Lipid mediators obtained from docosahexaenoic acid by soybean lipoxygenase attenuate RANKL-induced osteoclast differentiation and rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic immune-mediated inflammatory disease characterized by persistent inflammation and joint destruction. A lipid mediator (LM, namely, 17S-monohydroxy docosahexaenoic acid, resolvin D5, and protectin DX in a ratio of 3:47:50) produced by soybean lipoxygenase from DHA, exhibits anti-inflammatory activity. In this study, we determined the effect of LM on collagen antibody-induced arthritis (CAIA) in mice and receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast formation in RAW264.7 cells. LM effectively downregulated the expression of tartrate-resistant acid phosphatase (TRAP) and cathepsin K, inhibited osteoclast formation, and suppressed the NF-κB signaling pathway in vitro. In vivo, LM at 10 μg/kg/day significantly decreased paw swelling and inhibited progression of arthritis in CAIA mice. Moreover, proinflammatory cytokine (tumor necrosis factor-α, interleukin (IL)-6, IL-1β, IL-17, and interferon-γ) levels in serum were decreased, whereas IL-10 levels were increased following LM treatment. Furthermore, LM alleviated joint inflammation, cartilage erosion, and bone destruction in the ankles, which may be related to matrix metalloproteinase and Janus kinase (JAK)-signal transducer and activators of transcription (STAT) signaling pathway. Our findings suggest that LM attenuates arthritis severity, restores serum imbalances, and modifies joint damage. Thus, LM represents a promising therapy for relieving RA symptoms.

Low household income increases the risk of tuberculosis recurrence: a retrospective nationwide cohort study in South Korea

OBJECTIVES

We assessed the impact of household income on tuberculosis (TB) recurrence and the long-term impact of TB on household income.

STUDY DESIGN

This was a retrospective nationwide cohort study of patients with drug-susceptible TB (DS-TB) and TB recurrence.

METHODS

Using the South Korean national TB cohort database, we identified a sub-set cohort of patients with newly diagnosed drug-susceptible TB between 2013 and 2016 and tracked their TB recurrence and longitudinal income data from 2007 to 2018. Income levels were evaluated as 'Medical aid' and quintile categories. To assess risk factors associated with TB recurrence, we used a sub-distribution hazard model, adjusting for the competing risks of death.

RESULTS

Of 66,690 patients successfully treated with DS-TB, 2095 (3.1 %) experienced recurrence during a median follow-up of 39 months. The incidence of TB recurrence was 982.1/100,000 person-years, with 50.3 % of the recurrences occurring within 1 year of treatment completion. The risk of TB recurrence increased with decreasing income levels, with the highest risk observed in the lowest income group. The effect of income on TB recurrence was prominent in males but not in females. Overall, patients with TB recurrence experienced a linear decline in income levels, compared with those without recurrence.

CONCLUSIONS

Household income during the initial TB episode was an important risk factor for TB recurrence, particularly in males.

Combination Gene Delivery Reduces Spinal Cord Pathology in Rats With Peripheral Neuropathic Pain

Although peripheral neuropathic pain is caused by peripheral nerve injury, it is not simply a peripheral nervous system disease. It causes abnormalities in both the central and peripheral nervous systems. Pathological phenomena, such as hyperactivation of sensory neurons and inflammation, are observed in both the dorsal root ganglion and spinal cord. Pain signals originating from the periphery are transmitted to the brain via the SC, and the signals are modulated by pathologically changing SC conditions. Therefore, the modulation of SC pathology is important for peripheral NP treatment. We investigated the effects of KLS-2031 (recombinant adeno-associated viruses expressing glutamate decarboxylase 65, glial cell-derived neurotrophic factor, and interleukin-10) delivered to the dorsal root ganglion on aberrant neuronal excitability and neuroinflammation in the SC of rats with peripheral NP. Results showed that KLS-2031 administration restored excessive excitatory transmission and inhibitory signals in substantia gelatinosa neurons. Moreover, KLS-2031 restored the in vivo hypersensitivity of wide dynamic range neurons and mitigated neuroinflammation in the SC by regulating microglia and astrocytes. Collectively, these findings demonstrated that KLS-2031 efficiently suppressed pathological pain signals and inflammation in the SC of peripheral NP model, and is a potential novel therapeutic approach for NP in clinical settings. PERSPECTIVE: Our study demonstrated that KLS-2031, a combination gene therapy delivered by transforaminal epidural injection, not only mitigates neuroinflammation but also improves SC neurophysiological function, including excitatory-inhibitory balance. These findings support the potential of KLS-2031 as a novel modality that targets multiple aspects of the complex pathophysiology of neuropathic pain.

TissueGene-C induces long-term analgesic effects through regulation of pain mediators and neuronal sensitization in a rat monoiodoacetate-induced model of osteoarthritis pain

OBJECTIVE

TissueGene-C (TG-C), a combination of human allogeneic chondrocytes and irradiated GP2-293 cells engineered to overexpress transforming growth factor-β1 (TGF-β1), has been developed as a novel cell-based gene therapy and a candidate for disease modifying osteoarthritis drug (DMOAD). We aim to investigate analgesic mechanism of TG-C in a pre-clinical animal model with monoiodoacetate (MIA)-induced pain.

DESIGN

We used a rat MIA model of osteoarthritis (OA) pain. We examined that TG-C can regulate pain by inhibiting the upregulation of various pain mediators in both knee joint tissue and dorsal root ganglia (DRG) (n = 112) and alleviating pain behavior (n = 41) and neuronal hyperexcitability in DRG (n = 60), afferent nerve fiber (n = 24), and spinal cord (n = 35).

RESULTS

TG-C significantly alleviated pain-related behavior by restoring altered dynamic weight bearing and reduced mechanical threshold of the affected hindlimb. TG-C significantly suppressed the expression of nerve growth factor (NGF) and calcitonin gene-related peptide (CGRP) in inflamed joint tissue. TG-C significantly suppressed the upregulation of tropomyosin receptor kinase A (TrkA) and nerve injury/regeneration protein (GAP43) and activation of Iba1-positive microglial cells in DRG. TG-C significantly recovered neuronal hyperexcitability by restoring RMP and firing threshold and frequency of DRG neurons, attenuating firing rates of mechanosensitive C- or Aδ-nerve fiber innervating knee joint, and lowering increased miniature and evoked excitatory postsynaptic currents (mEPSCs and eEPSCs) in the spinal cord.

CONCLUSION

Our results demonstrated that TG-C exerted potent analgesic effects in a rat MIA model of OA pain by inhibiting the upregulation of pain mediators and modulating neuronal sensitization.

Lipid mediators derived from DHA alleviate DNCB-induced atopic dermatitis and improve the gut microbiome in BALB/c mice

Atopic dermatitis (AD) is a chronic inflammatory skin condition that primarily results from immune dysregulation. We determined the potential therapeutic benefits of lipid mediators (LM, 17S-monohydroxy DHA, resolvin D5, and protectin DX in a ratio of 3:47:50) produced by soybean lipoxygenase from DHA. The underlying molecular mechanisms involved in TNF-α/IFN-γ-stimulated HaCaT cells as well as its effect in an AD mouse model induced by DNCB in BALB/c mice were examined. The results indicated that LM effectively attenuates the production of inflammatory cytokines (IL-6 and IL-1β) and chemokines (IL-8 and MCP-1) by inhibiting the NF-κB signaling pathway in TNF-α/IFN-γ-stimulated HaCaT cells. The oral administration of LM at 5 or 10 μg/kg/day significantly reduced skin lesions, epidermal thickness, and mast cell infiltration in AD mice. Furthermore, LM reduced the production of IgE and inflammatory cytokines (TNF-α, IL-6, and IL-1β) in the serum, modulated gut microbiota diversity, and restored the microbial composition. Overall, our findings suggest that LM represents a potential therapeutic agent for improving AD symptoms through its ability to suppress inflammatory cytokines and alter the composition of gut microbiota.

Whole Regional Lymph Node Area Delineation with Deep Learning Model for Total Marrow and Lymphoid Irradiation

PURPOSE/OBJECTIVE(S)

Total body irradiation (TBI) has been performed for conditioning before hematopoietic stem cell transplantation. However, TBI can be related to diverse adverse events including radiation pneumonitis and cataract. Efforts to reduce these events include the total marrow irradiation (TMI) and total marrow and lymphoid irradiation (TMLI). Compared to TMI, TMLI requires more target delineations with lymph nodes which can be labor-intensive and time-consuming. However, with the TMI plans, the coverage to lymph node might be lower than TMLI and its clinical significance is unknown. In the current study, we aimed to develop a deep learning model for automatic delineation of whole regional lymph nodes area and assess the dose coverage of lymph nodes with TMI plans.

MATERIALS/METHODS

Whole regional lymph nodes (cervical, axillary, mediastinal, para-aortic, common iliac, external iliac, internal iliac, obturator, presacral, inguinal lymph nodes) were manually contoured by 3 radiation oncologists in 26 patients having whole body computed tomography (CT) images. Twenty patients were designated as the training/validation set and 6 patients as the testing set, and model was developed using the 'nnUNET' framework. The trained model was evaluated with dice coefficient score (DCS), precision, and recall. In addition, dose coverage of the automatically or manually delineated lymph nodes in TMI plans was calculated.

RESULTS

The mean value of DCS, precision, and recall of the trained model was 0.76, 0.81, and 0.74, respectively. Dose parameters for manually delineated lymph nodes in previously treated TMI plans showed the mean value of V100% (the percentage of volume receiving 100% of the prescribed dose), V95%, and V90% to be 46.50%, 62.12%, and 73.68%, respectively. The highest V90% was observed in presacral (93.61%), axillary (90.40%), obturator (88.78%), and internal iliac lymph nodes (84.67%). In contrast, the lowest V90% was identified in inguinal (47.95%), cervical (61.69%), and para-aortic (65.75%) and external iliac lymph nodes (68.97%). For automatically delineated lymph nodes, the mean value of V100%, V95%, and V90% of TMI plan was 38.35%, 55.06%, and 67.84%, respectively. The difference with dose coverage of lymph node between delineated manually and automatically was not statistically significant.

CONCLUSION

Automatic delineation of lymph node using deep learning showed the potential to reduce the labor-intensive process of TMLI. When treated with TMI, the coverage of inguinal, cervical, para-aortic and external iliac lymph nodes was lower than expected.

Mapping the Anatomical Distribution of MRI-Identified Locoregional Recurrence following Robotic-Assisted Laparoscopic Prostatectomy for Prostate Adenocarcinoma

PURPOSE/OBJECTIVE(S)

The pattern of locoregional recurrence specifically after robotic-assisted laparoscopic prostatectomy (RALP) for prostate adenocarcinoma is still unknown. In this study, we reviewed pelvic magnetic resonance images (MRI) after postoperative biochemical recurrence (BCR) and drew a map of locoregional recurrence to support evidence of determining the optimal target volume of salvage radiotherapy in a post-RALP BCR scenario.

MATERIALS/METHODS

We have retrospectively searched 7,583 prostate adenocarcinoma patients who have received RALP in our institution between January 2010 and December 2021, and found a pool of highly selected patients with gross tumor recurrence confirmed by post-BCR pelvic MRIs and did not have other histories of malignancy. BCR was defined as the serum PSA more or equal to 0.2 ng/mL, or three consecutive increases. Patients with serum PSA nadir more or equal to 0.2 ng/mL on the 90th postoperative day (POD 90) were excluded to guarantee successful tumor removal. We have reviewed serum PSA levels using R codes, MRI and pathological reports using Excel, and descriptive statistics using SPSS 25. The gross lesions were contoured on the correlating MRIs using MIM Maestro 7.1. The RT structure DICOM files were merged into a map using MATLAB 2022b. In addition, we have conducted Fisher exacted test, Mann-Whitney U test, and logistic regression to identify risk factors for regional recurrence.

