skin lesion suspected of being tophus, for MSU crystal identification, and provides a definitive diagnosis.

Improving the accuracy of automated gout flare ascertainment using natural language processing of electronic health records and linked Medicare claims data

BACKGROUND

We aimed to determine whether integrating concepts from the notes from the electronic health record (EHR) data using natural language processing (NLP) could improve the identification of gout flares.

METHODS

Using Medicare claims linked with EHR, we selected gout patients who initiated the urate-lowering therapy (ULT). Patients' 12-month baseline period and on-treatment follow-up were segmented into 1-month units. We retrieved EHR notes for months with gout diagnosis codes and processed notes for NLP concepts. We selected a random sample of 500 patients and reviewed each of their notes for the presence of a physician-documented gout flare. Months containing at least 1 note mentioning gout flares were considered months with events. We used 60% of patients to train predictive models with LASSO. We evaluated the models by the area under the curve (AUC) in the validation data and examined positive/negative predictive values (P/NPV).

RESULTS

We extracted and labeled 839 months of follow-up (280 with gout flares). The claims-only model selected 20 variables (AUC = 0.69). The NLP concept-only model selected 15 (AUC = 0.69). The combined model selected 32 claims variables and 13 NLP concepts (AUC = 0.73). The claims-only model had a PPV of 0.64 [0.50, 0.77] and an NPV of 0.71 [0.65, 0.76], whereas the combined model had a PPV of 0.76 [0.61, 0.88] and an NPV of 0.71 [0.65, 0.76].

CONCLUSION

Adding NLP concept variables to claims variables resulted in a small improvement in the identification of gout flares. Our data-driven claims-only model and our combined claims/NLP-concept model outperformed existing rule-based claims algorithms reliant on medication use, diagnosis, and procedure codes.

Single-nucleotide polymorphisms link gout with health-related lifestyle factors in Korean cohorts

Gout-a very painful inflammatory arthritis caused by the deposition of monosodium urate crystals in the joints-is influenced by several factors. We identified the association of single- nucleotide polymorphisms (SNPs) that link gout with health-related lifestyle factors using genomic data from the Korean Genome and Epidemiology Study. We conducted a genome-wide association study (GWAS) on 18,927 samples of 438 Korean patients with gout and 18,489 controls for the discovery stage. For the replication stage, another batch containing samples of 326 patients with gout and 2,737 controls were analyzed. Lastly, a meta-analysis was performed using these two cohorts. We analyzed the effects of health-related lifestyle factors, including eating habits, physical activity, drinking behavior, and smoking behavior, on gout. After identifying the association between GWAS-derived SNPs and health-related lifestyle factors, we confirmed the interaction between the polygenic risk score (PRS) and health-related lifestyle factors. We identified 15 SNPs related to gout, among which rs1481012 of ABCG2 located on chromosome 4 has been newly discovered (P = 2.46e-11). On examining the interaction between SNPs and health-related lifestyles, rs3109823-located in ABCG2-was found to be associated with smoking status. In addition, rs11936395-located in SLC2A9-was significantly associated with the average momentum of exercise per session, whereas rs11066325 located in PTPN11, showed a significant association with the number of exercise sessions per week, smoking status, drinking status, and amount of soju drink per session. rs9421589-located in FAM35A-was significantly associated with the duration of smoking. In addition, we verified that the association between PRS and duration of smoking affects gout. Thus, in this study, we identified novel SNPs that link gout with health-related lifestyle factors in the Korean population.

Diagnosis, Treatment, and Outcomes of Crystalline Arthropathy in the Setting of Total Knee Arthroplasty: A Critical Analysis Review

» Emerging evidence suggests the prevalence of crystalline arthropathy (CA) in the setting of total knee arthroplasty (TKA) is increasing, and diagnosis of CA is often intricate because of symptom overlap with other common postoperative complications such as periprosthetic joint infection (PJI). Consequently, an accurate and timely diagnosis becomes pivotal in guiding the choice of treatment.» CA includes gout and calcium pyrophosphate deposition (CPPD) disease, and accurate diagnosis in patients with prior TKA requires a multifaceted approach. The diagnosis algorithm plays a critical role in determining the appropriate treatment approach.» Management of CA typically involves a conservative strategy, encompassing the administration of nonsteroidal anti-inflammatory drugs, colchicine, and steroids, regardless of whether patients have undergone prior TKA.» There is conflicting evidence on the effect CA has on the surgical outcomes in postoperative TKA patients. While these patients may expect excellent functional outcomes and pain relief, they may be at a higher risk of complications such as infections, medical complications, and revision procedures.» Additional research is required to fully comprehend the impact of CA on postoperative TKA outcomes and to establish effective strategies for enhancing patient care and optimizing long-term joint function.

Non-loading versus loading low-dose colchicine in acute crystal-associated arthritis: A double-blinded randomized controlled study

INTRODUCTION

This study aimed to compare the efficacy of non-loading versus loading low-dose colchicine in patients with acute crystal-associated arthritis.

MATERIALS AND METHODS

All in-patients who were admitted to Chiang Mai University Hospital with non-arthritis disease and developed acute crystal-associated arthritis during admission (within 48 h after arthritis onset) were invited to join this study. The patients were randomized into two groups. Patients in Group I (non-loading group) and Group II (loading group) received colchicine at 1.2 and 2.4 mg in the first 24 h, respectively. The primary outcome was the patients' pain response at 24 h after treatment.

RESULTS

Of 80 patients, 49 were acute gouty arthritis, and 31 acute calcium pyrophosphate (CPP) arthritis. The mean [95% CI] pain score was no different between Groups I and II at the baseline level (6.46[5.72-7.19] vs. 6.654[5.85-7.44], p = .867) and at 24 h (3.13[2.43-3.82] vs. 3.18[2.42-3.93], p = .907). The proportion of patients with ≥50% pain reduction was not different (57.50% vs. 55.00%, p = .822). Sensitivity analysis among patients with a baseline pain score of ≥4 showed the same pattern of response. Mild diarrhea was common and comparable in both groups. Subgroup analysis according to renal function (eGFR < 60 vs. ≥60 mL/min/1.73 m2 ) or type of crystals (acute gouty arthritis vs. acute CPP arthritis) also showed the same pattern of response.

CONCLUSION

Non-loading low-dose colchicine was as effective as loading low-dose colchicine in patients with acute crystal-associated arthritis, regardless of renal function or type of crystals.

Prediction of renal and cardiometabolic outcomes in gout during urate-lowering therapy by sonography

OBJECTIVES

To assess whether the extent of monosodium urate (MSU) crystal deposition estimated by ultrasound could predict renal and cardiometabolic events during urate-lowering therapy (ULT).

METHODS

A prospective study on gout patients from two referral centers initiating ULT who underwent baseline ultrasound and were followed for 1 year. Ultrasound scans assessed six joints for double-contour (DC) signs and tophi. A five-point change (mL/min/1.73 m2 ) in the glomerular filtration rate at month 12 (M12) was considered significant. Outcomes of interest were renal function degraded versus improved and a composite cardiometabolic outcome (new hypertension, diabetes, atherosclerotic disease, and cardiovascular death). Homogeneity analyses and Cox regression models were performed.

