Gout: will the "King of Diseases" be the first rheumatic disease to be cured?

Association Between HLA-B5801 Positivity and Patient Characteristics and Clinical Outcomes in Gout

BACKGROUND/AIM

Allopurinol is a standard agent used for lowering uric acid levels. Human leukocyte antigen (HLA)-B5801 positivity increases the incidence of severe cutaneous adverse reactions (SCARs) in allopurinol users. HLA alleles HLA-B27 and HLA-B51 are frequently found in patients with ankylosing spondylitis and Behçet's disease, showing an association with distinct clinical features. In this study, we investigated the association between the HLA-B5801 genotype and patient characteristics and outcomes in gout.

PATIENTS AND METHODS

We retrospectively reviewed the medical records of 263 patients with gout who were not receiving uric acid-lowering therapy and were tested for HLA-B5801 positivity between March 2020 and February 2024. Patients were classified according to their HLA-B5801 status, and patient demographics and laboratory variables were compared. The incidence of gout flares or severe flares requiring hospital care within one year was investigated.

RESULTS

A total of 37 participants were HLA-B5801 positive (37/263, 14.1%). However, no significant differences were observed in demographic or laboratory variables between the HLA-B5801 positive and negative groups. Subgroup analyses of patients with new-onset gout, males, and those with an estimated glomerular filtration rate ≥60 ml/min/1.73 m2 also demonstrated no significant differences related to HLA-B5801 genotype positivity. The incidence of disease flares or severe flares between patients in the HLA-B5801 positive and negative groups was comparable during the one-year follow-up.

CONCLUSION

Although HLA-B5801 was a significant predictor of allopurinol-associated SCARs, the impact of HLA-B5801 positivity on the clinical characteristics or flares was not evident in this population of patients with gout.

Tomographic, Biomechanical, and In Vivo Confocal Microscopic Changes in Cornea in Chronic Gout Disease

PURPOSE

This study aimed to evaluate the tomographic, biomechanical, and in vivo confocal microscopic (IVCM) effects of chronic gout disease on human cornea.

METHODS

This prospective study included 60 eyes of 30 participants with chronic gout disease and 60 eyes of 30 healthy controls. Corneal thickness, keratometry (K) readings, and corneal aberrations were measured with Sirius 3 D corneal tomography system (Sirius, CSO, Italy). Corneal biomechanical properties (corneal hysteresis [CH], corneal resistance factor [CRF], and intraocular pressure [IOP] parameters) were assessed with an ocular response analyzer (ORA, Reichert Ophthalmic Instruments). The number and morphology of corneal endothelial cells and the number of basal epithelial cells were evaluated with IVCM (Confoscan 4.0). Tear breakup time (TBUT) was also evaluated.

RESULTS

The mean diagnosis time of the patients with gout was 91.2 ± 69.6 months (12-300 month). Among corneal tomography measurements, K readings were similar between the two groups, while total and higher-order aberrations(coma, trefoil,s pherical, and quadrafoil) were significantly higher in the gout group. In the evaluation of biomechanical measurements, the CH value was significantly lower and the corneal-compensated IOP value was significantly higher in the gout group (p = 0.02, p = 0.01, respectively). The two groups did not significantly differ regarding the CRF or Goldmann IOP (p = 0.61, p = 0.15, respectively). Among the IVCM parameters, the number of corneal basal epithelial cells and the percentage of corneal endothelial hexagonality were significantly lower in the gout group, but no significant difference was detected in terms of the number of endothelial cells or polymegathism (p = 0.02, p < 0.001, p = 0.18, p = 0.59, respectively). While TBUT was significantly lower in the gout group (p < 0.001).

CONCLUSION

This study showed that chronic gout disease increases the corneal aberrations and decreases the basal epithelial cell count, hexagonality ratio of endothelial cell and corneal biomechanics.

The inflammation process of gout arthritis and its treatment

Gout arthritis is an inflammatory condition that occurs suddenly in joints affected by high uric acid levels (hyperuricemia). The uric acid levels in this disease fluctuate throughout its various phases, resulting in frequent or recurrent attacks. This study aims to review some aspects of gout arthritis, such as its pathophysiology, treatment goals, and adverse drug reactions. This study employs review literature using articles published between 2017 and 2022 as the research methodology. Furthermore, articles under 2017 are used as references if they are relevant to the study's subject matter. The findings showed the importance of the pathogenesis of inflammation in the treatment of gout arthritis. It is also recommended to use anti-inflammatories such as colchicine and uric acid-lowering medications starting at a specific time to prevent unintended risks. Hence, pharmacotherapy management's adverse effects include nausea, vomiting, myalgia, neuropathy, and stomach pain.