RESULTS

A total of 173 patients were identified with locoregional recurrence from post-BCR pelvic MRIs, and 139 (80.3%) patients were in the high-risk group or very-high-risk group according to the NCCN guidelines: 57 (32.9%) patients with histological grade group 5, 50 (28.9%) patients with initial PSA over 20 ng/mL, 114 (65.9%) patients with extracapsular extension, 55 (31.8%) patients with seminal vesicle invasion, and 15 (9%) patients with pN1. The median follow-up was 4.7 (IQR 2.8-6.9) years for pelvic MRIs and 5.8 (IQR 4.0-8.6) years for serum PSA. The BCF survival was median of 10.7 (IQR 4.6-19.1) months, and the locoregional recurrence-free survival was median of 24.6 (IQR 9.7-49.4) months for this subgroup of patients. At first locoregional recurrence, 148 (85.5%) patients were local only, 20 (11.6%) patients were regional only, and 5 (2.9%) patients were both local and regional. Out of the 25 patients with regional recurrence, the incidence of gross tumor recurrence differed by nodal sites: 3 (12%) in perirectal space, 5 (20%) in internal iliac, 7 (28%) in obturator, 13 (52%) in external iliac, and 6 (24%) in common iliac lymph nodes.

CONCLUSION

We have found 173 patients and were able to map reliable gross tumor recurrence sites after RALP and confirmed by pelvic MRIs following BCR. The map supports evidence of using the existing consensus pelvic clinical target volume of salvage radiotherapy, in a post-RALP BCR scenario.

Transgenic viral expression of PH-20, IL-12, and sPD1-Fc enhances immune cell infiltration and anti-tumor efficacy of an oncolytic virus

Oncolytic viruses are of significant clinical interest due to their ability to directly infect and kill tumors and enhance the anti-tumor immune response. Previously, we developed KLS-3010, a novel oncolytic virus derived from the International Health Department-White (IHD-W) strain vaccinia virus, which has robust tumoricidal effects. In the present study, we generated a recombinant oncolytic virus, KLS-3020, by inserting three transgenes (hyaluronidase [PH-20], interleukin-12 [IL-12], and soluble programmed cell death 1 fused to the Fc domain [sPD1-Fc]) into KLS-3010 and investigated its anti-tumor efficacy and ability to induce anti-tumor immune responses in CT26.WT and B16F10 mouse tumor models. A single injection of KLS-3020 significantly decreased tumor growth. The roles of the transgenes were investigated using viruses expressing each single transgene alone and KLS-3020. PH-20 promoted virus spread and tumor immune cell infiltration, IL-12 activated and reprogrammed T cells to inflammatory phenotypes, and sPD1-Fc increased intra-tumoral populations of activated T cells. The tumor-specific systemic immune response and the abscopal tumor control elicited by KLS-3020 were demonstrated in the CT26.WT tumor model. The insertion of transgenes into KLS-3020 increased its anti-tumor efficacy, supporting further clinical investigation of KLS-3020 as a novel oncolytic immunotherapy.

Ion channels involved in inflammation and pain in osteoarthritis and related musculoskeletal disorders

Osteoarthritis (OA) is a currently incurable, chronic, progressive and debilitating musculoskeletal condition. One of its hallmark symptoms is chronic nociceptive and neuropathic pain, which significantly reduces the quality of life of OA patients. While research into the pathomechanisms of OA pain is ongoing and several pain pathways are well understood, the true source of OA pain remains unclear. Ion channels and transporters are key mediators of nociceptive pain. In this narrative review article, we summarize the state-of-the-art in relation to the distribution and function of ion channels in all major synovial joint tissues in the context of pain generation. We provide an update on the ion channels likely involved in mediating peripheral and central nociceptive pathways in the nervous system in OA pain, including voltage-gated sodium and potassium channels, members of the transient receptor potential (TRP) channel family, and purinergic receptor complexes. We focus on ion channels and transporters that have a potential to be candidate drug targets for pain management in OA patients. We propose that ion channels expressed by the cells of constituent tissues of OA-afflicted synovial joints including cartilage, bone, synovium, ligament and muscle, should be more thoroughly investigated and targeted in the context of OA pain. Based on key findings from recent basic research articles as well as clinical trials, we propose novel directions for the development of future analgesic therapies to improve the quality of life of OA patients.

The current state of the osteoarthritis drug development pipeline: a comprehensive narrative review of the present challenges and future opportunities

In this narrative review article, we critically assess the current state of the osteoarthritis (OA) drug development pipeline. We discuss the current state-of-the-art in relation to the development and evaluation of candidate disease-modifying OA drugs (DMOADs) and the limitations associated with the tools and methodologies that are used to assess outcomes in OA clinical trials. We focus on the definition of DMOADs, highlight the need for an updated definition in the form of a consensus statement from all the major stakeholders, including academia, industry, regulatory agencies, and patient organizations, and provide a summary of the results of recent clinical trials of novel DMOAD candidates. We propose that DMOADs should be more appropriately targeted and investigated according to the emerging clinical phenotypes and molecular endotypes of OA. Based on the findings from recent clinical trials, we propose key topics and directions for the development of future DMOADs.

Search for Dark Matter Axions with CAST-CAPP

The CAST-CAPP axion haloscope, operating at CERN inside the CAST dipole magnet, has searched for axions in the 19.74 μeV to 22.47 μeV mass range. The detection concept follows the Sikivie haloscope principle, where Dark Matter axions convert into photons within a resonator immersed in a magnetic field. The CAST-CAPP resonator is an array of four individual rectangular cavities inserted in a strong dipole magnet, phase-matched to maximize the detection sensitivity. Here we report on the data acquired for 4124 h from 2019 to 2021. Each cavity is equipped with a fast frequency tuning mechanism of 10 MHz/ min between 4.774 GHz and 5.434 GHz. In the present work, we exclude axion-photon couplings for virialized galactic axions down to g_aγγ = 8 × 10⁻¹⁴ GeV⁻¹ at the 90% confidence level. The here implemented phase-matching technique also allows for future large-scale upgrades.

Haloscopes aim at detecting axions by converting them into photons using high-quality resonant cavities, where the cavity resonance should be tuned with the unknown axion mass. Here, the authors improve exclusion limits using four phase-matched resonant cavities and a fast frequency scanning technique.

The association between cardiovascular risk factors and coronary CT angiography findings for predicting obstructive coronary artery disease in Korean patients with stable chest pain

Background/Introduction

The 2019 European Society of Cardiology (ESC) guidelines currently recommend the use of coronary computed tomography angiography (CCTA) as the initial test for diagnosing coronary artery disease (CAD) in symptomatic patients in whom obstructive CAD cannot be excluded by clinical assessment alone.

Purpose

The purpose of this study is to identify the prevalence of obstructive CAD in patients with stable chest pain, and the correlation between several clinical cardiovascular disease (CVD) risk factors and CCTA findings presented by Coronary Artery Disease Reporting and Data System (CAD-RADS).

Methods

The present study is a single-center retrospective cross-sectional study. A total of 1,892 patients with stable chest pain who underwent CCTA were enrolled in this study. Diamond-Forrester classification, Framingham risk score (FRS), atherosclerotic CVD (ASCVD) 10-year risk score, coronary artery calcium score (CACS) and CAD-RADS category were obtained from every patient.

Results

Among 1,892 patients (mean age, 60.5±8.6 years; men, 59.3%), 356 (18.8%) had obstructive CAD according to CCTA. Patients with high and intermediate ASCVD 10-year risk score had 2.59 times (aOR 2.59, 95% CI; 1.58 to 4.23) and 1.66 times (aOR 1.66, 95% CI; 1.04 to 2.65) higher odds of having obstructive CAD than patients with low ASCVD 10-year risk score, respectively (adjusted for Diamond-Forrester classification and CACS group). Higher ASCVD risk scores were significantly associated with higher CAD-RADS category (p<0.001), and patients with CAD-RADS category 3 had ASCVD 10-year risk score of 20.1±12.7. CACS showed the highest discrimination in presence of obstructive CAD, followed by ASCVD 10-year risk score, FRS, and Diamond-Forrester classification (AUC: 0.821 [95% CI; 0.797–0.845]; 0.711 [95% CI; 0.683–0.740]; 0.675 [95% CI; 0.646–0.704]; 0.600 [95% CI; 0.569–0.632], respectively).

Conclusion

This is the first study of CCTA findings in stable chest pain patients in Korea. The prevalence of obstructive CAD in patients with stable chest pain was 18.8%. Higher ASCVD score is significantly associated with presence of obstructive CAD and higher CAD-RADS category. As coronary stenosis of 50%-69% had a mean ASCVD score of 20.1, we should consider CCTA for identifying obstructive CAD in patients with ASCVD score over 20 with stable chest pain.

Funding Acknowledgement

Type of funding sources: None.

POS1443 IDENTIFYING THE NEW EMERGENCE OF RACIAL DISPARITIES IN GOUT OVER THE PAST 3 DECADES – US NATIONAL SURVEY AND PROSPECTIVE COHORT DATA

Background

Several studies published after 2010 reported a higher frequency of gout and hyperuricemia among US Blacks than Whites.1-4 However, Blacks (in the US and Africa) were previously thought to suffer gout less often than Whites.5 We hypothesized that the racial disparity in Blacks emerged over the past several decades, with flipped prevalence between the two races.

Objectives

To assess trends in racial differences in gout prevalence in the US using both national survey and cohort study data over the past 3 decades.

Methods

Using data from the NHANES (National Health and Nutrition Examination Survey) III (1988-1994) and latest decade (2007-2016), and data from 5 examination periods in the ARIC (Atherosclerosis Risk in Communities) Study between 1988 through 2013, we compared age- and sex-adjusted prevalences and odds ratios (OR) to determine the trend of racial differences in gout prevalence between Blacks and Whites. A time-race interaction term was used to assess differences in the rate of change between the two races.

Results

Among Whites, the sex- and age-standardised prevalence of gout in the NHANES rose from 2.8% (95% CI: 2.4 to 3.2) in 1988-94 to 3.7% (3.2 to 4.1) in 2007/16. Prevalence of gout among Blacks was lower than Whites in 1988-94 (2.6% [2.2 to 3.0]) but rose more sharply over the subsequent decades (p for race-time interaction=0.003), and in 2007/16 came to exceed that of Whites (5.0% [4.4 to 5.6]).

Corresponding age-sex-adjusted ORs for gout in Blacks vs. Whites were 0.93 (0.73 to 1.17) in 1988-94, increasing to 1.46 (1.22 to 1.74) in 2007/16 (Table 1). This disproportionate rise in gout prevalence among Blacks tended to be more prominent among women (OR 1.81 [1.29 to 2.53]) than men (OR 1.26 [1.02 to 1.55]; p for race-time interactions of 0.002 and 0.01, respectively). Similar trends were observed in the ARIC cohort, where the OR for gout among Blacks vs. Whites rose progressively from 0.82 (0.65 to 1.02) in 1987-89 to 1.81 (1.49 to 2.19) in 2011-13.

Table 1.

Temporal Trend of Racial Disparity in Gout Prevalence in NHANES Survey and the ARIC Study Cohort, overall and by sex

Odds Ratio (95% CI) for Gout Among Blacks vs. WhitesOVERALLNHANES1988-19942007-2016Age- and sex-adjusted0.93(0.73 to 1.17)1.46(1.22 to 1.74)ARICVisit 1: 1987-89Visit 2: 1990-92Visit 3: 1993-95Visit 4: 1996-98Visit 5: 2011-13Age- and sex-adjusted0.82(0.65 to 1.02)0.99(0.81 to 1.22)1.24(1.03 to 1.50)1.60(1.35 to 1.90)1.81(1.49 to 2.19)WOMENNHANES1988-19942007-2016Age-adjusted0.98(0.65 to 1.47)1.81(1.29 to 2.53)ARICVisit 1: 1987-89Visit 2: 1990-92Visit 3: 1993-95Visit 4: 1996-98Visit 5: 2011-13Age-adjusted0.92(0.64 to 1.32)1.14(0.82 to 1.59)1.45 (1.07 to 1.96)1.89 (1.45 to 2.46)2.28(1.73 to 3.01)MENNHANES1988-19942007-2016Age-adjusted0.91(0.68 to 1.21)1.26 (1.02 to 1.55)ARICVisit 1: 1987-89Visit 2: 1990-92Visit 3: 1993-95Visit 4: 1996-98Visit 5: 2011-13Age-adjusted0.73 (0.54 to 0.97)0.87 (0.66 to 1.14)1.03(0.79 to 1.33)1.29(1.02 to 1.64)1.34(1.00 to 1.78)

Conclusion

Gout prevalence tended to be lower in Blacks than Whites until late 80’s, then rose and surpassed that of Whites over the past several decades. These trends closely parallel the worsening obesity epidemic during this period,6 particularly in Blacks, partly due to enhanced Western lifestyle. Gout risk genetic profile change would not contribute to this emergence of racial differences, particularly among the same individuals in ARIC, although it remains to be clarified whether Blacks carry genetic profiles that enhance the effect of lifestyle risk factors for gout.