RESULTS

One hundred sixty patients were recruited. At baseline, 81.1% of patients (n = 129) showed sonographic tophi with a mean number of 1.4 joints (±1.3) with a DC sign. At M12, 18 patients (11.3%) were lost to follow-up. The serum urate (SU) target (<6.0 mg/dL) was reached in 86 patients (69.9%). Regarding renal function, 15.9% of patients showed improvement, while in 31.0% it degraded. Fourteen new cardiometabolic events occurred in 12 patients. Neither the DC sign nor tophi showed any significant impact on the outcomes of interest. Baseline SU level was higher in those with renal improvement but not with renal decline, while achieving the SU target protected against new cardiometabolic events (HR = 0.2; 95% CI: 0.05-0.81).

CONCLUSIONS

Sonographic MSU crystal burden was unhelpful in predicting renal and cardiometabolic events during the first year of ULT. Reaching the SU target prevented cardiometabolic events, while its benefit in preserving/improving renal function is unclear.

Test characteristics of Raman spectroscopy integrated with polarized light microscopy for the diagnosis of acute gouty arthritis

OBJECTIVES

We studied the performance of Raman spectroscopy integrated with polarized light microscopy (iRPolM) as a next-generation technique for synovial fluid analysis in gout.

METHODS

This is a prospective study, including consecutive synovial fluid samples drawn from any peripheral swollen joint. Diagnostic accuracy was compared to the 2015 ACR/EULAR Gout classification criteria as a reference test and to polarized light microscopy (PLM) analysis by a rheumatologist. Synovial fluid was analysed with iRPolM after unblinding the PLM results.

RESULTS

Two hundred unselected consecutive patient samples were included in this study. Validation against clinical criteria: 67 patients were classified as gout according to 2015 ACR/EULAR classification criteria. Compared to the 2015 ACR/EULAR gout classification criteria, iRPolM had a sensitivity of 77.6% (95% CI: 65.8-86.9), specificity of 97.7% (95% CI: 93.5-99.5), positive predictive value (PPV) of 94.5% (95% CI: 84.9-98.2), negative predictive value (NPV) of 89.7% (95% CI: 84.7-93.1), an accuracy of 91.0% (95% CI: 86.2-94.6), a positive likelihood ratio of 34.4 (95% CI: 11.16-106.10) and a negative likelihood ratio of 0.23 (95% CI: 0.15-0.36). Validation against PLM: 55 samples were positive for MSU according to PLM. The interrater agreement between PLM and iRPolM was near perfect (к=0.90). The sensitivity of iRPolM to identify MSU in PLM-positive samples was 91.2% (95% CI: 80.7-97.1), the specificity was 97.6% (95% CI: 93.0-99.5), the PPV was 94.6% (95% CI: 85.0-98.2), NPV was 96.0% (95% CI: 91.2-98.2) and the accuracy was 95.6% (95% CI: 91.4-98.2). The positive likelihood ratio was 37.4 (95% CI: 12.20-114.71), and the negative likelihood ratio was 0.09 (95% CI: 0.04-0.21).

CONCLUSION

iRPolM is a promising next-generation diagnostic tool for rheumatology by diagnosing gout with high specificity, increased objectivity, and a sensitivity comparable to PLM.

Emerging Urate-Lowering Drugs and Pharmacologic Treatment Strategies for Gout: A Narrative Review

Hyperuricemia with consequent monosodium urate crystal deposition leads to gout, characterized by painful, incapacitating inflammatory arthritis flares that are also associated with increased cardiovascular event and related mortality risk. This narrative review focuses on emerging pharmacologic urate-lowering treatment (ULT) and management strategies in gout. Undertreated, gout can progress to palpable tophi and joint damage. In oral ULT clinical trials, target serum urate of < 6.0 mg/dL can be achieved in ~ 80-90% of subjects, with flare burden reduction by 1-2 years. However, real-world ULT results are far less successful, due to both singular patient nonadherence and prescriber undertreatment, particularly in primary care, where most patients are managed. Multiple dose titrations commonly needed to optimize first-line allopurinol ULT monotherapy, and substantial potential toxicities and other limitations of approved, marketed oral monotherapy ULT drugs, promote hyperuricemia undertreatment. Common gout comorbidities with associated increased mortality (e.g., moderate-severe chronic kidney disease [CKD], type 2 diabetes, hypertension, atherosclerosis, heart failure) heighten ULT treatment complexity and emphasize unmet needs for better and more rapid clinically significant outcomes, including attenuated gout flare burden. The gout drug armamentarium will be expanded by integrating sodium-glucose cotransporter-2 (SGLT2) inhibitors with uricosuric and anti-inflammatory properties as well as clinically indicated antidiabetic, nephroprotective, and/or cardioprotective effects. The broad ULT developmental pipeline is loaded with multiple uricosurics that selectively target uric acid transporter 1 (URAT1). Evolving ULT approaches include administering selected gut anaerobic purine degrading bacteria (PDB), modulating intestinal urate transport, and employing liver-targeted xanthine oxidoreductase mRNA knockdown. Last, emerging measures to decrease the immunogenicity of systemically administered recombinant uricases should simplify treatment regimens and further improve outcomes in managing the most severe gout phenotypes.

The 2023 ACR/EULAR Classification Criteria for Calcium Pyrophosphate Deposition Disease

OBJECTIVE

Calcium pyrophosphate deposition (CPPD) disease is prevalent and has diverse presentations, but there are no validated classification criteria for this symptomatic arthritis. The American College of Rheumatology (ACR) and EULAR have developed the first-ever validated classification criteria for symptomatic CPPD disease.

METHODS

Supported by the ACR and EULAR, a multinational group of investigators followed established methodology to develop these disease classification criteria. The group generated lists of candidate items and refined their definitions, collected de-identified patient profiles, evaluated strengths of associations between candidate items and CPPD disease, developed a classification criteria framework, and used multi-criterion decision analysis to define criteria weights and a classification threshold score. The criteria were validated in an independent cohort.

RESULTS

Among patients with joint pain, swelling, or tenderness (entry criterion) whose symptoms are not fully explained by an alternative disease (exclusion criterion), the presence of crowned dens syndrome or calcium pyrophosphate crystals in synovial fluid are sufficient to classify a patient as having CPPD disease. In the absence of these findings, a score >56 points using weighted criteria, comprising clinical features, associated metabolic disorders, and results of laboratory and imaging investigations, can be used to classify as CPPD disease. These criteria had a sensitivity of 92.2% and specificity of 87.9% in the derivation cohort (190 CPPD cases, 148 mimickers), whereas sensitivity was 99.2% and specificity was 92.5% in the validation cohort (251 CPPD cases, 162 mimickers).

CONCLUSION

The 2023 ACR/EULAR CPPD disease classification criteria have excellent performance characteristics and will facilitate research in this field.

The 2023 ACR/EULAR classification criteria for calcium pyrophosphate deposition disease

OBJECTIVE

Calcium pyrophosphate deposition (CPPD) disease is prevalent and has diverse presentations, but there are no validated classification criteria for this symptomatic arthritis. The American College of Rheumatology (ACR) and EULAR have developed the first-ever validated classification criteria for symptomatic CPPD disease.

METHODS

Supported by the ACR and EULAR, a multinational group of investigators followed established methodology to develop these disease classification criteria. The group generated lists of candidate items and refined their definitions, collected de-identified patient profiles, evaluated strengths of associations between candidate items and CPPD disease, developed a classification criteria framework, and used multi-criterion decision analysis to define criteria weights and a classification threshold score. The criteria were validated in an independent cohort.