Specular Microscopic Corneal Endothelial Cell Changes following Uneventful Phacoemulsification in Patients with Gout

Purpose. To assess the effects of phacoemulsification on the corneal endothelium in patients with gout and age-related cataracts. Methods. Eighty-eight patients who underwent uneventful phacoemulsification for age-related cataracts were included in this retrospective comparative study. The patients were divided into two groups: group A included 31 patients with gout and tight control of uric acid levels and group B included 57 patients without gout or any other systemic disease. All patients completed follow-up assessments over 6 months, and the two groups were compared in terms of changes to their specular microscopic values. Results. Both groups showed marked improvement in uncorrected and best-corrected visual acuity at the end of the follow-up period. Corneal endothelial cell loss was more severe in group A than in group B, with a mean difference of 221.35 ± 43.87 in group A and 169.88 ± 52.67 in group B at the sixth month ( $p$  < 0.001). The difference between the two groups in terms of other specular microscopic values did not reach statistical significance. Conclusion. Patients with gout are more prone to corneal endothelial cell damage after phacoemulsification than those without gout. To confirm these results, future studies with a prospective design and longer durations of follow-up are needed.

EPIGENETIC FACTORS OF SERUM URIC ACID LEVEL AND RELATED GENE POLYMORPHISMS IN SHENYANG, CHINA

BACKGROUND

The purpose of this study was to explore the influencing factors of serum uric acid (SUA) level and related gene polymorphisms in the healthy population.

METHODS

A total of 346 healthy individuals screened from different areas in Shenyang City and 195 patients with high SUA levels were included.

RESULTS

The levels of TC (total cholesterol), HDL-C (high-density lipoprotein cholesterol), LDL-C (low-density lipoprotein cholesterol), TG (triglycerides), GLU (blood glucose) ALT (alanine aminotransferase), TBA (total bile acid), TBIL (total bilirubin), CR (creatinine) and CYSC (Cystatin C) were statistically different between the healthy and hyperuricemia population (P<0.05). However, there was no statistical difference in the UA level between the two groups (P>0.05). After adjusting for UA, TC, HDL-C, LDL-C, GLU, TBIL and CYSC, the additive and recessive models of rs2231142 were statistically significant in females (P<0.05). For males, haplotypes of A-C-A-A-G-G, A-C-G-C-G-G and A-T-G-A-A-G had significant difference between the healthy and hyperuricemia population (P<0.05). For females, the haplotypes of A-C-G-C-G-G and A-T-A-C-A-T had significant differences (P<0.05).

CONCLUSION

The distributions of SLC2A9 (solute carrier family 2 and facilitated glucose transporter member 9), ABCG2 (ATP-binding cassette G2), GCKR (glucokinase regulatory protein), KCNQ1, IGFIR (Insulin-like growth factor-I receptor) and VEGFR (Vascular Endothelial Growth Factor Receptor) were balanced in the population in Shenyang City. The haplotypes of A-C-A-A-G-G, A-C-G-C-G-G and A-T-G-A-A-G were the influencing factors of high SUA in the population in Shenyang City.

RDP3, A Novel Antigout Peptide Derived from Water Extract of Rice

Gout and hyperuricemia can seriously affect the quality of life; at present, however, existing medicines are unable to meet all clinical needs. In the current study, a novel peptide (i.e., rice-derived-peptide-3 (RDP3), AAAAMAGPK-NH₂, 785.97 Da) in water extract obtained from shelled Oryza sativa fruits was identified. Testing revealed that RDP3 (minimum effective concentration 100 μg/kg) did not show both hemolytic and acute toxicity, and reduced uric acid levels in the serum of hyperuricemic mice by inhibiting xanthine oxidase activity and decreasing urate transporter 1 expression. RDP3 also alleviated renal injury in hyperuricemic mice by decreasing NLRP3 inflammasome expression. Furthermore, RDP3 alleviated formalin-induced paw pain and reduced monosodium urate crystal-induced paw swelling and inflammatory factors in mice. Thus, this newly identified peptide reduced uric acid levels and renal damage in hyperuricemic mice and showed anti-inflammatory and analgesic activities, indicating the potential of RDP3 as an antigout medicine candidate.