References

[1]PMID 22225548 (2012)

[2]PMID 24330409 (2013)

[3]PMID 24335384 (2014)

[4]PMID: 30618180 (2019)

[5]NEJM PMID: 15014177

[6]JAMA PMID: 12365955

Disclosure of Interests

Natalie McCormick: None declared, Leo Lu: None declared, Chio Yokose: None declared, Amit Joshi: None declared, Yuqing Zhang: None declared, Hyon Choi Consultant of: Ironwood, Selecta, Horizon, Takeda, Kowa, and Vaxart., Grant/research support from: Ironwood and Horizon

POS0280 EXCESS RISK OF ALL-CAUSE AND CARDIOVASCULAR MORTALITY IN FEMALES WITH GOUT – A PROSPECTIVE COHORT STUDY OF 105,502 WOMEN

Background

Despite the disproportionately worsening disease burden of female gout in recent years1 and its frequent associations with key cardiovascular risk factors (more often than male gout2,3), there remains a paucity of specific data about female gout, particularly about its impact on mortality and fatal coronary heart disease (CHD).

Objectives

To prospectively examine the relation of female gout and risk of all-cause and cardiovascular and coronary heart disease-specific deaths.

Methods

Using data from the Nurses’ Health Study (NHS), an ongoing prospective cohort study in which female nurses in the United States completed detailed mailed questionnaires regarding their medical history, lifestyle, and other risk factors at baseline and every two years thereafter, we prospectively analyzed the relation between gout status at baseline and during the follow-up period and the risk of all-cause and cardiovascular mortality using Cox proportional hazards regression to adjust for cardiovascular risk factors such as comorbidities, body mass index, postmenopausal status, medication use, and dietary factors.

Results

The analysis included 105,502 women without gout and 1602 women with gout. Women with gout at baseline in 1982 tended to be older (mean age 54 vs. 50 years), and more likely to report a history of hypertension (44% vs. 22%), hypercholesterolemia (17% vs. 8%), and diabetes (11% vs. 6%). During 24 years of follow-up, we documented 15,255 deaths from all causes, including 3,128 deaths from cardiovascular disease (CVD) and 1,405 deaths from coronary heart disease (CHD). Compared to women without history of gout or CHD at baseline, the multivariable relative risks (RRs) among women with history of gout at baseline were 1.33 (95% CI, 1.21 to 1.46) for total mortality, 1.40 (95% CI, 1.17 to 1.67) for CVD deaths, and 1.49 (95% CI, 1.17 to 1.91) for fatal CHD (Table 1). The corresponding RRs for gout at baseline and during the follow-up were 1.33 (95% CI, 1.23 to 1.44), 1.43 (95% CI, 1.24 to 1.66), and 1.34 (95% CI, 1.08 to 1.66), respectively.

Table 1.

Relative Risks of Death from All-Causes, Cardiovascular Disease, and Coronary Heart Disease According to Gout Status at Baseline in 1982 in the Nurses’ Health Study

No CHDNo GoutGoutDeaths from all causesCases, n14,810445Age-adjusted RR (95% CI)1.01.58 (1.43, 1.73)Multivariable-adjusted* RR (95% CI)1.01.33 (1.21, 1.46)All cardiovascular deathsCases, n3,001127Age-adjusted RR (95% CI)1.02.06 (1.72, 2.46)Multivariable-adjusted* RR (95% CI)1.01.40 (1.17, 1.67)Fatal CHDCases, n1,33570Age-adjusted RR (95% CI)1.02.53 (1.99, 3.22)Multivariable-adjusted* RR (95% CI)1.01.49 (1.17, 1.91)

*Adjusted for age (continuous), history of hypertension, history of hypercholesterolemia, history of diabetes, aspirin use (yes, no), diuretic use (yes, no), smoking (never, past, current <15, current ≥15 cigarettes/day), body mass index (<23, 23-24.9, 25-29.9, 30-34.9, ≥35), physical activity (quintile), alcohol intake (nondrinker, <5, 5-9, 10-29, ≥30g/day), family history of MI (yes, no), menopausal status (premenopause, post menopause), hormone replacement therapy use (premenopause, never user, current user, past user). total energy intake (quintile), trans fat (quintile), dietary cholesterol (quintile), protein (quintile), linoleic fatty acid (quintile), and ratio of polyunsaturated fat/saturated fat.

CHD = coronary heart disease; CI = confidence interval; RR = relative risk.

Conclusion

These prospective data indicate that women with gout have a higher risk of all-cause mortality, which is primarily driven by higher risk of CVD deaths. These findings closely agree with the UK general population data of both sexes that showed unclosing mortality gap over the past two decades.4 Together, these findings provide support for rigorous cardiovascular risk factor modification specifically in female gout to help curtail the rising disease burden of gout worldwide.1

References

[1]Xia et al., PMID 31624843

[2]Puig et al., PMID 2012455

[3]Harrold et al., PMID 16644784

[4]Fisher et al., PMID 28122760

Disclosure of Interests

Chio Yokose: None declared, Natalie McCormick: None declared, Na Lu: None declared, Amit Joshi: None declared, Gary Curhan Consultant of: AstraZeneca, Allena Pharmaceuticals, Shire/Takeda, Dicerna, and Orfan, Grant/research support from: Decibel Therapeutics, Employee of: Chief Medical Officer at OM1, Inc., Hyon Choi Consultant of: Ironwood, Selecta, Horizon, Takeda, Kowa, and Vaxart, Grant/research support from: Ironwood and Horizon

POS0155 WHAT DRIVES RACIAL DISPARITIES IN GOUT IN THE US? – POPULATION-BASED, SEX-SPECIFIC, CASUAL MEDIATION ANALYSIS

Background

Traditionally viewed as a disease of White men, global frequency and disability burden of female gout are rising disproportionately to male gout.1 Moreover, emerging US cohort data suggest gout and hyperuricemia impart larger burdens on Black adults than Whites.2 These racial disparities may be largely attributable to differences in non-genetic, mainly modifiable gout risk factors e.g., BMI, diet,3,4 and chronic kidney disease (CKD). However, national-level, general population data on racial differences in burden of gout, and potential mediators, are lacking.

Objectives

To determine and quantify sex-specific mediators of racial disparities in gout prevalence among a nationally representative sample of US adults.

Methods

Using recent decadal data (2007-2016) on physician-diagnosed gout and hyperuricemia from the National Health and Nutrition Examination Survey, we compared contemporary sex- and race-specific prevalences and conducted sequential causal mediation analysis (adjusting for upstream mediators following causal pathways)5 to determine the proportion of the racial differences attributable to 7 potentially mediating social and clinical factors (see DAG in Figure 1): low education, poverty, body mass index (BMI), alcohol, poor quality diet (poor DASH adherence), diuretic use, and CKD (eGFR <60 mL/min, using the latest equations that do not include a coefficient for Black race6, per National Kidney Foundation and American Society of Nephrology recommendations.7)

Results

Age standardised prevalence of gout was 3.5% and 2.0% in Black and White women, respectively (age-adjusted OR =1.8 [95% CI: 1.3 to 2.5]), and 7.0% and 5.4% in Black and White men (age-adjusted OR =1.3 [1.0 to 1.6]). Most risk factors were more frequent/elevated in Blacks than Whites, except alcohol consumption, which was lower in Blacks (both sexes). BMI levels and poverty were higher in Black women, but similar between Black and White men.

Largest mediating factor of excess gout cases among Black women was excess BMI, accounting for 56% of the racial difference (independent of education, poverty, diet, and alcohol), followed by CKD (24%), poverty (17%), and poor diet (12%) (see Table 1).

Table 1.

Indirect (mediation) effects of potential mediators, using sequential mediation analysis, for the association between Black race and odds of gout in US women and men.

WOMENMENEffect Estimate (OR), 95% CIProportion Mediated, %Effect Estimate (OR), 95% CIProportion Mediated, %Indirect (Mediation) EffectEducation (high school or less)1.01 (0.98 to 1.03)2.4%1.01 (0.98 to 1.03)3.3%Poverty1.07 (1.04 to 1.10)16.9%1.00 (0.99 to 1.00)0.53%Alcohol consumption (# drinks/week, continuous)0.99 (0.96 to 1.01)-3.4%0.99 (0.98 to 1.00)-4.5%DASH diet score (continuous; higher scores = ↓ adherence)1.05 (0.96 to 1.01)12.0%1.05 (1.01 to 1.10)19.8%Body mass index (continuous)1.25 (1.14 to 1.37)55.9%1.03 (1.02 to 1.04)11.9%Diuretic use1.03 (1.01 to 1.05)7.6%1.04 (1.02 to 1.06)14.2%Chronic kidney disease1.10 (1.04 to 1.16)23.9%1.12 (1.08 to 1.17)45.6%Direct Effect0.94 (0.68 to 1.30)a−15.2%1.02 (0.83 to 1.26)b9.2%Total Effect1.49 (1.12 to 1.98)100%1.29 (1.05 to 1.57)100%

DASH=Dietary Approaches to Stop Hypertension;

ap=0.52,

bp=0.83

Among men, CKD was the largest mediator (46%), followed by poor diet (20%) and diuretic use (14%). BMI (12%) and poverty (0.5%) mediated smaller proportions of the racial difference among men compared to women. Mediators of racial differences in hyperuricemia closely agreed with gout results.

Conclusion

Contrasting with historical views, gout is more frequent among Black adults in the US than their White counterparts, especially women (two-times greater in Black women vs. White). Culturally informed efforts to reduce these disparities should focus on excess adiposity, diet quality, and kidney disease while recognising the impact of poverty in female gout.

References

[1]Xia; PMID 31624843

[2]PMID 24335384

[3]Rai BMJ PMID 28487277

[4]Yokose JAMA IM (2022)

[5]VanderWeele; PMID 25580377

[6]NEJM PMID 34554658

[7]JASN PMID 34556489

Disclosure of Interests

Natalie McCormick: None declared, Leo Lu: None declared, Chio Yokose: None declared, Amit Joshi: None declared, Tony Merriman: None declared, Kenneth Saag Consultant of: Arthrosi, Atom Bioscience, Horizon Therapeutics, LG Pharma, Mallinkrodt, SOBI, Takeda, Grant/research support from: Horizon Therapeutics, SOBI, Shanton, Yuqing Zhang: None declared, Hyon Choi Consultant of: Ironwood, Selecta, Horizon, Takeda, Kowa, and Vaxart.

Grant/research support from: Ironwood, Horizon

OP0166 CHRONIC KIDNEY DISEASE AND AMPLIFICATION OF SERUM URATE IMPACT ON GOUT RISK: POPULATION-BASED STUDY OF > 450,000 UK BIOBANK PARTICIPANTS

Background

Serum urate (SU) is a necessary causal factor for development of gout, while chronic kidney disease (CKD) is associated with increased inflammatory biomarkers, cytokines, and reduced AMPK activity levels. Furthermore, CKD has been found to be associated with an increased risk of incident gout, even beyond (i.e., independent of) SU levels. As such, the impact of SU may be enhanced by presence of CKD, but this hypothesis has not been evaluated.

Objectives

To prospectively examine whether CKD modifies the relation between SU levels and risk of incident gout.