RESULTS

Among patients with joint pain, swelling, or tenderness (entry criterion) whose symptoms are not fully explained by an alternative disease (exclusion criterion), the presence of crowned dens syndrome or calcium pyrophosphate crystals in synovial fluid are sufficient to classify a patient as having CPPD disease. In the absence of these findings, a score>56 points using weighted criteria, comprising clinical features, associated metabolic disorders, and results of laboratory and imaging investigations, can be used to classify as CPPD disease. These criteria had a sensitivity of 92.2% and specificity of 87.9% in the derivation cohort (190 CPPD cases, 148 mimickers), whereas sensitivity was 99.2% and specificity was 92.5% in the validation cohort (251 CPPD cases, 162 mimickers).

CONCLUSION

The 2023 ACR/EULAR CPPD disease classification criteria have excellent performance characteristics and will facilitate research in this field.

Acute severe gouty arthritis secondary to isotretinoin toxicity in a young male: a case report

Acute gouty arthritis is a recognized complication of hyperuricemia and one of the most common forms of inflammatory arthritis in adults. Drug-induced hyperuricemia is increasingly prevalent in clinical practice. Diuretics, antitubercular medications, and immunosuppressants are the common drugs associated with hyperuricemia. Oral isotretinoin is the drug of choice for different forms of severe acne and is rarely associated with hyperuricemia. We present the case of a 30-year-old male with severe acne vulgaris who was prescribed isotretinoin and later presented with acute gout. The patient developed hyperuricemia and swelling of the right first metatarsophalangeal joint within two months of isotretinoin commencement. There was a second episode of similar joint swelling three months later, parallel to the isotretinoin rechallenge. The dose of isotretinoin was reduced with the addition of febuxostat. The patient did not develop further episodes and remained symptom-free without urate-lowering therapy.

Reliability and Validity of the Korean Version of the Gout Impact Scale

BACKGROUND

The Gout Impact Scale (GIS), part of the Gout Assessment Questionnaire 2.0, measures gout-specific health-related quality of life (HRQOL). This study aimed to translate the GIS into Korean and validate the Korean version (K-GIS) using generic HRQOL measures.

METHODS

The GIS was translated into Korean and back-translated into English. We asked patients aged 18 years or older who met the 2015 gout classification criteria to fill out the questionnaires (from January 2022 to June 2022); the K-GIS (5 scales [0-100 scores each]), along with the Korean version of Health Assessment Questionnaire (HAQ) and EuroQol-5 dimension (EQ-5D). We investigated the internal consistency, construct validity, and discriminative validity for gout characteristics of K-GIS. The K-GIS form was administrated to patients 4 weeks later to assess the test-retest reliability using the intraclass correlation coefficient (ICC).

RESULTS

One hundred patients completed the questionnaire. The mean ± standard deviation age of the patients was 53.0 ± 15.1 years, and 99.0% of the patients were men. All scales had high degree of internal consistency (Cronbach's α = 0.59 to 0.96) and test-retest reliability (n = 18, ICC = 0.83 to 0.94, all P < 0.001), except for unmet gout treatment needs. Weak-to-moderate correlations were observed between the K-GIS scales and HAQ or EQ-5D (r = 0.21 to 0.46). The K-GIS scores were significantly higher in the presence of bone erosion, absence of urate-lowering therapy, serum urate levels > 6 mg/dL, frequent gout flares in the past year, and fewer comorbidities. In contrast, neither the HAQ nor the EQ-5D could discern these subsets of patients.

CONCLUSION

The K-GIS is a reliable and valid HRQOL measure for patients with gout. Higher K-GIS scores were associated with clinical characteristics leading to unfavorable outcomes, which were not demonstrated by the HAQ and EQ-5D.

Changes in the structure and function of the left ventricle in patients with gout: A study based on three-dimensional speckle tracking echocardiography

PURPOSE

Studies have shown that gout can increase the risk of cardiovascular disease. Three-dimensional speckle-tracking echocardiography (3D-STE), a sensitive imaging technology, enables the detection of subtle myocardial dysfunctions. Our aim is to evaluate the left ventricular (LV) functions in patients with gout using 3D-STE.

METHODS

80 subjects: 40 with gout and 40 as normal controls were involved. We obtained and analyzed these parameters from the dynamic images of a 3D full-volume dataset: global longitudinal strain (GLS), global circumferential strain (GCS), global radial strain (GRS), Twist, 16-segmental time-to-peak longitudinal strain (TTP) and systolic dyssynchrony index (SDI)besides other relevant parameters.

RESULTS

Compared with the normal group, gout patients were more likely to have left ventricular remodeling. The patients with gout showed decreased Em, increased E/Em and larger volume index of the left atrium (LAVI) indicating reduced diastolic function. The peak GLS (-17.42 ± 2.02 vs. -22.40 ± 2.57, P < 0.001), GCS (-27.04 ± 3.75 vs. -34.85 ± 4.99, P < 0.001), GRS (38.22 ± 4.28 vs. 46.15 ± 5.17, P < 0.001), and Twist (15.18 ± 5.45 vs. 19.02 ± 5.29, P = 0.015) were significantly lower in patients with gout than in healthy participants. The SDI (5.57 ± 1.46 vs. 4.91 ± 1.19, P = 0.016) was significantly increased in patients with gout compared with normal controls. There was no significant between-group difference in TTP (P = 0.43). The systolic GLS, GRS and GCS peak values increased gradually from the base to the apex, with the lowest values in the basal segment in patients with gout. Receiver-operating characteristic curve analysis revealed among these strains GLS has the largest area under the curve (AUC: 0.93, P < 0.001), the cutoff value of -18.97% with a sensitivity and specificity of 80.0% and 92.0%, respectively, for differentiating two groups. A multivariate linear regression analysis shows that the relationship between gout and strain parameters including GLS, GRS, and GCS is statistically significant (P < 0.001).

CONCLUSION

Although patients with gout having a normal ejection fraction, structural remodeling of the left ventricle and subclinical LV deformation may occur. 3D-STE can detect subtle cardiac dysfunctions in patients with gout at an early stage.

Approach to laboratory ordering and interpretation in rheumatology

Evaluation of suspected rheumatic disease is a significant challenge due to overlapping and sometimes non-specific clinical features. Most laboratory tests in rheumatic disease have incomplete sensitivity and specificity, leading to positive results without disease and negative results despite disease presence. Therefore, judicious ordering and correct interpretation of laboratory testing in rheumatology is critical in order to provide high-value care. Herein we review laboratory testing in rheumatology in the context of a framework for approaching rheumatic disease.

The Role of Ultrasound in Cancer and Cancer-Related Pain-A Bibliometric Analysis and Future Perspectives

Ultrasound has a deep penetrating ability with minimal or no tissue injury, while cancer-mediated complications during diagnosis, therapy, and surgery have become a serious challenge for clinicians and lead to the severity of the primary condition (cancer). The current study highlights the importance of ultrasound imaging and focused ultrasound therapy during cancer diagnosis, pain reduction, guidance for surgical resection of cancer, and the effectiveness of chemotherapy. We performed the bibliometric analysis on research domains involving ultrasound, cancer management, pain, and other challenges (chemotherapy, surgical guidance, and postoperative care), to observe the trend by which the research field has grown over the years and propose a possible future trend. The data was obtained from the Web of Science, processed, and exported as plain text files for analysis in the Bibliometrix R web interface using the Biblioshiny package. A total of 3248 documents were identified from 1100 journal sources. A total of 390 articles were published in 2022, with almost a 100% growth rate from previous years. Based on the various network analysis, we conclude that the outcome of the constant research in this domain will result in better patient care during the management of various diseases, including cancer and other co-morbidities.

