Changes of serum uric acid level during acute gout flare and related factors

Daphnetin alleviates inflammation and promotes autophagy via the AMPK/mTOR pathway in gouty arthritis

Gouty arthritis (GA) is an inflammatory disease resulting from monosodium urate (MSU) crystal deposition in joints and surrounding tissues. Daphnetin (DAP) is a coumarin derivative with potent anti-inflammatory activity. Nonetheless, whether DAP can protect against MSU-induced acute GA remains unclarified. In this study, C57BL/6 mice were injected intra-articularly with MSU crystal suspension to induce acute GA. THP-1 cells were stimulated with MSU to mimic the microenvironment of GA in vitro. Hematoxylin-eosin staining was conducted to observe the pathological changes in mouse synovial tissues. ELISA and RT-qPCR were employed for inflammatory cytokine level determination. Immunofluorescence staining was performed to estimate LC3 expression in THP-1 cells. Western blotting was used for protein expression analysis. The results showed that DAP pretreatment mitigated MSU-elicited ankle joint swelling and synovial damage in mice. Moreover, DAP hindered proinflammatory factor expression and promoted autophagy in MSU-stimulated GA mice and THP-1 cells. Mechanistically, DAP induced AMPK activation and mTOR inactivation. Blocking AMPK signaling counteracted DAP-mediated effects on inflammation and autophagy in MSU-stimulated THP-1 cells. In conclusion, DAP prevents MSU-elicited GA by alleviating inflammation and enhancing autophagy via AMPK/mTOR signaling transduction.

Tophaceous Gout Mimicking a Neoplasm of the Patella

Tophaceous gout of the patella and extensor apparatus of the knee can mimic a musculoskeletal neoplasm. Considering gout, correlation with clinical history and presentation, and meticulous analysis of imaging semiology are key to a correct diagnosis. The most useful signs are periarticular erosion with overhanging edges, increased soft tissue on radiography and computed tomography, the "snowstorm sign" on ultrasound, variable signal and enhancement, bandlike infiltration of tendons, and osseous erosions with no or little bone marrow edema on magnetic resonance imaging. Dual-energy computed tomography is both a sensitive and specific tool for noninvasive characterization of gout and for differentiating other crystal arthropathies.

Hyperuricemia and elevated uric acid/creatinine ratio are associated with stages III/IV periodontitis: a population-based cross-sectional study (NHANES 2009-2014)

OBJECTIVES

To explore the association between hyperuricemia and having periodontitis.

MATERIALS AND METHODS

A representative cross-sectional dataset of 10,158 adults was extracted from the National Health and Nutrition Examination Survey (NHANES) 2009-2014. The association between hyperuricemia (the primary exposure) and having periodontitis (outcome) were evaluated using weighted logistic regression models. Serum uric acid (UA) levels and the UA to creatinine (UA/Cr) ratio were used as secondary exposures. Their associations with the diagnosis periodontitis were analyzed using weighted logistic regression or restricted cubic spline regression.

RESULTS

The prevalence of Stages III/IV periodontitis was 47.7% among individuals with hyperuricemia and 37.4% among those without. After adjustment, individuals with hyperuricemia had 0.281 times higher odds of developing Stages III/IV periodontitis compared to those without hyperuricemia (adjusted OR = 1.286, 95% CI = 1.040 to 1.591, P = 0.024). The increased odds could be explained by a linear relationship with the serum UA/Cr ratio and a U-shaped relationship with serum UA levels. Each unit increase in the serum UA/Cr ratio was associated with 0.048 times higher odds of developing Stages III/IV periodontitis (adjusted OR = 1.048, 95% CI = 1.008 to 1.088, P = 0.021). Additionally, each 1 mg/dL increase in serum UA was associated with 0.156 times higher odds (adjusted OR = 1.156, 95% CI = 1.009 to 1.323, P = 0.038) of developing Stages III/IV periodontitis when UA levels were greater than 5.9 mg/dL, but 0.118 times lower odds when UA levels were 5.9 mg/dL or lower (adjusted OR = 0.882, 95% CI = 0.790 to 0.984, P = 0.027). Sensitivity analyses validated the robustness of the findings.

CONCLUSIONS

This study provides the first direct evidence that hyperuricemia is associated with Stages III/IV periodontitis.

CLINICAL RELEVANCE

Hyperuricemia may represent a new potential comorbidity of periodontitis, possibly contributing directly or indirectly to the disease burden in patients with periodontitis.

CLINICAL TRIAL NUMBER

Not applicable.