Gout and the risk of epilepsy: A population-based cohort study

Gout is a chronic disease related to uric acid metabolism. It involves crystals of uric acid accumulating in the joints, causing joint pain and releasing cytokines that trigger inflammation. Inflammation is a key component in the pathogenesis of epilepsy. Thus, we conducted a cohort study to investigate if epilepsy is associated with gout and determine the risk of epilepsy in patients with gout.The gout cohort was obtained from the Registry of Catastrophic Illnesses Patient Database (RCIPD). We identified 104,238 patients who were aged 20 years or more and newly diagnosed with gout between 2000 and 2011 and 3 outpatient visits or history of gout-specific hospitalization between 2000 and 2011. Patients without gout were frequency matched with the gout cohort at a 2:1 ratio according to age, sex, comorbidities, and year of gout diagnosis.The gout cohort showed a 1.27-fold higher overall crude hazard ratio (HR) for epilepsy compared with the control cohort. After we adjusted the analyses by age, sex, and comorbidities the gout patients displayed an increased risk of epilepsy compared with the control group (adjusted HR = 1.25, 95% confidence interval = 1.15-1.36).This study revealed a significantly higher risk of epilepsy in patients with gout. It provides further evidence for the debate around the effect of gout on brain health.

Corneal Endothelial Morphology and Thickness Changes in Patients with Gout

OBJECTIVES

To investigate corneal endothelial cell density (ECD), morphology, and central corneal thickness (CCT) in patients with gout compared with healthy subjects.

MATERIALS AND METHODS

Fifty eyes of 50 gout patients and 50 eyes of 50 healthy subjects without gout or any other systemic disease were included in this study. After detailed ophthalmologic examination, specular microscopy (Tomey EM-4000; Tomey Corp) measurement was performed for all participants. ECD, average cell area (ACA), coefficient of variation (CV), hexagonality ratio, and CCT values were recorded.

RESULTS

Mean ECD and hexagonality ratio were lower (p=0.004 and p=0.002) and CV, ACA, and CCT values were higher (p=0.001, p=0.007, and p=0.001) in patients with gout when compared to healthy subjects. There were significant correlations between gout disease duration and CD and hexagonality ratio (p=0.019 and p=0.043) and also between uric acid value and hexagonality ratio and CCT (p=0.044 and p=0.003).

CONCLUSION

Altered corneal endothelial function was found in patients with gout when compared to healthy subjects and the alteration increased as gout duration and uric acid value increased.

Could corneal densitometry be used as a diagnostic and screening tool for ocular involvement in patients with gout?

PURPOSE

To evaluate the corneal and tear film characteristics in patients with gout and compare these data with those of healthy subjects and to investigate the correlation of corneal densitometry with uric acid value and duration of disease.

METHODS

Forty-one eyes of 41 patients with gout (group 1) and 40 eyes of 40 healthy subjects (group 2) were included in this study. Detailed ophthalmologic examinations were performed on all participants. Corneal tomographic analyses were performed with the Pentacam HR Scheimpflug imaging system (Oculus, Wetzlar, Germany). Maximum keratometry (Kmax), central corneal thickness (CCT), corneal volume (CV), and corneal densitometric values were compared between groups. Tear function tests including Schirmer, tear breakup time, and fluorescein staining were performed and compared between groups.

RESULTS

Groups were similar in terms of age and gender. Kmax, CCT, and CV values were similar between groups. The outcomes of tear function tests were similar between groups. Corneal densitometric values for the 0-2 and 2-6 mm zones of the anterior and center layers were significantly higher in group 1 compared to group 2. This densitometric increase was positively correlated with uric acid levels and gout duration.

CONCLUSIONS

Corneal densitometry values of the 0-2 and 2-6 mm zones of the anterior and central layers were higher in patients with gout than those of the control subjects, and the densitometric values increased as uric acid level and disease duration increased.