Methods

We conducted a prospective cohort analysis of UK Biobank participants with urate and creatinine levels available from baseline blood samples (2006-2010), and no prior diagnosis of gout or urate lowering therapy use. CKD Stage ≥ 3 status (eGFR <60 mL/min) was determined from latest CKD-Epi equations (NEJM 2021; JASN 2021).1,2 Incident cases of gout were ascertained from linked hospitalisation, primary care, and death records. Participants were followed from baseline up to 10 years or until gout diagnosis, death, or end of study period (Dec 31/19).

We calculated 10-year cumulative incidence of gout according to baseline SU category and CKD status and evaluated their individual and joint impact on gout risk using multivariable Cox proportional hazards models.

We further assessed for additive and multiplicative interactions3 between levels of SU and inverted eGFR, on a standardized continuous scale per SD.

Results

We included 458,244 individuals (45% male, mean age 56.5 years), of whom 6,559 had CKD at baseline, and documented 5,847 cases of incident gout over 4,442,866 person-years.

10-year cumulative incidence of gout ranged from 0.2% (baseline SU < 5 mg/dL) to 33% (baseline SU ≥ 10 mg/dL), and in each category incidence was higher for those with CKD than without (Table 1; Figure 1-left), Multivariable hazard ratio (HR) for the joint effect of CKD and highest SU level (≥ 10 mg/dL), compared to non-CKD and lowest SU (<5mg/dL), was 242 (95% CI: 189 to 309) (Figure 1-right).

Table 1.

Cumulative incidence and hazard ratio (HR) of incident gout according to baseline serum urate levels and CKD status

CKD Stage ≥ 3Hyperuricemia (Dichotomous)Serum urate, mg/dL<55.0 to < 6.06.0 to < 7.07.0 to < 8.08.0 to < 9.09.0 to < 10.0≥10<7.0≥7.0N cases6152895150104874943610-Year Cumulative Incidence0.6%1.1%1.7%7.6%19.1%28.0%42.0%1.2%16.6%Incidence Rate Ratio1.0 (Ref)1.72.712.333.856.1107.71.0 (Ref)15.2No CKDSerum urate, mg/dL<55.0 to < 6.06.0 to < 7.07.0 to < 8.08.0 to < 9.09.0 to < 10.0≥10<7.0≥7.0N cases393446105617691251363841,8953,46710-Year Cumulative Incidence,0.2%0.4%1.4%6.0%15.6%23.5%27.5%0.5%8.8%Incidence Rate Ratio1.0 (Ref)2.18.034.696.9155.9198.81.0 (Ref)20.2Joint Effect of Serum Urate and CKDSerum urate, mg/dL<55.0 to < 6.06.0 to < 7.07.0 to < 8.08.0 to < 9.09.0 to < 10.0≥10<7.0≥7.0Age-, Sex-, and Race- Adjusted HRNo CKD1.0 (Ref)1.97.029.883.0133.3170.31.0 (Ref)15.7CKD3.25.17.834.193.3155.9302.32.530.5Fully adjusted HR*No CKD1.0 (Ref)1.86.425.869.4108.7132.91.0 (Ref)12.5CKD3.14.76.828.975.2121.1241.82.322.4

*Adjusted for age, sex, race, body mass index, hypertension, diuretic use, smoking, and consumption of alcohol, coffee, meat, fish, poultry, and milk.

There was a significant additive interaction between continuous SU and eGFR (relative excess risk due to interaction=0.16 [0.09 to 0.24], p < 0.001), with HRs of 3.7 (3.6 to 3.8) per SD increase of SU, 1.2 (1.2 to 1.3) per SD increase of inverted eGFR, and 4.1 (3.9 to 4.2) for their joint effect. Their multiplicative interaction was also significant (p < 0.001).

Conclusion

These large prospective cohort data suggest CKD presence enhances the effect of elevated SU levels on risk of incident gout. They support roles of CKD-associated factors beyond SU in developing gout, such as reduced AMPK activity levels and altered inflammatory factors in CKD, which warrant further investigation.

References

[1]PMID 34554658

[2]PMID 34556489

[3]ARD (2021) PMID 34857519

Disclosure of Interests

Natalie McCormick: None declared, Leo Lu: None declared, Chio Yokose: None declared, Amit Joshi: None declared, Yuqing Zhang: None declared, Hyon Choi Consultant of: Ironwood, Selecta, Horizon, Takeda, Kowa, and Vaxart., Grant/research support from: Ironwood and Horizon

POS0276 TRADITION VS INNOVATION! CONVENTIONAL RADIOGRAPHY AND ULTRASOUND IN THE DIAGNOSIS OF CPPD: INSTRUCTIONS FOR USE

Background

Conventional radiography (CR) is widely used as the first-line investigation for calcium pyrophosphate deposition (CPPD) disease, given its widespread use and the low cost. Next to it a series of advanced imaging techniques have been evaluated for accuracy and reliability. Among them, ultrasound (US) has been thoroughly tested and demonstrated to be accurate and reliable for CPPD diagnosis. However, even if there are data on the diagnostic accuracy of US and CR alone, it is not clear if performing both diagnostic tests and in which sequential order provides an added value for the diagnosis of CPPD.

Objectives

The aim of this study was to assess which diagnostic test performs better for the diagnosis of CPPD and if a combination of the two exams provides an additional value.

Methods

This is an ancillary study of the criterion validity of US in CPPD study1. Consecutive patients with knee osteoarthritis requiring total joint replacement were enrolled in 8 centres. Participants underwent US and CR of the affected knee prior to surgery. US was performed by experienced sonographers following the same scanning protocol described in the main study, while CR were performed in weight bearing AP and lateral views and were read by 2 experienced radiologists that reached a consensus on the presence/absence of CPPD. The evaluation of CPPD at the level of menisci and hyaline cartilage (HC) was based on the OMERACT definitions for US and on the new definitions developed by the ACR/EULAR CPPD classification criteria working group for CR [paper under submission]. Patients were classified as having CPPD considering histological examination as reference standard. Diagnostic indexes were calculated for US and CR alone and combined. Poisson models with robust estimation were used to estimate the best sequence of these diagnostic methods for a more accurate diagnosis of CPPD.

Results

51 pts were enrolled (63% F, mean age 74y ± 8). Diagnostic indexes of US and CR alone and combined are indicated in Table 1. Compared to histology, US demonstrated to be a sensitive tool for identification of CPPD at the knee, with a good sensitivity in all sites and in the overall evaluation. Instead, CR was less sensitive, but it was a highly specific exam for CPPD identification. Combining US and CR led to a higher sensitivity compared with CR alone, but a lower specificity compared to both CR and US alone, and it offered no additional increase in diagnostic accuracy. The Figure 1 shows the results of the appropriate sequence of use of US and CR in patients with suspected CPPD: in case of a positive CR at any of the 3 sites (menisci and HC) no additional exam is necessary, and the same in case of a positive US in at least two sites; however in case of a negative CR, US could help in a statistically significant way to identify CPPD patients, and further in case of a positive US in a single site CR can offer additional information.

Table 1.

diagnostic indexes of US, CR and US + CR in the identification of CPPD. MM: medial meniscus, LM: lateral meniscus, HC: hyaline cartilage, SN: sensitivity, SP: specificity, PPV: positive predictive value, NPV: negative predictive value, ACC: accuracy.

USSNSPPPVNPVACCMM0.880.810.820.880.84LM0.880.730.760.860.80HC0.780.860.820.830.82Overall0.920.640.730.890.78CRMM0.32110.610.67LM0.400.960.910.630.69HC0.480.930.850.680.73Overall0.540.920.880.660.73US + CRMM0.880.810.820.880.84LM0.920.690.740.900.80HC0.870.820.800.890.84Overall0.920.560.670.880.75Figure 1.

evaluation of sequence of US and CR

Conclusion

US confirmed a high diagnostic accuracy in identifying patients affected by CPPD at knee level, while CR demonstrated a high specificity but a low sensitivity. Performing both diagnostic tests could make sense in case of a negative CR or in case of an inconclusive US (only one positive site). To our knowledge, this is the first study that investigates the role of the combination of the two exams in CPPD. Further studies in a large number of patients and in different joints would be helpful to address this point.

References

[1]Filippou G. et al, Ann Rheum Dis, 2020

Disclosure of Interests

None declared

OP0164 A POPULATION-BASED, PROSPECTIVE METABOLOMICS STUDY IN THE UK BIOBANK IDENTIFIES GLYCOPROTEIN ACETYLS AS A NOVEL BIOMARKER OF INCIDENT GOUT

Background

Serum urate (SU) level is the strongest known causal predictor of clinical gout, but only ~20% with prolonged hyperuricemia develop gout, motivating the need for additional biomarkers for risk prediction and stratification. The metabolome represents a compelling intermediate trait between genome and phenome to elucidate disease mechanisms. Multiple cross-sectional studies of prevalent gout from men in Asia have been conducted, but no prospective data for incident gout (prediagnostic metabolome) are available.

Objectives

Our objectives were to (1) conduct a discovery-based metabolome-wide study to identify novel biomarkers of incident gout; and (2) replicate novel metabolomic biomarkers of gout in independent samples.

Methods

We conducted a prospective cohort analysis of 105,703 UK Biobank (UKB) participants (46% males, mean age 57.2 years) with targeted NMR metabolomic profiling (N=168 metabolites, including routine lipids and amino acids) available from baseline samples (2006-10), and no prior diagnosis of gout or urate lowering therapy use. Incident cases of gout were documented from linked medical records until gout diagnosis, death, or end of study period (Dec 31/19). We used Cox proportional hazard models to obtain hazard ratios (HR) and 95% confidence intervals (CIs) per standard deviation (SD) increase in each of the 168 metabolites to determine associations with incident gout.

To replicate our findings, we assessed association of metabolome-wide significant metabolites in a replication set, restricted to 4,804 non-overlapping participants who provided blood in the repeat assessment visit (2012-13).

Results

During a median 10.4 years follow-up, we documented 1,367 cases of incident gout in the discovery set. After correction for multiple comparisons, glycoprotein acetyls (GlycA) were positively associated with risk of incident gout (multivariable HR per 1SD increase = 1.34 (1.27 to 1.41), P = 9.04x 10-28) after adjusting for age, sex, and lifestyle and clinical covariates (Table 1). This association persisted even after SU adjustment (HR 1.07, P = 0.0091). In the replication set, among 4,804 participants followed for a median of 6.8 years, we documented 22 cases. In this dataset, we replicated GlycA association with incident gout (multivariable HR per 1SD increase =1.56 (1.08 to 2.25), P = 0.017).

Table 1.

Association of glycoprotein acetyls (GlycA) with risk of incident gout in the UK Biobank

ModelUnivariable HR, (95% CI)PMultivariable HR, (95% CI)PDiscovery (N= 105,703)Per Standard deviation:GlycA, per SD1.48 (1.41 to 1.60)3.7x10-591.34 (1.27 to 1.41)9.04x 10-28Categorized as quintiles:GlycA, Q11.0 Ref1.0 RefGlycA, Q21.43 (1.13 – 1.80)0.0021.30 (1.03 – 1.64)0.0252GlycA, Q32.06 (1.66 – 2.56)4.88 x 10-111.73 (139 – 2.15)7.64 x 10-07GlycA, Q42.53 (2.05 – 3.12)4.15 x 10-181.98 (1.60 – 2.45)3.96 x 10-10GlycA, Q53.70 (3.02 – 4.52)3.21 x 10-372.63 (2.12 – 3.23)2.01 x 10-19Replication (N= 4804)Per Standard deviation:GlycA, per SD1.65 (1.19 to 2.29)0.00271.56 (1.08 to 2.25)0.0172

1 Hazard ratios (HR) and 95% confidence intervals (CIs) obtained after adjusting for the first 4 genomic principal components (controlling for population stratification), age, sex, fasting (<4 hrs, 4-8 hrs and ≥8 hrs), smoking (never, former, current), freq of alcohol, BMI, diabetes (yes/no) and hypertension at baseline (yes/ no).