High blood pressure prevalence, awareness, treatment, and blood pressure control among Ugandans with rheumatic and musculoskeletal disorders

BACKGROUND

Rheumatic and musculoskeletal disorders (RMDs) are associated with cardiovascular diseases (CVDs), with hypertension being the most common. We aimed to determine the prevalence of high blood pressure (HBP), awareness, treatment, and blood pressure control among patients with RMDs seen in a Rheumatology clinic in Uganda.

METHODS

We conducted a cross-sectional study at the Rheumatology Clinic of Mulago National Referral Hospital (MNRH), Kampala, Uganda. Socio-demographic, clinical characteristics and anthropometric data were collected. Multivariable logistic regression was performed using STATA 16 to determine factors associated with HBP in patients with RMDs.

RESULTS

A total of 100 participants were enrolled. Of these, majority were female (84%, n = 84) with mean age of 52.1 (standard deviation: 13.8) years and median body mass index of 28 kg/m2 (interquartile range (IQR): 24.8 kg/m2-32.9 kg/m2). The prevalence of HBP was 61% (n = 61, 95% CI: 51.5-70.5), with the majority (77%, n = 47, 95% CI: 66.5-87.6) being aware they had HTN. The prevalence of HTN was 47% (n = 47, 37.2-56.8), and none had it under control. Factors independently associated with HBP were age 46-55years (adjusted prevalence ratio (aPR): 2.5, 95% confidence interval (CI): 1.06-5.95), 56-65 years (aPR: 2.6, 95% CI: 1.09-6.15), >65 years (aPR: 2.5, 95% CI: 1.02-6.00), obesity (aPR: 3.7, 95% CI: 1.79-7.52), overweight (aPR: 2.7, 95% CI: 1.29-5.77).

CONCLUSION

There was a high burden of HBP among people with RMDs in Uganda with poor blood pressure control, associated with high BMI and increasing age. There is a need for further assessment of the RMD specific drivers of HBP and meticulous follow up of patients with RMDs.

The Patient Experience of Gout Remission: A Qualitative Study

OBJECTIVE

Preliminary remission criteria for gout have been developed. However, the patient experience of gout remission has not been described. This qualitative study aimed to understand the patient experience of gout remission and views about the preliminary gout remission criteria.

METHODS

Semistructured interviews were conducted. All participants had gout, had not had a gout flare in the preceding 6 months, and were on urate-lowering medication. Participants were asked to discuss their experience of gout remission and views about the preliminary remission criteria. Interviews were audio recorded and transcribed verbatim. Data were analyzed using a reflexive thematic approach.

RESULTS

Twenty participants with gout (17 male participants, median age 63 years) were interviewed. Four key themes of the patient experience of remission were identified: 1) minimal or no gout symptoms (absence of pain due to gout flares, good physical function, smaller or no tophi), 2) freedom from dietary restrictions, 3) gout is "not on the mind", and 4) multifaceted management strategies to maintain remission (regular urate-lowering therapy, exercise, healthy eating). Participants believed that the preliminary remission criteria contained all relevant domains but considered that the pain and patient global assessment domains overlapped with the gout flares domain. Participants regarded 12 months as a more suitable time frame than 6 months to measure remission.

CONCLUSION

Patients experience gout remission as a return to normality with minimal or no gout symptoms, dietary freedom, and absence of mental load. Patients use a range of management strategies to maintain gout remission.

Development and Validation of an Emergency Department Electronic Medical Record Gout Flare Alert

OBJECTIVE

Patients with acute gout are frequently treated in the emergency department (ED) and represent a typically underresourced and understudied population. A key limitation for gout research in the ED is the timely ability to identify acute gout patients. Our goal was to refine a multicriteria, electronic medical record alert for gout flares and to determine its diagnostic characteristics in the ED.

METHODS

The gout flare alert used electronic medical record data from ED nursing notes and was triggered by the term 'gout' preceding past medical history in the chief complaint, the term 'gout' and a musculoskeletal problem in the chief complaint, or the term 'gout' in the problem list and a musculoskeletal chief complaint. We validated its diagnostic properties to assess presence/absence of gout through manual medical record review using adjudicated expert consensus as the gold standard.

RESULTS

In January 2020, we analyzed 202 patient records from 2 university-based EDs; from these records, 57 patients were identified by our gout flare alert, and 145 were identified by other means as potentially having an acute gout flare. The gout flare alert's positive predictive value was 47% (95% confidence interval [95% CI] 34-60%), negative predictive value was 94% (95% CI 90-98%), sensitivity was 75% (95% CI 61-89%), and specificity was 82% (95% CI 76-88%). The diagnostic properties were similar at both institutions.

CONCLUSION

Our multicomponent gout flare alert had reasonable sensitivity and specificity, albeit a modest positive predictive value. An electronic gout flare alert may help enable the conduct of gout research in the ED setting.

Assessment of Cardiovascular Disease Among Predominantly Black Gout Patients

INTRODUCTION

Although the association between gout and cardiovascular disease (CVD) has been extensively studied, scarce data are available for the Black population. We aimed to assess the association between gout and CVD in a predominantly Black urban population with gout.

METHODS

A cross-sectional analysis was performed between a gout cohort and an age-/sex-matched control group. Clinical parameters and 2D echocardiograms were reviewed for the patients with gout and heart failure (HF). The primary outcome studied includes the prevalence and strength of association between gout and CVD. Secondary outcomes studied includes strength of association of gout and HF categorized by ejection fraction, mortality, and HF readmissions.

RESULTS

Four hundred seventy-one patients with gout had a mean age of 63.7 ± 0.5 years; 89% were Black, 63% were men, and mean body mass index was 31.3 ± 0.4 kg/m 2 . Hypertension, diabetes mellitus, and dyslipidemia were present in 89%, 46%, and 52%, respectively. Compared with controls, patients with gout had significantly higher rates of angina, arrhythmia, coronary artery disease/stents, myocardial infarction, coronary artery bypass graft surgery, cerebrovascular accident, and peripheral vascular disease. The adjusted odds ratio for CVD was 2.9 (95% confidence interval, 1.9-4.5; p < 0.001). Gout patients had a higher prevalence of HF with 45% (n = 212) compared with controls with 9.4% (n = 44). Adjusted odds ratio for HF risk was 7.1 (95% confidence interval, 4.7-10.6; p < 0.01).

CONCLUSIONS

Gout in a predominantly Black population confers 3 times the CVD risk and 7 times HF-specific risk compared with age- and sex-matched cohort. Further research is needed to confirm our findings and to develop interventions to reduce morbidity associated with gout.

Exploring the role of gut microbiota dysbiosis in gout pathogenesis: a systematic review

Objectives

Gut dysbiosis is believed to be one of the several mechanisms that are involved in the pathogenesis of gout. This systematic review aimed to summarize the role of gut dysbiosis in gout disease and uncover the underlying mechanisms.

Methods

A comprehensive search was conducted on PubMed, Web of Science, and Scopus databases up to October 2021. Animal studies and human observational studies, including case-control, cross-sectional, and cohort studies assessing the association between gut microbiota composition and gout were included. The quality of included studies has been evaluated using the Newcastle-Ottawa Quality Assessment scale (NOS) and the SYRCLE's risk of bias tool.