[Ru(bpy)2(NO)SO3](PF6), a Nitric Oxide Donating Ruthenium Complex, Reduces Gout Arthritis in Mice

Monosodium urate crystals (MSU) deposition induces articular inflammation known as gout. This disease is characterized by intense articular inflammation and pain by mechanisms involving the activation of the transcription factor NFκB and inflammasome resulting in the production of cytokines and oxidative stress. Despite evidence that MSU induces iNOS expression, there is no evidence on the effect of nitric oxide (NO) donors in gout. Thus, the present study evaluated the effect of the ruthenium complex donor of NO {[Ru(bpy)₂(NO)SO₃](PF₆)} (complex I) in gout arthritis. Complex I inhibited in a dose-dependent manner MSU-induced hypersensitivity to mechanical stimulation, edema and leukocyte recruitment. These effects were corroborated by a decrease of histological inflammation score and recruitment of Lysm-eGFP⁺ cells. Mechanistically, complex I inhibited MSU-induced mechanical hypersensitivity and joint edema by triggering the cGMP/PKG/ATP-sensitive K (+) channels signaling pathway. Complex I inhibited MSU-induced oxidative stress and pro-inflammatory cytokine production in the knee joint. These data were supported by the observation that complex I inhibited MSU-induced NFκB activation, and IL-1β expression and production. Complex I also inhibited MSU-induced activation of pro-IL-1β processing. Concluding, the present data, to our knowledge, is the first evidence that a NO donating ruthenium complex inhibits MSU-induced articular inflammation and pain. Further, complex I targets the main physiopathological mechanisms of gout arthritis. Therefore, it is envisaged that complex I and other NO donors have therapeutic potential that deserves further investigation.

Emergent nanotherapies in microcrystal-induced arthritis

The anti-inflammatory and immunomodulatory effects of nanoparticles in several chronic diseases have been extensively researched. The aim of this review is to examine how nanoparticles modulate the inflammatory pathways that characterize the most prevalent forms of microcrystal-induced arthritis, including gout, pseudogout, and BCP-induced arthritis. The nanoparticles of chitosan-coated calcium phosphate, uricase, aceclofenac, and gold have been investigated in crystal-inducedarthritis. The most important results of the studies outlined in this review show that nanoparticles can inhibit the expression and the release of some pro-inflammatory mediators and proteolytic enzymes, and the activity of different transcriptional factors in vitro, as well as decrease the uric acid levels in several studies of in vitro and in vivo models of gout, which show interesting results in terms of decreasing the amount of crystals and tissue damage, respectively. In view of their multiple beneficial effects, nanoparticles can be considered a valuable therapy that contributes to the pharmacological treatment in crystalinduced arthritis.

Targeting immune-driven opioid analgesia by sigma-1 receptors: Opening the door to novel perspectives for the analgesic use of sigma-1 antagonists

Immune cells have a known role in pronociception, since they release a myriad of inflammatory algogens which interact with neurons to facilitate pain signaling. However, these cells also produce endogenous opioid peptides with analgesic potential. The sigma-1 receptor is a ligand-operated chaperone that modulates neurotransmission by interacting with multiple protein partners, including the μ-opioid receptor. We recently found that sigma-1 antagonists are able to induce opioid analgesia by enhancing the action of endogenous opioid peptides of immune origin during inflammation. This opioid analgesia is seen only at the inflamed site, where immune cells naturally accumulate. In this article we review the difficulties of targeting the opioid system for selective pain relief, and discuss the dual role of immune cells in pain and analgesia. Our discussion creates perspectives for possible novel therapeutic uses of sigma-1 antagonists as agents able to maximize the analgesic potential of the immune system.

Burden of gout in the Nordic region, 1990-2015: findings from the Global Burden of Disease Study 2015

OBJECTIVE

To explore the burden of gout in the Nordic region, with a population around 27 million in 2015 distributed across six countries.

METHOD

We used the findings of the 2015 Global Burden of Diseases study to report prevalence and disability associated with gout in the Nordic region.

RESULTS

From 1990 to 2015, the number of prevalent gout cases rose by 30% to 252 967 [95% uncertainty interval (UI) 223 478‒287 288] in the Nordic region. In 2015, gout contributed to 7982 (95% UI 5431‒10 800) years lived with disability (YLDs) in the region, an increase of 29% (95% UI 24‒35%) from 1990. While the crude YLD rate of gout increased by 12.9% (95% UI 7.8‒18.1%) between 1990 and 2015, the age-standardized YLD rate remained stable. Gout was ranked as the 63rd leading cause of total YLDs in the region in 2015, with the highest rank in men aged 55-59 years (38th leading cause of YLDs). The corresponding rank at the global level was 94. Of 195 countries studied, four Nordic countries [Greenland (2nd), Iceland (12th), Finland (14th), and Sweden (15th)] were among the top 15 countries with the highest age-standardized YLD rate of gout.

CONCLUSION

The burden of gout is rising in the Nordic region. Gout's contribution to the total burden of diseases in the region is more significant than the global average. Expected increases in gout burden owing to population growth and ageing call for stronger preventive and therapeutic strategies for gout management in Nordic countries.

