HLA Class II Associations With Rheumatic Heart Disease Are More Evident and Consistent Among Clinically Homogeneous Patients

Abstract

Significant increases in DRB1*0701 and DQA1*0201 alleles and DRB1*0701-DQA1*0201 haplotypes were found in patients. Removal of the MVL patients from analysis increased the strength of HLA associations among the MVD sample. The frequency of DQA1*0103 allele was decreased and the DQB1*0603 allele was absent from the patient group, suggesting that these alleles may confer protective effects against RHD. DQ alleles in linkage disequilibrium with DR alleles appear to influence risk/protection effect: whereas the DRB1*13-DQA1*0501-3-DQB1*0301 haplotype showed a trend toward risk, the DRB1*13-DQA1*0103-DQB1*0603 haplotype was absent in the RHD sample. Our data indicate that certain class II alleles/haplotypes are associated with risk or protection from RHD and that these associations appear to be stronger and more consistent when analyzed in patients with relatively more homogeneous clinical manifestations.