Advancements in the study of IL-6 and its receptors in the pathogenesis of gout

Gout is an autoinflammatory disease characterized by the deposition of monosodium urate crystals in or around the joints, primarily manifesting as inflammatory arthritis that recurs and resolves spontaneously. Interleukin-6 (IL-6) is a versatile cytokine with both anti-inflammatory and pro-inflammatory capabilities, linked to a variety of inflammatory diseases such as gouty arthritis, rheumatoid arthritis, inflammatory bowel disease, vasculitis, and several types of cancer. The rapid production of IL-6 during infections and tissue damage aids in host defense. However, excessive synthesis of IL-6 and dysregulation of its receptor signaling (IL-6R) might contribute to the pathology of diseases. Recent advancements in clinical and basic research, along with developments in animal models, have established the significant role of IL-6 and its receptors in the pathogenesis of gout, although the precise mechanisms remain to be fully elucidated. This review discusses the role of IL-6 and its receptors in gout progression and examines contemporary research on modulating IL-6 and its signaling pathways for treatment. It aims to provide insights into the pathogenesis of gout and to advance the development of targeted therapies for gout-related inflammation.

Concomitant atypical knee gout and seronegative rheumatoid arthritis: A case report

BACKGROUND

Gout and seronegative rheumatoid arthritis (SNRA) are two distinct inflammatory joint diseases whose co-occurrence is relatively infrequently reported. Limited information is available regarding the clinical management and prognosis of these combined diseases.

CASE SUMMARY

A 57-year-old woman with a 20-year history of joint swelling, tenderness, and morning stiffness who was negative for rheumatoid factor and had a normal uric acid level was diagnosed with SNRA. The initial regimen of methotrexate, leflunomide, and celecoxib alleviated her symptoms, except for those associated with the knee. After symptom recurrence after medication cessation, her regimen was updated to include iguratimod, methotrexate, methylprednisolone, and folic acid, but her knee issues persisted. Minimally invasive needle-knife scope therapy revealed proliferating pannus and needle-shaped crystals in the knee, indicating coexistent SNRA and atypical knee gout. After postarthroscopic surgery to remove the synovium and urate crystals, and following a tailored regimen of methotrexate, leflunomide, celecoxib, benzbromarone, and allopurinol, her knee symptoms were significantly alleviated with no recurrence observed over a period of more than one year, indicating successful management of both conditions.

CONCLUSION

This study reports the case of a patient concurrently afflicted with atypical gout of the knee and SNRA and underscores the significance of minimally invasive joint techniques as effective diagnostic and therapeutic tools in the field of rheumatology and immunology.

Mechanism of flavonoids in the treatment of gouty arthritis (Review)

The present review expounds the advancements in the application and mechanisms of flavonoids in gouty arthritis, highlighting their significance in managing the disease. Gouty arthritis is among the most common and severe inflammatory diseases, caused by hyperuricemia and the deposition of sodium urate crystals in the joints and surrounding tissues, posing a serious threat to human life and health. Flavonoids, extracted from various herbs, have attracted significant attention due to their efficacy in improving gouty arthritis. The present study systematically reviews the in vivo studies and in vitro animal studies on flavonoids from herbal medicines for the treatment of gouty arthritis that have been previously published in the PubMed, ScienceDirect, Google Scholar and China National Knowledge Infrastructure databases between 2000 and 2023. The review of the literature indicated that flavonoids can improve gouty arthritis through multiple mechanisms. These include lowering xanthine oxidase activity, inhibiting uric acid (UA) synthesis, regulating UA transporters to promote UA excretion, reducing the inflammatory response and improving oxidative stress. These mechanisms predominantly involve regulating the NOD‑like receptor 3 inflammasome, the Toll‑like receptor 4/myeloid differentiation factor 88/nuclear factor‑κB signaling pathway, and the levels of UA transporter proteins, namely recombinant urate transporter 1, glucose transporter 9, organic anion transporter (OAT)1 and OAT3. Various flavonoids used in traditional Chinese medicine hold therapeutic promise for gouty arthritis and are anticipated to pave the way for novel pharmaceuticals and clinical applications.

Fractional Excretion of Urate is Positively Associated with Type 2 Diabetes in HUA Patients: A Cross-Sectional Study

Purpose

People with hyperuricemia (HUA) are often related to metabolic disorders such as diabetes, metabolic syndrome (MetS), and obesity. However, the correlation between excretion of uric acid and these diseases is unclear. Our study aimed to explore the relationship between uric acid excretion and type 2 diabetes (T2D).

Methods

A total of 228 HUA patients from Tianjin Medical University General Hospital from 2022 to 2023 were included in this study. We collected demographic, biochemical, and anthropometric data on each subject. Urine uric acid excretion (UUAE) was calculated enzymatically from a single urine collection that lasted 24 hours. And fractional excretion of uric acid (FEUA) was calculated from serum uric acid and creatinine and uric acid and creatinine. Binary logistic regression modeling assessed the association between uric acid excretion and T2D.

Results

Of the 228 subjects, 13.4% had T2D and 48.7% had obesity. The obesity group had a lower FEUA (p<0.05) and a higher UUAE compared to the control group (p<0.05). And FEUA had a stronger correlation with the risk of T2D (p<0.001). Also, there was a negative association between BMI and FEUA and a positive link between BMI and UUAE in the outpatients.

Conclusion

Increased FEUA levels were significantly associated with T2D in HUA patients. Therefore, routine calculating of FEUA is essential for proper diagnosis and appropriate treatment T2D of in HUA patients.