P217: Use of HLA-B*58:01 Genotyping to Prevent Allopurinol-Induced Severe Cutaneous Adverse Reactions in Korea
Poster Presenter
Sohyeon Park
pharmacist
KIDS Korea, Republic of
Objectives
To assess the current status of allopurinol use and HLA-B*58:01 genetic testing in South Korea
Method
We conducted a cross-sectional analysis using claims data from Korea’s National Health Insurance. Patients diagnosed with gout from Aug 2021 to Oct 2023 were included. The first diagnosis date was the index date. Those without a gout diagnosis in the past five years were classified as new patients.
Results
Among 3,668,461 gout patients, 284,591 (7.8%) were new patients, of whom 14,232 (5.0%) underwent HLA-B*58:01 testing. Most visited primary clinics, but the highest test rate was in general tertiary hospitals (16.2%). By specialty, allergy (21.3%), rheumatology (19.7 had the highest rates. Among those tested, 12,495 (87.8%) underwent testing before or without an allopurinol prescription.
Logistic regression identified factors associated with testing. Medically vulnerable groups, including females (adj. OR: 0.78, 95% CI: 0.74–0.83), older adults (=60 years) (adj. OR: 0.56, 95% CI: 0.53–0.59), and those with mild (adj. OR: 0.84, 95% CI: 0.76–0.93) or severe disabilities (adj. OR: 0.66, 95% CI: 0.56–0.78), were less likely to be tested. In contrast, higher-income patients (adj. OR: 1.13, 95% CI: 1.09–1.17) were more likely to be tested. Compared to spring, fall (adj. OR: 0.88, 95% CI: 0.84–0.92) and winter (adj. OR: 0.92, 95% CI: 0.87–0.97) diagnoses were linked to lower test likelihood. Patients with hypertension (adj. OR: 0.73, 95% CI: 0.69–0.77), diabetes (adj. OR: 0.79, 95% CI: 0.74–0.85), hyperlipidemia (adj. OR: 0.85, 95% CI: 0.81–0.90), chronic pulmonary disease (adj. OR: 0.95, 95% CI: 0.90–0.99), depression (adj. OR: 0.91, 95% CI: 0.85–0.97), or chronic renal failure (= stage 3) (adj. OR: 0.79, 95% CI: 0.66–0.95) were less likely to be tested. Corticosteroid (adj. OR: 1.19, 95% CI: 1.10–1.28) and NSAID prescriptions (adj. OR: 1.32, 95% CI: 1.27–1.38) increased test likelihood, as did uric acid testing (adj. OR: 1.26, 95% CI: 1.19–1.32). Regarding medical utilization, visiting general tertiary hospitals (adj. OR: 2.09, 95% CI: 1.95–2.25), hospitals in Seoul (adj. OR: 2.32, 95% CI: 2.18–2.48), or internal medicine departments (adj. OR: 3.16, 95% CI: 3.04–3.29) were associated with higher test likelihood.
Conclusion
In this study, we assessed the use of HLA-B*58:01 genotyping among gout patients and identified significant factors associated with testing. Although the test has been fully covered by national health insurance since August 2021 in South Korea, only 5.0% of new gout patients underwent testing. Based on these findings, we emphasize the need to raise awareness of HLA-B*58:01 testing, particularly among medically vulnerable patients and healthcare providers in primary care clinics and orthopedic hospitals, where gout patients are frequently treated. We believe our results can help inform strategies to promote genetic testing and ensure broader implementation, serving as real-world evidence for regulatory decision-making. Furthermore, we anticipate that these findings will contribute to expanding prior testing in clinical settings across South Korea, ultimately reducing the risk and socioeconomic burden associated with allopurinol-induced SCAR.
