1793: Prevalence of HLA B*5801 Allele Among African American Patients with Gout in an Academic Health Center

Namitha Nair, Dipanjan Debnath and FLORINA CONSTANTINESCU, MedStar Washington Hospital Center, Washington, DC

Background/Purpose: The presence of the HLA-B*5801 allele is strongly associated with Allopurinol Hypersensitivity Syndrome (AHS) manifesting as severe cutaneous adverse reactions (SCARs) like Drug rash with Eosinophilia and Systemic symptoms (DRESS), Stevens-Johnson syndrome (SJS) and toxic epidermal necrosis (TEN), especially in patients of East Asian or African descent. The primary aim of our study was to assess the prevalence of HLA B*5801 allele in African American patients with gout in a large academic health center. The secondary aim was to study the prevalence of AHS in our cohort of African American patients with gout on allopurinol therapy.

Methods: We conducted retrospective chart reviews of gout patients at a large academic health center between January 2019 and February 2022. Adult patients with self-reported race as African-American with a diagnosis of gout seen as inpatients or outpatients were included in the study. Analyses were performed using Microsoft Excel.

Results: A total of 257 patients' charts were reviewed. 62 (24.12%) patients were screened for the HLA B*5801 allele. The mean age of the screened patients was 65.52 + 11.12 years with 40 (64.52%) males and 22 (35.48%) females. The mean BMI was 32.69 + 7.16 (kg/m2). The mean GFR was 60.66 + 29.60 ml/min/1.73m². 14 (22.58%) patients had congestive heart failure and 17 (27.42%) were on diuretic therapy. From 62 patients screened for the HLA B*5801, 5 (8.07%) patients tested positive for the risk allele and 2 (40%) out of the 5 patients, who received allopurinol prior to testing, developed SJS/TEN. Among all charts reviewed, 208 (80.93%) patients received allopurinol, out of which 2 (0.96%) patients developed SCAR.

Conclusion: Our study shows a risk allele prevalence of 8.07% among African American patients which is higher than 3.8% previously reported in the study by Jutkowitz et al. Both patients who developed SCAR while on allopurinol were found to be HLA B*5801 positive when admitted to the hospital, thus reinforcing the strong association between this risk allele and SCARs. In our study, the incidence of AHS was 1 in 104 African American allopurinol users, which was also higher than 1 in 1972 users as reported in the study by Keller et al. Though our study sample size was small, the results point towards a possible underreported prevalence of both the risk allele and AHS in African Americans. Although, guidelines are in effect to test African American patients for HLA-B*5801 allele prior to initiating allopurinol, further physician, both specialist and primary care, as well as patient education is required to reinforce the importance of screening and in turn decrease the morbidity and mortality associated with AHS in this population. Large scale multi-institutional studies are required to better characterize the actual prevalence of HLA B*5801 allele and burden of AHS in African American patients with gout requiring urate lowering therapy.
Table 1: Demographic characteristics of patients screened for HLA B*5801 allele
Disclosures: N. Nair, None; D. Debnath, None; F. CONSTANTINESCU, None.