Conclusion

In this large-scale, prospective metabolomics study, we identified and independently replicated our findings that plasma levels of GlycA are associated with incident gout in UKB participants. GlycA is novel for gout, though this pro-inflammatory biomarker has predicted risk of other cardiometabolic-inflammatory phenotypes, independent of CRP.1 These findings may provide insight into the metabolic-inflammatory pathogenesis of gout, with implications for risk prediction, even beyond SU, but call for further investigation with more extensive metabolome profiling and external replication.

References

[1]Kettunen; PMID 30571186

Disclosure of Interests

Amit Joshi: None declared, Natalie McCormick: None declared, Chio Yokose: None declared, Na Lu: None declared, Hyon Choi Consultant of: Ironwood, Selecta, Horizon, Takeda, Kowa, Vaxart, Grant/research support from: Ironwood, Horizon

POS1171 TRIPLE THE RATE OF EMERGENCY ROOM VISITS AND HOSPITALIZATIONS FOR GOUT AMONG US BLACKS VS WHITES – 2019 NATIONWIDE ANALYSIS

Background

Gout is a highly prevalent inflammatory arthritis with increasing global disease burden in recent years.1,2 Gout prevalence has been reported to be higher among Blacks compared to Whites,3 and that they are less likely to receive allopurinol in outpatient care.4 The potential nationwide impact of these racial disparities on emergency department (ED) visits and hospitalizations is unknown.

Objectives

To examine the contemporary racial disparities in ED visits and hospitalizations with a primary discharge diagnosis of gout in the US (2019).

Methods

We compared ED visits and hospitalizations between Blacks and Whites in the latest data (2019) from the US National Emergency Department Sample (NEDS) and National Inpatient Sample (NIS). We focused on encounters for which the primary diagnosis was gout based on ICD codes (M1A.xx, M10.xx). We calculated annual population rates of ED visits and hospitalizations for gout (per 100,000 US adults) using the 2019 US census adult population (>18 years) according to race.

Results

There were a total of 160,759 ED visits and 9,560 hospitalizations among White and Blacks with a gout diagnosis in the US in 2019. The mean age (58.2 years vs. 56.5 years) and male proportion (78.0% vs. 74.8%) tended to be higher among Whites, while more Blacks tended to live in the South (40.7% vs. 66.5%) and reported a median household income of < $50,000 (30.7% vs. 57.1%). Compared to Whites, Blacks had 2.7- and 3.2-fold higher rates of gout ED visits and hospitalizations, respectively, after adjusting for age, sex, payer, region, and household income (Table 1 & Figure 1). Black women, in particular, had 3.4- and 4.0-fold higher rates of ED visits and hospitalizations compared to White women, while the corresponding rate ratios for men were 2.5 and 2.8, respectively. The mean costs per gout ED visit were similar for Blacks compared to Whites (adjusted difference, -$7.6 [95% CI, -25.4 to 1.0]), while hospitalizations were more costly (adjusted difference, $1,055.3 [95% CI, 553.1 to 1557.5]). The duration of ED visits and hospitalizations was also higher among Blacks than Whites (adjusted difference of 0.41 days [95% CI, 0.19 to 0.63] and 0.59 days [95% CI, 0.25 to 0.94], respectively).

Table 1.

Racial Disparities in Emergency Department Visits and Hospitalizations with Primary Diagnosis of Gout in 2019

Emergency Department VisitsHospitalizationsRaceWhiteBlackWhiteBlackAll6801196524521330198510434519150Visits, N888107194962003360Rate per 100,000130.6293.431.274.4Rate Ratio (95% CI)*1.0 (ref)2.81 (2.63, 3.00)1.0 (ref)3.08 (2.79, 3.40)Rate Ratio (95% CI)**1.0 (ref)2.66 (2.50, 2.82)1.0 (ref)3.17 (2.86, 3.50)Women3785136914363031110390932647105Visits, N195671816317701145Rate per 100,00051.7126.516.043.3Rate Ratio (95% CI)*1.0 (ref)3.68 (3.39, 3.99)1.0 (ref)4.01 (3.40, 4.73)Rate Ratio (95% CI)**1.0 (ref)3.36 (3.11, 3.62)1.0 (ref)4.02 (3.39, 4.78)Men301561011015657388098151871620Visits, N692285378344302215Rate per 100,000229.6529.550.3118.3Rate Ratio (95% CI)*1.0 (ref)2.59 (2.42, 2.78)1.0 (ref)2.66 (2.36, 3.00)Rate Ratio (95% CI)**1.0 (ref)2.47 (2.32, 2.64)1.0 (ref)2.77 (2.45, 3.14)

*Adjusted for age and sex for all, adjusted for age for sex-specific rate ratios

**Adjusted for age, sex, payment, region, and household income

Conclusion

These latest national data indicate that ED visits and hospitalization due to gout are both 3 times higher among Blacks than Whites; this disparity was particularly prominent among women with gout. Higher risk of developing gout3 and suboptimal care4 both translate to these avoidable costly healthcare utilizations, calling for improved primary prevention and gout care.

References

[1]Safiri et al., PMID 32755051

[2]Xia et al., PMID 31624843

[3]Chen-Xu et al., PMID 30618180

[4]Krishnan et al., PMID 18260174

Disclosure of Interests

Chio Yokose: None declared, Natalie McCormick: None declared, Na Lu: None declared, Amit Joshi: None declared, Lesley Jackson: None declared, Minna Kohler Speakers bureau: Lilly, Consultant of: Mymee, Novartis, Grant/research support from: Setpoint Medical, Janeth Yinh: None declared, Yuqing Zhang: None declared, Kenneth Saag Consultant of: Arthrosi, Atom Bioscience, Horizon Therapeutics, LG Pharma, Mallinkrodt, SOBI, Takeda, Grant/research support from: Horizon Therapeutics, SOBI, Shanton, Hyon Choi Consultant of: Ironwood, Selecta, Horizon, Takeda, Kowa, and Vaxart, Grant/research support from: Ironwood and Horizon

AB0624 Patients with vasculitis have a high prevalence of coronary microvascular dysfunction

Background

Vasculitides are a heterogenous group of diseases characterized by intense vessel wall inflammation, endothelial injury, and systemic inflammation. Several vasculitides are associated with high risk of cardiovascular (CV) disease, an important source of morbidity and mortality in this population. This excess CV risk is attributed both to a high burden of traditional risk factors and to inflammation, but this remains poorly studied. Indeed, inflammation is a known risk factor for CV disease and implicated in coronary microvascular dysfunction (CMD) which may precede obstructive coronary artery disease (CAD).

Objectives

We sought to assess whether vasculitis is associated with CMD in the absence of obstructive CAD.

Methods

We retrospectively identified subjects with systemic vasculitis who underwent symptom prompted rest/stress myocardial perfusion PET. Patients with an abnormal myocardial perfusion study (summed stress score ≥3) or LVEF<40% were excluded. Controls were identified from the same population and matched on age, gender and cardiovascular risk factors (CAD, hypertension, dyslipidemia, diabetes mellitus, and obesity). Coronary flow reserve (CFR), was calculated as the ratio of myocardial blood flow (ml/min/g) at peak stress compared to rest. CMD was defined as CFR <2.

Results

We studied 26 vasculitis cases and 66 matched controls. The most common vasculitides were giant cell arteritis (38%), ANCA-associated vasculitis (31%), and Takayasu’s arteritis (12%). Median (IQR) time between diagnosis and PET was 6.5 (2.9, 14.2) years. Seven (27%) cases had active vascultis at the time of PET. Cases and controls were well-matched on age, sex, and CV risk factors (Table 1). Despite a similar prevalence of CV risk factors, coronary flow reserve (reflected by CMD) was abnormal in 38% of vasculitis cases compared to 15% of controls (p=0.004). The mean [SD] CFR was 19% lower in vasculitis cases vs controls (2.11 [0.5] versus 2.6 [0.7], p=0.003).

Table 1.

The presence of coronary microvasculature dysfunction in patients with systemic vasculitis without obstructive coronary artery disease

Cohort characteristicsVasculitis (n=26)Control (n=66)P-valueAge at PET, years62 (18)61 (17)0.24Time from Vasculitis Diagnosis to PET, years (median, IQR)6.5 (2.9, 14.2)n/aFemale, n (%)18 (72%)43 (65%)0.99Vasculitis CharacteristicsLarge Vessel (e.g., giant cell arteritis, Takayasu’s), n(%)13 (50%)n/an/aMedium Vessel (e.g., polyarteritis nodosa, Kawasaki’s arteritis), n(%)2 (8%)n/an/aSmall Vessel (e.g., ANCA-associated vasculitis, Henoch-Schonlein Purpura), n(%)11 (42%)n/an/aCardiovascular Risk FactorsAt DiagnosisAt PETAt PETHypertension, n (%)12 (46%)20 (71%)47 (80%)0.47Obesity, n (%)3 (12%)2 (32%)2 (32%)0.84Diabetes, n (%)3 (12%)5 (20%)13 (20%)0.99Dyslipidemia, n (%)4 (15%)15 (58%)40 (61%)0.99Known CAD, n (%)0 (0%)1 (4%)1 (2%)0.48Imaging FindingsRest myocardial blood flow, ml/min/g1.0 (0.3)1.0 (0.3)0.8Stress myocardial blood flow, ml/min/g2.1 (0.6)2.6 (1.0)0.008Coronary Flow Reserve, ml/min/g*2.1 (0.5)2.6 (0.7)0.003Coronary Microvasculature Dysfunction** (CMD), n (%)10 (38%)11 (15%)0.004

Conclusion

Patients with systemic vasculitis, even in the absence of obstructive CAD, have a high prevalence of CMD compared with non-vasculitis patients. These differences were observed despite matching cases and controls on traditional CV risk factors, highlighting the importance of other factors, such as inflammation and vasculitis treatments on CMD and CV disease in this population. CMD is a known independent risk factor for CV mortality. Future prospective studies are needed to understand the relationship between vasculitis, systemic inflammation, and CMD.

Disclosure of Interests

None declared

POS0370 COMPARATIVE RETINOPATHY RISK OF HIGH- VS LOW-DOSE HYDROXYCHLOROQUINE AMONG 4,677 INCIDENT LONG-TERM USERS: EMULATED TARGET TRIAL ANALYSES

Background

Hydroxychloroquine (HCQ) is a key treatment for patients with lupus, but the major long-term toxicity is HCQ retinopathy. A large cross-sectional study found a prevalence of HCQ retinopathy of 7.5% overall and 5 times higher odds associated with HCQ dose >5 mg/kg/day, which led to ophthalmology guidelines recommending the avoidance of HCQ dosing >5 mg/kg.1 However, whether this dosing recommendation is applicable to the future risk of HCQ retinopathy is unknown, as is the incidence of severe bullseye retinopathy vs. the mild, pre-symptomatic stage. Furthermore, recent studies have indicated that the use of lower doses of HCQ may increase the risk of lupus flares and hospitalizations.2

Objectives

To determine the incidence of HCQ retinopathy associated with long-term HCQ use and compare them according to HCQ dose.

Methods

We emulated a hypothetical target trial using observational data3 from the US integrated health network Kaiser Permanente Northern California to compare two HCQ weight-based dosing strategies, >5 vs ≤5 mg/kg/day, based on dispensed tablets per year. A secondary analysis evaluated >80% of prescription days covered by dispensed tablets per year with HCQ dose >5 vs ≤5 mg/kg. We included 4,677 patients who initiated and continued HCQ for at least 5 years between 1997-2020. We emulated randomization of treatment strategy by cloning each subject and assigning a replicate to each treatment group.3 We censored replicates if and when they deviated from the assigned treatment group, assessed as the average dose in the first 5 years and annually thereafter. We used inverse probability weighting to account for censoring. The primary outcome was HCQ retinopathy, assessed by expert adjudication of spectral domain-optical coherence tomography (SD-OCT) and graded by severity. All SD-OCTs were prospectively reviewed by an expert ophthalmologist (RM), and a second expert ophthalmologist (MM) reviewed all abnormal scans and a random subset of normal scans. We assessed intra-rater reliability of SD-OCT findings. We used pooled logistic regression to estimate the cumulative incidence of HCQ retinopathy for each HCQ dose strategy from initiation. The odds ratios approximated hazard ratios (HRs) because the outcome at each one-year time block is <5%.

