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.