Results

Initially, we found 274 studies among which 15 studies were included in this systematic review. Of them, 10 studies were conducted on humans and 5 studies were conducted on animals. Increased abundance of Alistipes and decreased abundance of Enterobacteriaceae alters purine metabolism, thereby aggravating gout condition. Moreover, a higher abundance of Phascolarctobacterium and Bacteroides in gout modulates enzymatic activity in purine metabolism. Butyrate-producing bacteria such as Faecalibacterium, prausnitzii, Oscillibacter, Butyricicoccus, and Bifidobacterium have higher abundance in healthy controls compared to gout patients, suggesting the anti-inflammatory and anti-microbial role of short-chain fatty acids (SCFAs). Lipopolysaccharides (LPS)-releasing bacteria, such as Enterobacteriaceae, Prevotella, and Bacteroides, are also involved in the pathogenesis of gout disease by stimulating the innate immune system.

Conclusion

Exploring the role of gut dysbiosis in gout and the underlying mechanisms can help develop microbiota-modulating therapies for gout.

Amplification of Inflammation by Lubricin Deficiency Implicated in Incident, Erosive Gout Independent of Hyperuricemia

OBJECTIVE

In gout, hyperuricemia promotes urate crystal deposition, which stimulates the NLRP3 inflammasome and interleukin-1β (IL-1β)-mediated arthritis. Incident gout without background hyperuricemia is rarely reported. To identify hyperuricemia-independent mechanisms driving gout incidence and progression, we characterized erosive urate crystalline inflammatory arthritis in a young female patient with normouricemia diagnosed as having sufficient and weighted classification criteria for gout according to the American College of Rheumatology (ACR)/EULAR gout classification criteria (the proband).

METHODS

We conducted whole-genome sequencing, quantitative proteomics, whole-blood RNA-sequencing analysis using serum samples from the proband. We used a mouse model of IL-1β-induced knee synovitis to characterize proband candidate genes, biomarkers, and pathogenic mechanisms of gout.

RESULTS

Lubricin level was attenuated in human proband serum and associated with elevated acute-phase reactants and inflammatory whole-blood transcripts and transcriptional pathways. The proband had predicted damaging gene variants of NLRP3 and of inter-α trypsin inhibitor heavy chain 3, an inhibitor of lubricin-degrading cathepsin G. Changes in the proband's serum protein interactome network supported enhanced lubricin degradation, with cathepsin G activity increased relative to its inhibitors, SERPINB6 and thrombospondin 1. Activation of Toll-like receptor 2 (TLR-2) suppressed levels of lubricin mRNA and lubricin release in cultured human synovial fibroblasts (P < 0.01). Lubricin blunted urate crystal precipitation and IL-1β induction of xanthine oxidase and urate in cultured macrophages (P < 0.001). In lubricin-deficient mice, injection of IL-1β in knees increased xanthine oxidase-positive synovial resident M1 macrophages (P < 0.05).

CONCLUSION

Our findings linked normouricemic erosive gout to attenuated lubricin, with impaired control of cathepsin G activity, compounded by deleterious NLRP3 variants. Lubricin suppressed monosodium urate crystallization and blunted IL-1β-induced increases in xanthine oxidase and urate in macrophages. The collective activities of articular lubricin that could limit incident and erosive gouty arthritis independently of hyperuricemia are subject to disruption by inflammation, activated cathepsin G, and synovial fibroblast TLR-2 signaling.