Results

Among 4,677 patients, the mean age at HCQ initiation was 52 years; 83% were female. The racial/ethnic composition included 51% non-Hispanic White, 19% Hispanic, 14% Asian, and 11% Black patients. 756 (16.2%) and 3,921 (83.8%) patients initiated HCQ with the primary definition of the treatment strategies >5 and ≤5 mg/kg/day, respectively. The weighted kappa was 0.80 for SD-OCT reliability. 164 patients developed HCQ retinopathy (100 mild, 38 moderate, and 26 severe cases). The cumulative incidence of retinopathy over 18 years was 37.6% for >5 and 5.7% for ≤5mg/kg of HCQ in our primary analysis. The corresponding risk was 26.5% for >5 and 3.2% for ≤5 mg/kg in our secondary analysis using >80% of prescription days. Compared with ≤5 mg/kg of HCQ, the HRs of retinopathy were 9.65 (95% CI 5.73-16.65) and 10.79 (95% CI 6.40-20.07) for >5 mg/kg using the primary and secondary definitions of HCQ dose categories, respectively (Figure 1).

Conclusion

The risk of HCQ retinopathy associated with long-term adherence to >5 mg/kg dosing was high, approximately 10 times that of ≤5 mg/kg dosing. However, most cases identified during the study were mild and pre-symptomatic, supporting the value of regular screening. These data should be incorporated into individualized decisions about long-term use of HCQ.

References

[1]Melles RB, Marmor MF. The risk of toxic retinopathy in patients on long-term hydroxychloroquine therapy. JAMA Ophthalmol 2014;132(12):1453-60

[2]Almeida-Brasil CC et al. Flares after hydroxychloroquine reduction or discontinuation: results from the SLICC inception cohort. Ann Rheum Dis 2021 Dec 15, epub ahead of print

[3]Hernán MA, Robins JM. Using Big Data to Emulate a Target Trial When a Randomized Trial Is Not Available. Am J Epidemiol 2016;183(8):758-64

Disclosure of Interests

April Jorge: None declared, Ronald Melles: None declared, Michael Marmor: None declared, Carol Conell: None declared, Baijun Zhou: None declared, Jingbo Niu: None declared, Yuqing Zhang: None declared, Hyon Choi Consultant of: Ironwood, Selecta, Horizon, Takeda, Kowa, and Vaxart., Grant/research support from: Ironwood and Horizon

Impact of COVID-19 on TB epidemiology in South Korea

SETTING: Five referral hospitals, South Korea.OBJECTIVE: To assess epidemiological changes in TB before and during the COVID-19 pandemic.DESIGN: This was a multicentre cohort study of 3,969 patients diagnosed with TB.RESULTS: We analysed 3,453 patients diagnosed with TB prior to the COVID-19 pandemic (January 2016-February 2020) and 516 during the pandemic (March-November 2020). During the pandemic, the number of patients visits declined by 15% from the previous 4-year average, and the number of patients diagnosed with TB decreased by 17%. Patients diagnosed during the pandemic were older than those diagnosed before the pandemic (mean age, 60.2 vs. 56.6 years, P < 0.001). The proportion of patients to have primary TB at a younger age (births after 1980) among those diagnosed with TB was significantly lower during the pandemic than before (17.8% in 2020 vs. 23.5% in 2016, 24.0% in 2017, 22.5% in 2018, 23.5% in 2019; P = 0.005).CONCLUSIONS: The COVID-19 pandemic resulted in a reduction in the number of visits to respiratory departments, leading to fewer patients being diagnosed with TB. However, our results suggest that universal personal preventive measures help to suppress TB transmission in regions with intermediate TB burden.

Inverse Laplace transformation analysis of stretched exponential relaxation

We investigate the effectiveness of the Inverse Laplace Transform (ILT) analysis method to extract the distribution of relaxation rates from nuclear magnetic resonance data with stretched exponential relaxation. Stretched-relaxation is a hallmark of a distribution of relaxation rates, and an analytical expression exists for this distribution for the case of a spin-1/2 nucleus. We compare this theoretical distribution with those extracted via the ILT method for several values of the stretching exponent and at different levels of experimental noise. The ILT accurately captures the distributions for β≲0.7, and for signal to noise ratios greater than ∼40; however the ILT distributions tend to introduce artificial oscillatory components. We further use the ILT approach to analyze stretched relaxation for spin I>1/2 and find that the distributions are accurately captured by the theoretical expression for I=1/2. Our results provide a solid foundation to interpret distributions of relaxation rates for general spin I in terms of stretched exponential fits.

The mucin protein MUCL1 regulates melanogenesis and melanoma genes in a manner dependent on threonine content

Background

The regulation of melanogenesis has been investigated as a long‐held aim for pharmaceutical manipulations with denotations for malignancy of melanoma. Mucins have a protective function in epithelial organs; however, in the most outer organ, the skin, the role of mucins has not been studied enough.

Objectives

Our initial hypothesis developed from the identification of correlations between pigmentation and expressions of skin mucins, particularly those existing in skin tissue. We aimed to investigate the action of mucins in human melanocytic cells.

Materials and methods

The expression of mucin proteins in human skin was investigated using microarray data from the Human Protein Atlas consortium (HPA) and the Genotype‐Tissue Expression consortium (GTEx) database. Mucin expression was measured at RNA and protein levels in melanoma cells. The findings were further validated and confirmed by analysis of independent experiments.

Results

We found that the several mucin proteins showed expression in human skin cells and among these, mucin‐like protein 1 (MUCL1) showed the highest expression and also clear negative correlation with melanogenesis in epidermal melanocytes. We confirmed the correlations between melanogenesis and MUCL1 by revealing negative correlations in melanocytes with different melanin production, resulting from increased composition of threonine, mucin‐conforming amino acid, and increased autophagy‐related forkhead‐box O signalling. Furthermore, threonine itself affects melanogenesis and metastatic activity in melanoma cells.

Conclusions

We identified a significant association between MUCL1 and threonine with melanogenesis and metastasis‐related genes in melanoma cells. Our results define a novel mechanism of mucin regulation, suggesting diagnostic and preventive roles of MUCL1 in cutaneous melanoma.

Whatis already known about this topic?

Despite considerable advances in radioactive therapeutics or chemotherapeutic approaches for the treatment of abnormal melanogenesis, there are still many caveats to delivery, effectiveness and safety, thus leaving a necessity for more immediate pharmaceutical targets.

Mucins have protective and chemical barrier functions in epithelial organs; however, in the skin, mucin has scarce expression and is known only as a diagnostic aid in skin disorders such as mucinosis.

Whatdoes this study add?

We provide detailed analysis demonstrating the potential of mucin‐like protein 1 (MUCL1), which showed negative correlations in melanocytes with different melanin production, resulting from increased composition of threonine and increased autophagy‐related forkhead‐box O signalling in epidermal melanocytes and melanoma cells.

We established that through an alternative pathway for MUCL1 biosynthesis, threonine supplementation recovers MUCL1 levels in melanoma. Changes, brought on by the essential amino acid threonine, resulted in substantial modulations in melanogenesis and reduced metastasis‐related genes.

Whatis the translational message?

This study demonstrates for the first time that the mucin protein of skin cells is compounded by distorted mucin homeostasis, with major effects on melanogenesis and metastasis‐related genes in melanoma.

We anticipate that these novel findings will be of keen interest to the community of scientists and medical practitioners examining skin dysfunction.

Linked Comment: C. Casalou and D.J. Tobin. Br J Dermatol 2022; 186:388–389.

Plain language summary available online

Rising rates of hospital-onset Klebsiella spp. and Pseudomonas aeruginosa bacteraemia in NHS acute trusts in England: a review of national surveillance data, August 2020-February 2021

Increases in hospital-onset Klebsiella spp. and Pseudomonas aeruginosa bacteraemia rates in England were observed between August 2020 and February 2021 to the highest levels recorded since the start of mandatory surveillance in April 2017. Cases were extracted from England's mandatory surveillance database for key Gram-negative bloodstream infections. Incidence rates for hospital-onset bacteraemia cases increased from 8.9 (N=255) to 14.9 (N=394) per 100,000 bed-days for Klebsiella spp. [incidence rate ratio (IRR) 1.7, P<0.001], and from 4.9 (N=139) to 6.2 (N=164) per 100,000 bed-days for P. aeruginosa (IRR 1.3, P<0.001) (August 2020-February 2021). These incidence rates were higher than the average rates observed during the same period in the previous 3 years. These trends coincided with an increase in the percentage of hospital-onset bacteraemia cases that were also positive for severe acute respiratory syndrome coronavirus-2.

POS1148 RISK FACTORS FOR POLYARTICULAR GOUT FLARES—ANALYSIS OF A LONGITUDINAL ONLINE GOUT FOLLOW-UP STUDY

Background:

There are known and established risk factors for gout flares; however, no study has examined the factors specifically associated with a polyarticular gout flare.

Objectives:

Evaluate risk factors of a polyarticular gout flare in a longitudinal study of individuals with gout.

Methods:

We used data from the Boston Online Gout Study, a longitudinal internet-based case-crossover study, where gout patients with at least one flare within the past year were enrolled across the US. Participants (N=903) were followed prospectively for 1 year via the internet to collect information on gout flares and related data including number and specific joints involved, medical comorbidities, diet, exercise and medications.

A polyarticular gout flare was defined as having 3 or more joints involved during a patient-reported flare period. Individuals with at least one flare (to determine flare pattern) during follow-up were included in the analysis. Univariable associations were first assessed to determine factors were associated with polyarticular joint flares. was used to adjust for confounders. When assessing the association of each risk factor with prevalent polyarticular joint involvement, we used multivariable logistic regression, adjusting specific confounders guided by causal diagram.

Results:

There were 724 participants with at least one flare with a mean and median age of 55 years. The cohort was 78% male and 89% White with a mean gout disease duration of 8.1 years (median 5). 197 (27%) had a polyarticular gout flare. In univariable analysis (Table 1), female sex, osteoarthritis, obesity, heart failure, hypertension, chronic kidney disease and gout related medication use were each associated with higher odds of polyarticular gout flare, whereas higher education, alcohol use at study enrollment and aspirin use were associated with lower odds. In multivariable analysis, obesity, osteoarthritis and heart failure remained associated with a higher odds of polyarticular gout flare, whereas education remained inversely associated.

Conclusion:

In this prospective cohort of gout patients, obesity, heart failure and osteoarthritis were independently associated with higher odds for polyarticular gout flares. Female sex was also positively associated, whereas higher education was protective. The positive association with gout-related medications likely reflects residual confounding by indication. If confirmed, these findings would help identify those at risk for polyarticular flares to help improve clinical care.

Table 1.

Associations with Polyarticular Gout Flare (≥ 3 joints)

Risk FactorUnivariable OR (95% CI)Age- and Sex-Adjusted OR (95% CI)Multivariable OR* (95% CI)Age ≥ 55 years (vs < 55)0.82 (0.59,1.14)0.77 (0.56,1.08)0.70 (0.49,1.01)Female Sex1.51 (1.04,2.22)1.55 (1.03,2.32)1.21 (0.78,1.88)White Race (vs Non-White)0.89 (0.54,1.48)0.93 (0.56,1.54)0.75 (0.44,1.28)Education (vs High School or Less)Some college0.63 (0.37,1.07)0.53 (0.37,1.07)0.68 (0.39,1.17)College0.45 (0.25,0.78)0.46 (0.26,0.81)0.49 (0.27,0.88)Post-graduate0.42 (0.25,0.72)0.44 (0.26,0.76)0.48 (0.28,0.84)Body Mass Index (kg/m2) at Enrollment (vs < 25)25-29.91.69 (0.85,3.33)1.77 (0.89,3.51)1.82 (0.90,3.65)≥ 302.38 (1.24,4.58)2.30 (1.19,4.43)2.19 (1.12,4.28)Alcohol Use at Enrollment (vs. Non-Use)0.60 (0.40,0.89)0.60 (0.40,0.91)**Gout Duration ≥ 5 years (vs < 5)0.85 (0.61,1.18)0.93 (0.66,1.31)0.95 (0.66,1.35)Presence of Comorbidities at Enrollment (vs Absence)Osteoarthritis2.35 (1.45,3.81)2.37 (1.43,3.95)2.39 (1.42,4.04)Heart Failure2.06 (1.11,3.81)2.21 (1.17,4.17)2.03 (1.06,3.91)Hypertension1.61 (1.08,2.40)1.69 (1.10,2.60)**Chronic Kidney Disease1.97 (1.03,3.78)2.11 (1.09,4.11)**Medication Use at Enrollment (vs No Use)Allopurinol1.58 (1.13,2.22)1.59 (1.13,2.23)**Diuretics1.53 (1.06,2.21)1.59 (1.06,2.38)**Oral Steroids2.21 (1.16,4.18)2.26 (1.19,4.31)**Aspirin0.68 (0.47,0.98)0.72 (0.49,1.07)**

*Mutually adjusted for the variables in this column

**Not included in model

Acknowledgements:

NIH P50AR060772.

