The Hong Kong Society of Rheumatology consensus recommendations for the management of gout

Implementation of HLA-related genotype-guided prescribing in Singapore

PURPOSE

To describe the implementation of human leukocyte antigen (HLA)-related genotype-guided prescribing in Singapore.

SUMMARY

Various HLA alleles have been implicated in drug hypersensitivity syndromes (DHS). These include HLA-B*15:02, which has been associated with carbamazepine-induced Stevens-Johnson syndrome/toxic epidermal necrolysis, HLA-B*58:01, which has been associated with increased risk of severe cutaneous adverse reactions with allopurinol use, and HLA-B*57:01, which has been associated with increased risk of hypersensitivity reactions with abacavir use. Integrating pharmacogenomics into patient care through genotype-guided prescribing potentially optimizes use of these drugs by reducing DHS-related and healthcare costs. We describe the prevalence of HLA-related DHS in Singapore, the cost-effectiveness of genotype-guided prescribing, and local policies and guidelines, as well as the impact of genotype-guided prescribing where available.

CONCLUSION

HLA-related genotype-guided prescribing has the potential to reduce the incidence of DHS and decrease healthcare costs, as seen in the success with carbamazepine. However, not all genotype-guided prescribing is cost-effective when implemented across the population, as was evident from local studies for allopurinol and abacavir. The cost-effectiveness of such measures may change over time with new data (eg, allele frequencies, test costs, drug prices, genotyping approach) and should be evaluated periodically and locally. Implementation of preemptive pharmacogenomics panel testing as part of routine clinical care may shift the threshold for cost-effectiveness and brings promise of further optimization of pharmacotherapy through precision medicine.

Management of gout in primary care of Hong Kong in accordance with international guidelines: any gaps to bridge?

BACKGROUND

The global prevalence of gout ranges from 1 to 6.8% in different countries, while around 3% in Hong Kong. Sudden elevated serum urate level (SUA) will result in acute arthritis and repeated flare-ups. If not properly managed, tophi formation and joint damage will occur, leading to disabilities. Gout is one of the most common conditions encountered in primary care. This study aims to assess urate control among gout patients managed in primary care settings of Hong Kong and to evaluate its associated risk factors.

METHOD

This was retrospective cross-sectional study. Adult Chinese gout patients who had been followed up in public primary care clinics of Hong Kong from 1 January 2021 to 31 December 2021 were included. Patient demographics, clinical and biochemical parameters were retrieved from the clinical management computer system. Student's t-test was used for analyzing continuous variables and Chi-square test was used for categorical data. Multivariate stepwise logistic regression was used to determine the associated risk factors for poor urate control.

RESULTS

Among the 385 gout patients included, 115 (29.9%) met the target serum urate level (TSUL). 4.4% of gout patients developed tophaceous gout, while none of them could achieve the TSUL. 60.3% of gout patients were put on urate-lowering agents (ULT), while allopurinol was the most commonly used, i.e. 95.7%. In multivariate studies, patients who are male (OR 2.59, 95% CI: 1.37-4.87), active smokers (OR 3.17, 95% CI: 1.08-9.33), with chronic kidney disease (CKD) with stage 3a, 3b and 4, (OR 3.24, 3.12 and 10.25 respectively; 95% CI: 1.56-6.73, 1.11-8.76 and 1.08-97.48 respectively) were less likely to meet TSUL whereas those on urate-lowering agents (OR 0.23, 95% CI: 0.13-0.40) were more likely to achieve satisfactory urate control.

CONCLUSION

60.3% of gout patients were treated with urate-lowering agents in public primary care settings in Hong Kong, while only 29.9% of gout patients and none of tophaceous gout patients were adequately treated. Male patients, active smokers or comorbid with CKD stage 3a, 3b and 4 were less likely to achieve target urate control.

Targeting Neutrophil Extracellular Traps in Gouty Arthritis: Insights into Pathogenesis and Therapeutic Potential

Gouty arthritis (GA) is an immune-mediated disorder characterized by severe inflammation due to the deposition of monosodium urate (MSU) crystals in the joints. The pathophysiological mechanisms of GA are not yet fully understood, and therefore, the identification of effective therapeutic targets is of paramount importance. Neutrophil extracellular traps (NETs), an intricate structure of DNA scaffold, encompassing myeloperoxidase, histones, and elastases - have gained significant attention as a prospective therapeutic target for gouty arthritis, due to their innate antimicrobial and immunomodulatory properties. Hence, exploring the therapeutic potential of NETs in gouty arthritis remains an enticing avenue for further investigation. During the process of gouty arthritis, the formation of NETs triggers the release of inflammatory cytokines, thereby contributing to the inflammatory response, while MSU crystals and cytokines are sequestered and degraded by the aggregation of NETs. Here, we provide a concise summary of the inflammatory processes underlying the initiation and resolution of gouty arthritis mediated by NETs. Furthermore, this review presents an overview of the current pharmacological approaches for treating gouty arthritis and summarizes the potential of natural and synthetic product-based inhibitors that target NET formation as novel therapeutic options, alongside elucidating the intrinsic challenges of these inhibitors in NETs research. Lastly, the limitations of HL-60 cell as a suitable substitute of neutrophils in NETs research are summarized and discussed. Series of recommendations are provided, strategically oriented towards guiding future investigations to effectively address these concerns. These findings will contribute to an enhanced comprehension of the interplay between NETs and GA, facilitating the proposition of innovative therapeutic strategies and novel approaches for the management of GA.