Genetic and Epigenetic Regulation of the Innate Immune Response to Gout

Gout is a disease caused by uric acid (UA) accumulation in the joints, causing inflammation. Two UA forms - monosodium urate (MSU) and soluble uric acid (sUA) have been shown to interact physically with inflammasomes, especially with the nod-like receptor (NLR) family pyrin domain containing 3 (NLRP3), albeit the role of the immune response to UA is poorly understood, given that asymptomatic hyperuricemia does also exist. Macrophage phagocytosis of UA activate NLRP3, lead to cytokines release, and ultimately, lead to chemoattract neutrophils and lymphocytes to the gout flare joint spot. Genetic variants of inflammasome genes and of genes encoding their molecular partners may influence hyperuricemia and gout susceptibility, while also influencing other comorbidities such as metabolic syndrome and cardiovascular diseases. In this review, we summarize the inflammatory responses in acute and chronic gout, specifically focusing on innate immune cell mechanisms and genetic and epigenetic characteristics of participating molecules. Unprecedently, a novel UA binding protein - the neuronal apoptosis inhibitor protein (NAIP) - is suggested as responsible for the asymptomatic hyperuricemia paradox.Abbreviation: β2-integrins: leukocyte-specific adhesion molecules; ABCG2: ATP-binding cassete family/breast cancer-resistant protein; ACR: American college of rheumatology; AIM2: absent in melanoma 2, type of pattern recognition receptor; ALPK1: alpha-protein kinase 1; ANGPTL2: angiopoietin-like protein 2; ASC: apoptosis-associated speck-like protein; BIR: baculovirus inhibitor of apoptosis protein repeat; BIRC1: baculovirus IAP repeat-containing protein 1; BIRC2: baculoviral IAP repeat-containing protein 2; C5a: complement anaphylatoxin; cAMP: cyclic adenosine monophosphate; CARD: caspase activation and recruitment domains; CARD8: caspase recruitment domain-containing protein 8; CASP1: caspase 1; CCL3: chemokine (C-C motif) ligand 3; CD14: cluster of differentiation 14; CD44: cluster of differentiation 44; Cg05102552: DNA-methylation site, usually cytosine followed by guanine nucleotides; contains arbitrary identification code; CIDEC: cell death-inducing DNA fragmentation factor-like effector family; CKD: chronic kidney disease; CNV: copy number variation; CPT1A: carnitine palmitoyl transferase - type 1a; CXCL1: chemokine (CXC motif) ligand 1; DAMPs: damage associated molecular patterns; DC: dendritic cells; DNMT(1): maintenance DNA methyltransferase; eQTL: expression quantitative trait loci; ERK1: extracellular signal-regulated kinase 1; ERK2: extracellular signal-regulated kinase 2; EULAR: European league against rheumatism; GMCSF: granulocyte-macrophage colony-stimulating factor; GWAS: global wide association studies; H3K27me3: tri-methylation at the 27th lysine residue of the histone h3 protein; H3K4me1: mono-methylation at the 4th lysine residue of the histone h3 protein; H3K4me3: tri-methylation at the 4th lysine residue of the histone h3 protein; HOTAIR: human gene located between hoxc11 and hoxc12 on chromosome 12; IκBα: cytoplasmatic protein/Nf-κb transcription inhibitor; IAP: inhibitory apoptosis protein; IFNγ: interferon gamma; IL-1β: interleukin 1 beta; IL-12: interleukin 12; IL-17: interleukin 17; IL18: interleukin 18; IL1R1: interleukin-1 receptor; IL-1Ra: interleukin-1 receptor antagonist; IL-22: interleukin 22; IL-23: interleukin 23; IL23R: interleukin 23 receptor; IL-33: interleukin 33; IL-6: interleukin 6; IMP: inosine monophosphate; INSIG1: insulin-induced gene 1; JNK1: c-jun n-terminal kinase 1; lncRNA: long non-coding ribonucleic acid; LRR: leucine-rich repeats; miR: mature non-coding microRNAs measuring from 20 to 24 nucleotides, animal origin; miR-1: miR followed by arbitrary identification code; miR-145: miR followed by arbitrary identification code; miR-146a: miR followed by arbitrary identification code, "a" stands for mir family; "a" family presents similar mir sequence to "b" family, but different precursors; miR-20b: miR followed by arbitrary identification code; "b" stands for mir family; "b" family presents similar mir sequence to "a" family, but different precursors; miR-221: miR - followed by arbitrary identification code; miR-221-5p: miR followed by arbitrary identification code; "5p" indicates different mature miRNAs generated from the 5' arm of the pre-miRNA hairpin; miR-223: miR followed by arbitrary identification code; miR-223-3p: mir followed by arbitrary identification code; "3p" indicates different mature miRNAs generated from the 3' arm of the pre-miRNA hairpin; miR-22-3p: miR followed by arbitrary identification code, "3p" indicates different mature miRNAs generated from the 3' arm of the pre-miRNA hairpin; MLKL: mixed lineage kinase domain-like pseudo kinase; MM2P: inductor of m2-macrophage polarization; MSU: monosodium urate; mTOR: mammalian target of rapamycin; MyD88: myeloid differentiation primary response 88; n-3-PUFAs: n-3-polyunsaturated fatty-acids; NACHT: acronym for NAIP (neuronal apoptosis inhibitor protein), C2TA (MHC class 2 transcription activator), HET-E (incompatibility locus protein from podospora anserina) and TP1 (telomerase-associated protein); NAIP: neuronal apoptosis inhibitory protein (human); Naip1: neuronal apoptosis inhibitory protein type 1 (murine); Naip5: neuronal apoptosis inhibitory protein type 5 (murine); Naip6: neuronal apoptosis inhibitory protein type 6 (murine); NBD: nucleotide-binding domain; Nek7: smallest NIMA-related kinase; NET: neutrophil extracellular traps; Nf-κB: nuclear factor kappa-light-chain-enhancer of activated b cells; NFIL3: nuclear-factor, interleukin 3 regulated protein; NIIMA: network of immunity in infection, malignancy, and autoimmunity; NLR: nod-like receptor; NLRA: nod-like receptor NLRA containing acidic domain; NLRB: nod-like receptor NLRA containing BIR domain; NLRC: nod-like receptor NLRA containing CARD domain; NLRC4: nod-like receptor family CARD domain containing 4; NLRP: nod-like receptor NLRA containing PYD domain; NLRP1: nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain containing 1; NLRP12: nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain containing 12; NLRP3: nod-like receptor family pyrin domain containing 3; NOD2: nucleotide-binding oligomerization domain; NRBP1: nuclear receptor-binding protein; Nrf2: nuclear factor erythroid 2-related factor 2; OR: odds ratio; P2X: group of membrane ion channels activated by the binding of extracellular; P2X7: p2x purinoceptor 7 gene; p38: member of the mitogen-activated protein kinase family; PAMPs: pathogen associated molecular patters; PBMC: peripheral blood mononuclear cells; PGGT1B: geranylgeranyl transferase type-1 subunit beta; PHGDH: phosphoglycerate dehydrogenase; PI3-K: phospho-inositol; PPARγ: peroxisome proliferator-activated receptor gamma; PPARGC1B: peroxisome proliferative activated receptor, gamma, coactivator 1 beta; PR3: proteinase 3 antigen; Pro-CASP1: inactive precursor of caspase 1; Pro-IL1β: inactive precursor of interleukin 1 beta; PRR: pattern recognition receptors; PYD: pyrin domain; RAPTOR: regulatory associated protein of mTOR complex 1; RAS: renin-angiotensin system; REDD1: regulated in DNA damage and development 1; ROS: reactive oxygen species; rs000*G: single nuclear polymorphism, "*G" is related to snp where replaced nucleotide is guanine, usually preceded by an id number; SLC2A9: solute carrier family 2, member 9; SLC7A11: solute carrier family 7, member 11; SMA: smooth muscular atrophy; Smac: second mitochondrial-derived activator of caspases; SNP: single nuclear polymorphism; Sp3: specificity protein 3; ST2: serum stimulation-2; STK11: serine/threonine kinase 11; sUA: soluble uric acid; Syk: spleen tyrosine kinase; TAK1: transforming growth factor beta activated kinase; Th1: type 1 helper T cells; Th17: type 17 helper T cells; Th2: type 2 helper T cells; Th22: type 22 helper T cells; TLR: tool-like receptor; TLR2: toll-like receptor 2; TLR4: toll-like receptor 4; TNFα: tumor necrosis factor alpha; TNFR1: tumor necrosis factor receptor 1; TNFR2: tumor necrosis factor receptor 2; UA: uric acid; UBAP1: ubiquitin associated protein; ULT: urate-lowering therapy; URAT1: urate transporter 1; VDAC1: voltage-dependent anion-selective channel 1.

Dual-Energy Computed Tomography (DECT) Resolves the Diagnostic Dilemma in an Atypically Presenting Case of Gout

Gout is a common inflammatory arthropathy that presents as acute monoarthritis, most commonly of the first metatarsophalangeal (MTP) joint. Chronic polyarticular involvement may lead to confusion with other inflammatory arthropathies, including rheumatoid arthritis (RA). A thorough history, physical examination, synovial fluid analysis, and imaging are keys to establishing a correct diagnosis. Although a synovial fluid analysis remains the gold standard, the affected joints may be difficult to access by arthrocentesis. In cases where a large monosodium urate (MSU) crystal deposition is in the soft tissues - the ligaments, bursae, and tendons, it becomes a clinical impossibility. In such cases, dual-energy computed tomography (DECT) can assist in differentiating gout from other inflammatory arthropathies, including RA. Additionally, DECT can perform quantitative analysis of tophaceous deposits and, therefore, assess response to treatment.

Imaging Features of Calcium Pyrophosphate Deposition Disease: Consensus Definitions From an International Multidisciplinary Working Group

OBJECTIVE

To develop definitions for imaging features being considered as potential classification criteria for calcium pyrophosphate deposition (CPPD) disease, additional to clinical and laboratory criteria, and to compile example images of CPPD on different imaging modalities.

METHODS

The American College of Rheumatology and European Alliance of Associations for Rheumatology CPPD classification criteria Imaging Advisory Group (IAG) and Steering Committee drafted definitions of imaging features that are characteristic of CPPD on conventional radiography (CR), conventional computed tomography (CT), dual-energy CT (DECT), and magnetic resonance imaging (MRI). An anonymous expert survey was undertaken by a 35-member Combined Expert Committee, including all IAG members. The IAG and 5 external musculoskeletal radiologists with expertise in CPPD convened virtually to further refine item definitions and voted on example images illustrating CR, CT, and DECT item definitions, with ≥90% agreement required to deem them acceptable.

RESULTS

The Combined Expert Committee survey indicated consensus on all CR definitions. The IAG and external radiologists reached consensus on CT and DECT item definitions, which specify that calcium pyrophosphate deposits appear less dense than cortical bone. The group developed an MRI definition and acknowledged limitations of this modality for CPPD. Ten example images for CPPD were voted acceptable (4 CR, 4 CT, and 2 DECT), and 3 images of basic calcium phosphate deposition were voted acceptable to serve as contrast against imaging features of CPPD.