Disclosure of Interests:

Jonathan Dau: None declared, Natalie McCormick: None declared, Sarah Stratton: None declared, Chio Yokose: None declared, Clara Chen: None declared, Tuhina Neogi Shareholder of: Lilly, EMD Merck Serono, Novartis, Regeneron, Pfizer/Lilly, David Hunter Shareholder of: Pfizer, Lilly, Merck Serono, Kenneth Saag Consultant of: Arthrosi, Horizon Therapeutics plc, Atom Bioscience, LG Pharma, Takeda, Mallinkrodt, SOBI, Grant/research support from: Horizon Therapeutics plc, Shanton, SOBI, Yuqing Zhang: None declared, Hyon Choi Consultant of: Ironwood, Selecta, Horizon, Takeda, Kowa, Vaxart, Grant/research support from: Ironwood, Horizon.

POS1150 ANATOMICAL LOCATIONS AND CORRELATES OF CALCIUM PYROPHOSPHATE CRYSTAL DEPOSITS OF THE SPINE – PATHOLOGIC EXAMINATION OF 77 SURGICAL CASES

Background:

Spinal involvement in calcium pyrophosphate deposition disease (CPPD) is thought to be a rare occurrence and is seen infrequently as crowned dens syndrome. Furthermore, data on anatomical locations and correlates of calcium pyrophosphate (CPP) deposits in spinal CPPD are scarce.

Objectives:

To describe the anatomical locations and correlates of pathologically confirmed CPPD of the spine.

Methods:

Consecutive patients with spinal CPPD were identified via retrospective chart review of individuals who underwent spine surgery for intractable chronic neck or back pain at Massachusetts General Hospital between 2009 and 2014. These deposits and surrounding anatomical structures were surgically resected and confirmed to have calcium pyrophosphate deposition upon pathologic review. We reviewed musculoskeletal imaging (CT, MRI, XR) and laboratory data from these pathologically confirmed cases.

Results:

From April 2009 to August 2014, we identified 77 individuals with pathologically confirmed CPPD of the spine. The mean age was 68 years; 41 (53%) were female; mean BMI was 28.7. Calcium pyrophosphate (CPP) was grossly identified intraoperatively by the surgeon in 38 cases (50%), typically as “chalky white deposits” (Figure 1). CPP deposits were seen most frequently in the ligamentum flavum (23%) and intervertebral disc (23%), followed by other less common locations (Table 1). Imaging findings in the soft tissue or intervertebral disc suggestive of CPPD were found in 5 cases (6%), whereas findings of spinal canal narrowing, facet arthropathy, or ligamentum flavum thickening were eventually correlative with CPP deposits in pathologic specimens. Only 7 (9%) experienced a prior episode of acute CPP arthritis (pseudogout). Chondrocalcinosis on x-ray was seen in 26 cases (34%), most commonly in the wrist and/or knees. Osteoarthritis was present in all spinal imaging, and 65% had comorbid scoliosis. Laboratory abnormalities associated with secondary causes of CPPD (hypercalcemia, hypomagnesemia, hyperparathyroidism) were not seen with spinal CPPD.

Conclusion:

Spinal CPPD may occur more frequently than previously perceived. The ligamentum flavum and intervertebral discs were common anatomical locations for spinal CPPD. Advanced imaging of the spine showed low sensitivity for detecting spinal CPPD. Only a small minority had typical peripheral joint involvement or imaging with peripheral joint chondrocalcinosis. Thus, without pathologic confirmation, the vast majority of cases would remain unidentified. These findings call for the need to seek pathologic confirmation to determine the robust epidemiology and also raise the potential role for preoperative CPPD treatment.

Table 1.

Spinal Anatomic Locations of Pathologically Confirmed CPPD

Spinal Anatomic LocationNo. of Sites (%)*ligamentum flavum29 (23)Intervetebral Disc28 (23)Other Location19 (15)Posterior Elements18 (15)Facet14 (11)Synovium8 (6)Interspinous Ligament3 (2)Subarticular/Lateral Recess2 (2)Fibrocartilaginous Tissue1 (1)Inner Spine1 (1)Other Ligament1 (1)

*Some patients had more than one anatomic location where CPP was isolated

Figure 1.

Gross visualization of calcium pyrophosphate deposition (black arrow)

Disclosure of Interests:

Jonathan Dau: None declared, Gary Ho: None declared, Hyon Choi Consultant of: Ironwood, Selecta, Horizon, Takeda, Kowa, Vaxart, Grant/research support from: Ironwood, Horizon, Joseph Schwab: None declared, Minna Kohler Speakers bureau: Eli Lily, Consultant of: Novartis.

OP0005 DIETARY HYPERINSULINEMIC POTENTIAL AND RISK OF INCIDENT GOUT: 3 PROSPECTIVE COHORT STUDIES OF US MEN AND WOMEN

Background:

Gout and the metabolic (insulin resistance) syndrome frequently coexist. Intravenous insulin has been shown to raise serum urate (SU) levels in physiologic studies and a Mendelian Randomization study also showed a causal role of insulin on the risk of gout. However, it is unknown whether habitual hyperinsulinemic dietary intake confers gout risk.

Objectives:

Prospectively examine the relation between two distinct insulin-related dietary indices and risk of incident gout in three large cohorts of US women and men over 30 years.

Methods:

We studied 164,090 women from Nurses Health Study I (1986-2016) and II (1989-2017) and 40,598 men from Health Professionals Follow-up Study (1986-2016), who were free of gout at baseline. Dietary intake and covariates were assessed by validated questionnaires every 4 years. Insulinemic potential of diet was evaluated using 1) food-based empirical dietary index for hyperinsulinemia (EDIH) score that was pre-defined based on circulating C-peptide levels1 and reflects insulin resistance;2 and 2) dietary insulin index (DII), which reflects transient, postprandial insulin secretion.2 We assigned EDIH and DII scores for each participant, adjusted for total energy intake, and prospectively examined the association between scores and incident gout (using ACR survey criteria for gout3), adjusting for potential confounders.

Results:

We ascertained 2,874 incident gout cases over 5,124,490 person-years of follow-up. In pooled multivariable-adjusted analyses, those in the highest EDIH quintile had 1.76-times (95% CI: 1.56 to 1.99) higher gout risk, compared with the lowest (Table 1). This attenuated with further adjustment for BMI (a likely causal intermediate) but remained positive (RR 1.30, 1.15 to 1.48). DII scores were inversely associated with gout risk (RR 0.66, 0.58 to 0.74) (Table 1).

Table 1.

Risk Ratio (95% CI) of Gout According to Quintiles of Insulin-Related Dietary Index

EDIH (measure of insulin resistance)Q1:lowest circulating insulin levelsQ2Q3Q4Q5:highest circulating insulin levelsP for trendN cases430482598631733Person-years1,025,1291,025,2851,025,5741,025,3011,023,651Age-adjusted RR1.00 (Ref)1.13 (1.00-1.29)1.43 (1.26-1.61)1.53 (1.36-1.73)1.85 (1.64-2.09)<.0001MV-Adjusted*RR1.00 (Ref)1.11 (0.98-1.27)1.39 (1.22-1.57)1.47 (1.30-1.67)1.76 (1.56-1.99)<.0001MV-Adjusted**RR (+ BMI)1.00 (Ref)1.03 (0.90-1.17)1.21 (1.06-1.37)1.21 (1.07-1.37)1.30 (1.15-1.48)<.0001Dietary Insulin Index (measure of transient, post-prandial secretion and sensitivity)Q1:lowest insulin sensitivityQ2Q3Q4Q5:greatest insulin sensitivityP for trendN cases783611527498455Person-years1,024,7631,025,7301,025,0751,025,5381,023,834Age-adjusted RR1.00 (Ref)0.79 (0.71-0.88)0.69 (0.62-0.77)0.65 (0.58-0.73)0.59 (0.53-0.66)<.0001MV-Adjusted*RR1.00 (Ref)0.79 (0.71-0.88)0.69 (0.62-0.77)0.66 (0.59-0.74)0.60 (0.53-0.67)<.0001MV-Adjusted**RR (+ BMI)1.00 (Ref)0.78 (0.70-0.87)0.69 (0.62-0.77)0.67 (0.60-0.75)0.66 (0.58-0.74)<.0001

*Multivariable (MV) models adjusted for age (month), White race, smoking, menopause (women only), hormone use (women only), physical activity, history of hypertension, and diuretic use **MV + BMI models further adjusted for BMI (a likely causal intermediate)

Conclusion:

EDIH scores, reflecting chronic hyperinsulinemia (i.e., greater insulin resistance with reduced clearance), were positively associated with the risk of incident gout, even beyond the pathway through adiposity. Conversely, higher DII scores, which reflect short-term, postprandial elevations in insulin levels (and also greater insulin clearance and sensitivity) conferred a lower risk. This corroborates human physiologic experiments and Mendelian Randomization studies showing insulin resistance can increase SU levels by decreasing renal excretion of urate, and supports lowering insulinemic potential of diet as a strategy to reduce gout risk.

References:

[1]Tabung et al. PMID 27821188

[2]Lee et al. PMID 32618519

[3]Wallace et al. PMID 856219

Disclosure of Interests:

Natalie McCormick: None declared, Chio Yokose: None declared, Leo Lu: None declared, Amit Joshi: None declared, Hyon Choi Consultant of: Ironwood, Selecta, Horizon, Takeda, Kowa, Vaxart, Grant/research support from: Ironwood, Horizon

OP0202 DOES EXCESS WEIGHT AFFECT GOUT RISK DIFFERENTLY AMONG GENETICALLY PREDISPOSED INDIVIDUALS? – SEX-SPECIFIC PROSPECTIVE COHORT FINDINGS OVER >26 YEARS

Background:

Global burden of gout has increased substantially, particularly among women.1,2 Addressing obesity, a major modifiable risk factor for gout, may alleviate this burden; however, there is also a significant genetic contribution to gout risk according to the genome-wide association studies (GWAS).3,4 Genetic predisposition may modify the excess weight effect on gout risk.

Objectives:

To investigate the potential role of genetic predisposition on the association between excess weight (i.e., BMI ≥ 25 kg/m2) and gout risk in two US prospective longitudinal cohorts over >26 years, stratified by sex.

Methods:

We examined the association between excess weight and risk of incident gout meeting the ACR survey criteria,5 according to genetic risk, in 18,512 women from the Nurses’ Health Study (NHS) over 32 years, and 10,917 men from Health Professionals Follow-Up Study (HPFS) over 26 years. We derived a genetic risk score (GRS) using 114 serum urate single nucleotide polymorphisms from the latest GWAS.3 We also calculated the population attributable risk (PAR) for excess weight according to GRS stratum.