Natriuretic Peptides: The Case of Prostate Cancer

Cardiac natriuretic peptides have long been known to act as main players in the homeostatic control of blood pressure, salt and water balance. However, in the last few decades, new properties have been ascribed to these hormones. A systematic review of English articles using MEDLINE Search terms included prostate cancer, inflammation, cardiac hormones, atrial natriuretic peptide, and brain natriuretic peptide. Most recent publications were selected. Natriuretic peptides are strongly connected to the immune system, whose two branches, innate and adaptive, are finely tuned and organized to kill invaders and repair injured tissues. These peptides control the immune response and act as anti-inflammatory and immune-modulatory agents. In addition, in cancers, natriuretic peptides have anti-proliferative effects by molecular mechanisms based on the inhibition/regulation of several pathways promoting cell proliferation and survival. Nowadays, it is accepted that chronic inflammation is a crucial player in prostate cancer development and progression. In this review, we summarize the current knowledge on the link between prostate cancer and inflammation and the potential use of natriuretic peptides as anti-inflammatory and anticancer agents.

Amputation of the first metatarsophalangeal joint due to a giant gouty tophi: A case report

RATIONALE

The first metatarsophalangeal joint (MTP1) is the most frequent site of gouty tophi. We report an unusual case with a giant skin-perforating tophi. This is the first case of gouty tophi at MTP1 which accepts surgical debulking and amputation.

PATIENT CONCERNS

A 42-year-old man presented with a seven-year history of gout and a giant tophi at MTP1. The patient was referred to hospital due to persistent pain and ulcerations on the surface of the left MTP1. This rounded, giant, swelling, tophaceous tophi severely interfered with his normal walking.

DIAGNOSES

The patient was diagnosed with gouty arthritis seven years ago, and did not receive regular anti-gout treatments.

OUTCOMES

Biochemical examination showed he had raised serum uric acid (SUA, 11.92 mg/dl) and creatinine (258 μmol/l). There was a severe joint destruction of MTP1 by X-ray examination. We controlled the skin infection by sulbenicillin. He was given febuxostat to reduce SUA. After 3 months of treatment, SUA fell to 6.8 mg/dl. Then we performed surgical debulking of MTP1 and amputation of hallux. Surgical operations obviously relieved the pain, and improved the function of his left foot. The visual closure after amputation was good.

CONCLUSION

Surgical amputation of the gout lesion at MTP1 maximized the function, and reduced the pain of this patient. In the case of giant tophi with severe gouty arthritis or skin infections, surgical decisions need to weigh gains and losses carefully.

Long-term allopurinol use decreases the risk of prostate cancer in patients with gout: a population-based study

BACKGROUND

Clinical observations indicated an increased risk of developing prostate cancer in gout patients. Chronic inflammation is postulated to be one crucial mechanism for prostate carcinogenesis. Allopurinol, a widely used antigout agent, possesses potent anti-inflammation capacity. We elucidated whether allopurinol decreases the risk of prostate cancer in gout patients.

METHODS

We analyzed data retrieved from Taiwan National Health Insurance Database between January 2000 and December 2012. Patients diagnosed with gout during the study period with no history of prostate cancer and who had never used allopurinol were selected. Four allopurinol use cohorts (that is, allopurinol use (>365 days), allopurinol use (181-365 days), allopurinol use (91-180 days) and allopurinol use (31-90 days)) and one cohort without using allopurinol (that is, allopurinol use (No)) were included. The study end point was the diagnosis of new-onset prostate cancer. Multivariable Cox proportional hazards regression and propensity score-adjusted Cox regression models were used to estimate the association between the risk of prostate cancer and allopurinol treatment in gout patients after adjusting for potential confounders.

RESULTS

A total of 25 770 gout patients (aged between 40 and 100 years) were included. Multivariable Cox regression analyses revealed that the risk of developing prostate cancer in the allopurinol use (>365 days) cohort was significantly lower than the allopurinol use (No) cohort (adjusted hazard ratio (HR)=0.64, 95% confidence interval (CI)=0.45-0.9, P=0.011). After propensity score adjustment, the trend remained the same (adjusted HR=0.66, 95% CI=0.46-0.93, P=0.019).

CONCLUSIONS

Long-term (more than 1 year) allopurinol use may associate with a decreased risk of prostate cancer in gout patients.