CONCLUSION

An international group of rheumatologists and musculoskeletal radiologists defined imaging features characteristic of CPPD on CR, CT, and DECT and assembled a set of example images as a reference for future clinical research studies.

Pattern of gout and its association with chronic kidney disease in Maiduguri, northeastern Nigeria

INTRODUCTION

Gout is considered uncommon among Black Africans. It is commoner in men and associated with obesity, hypertension, and chronic kidney disease (CKD). This study aims to determine the pattern and frequency of gout and its associated factors in Maiduguri, north-eastern Nigeria.

METHOD

A retrospective study of gout patients managed at the rheumatology clinic of the University of Maiduguri Teaching Hospital (UMTH), Nigeria, from January 2014 to December 2021. Diagnosis of gout was made using the Netherlands 2010 criteria, and CKD was defined as an estimated glomerular filtration rate (eGFR) of < 60 ml/min/1.73m² using the 2021 CKD-epidemiology collaboration (CKD-EPI) creatinine equation. A P-value of < 0.05 was considered statistically significant.

RESULTS

Out of 1409 patients seen during the study period, 150 (10.7%) had gout. They comprised 57.0% males, mostly presented with mono-articular disease (47.7%) with the ankle predominantly involved (52.3%). First metatarsophalangeal and knee joint involvement were commoner among males than females (59% vs 39%, p = 0.052 and 55.7% vs 34.8%, p = 0.05 respectively). The mean serum uric acid (SUA) level was 557.6 ± 176.2 mmol/l, and the levels did not differ between gender (p = 0.118, CI [- 126.6 to 14.5]). Ninety (84.1%) had CKD with 20.6% in end-stage renal disease (eGFR < 15 ml/min/1.73m²). Polyarticular involvement and tophi were commoner among patients with CKD (21.1% versus 11.8% p = 0.652 and χ = 4.364, p = 0.022 respectively) Serum uric acid levels positively correlated with serum creatinine (p = 0.006) and negatively correlated with eGFR (p = 0.001). The best predictor of SUA level was the eGFR (B =  - 2.598, p < 0.001).

CONCLUSION

Gout in north-eastern Nigeria constitutes about 11% of all rheumatic diseases and is typically monoarticular; however, polyarticular form and tophi were commonly seen in patients with CKD. Further studies will be needed to evaluate the relationship between the pattern of gout and CKD in the region. Key Points • Gout in Maiduguri is commonly monoarticular; however, polyarticular presentations and tophi are commoner among gout patients with chronic kidney disease (CKD). • The increase in the burden of CKD might have resulted in the increase in the number of females with gout. • The use of the validated and simple Netherlands criteria for the diagnosis of gout is useful in developing countries to overcome the challenges associated with the use of polarized microscope and thereby allowing further research on gout. • There is a need for further research on the pattern and prevalence of gout and its relationship with CKD in Maiduguri, Nigeria.

The value of ultrasound-defined tenosynovitis and synovitis in the prediction of persistent arthritis

OBJECTIVES

The value of US-defined tenosynovitis in predicting the persistence of inflammatory arthritis is not well described. In particular, the predictive utility of US-defined tenosynovitis of larger tendons is yet to be reported. We assessed the value of US-defined tenosynovitis alongside US-defined synovitis and clinical and serological variables in predicting persistent arthritis in an inception cohort of DMARD-naïve patients with early arthritis.

METHODS

One hundred and fifty DMARD-naïve patients with clinically apparent synovitis of one or more joints and a symptom duration of ≤3 months underwent baseline clinical, laboratory and US (of 19 bilateral joints and 16 bilateral tendon compartments) assessments. Outcomes were classified as persistent or resolving arthritis after 18 months' follow-up. The predictive value of US-defined tenosynovitis for persistent arthritis was compared with those of US-defined synovitis, and clinical and serological variables.

RESULTS

At 18 months, 99 patients (66%) had developed persistent arthritis and 51 patients (34%) had resolving disease. Multivariate logistic regression analysis showed that US-detected digit flexor tenosynovitis [odds ratio (OR): 6.6, 95% CI: 2.0 , 22.1, P = 0.002] provided independent predictive data for persistence over and above the presence of US-detected joint synovitis and RF antibodies. In the RF/ACPA-negative subcohort, US-defined digit flexor tenosynovitis remained a significant predictive variable (OR: 4.7, 95% CI: 1.4, 15.8, P = 0.012), even after adjusting for US-defined joint synovitis.

CONCLUSION

US-defined tenosynovitis provided independent predictive data for the development of persistent arthritis. The predictive role of US-defined digit flexor tenosynovitis should be further assessed; investigators should consider including this tendon site as a candidate variable when designing imaging-based predictive algorithms for persistent inflammatory arthritis development.

Type II collagen facilitates gouty arthritis by regulating MSU crystallisation and inflammatory cell recruitment

OBJECTIVE

Increasing evidence suggests that impaired cartilage is a substantial risk factor for the progression from hyperuricaemia to gout. Since the relationship between cartilage matrix protein and gout flares remains unclear, we investigated its role in monosodium urate (MSU) crystallisation and following inflammation.

METHODS

Briefly, we screened for cartilage matrix in synovial fluid from gouty arthritis patients with cartilage injuries. After identifying a correlation between crystals and matrix molecules, we conducted image analysis and classification of crystal phenotypes according to their morphology. We then evaluated the differences between the cartilage matrix protein-MSU complex and the pure MSU crystal in their interaction with immune cells and identified the related signalling pathway.

RESULTS

Type II collagen (CII) was found to be enriched around MSU crystals in synovial fluid after cartilage injury. Imaging analysis revealed that CII regulated the morphology of single crystals and the alignment of crystal bows in the co-crystalline system, leading to greater phagocytosis and oxidative stress in macrophages. Furthermore, CII upregulated MSU-induced chemokine and proinflammatory cytokine expression in macrophages, thereby promoting the recruitment of leucocytes. Mechanistically, CII enhanced MSU-mediated inflammation by activating the integrin β1(ITGB1)-dependent TLR2/4-NF-κB signal pathway.

CONCLUSION

Our study demonstrates that the release of CII and protein-crystal adsorption modifies the crystal profile and promotes the early immune response in MSU-mediated inflammation. These findings open up a new path for understanding the relationship between cartilage injuries and the early immune response in gout flares.

CXCL12 and CXCR4 as Novel Biomarkers in Uric Acid-Induced Inflammation and Patients with Gouty Arthritis

The aim of this study was to evaluate the expression of chemokine receptor CXCR4 and its ligand CXCL12 in patients with gout and uric acid-induced inflammation. A total of 40 patients with intercritical gout and 27 controls were consecutively enrolled. The serum levels of interleukin-1β (IL-1β), IL-18, CXCL12, and CXCR4 were assessed using an enzyme-linked immunosorbent assay. The gene and protein expressions for these target molecules were measured in human U937 cells incubated with monosodium urate (MSU) crystals using a real-time reverse transcription polymerase chain reaction and Western blot analysis. Patients with intercritical gout showed higher serum IL-1β, IL-18, and CXCL12 levels, but not the serum CXCR4 level, than in the controls.The serum CXCR4 level in gout patients was associated with the serum IL-18 level, uric acid level, and uric acid/creatinine ratio (r = 0.331, p = 0.037; r = 0.346, p = 0.028; and r = 0.361, p = 0.022, respectively). U937 cells treated with MSU crystals significantly induced the CXCL12 and CXCR4 mRNA and protein expression in addition to IL-1β and IL-18. In cells transfected with IL-1β siRNA or IL-18 siRNA, the CXCL12 and CXCR4 expression was downregulated compared with the non-transfected cells in MSU crystal-induced inflammation. In this study, we revealed that CXCL12 and CXCR4 were involved in the pathogenesis of uric acid-induced inflammation and gouty arthritis.

