HLA-DQB genetic susceptibility and rheumatic heart disease: a case-control study

Background Rheumatic heart disease is a major global health concern, especially in low- and middle-income countries. The pathogenesis is attributable to an aberrant immune response, host genetic factors, and socioeconomic status. The objective of this study was to screen HLA-DQB1 alleles as genetic susceptibility markers in rheumatic heart disease patients in Assam, North East India, and to correlate the predominant allele with socioeconomic status and clinical profile. Methods A case-control study of 100 echocardiography-confirmed rheumatic heart disease patients and age- and sex-matched healthy controls from Assam Medical College and Hospital was conducted. Human leukocyte antigen typing was performed using HLA-DQ typing kit. A questionnaire was designed to study the socioeconomic status and clinical profile of rheumatic heart disease patients. Results Among the 9 alleles studied, HLA-DRBQ1*03:01 was found to be the statistically significant predominant allele in this population, especially in the Ahom ethnic group. In the HLA-DRBQ1*03:01-positive population, rural dwelling was found to be a significantly increased risk factor for rheumatic heart disease. Among severe cases, 90% of mitral stenosis, 40% of mitral regurgitation, and 33.3% of aortic regurgitation cases were HLA-DRBQ1*03:01-positive. Also, 50% of aortic valve thickening and 36.8% of mitral valve thickening cases were found in this population. Conclusion Our data suggest that HLA-DRBQ1*03:01 is a significant susceptibility marker in this population, and predominant in the rural population. Furthermore, it may play an important role in determining the pattern of valve damage in rheumatic heart disease patients.