Results:

We ascertained 530 incident gout cases in NHS and 983 in HPFS. While the relative risks (RRs) due to excess weight (overweight or obesity) appeared larger among women above the mean than below the mean, the RRs among men appeared similar according to genetic predisposition (Table 1). The RRs among women for excess weight compared to normal were 1.66 (95% CI, 1.17 to 2.37) and 2.55 (1.95 to 3.34) below and above the mean GRS, respectively (P for multiplicative interaction = 0.06), whereas corresponding RRs among men were 1.68 (95% CI, 1.31 to 2.16) and 1.76 (1.47 to 2.10) (P for multiplicative interaction = 0.8). The risk differences (RD) among women for excess weight were 0.69 and 2.38 with GRS below and above the mean, respectively, resulting in the relative excess risk due to interaction (RERI) of 1.69 (95% CI, 1.03 to 2.35, P for additive interaction = 5.4x10-7); for men, the corresponding RDs were 0.70 and 1.46, with RERI = 0.76 (0.26, 1.25; P for additive interaction = 2.6x10-3). Excess weight accounted for a larger proportion of incident gout cases among women with GRS above the mean (PAR, 48.5% [95% CI, 38.8 to 55.9]) compared to those with GRS below the mean (PAR, 29.0% [95% CI, 10.5 to 42.1]), whereas the PARs among men were similar (31.6% vs 29.7%, respectively).

Table 1.

Relative Risk of Gout by Body Mass Index, Stratified by Mean Genetic Score

HPFS (men)Below MeanAbove MeanBMIOverall<2525-30>30Overall<2525-30>30No. Cases3338817273650172349129Person-Years10405543314492531148898634419944609610544Age-Adjusted RR-1.0 (ref)1.71 (1.32, 2.22)3.00 (2.18, 4.12)-1.0 (ref)1.80 (1.50, 2.16)2.87 (2.27, 3.62)MV Adjusted* RR-1.0 (ref)1.53 (1.18, 1.99)2.31 (1.66, 2.21)-1.0 (ref)1.63 (1.35, 1.96)2.38 (1.87, 3.03)NHS (women)Below MeanAbove MeanBMIOverall<2525-30>30Overall<2525-30>30No. Cases17347408635772120165Person-Years24439212384976414441292392591202297612342907Age-Adjusted RR-1.0 (ref)1.23 (0.81, 1.88)4.46 (3.10, 6.41)-1.0 (ref)2.41 (1.79, 3.23)5.68 (4.82, 7.52)MV Adjusted* RR-1.0 (ref)1.00 (0.65, 1.53)2.84 (1.92, 4.20)-1.0 (ref)1.97 (1.46, 2.65)3.61 (2.68, 4.87)

*Adjusted for age (continuous), menopause, use of hormone therapy (never, past or current), history of hypertension, and systolic and diastolic blood pressure, alcohol, total energy intake and intake of meat, seafood and dairy foods (all continuous).

Conclusion:

These large scale longitudinal prospective cohorts suggest maintaining healthy weight is an important gout prevention strategy, regardless of underlying genetic risk. In genetically predisposed individuals, addressing excess weight may prevent a large proportion of gout cases, especially among women.

References:

[1]Safiri et al., PMID 32755051

[2]Xia et al., PMID 31624843

[3]Tin et al., PMID 31578528

[4]Tai et al., PMID: 32017447

[5]Wallace et al., PMID: 856219

Acknowledgements:

The authors thank the participants of the NHS and HPFS.

CY is supported by the Rheumatology Research Foundation Scientist Development Award and NIH T32 AR007258. HC is supported by NIH P50AR060772 and R01AR065944.

Disclosure of Interests:

None declared

POS1132 DIAGNOSTIC ACCURACY OF CONVENTIONAL RADIOGRAPHY OF THE KNEE FOR CALCIUM PYROPHOSPHATE DEPOSITION DISEASE: AN ANCILLARY STUDY OF THE OMERACT ULTRASOUND – CPPD GROUP

Background:

Conventional Radiography (CR) has been widely used in the assessment of knee chondrocalcinosis (CC) and is still considered one of the most important diagnostic methods for the diagnosis. However, there are very few studies that examine the diagnostic accuracy of CR compared to histology of the knee tissues.

Objectives:

To assess the diagnostic accuracy of CR of the knee in Calcium Pyrophosphate Deposition Disease (CPPD) by using the recently created definitions for CPPD in CR of the ACR/EULAR taskforce for the new classification criteria for CPPD.

Methods:

This is an ancillary study of the Criterion Validity of Ultrasound in CPPD study [1]. Consecutive patients with osteoarthritis (OA) awaiting total knee replacement were enrolled in 4 centres from Romania, Italy, USA and Mexico. All patients underwent CR of the knees taken maximum 6 months before surgery, in posterior-anterior weight baring and lateral projections. DICOM files of the radiographs were anonymised and read independently by two musculoskeletal radiologists with experience in microcrystalline arthropathies. For each patient, a dichotomic score was used (absence/presence of CC) at the level of the menisci and tibiofemoral hyaline cartilage by each reader. The definitions of the ACR/EULAR taskforce for identification of CPPD in CR were used in this study [paper in preparation]. According to these definitions CPPD in CR appears as “linear or punctate opacities in the region of fibro- or hyaline articular cartilage/synovial membrane or joint capsule/within tendons or entheses that are distinct from denser, nummular radio-opaque deposits due to basic calcium phosphate deposition”. In case of disagreement a consensus decision was taken by both radiologists after discussion of the case. Menisci and the hyaline cartilage were analysed using compensated polarized light microscopy as described previously [1], patients were considered positive for CPPD if at least one of their tissue specimens revealed the presence of calcium pyrophosphate crystals. All examiners were blind to each other’s findings.

Results:

We enrolled 33 patients with OA (61% female, mean age 69yo). The accuracy values of CR in the various sites of the knee are indicated in Table 1. CR demonstrated to be a specific exam for identification of CPPD at the knee, but sensitivity remains low in all sites and in the overall evaluation. Identification of CPPD appears challenging and this could be due to the advanced grade of OA in our cohort of patients. Advanced degeneration, dislocation of the menisci and thinning of the hyaline cartilage in these patients is frequent and the eventual presence of calcific deposits in one of these structures could overlap with other anatomical structures making the exact localisation difficult. According to the results of the predictive values, the presence of typical deposition on CR allows a definite confirmation of the diagnosis, but a negative radiography does not exclude CPPD as testified by the low negative predictive value.

Table 1.

Sensitivity, specificity, PPV, NPV, accuracy and AUC of CR for identification of CPPD by using the new ACR/EULAR taskforce definitions.

Medial meniscusLateral meniscusHyaline cartilageOverallSensitivity22%33%31%42%Specificity100%100%85%90%Positive predictive value100%100%67%80%Negative predictive value56%60%55%61%Accuracy61%68%58%66%AUC0.60.70.60.7

Conclusion:

CR has been extensively used for the diagnosis of OA and CPPD and has been tested previously for diagnostic accuracy. The results of our study confirm that the presence of typical CPPD calcifications, as defined by the ACR/EULAR task force, are highly specific but have low sensitivity for disease identification when using CR. Absence of CPPD on CR does not exclude the diagnosis.

References:

[1]Filippou G, et al. Criterion validity of ultrasound in the identification of calcium pyrophosphate crystal deposits at the knee: an OMERACT ultrasound study. Ann Rheum Dis 2020. doi:10.1136/annrheumdis-2020-217998

Disclosure of Interests:

None declared.

OP0235 PRO-INFLAMMATORY DIET AND RISK OF INCIDENT GOUT: 3 PROSPECTIVE COHORT STUDIES OF US MEN AND WOMEN

Background:

Emerging evidence suggests inflammation may drive progression from hyperuricemia to clinical gout, but the role of extrinsic, modifiable sources of chronic inflammation, such as diet, on gout risk is unknown. Notably, greater dietary inflammatory potential has been independently associated with increased risk of incident cardiovascular disease (CVD)1 and type 2 diabetes (T2D).2

Objectives:

Prospectively examine the relation between dietary inflammatory potential and risk of gout in three large cohorts of US women and men over 30 years.

Methods:

Ascertaining the ACR survey criteria for gout for several decades,3 we studied gout risk among 164,090 women from Nurses Health Study I (1986-2016) and II (1989-2017) and 40,598 men from Health Professionals Follow-up Study (1986-2016), free of gout at baseline. Dietary intake and covariates were assessed by validated questionnaires every 4 years. Inflammatory potential of diet was evaluated using a food-based empirical dietary index of inflammatory potential score (EDIP) pre-defined based on circulating levels of IL-6, C-reactive protein, adiponectin, and TNFαR2.4

We assigned an EDIP score for each participant, adjusted for total energy take, and prospectively examined the association between quintiles of EDIP score and incident gout, adjusting for potential confounders. We also stratified by alcohol intake, as alcohol has anti-inflammatory properties,4 but is associated with a higher gout risk, particularly beer.5

Results:

We documented 2,874 incident gout cases over 5,124,940 person-years of follow-up. In pooled multivariable-adjusted analyses, those in the highest EDIP quintile had 59% higher gout risk (multivariable RR 1.59; 95% CI 1.41–1.79), compared with the lowest (Table 1). This remained positive with further adjustment for BMI, a likely causal intermediate (RR 1.27, 1.12 to 1.42), and was stronger among non-drinkers (RR 2.37, 1.58 to 2.56) than drinkers (RR 1.57, 1.38 to 1.78) (Table 1).

Table 1.

Risk Ratio (95% CI) of Gout According to Quintiles of Inflammatory Diet Score, Overall and by Alcohol Use

Q1:lowestQ2Q3Q4Q5:highestP for trendOverallN cases473493530623755Person-years1,024,5711,025,6181,025,2841,024,7791,024,688Age-adjusted RR1.00 (Ref)1.05 (0.92, 1.19)1.13 (0.99, 1.27)1.33 (1.18, 1.50)1.64 (1.46, 1.84)<0.001MV-Adjusted* RR1.00 (Ref)1.04 (0.92, 1.18)1.12 (0.98, 1.26)1.31 (1.16, 1.48)1.59 (1.41, 1.79)<0.001MV-Adjusted** RR (+ BMI)1.00 (Ref)1.00 (0.88, 1.13)1.03 (0.91, 1.17)1.16 (1.02, 1.31)1.27 (1.12, 1.42)<0.001No Alcohol UseN cases265884143251Person-years118,301189,938249,389313,511396,080MV-Adjusted* RR1.00 (Ref)1.31 (0.82, 2.08)1.37 (0.88, 2.13)1.80 (1.18, 2.74)2.37 (1.58, 2.56)<0.001MV-Adjusted**RR (+ BMI)1.00 (Ref)1.28 (0.80, 2.03)1.32 (0.85, 2.05)1.61 (1.06, 2.45)1.85 (1.23, 2.79)<0.001Alcohol UseN cases447435446480504Person-years906,271835,680775,895711,267628,609MV-Adjusted* RR1.00 (Ref)1.04 (0.91, 1.19)1.13 (0.99, 1.29)1.31 (1.15, 1.50)1.57 (1.38, 1.78)<0.001MV-Adjusted** RR (+ BMI)1.00 (Ref)1.00 (0.88, 1.14)1.05 (0.92, 1.20)1.17 (1.03, 1.33)1.28 (1.12, 1.46)<0.001

*Multivariable (MV) models adjusted for age (month), White race, smoking, menopause (women only), hormone use (women only), physical activity, history of hypertension, and diuretic use. **MV + BMI models additionally adjusted for BMI (a likely causal intermediate)

Conclusion:

Habitual pro-inflammatory dietary pattern was independently associated with higher risk of incident gout in these prospective cohorts, even beyond the pathway through adiposity. Our findings support a role for chronic inflammation in development of gout, similar to CVD1 and T2D.2 Adhering to a diet with lower inflammatory potential may modulate systemic inflammation, potentially reducing gout risk and these life-threatening comorbidities.

References:

[1]Li et al. J Amer Coll Cardiology (2020) PMID 33153576

[2]Lee et al. Diabetes Care (2020) PMID 32873589

[3]Wallace et al. PMID 856219

[4]Tabung et al. PMID 27358416

[5]Choi et al. PMID 15094272

Disclosure of Interests:

Natalie McCormick: None declared, Chio Yokose: None declared, Leo Lu: None declared, Amit Joshi: None declared, Hyon Choi Consultant of: Ironwood, Selecta, Horizon, Takeda, Kowa, Vaxart, Grant/research support from: Ironwood, Horizon