Prediction of coronary heart disease in gout patients using machine learning models

Growing evidence shows that there is an increased risk of cardiovascular diseases among gout patients, especially coronary heart disease (CHD). Screening for CHD in gout patients based on simple clinical factors is still challenging. Here we aim to build a diagnostic model based on machine learning so as to avoid missed diagnoses or over exaggerated examinations as much as possible. Over 300 patient samples collected from Jiangxi Provincial People's Hospital were divided into two groups (gout and gout+CHD). The prediction of CHD in gout patients has thus been modeled as a binary classification problem. A total of eight clinical indicators were selected as features for machine learning classifiers. A combined sampling technique was used to overcome the imbalanced problem in the training dataset. Eight machine learning models were used including logistic regression, decision tree, ensemble learning models (random forest, XGBoost, LightGBM, GBDT), support vector machine (SVM) and neural networks. Our results showed that stepwise logistic regression and SVM achieved more excellent AUC values, while the random forest and XGBoost models achieved more excellent performances in terms of recall and accuracy. Furthermore, several high-risk factors were found to be effective indices in predicting CHD in gout patients, which provide insights into the clinical diagnosis.

Expression Profile of Pyroptosis-Related Genes and the Associated Regulatory Axis in Primary Gout Patients

Purpose

Analyzed the expression characteristics of pyroptosis-related genes (PRGs) in peripheral blood mononuclear cells (PBMCs) of gout patients by microarray, and constructed ceRNA network to explore the molecular mechanism of RNA-mediated pyroptosis regulation.

Patients and Methods

Human mRNA, lncRNA, circRNA microarray data were used to identify differentially expressed in PBMCs from patients with primary gout and healthy controls. Differential PRGs in PBMCs of gout patients identified by Genecard database and mRNA microarray data. GO and KEGG enrichment analyses of these genes were then conducted. Protein-protein interaction networks and cytoHubba were used to identify hub genes. Combining the lncRNA and circRNA microarray data, a ceRNA network was constructed by Cytoscape to screen out key non-coding RNA molecules that can regulate target PRGs. Finally, the relative expression levels of target miRNA and circRNA in 60 gout patients and 40 healthy subjects were detected by qRT-PCR.

Results

The results revealed 30 differentially expressed PRGs. GO and KEGG analysis of these genes were mainly concentrated in the production and regulation of cytokines, NOD-like receptor signaling pathway and so on. Nine hub genes were screened by PPI network, including IL1B, DDX3X, NLRP3, NLRP9, AIM2, CASP8, P2XR7, CARD8 and IFI16. The has_circRNA_102906\hsa_circRNA_102910\hsa_circRNA_102911-hsa-miR-129-5p-DDX3X\NLRP3\NLRP9 regulatory network was constructed. The expression of has_circRNA_102906, hsa_circRNA_102910, hsa_circRNA_102911 were up-regulated and hsa-miR-129-5p down-regulated in PBMCs of gout patients. The relative expression of hsa_circRNA_102911 was positively correlated with clinical inflammatory indicators associated with gout, and the area under the curve of hsa_circRNA_102911 for gout diagnosis was 0.85 (95% CI: 0.775-0.925; p < 0.001).

Conclusion

There are several differentially expressed PRGs in PBMCs of gout patients, which are involved in the regulation of gout inflammation through multiple pathways. hsa_circRNA_102911-hsa-miR-129-5p-DDX3X\NLRP3\NLRP9 may be the key regulatory pathway for pyroptosis to regulate gout inflammation, and hsa_circRNA_102911 may be a potential biomarker for the diagnosis of primary gout.

[Tophaceous gout as a differential diagnosis of preauricular tumor]

Primary gout is a hereditary disorder in nucleotide metabolism. In addition to typical manifestations in the feet, hands, and large joints, there may be rare manifestations in the head and neck. We report a case of tophaceous gout in the temporomandibular joint in a patient who presented with preauricular swelling and progressive hearing impairment. Physical examination showed obliteration of the auditory canal and imaging revealed a destructive process involving the skull base. The diagnosis was confirmed by imaging and biopsy.

[Detection of Monosodium Urate Crystal of Hand and Wrist in Suspected Gouty Arthritis Patients on Dual-Energy CT and Relationship with Serum Urate Level]

Purpose

We retrospectively investigated the characteristics of patients with monosodium urate (MSU) deposits of the hand and wrist on dual-energy CT (DECT) compared to those without. We also attempted to determine the pattern of MSU distribution in DECT.

Materials and Methods

In total, 93 patients were included who had undergone DECT for evaluation of the hand or wrist pain under the clinical impression of gouty arthritis. The total volume of MSU deposits on DECT was calculated and the pattern of MSU distribution on DECT was analyzed. Also, the level of the serum urate at the time of DECT and the highest level of the serum urate of the patients were obtained from their records and the relationship between MSU and serum urate level was evaluated.

Results

The range of the volume of MSU deposits on DECT was 0.01-16.11 cm³ (average: 1.07 cm³). The average level of serum urate was significantly higher in the MSU positive group than that in the MSU negative group. MSU deposits were most frequently observed in the wrists followed by fingers and digitorum tendons.

Conclusion

On DECT, MSU deposits were most frequently detected in the wrist and related with high serum urate level.

Performance of a diagnostic score for gouty arthritis: results from a cohort of acute arthritis suspected of being septic

Septic arthritis (SA) and gout are the main suspected etiologies of acute monoarthritis. Differentiating them is essential because SA is an emergency. The performance of a gout diagnostic score developed by Janssens et al. was investigated in a cohort of patients with acute arthritis suspected of being septic. This was an ancillary study of a single-center cohort of patients with suspected SA. Patients were classified into three groups according to the final diagnosis (gout, SA or other diagnosis). We assessed the performance of the score (sensitivity [Se], specificity [Sp], positive and negative predictive value [PPV, NPV], area under the receiver operating characteristic [ROC] curve) for the diagnosis of gouty arthritis. In total, 138 patients were included: 28 (20.3%) had gout, 42 (30.4%) SA, and 68 (49.3%) another diagnosis. The median diagnostic score was 7.0 [4.5; 8.8] for patients with gout, 3.5 [2.5; 6.0] for those with SA and 3.0 [2.0-5.0] for those with another diagnosis. With a score threshold of ≥ 8, the Se for a diagnosis of gout was 28.6%, Sp 96.4%, PPV 66.7%, and NPV 84.1%. With a threshold of ≤ 4, the Se was 82.1%, Sp 64.5%, PPV 37.1%, and NPV 93.4%. The area under the ROC for the diagnostic score was 0.79. The performance of the clinico-biological score of Janssens et al. for a diagnosis of gout applied to a cohort of patients with acute arthritis and suspected of being septic was poor. Joint aspiration remains necessary to differentiate SA from another etiology.

Infected nasal gout tophus: A case report

Gout is a common form of inflammatory arthritis, characterized by the deposition of monosodium urate crystals. If chronically present and not adequately treated by serum urate reducers, gout tophi can develop at various locations. Here, we report the first infected gout tophus at the septal cartilage and nasal tip.