Human leukocyte antigen class II genetic variants are highly associated with rheumatic heart disease in Yemeni patients

BackgroundHuman leukocyte antigen (HLA) class II polymorphisms have been reported as a risk factor for rheumatic heart disease (RHD); however, the predisposing HLA genetic variants were different in various populations.The aim of the studyThe aim of the study was to investigate the association of RHD with HLA class II alleles in Yemeni patients.MethodsHLA-DRB1 and-DQB1 polymorphisms were genotyped by PCR-SSOP reverse dot blot hybridization in 100 RHD patients and 50 healthy subjects with normal echocardiography (control group).Materials and methodsSubjects: Yemeni RHD patients aged …14 and 45 years who attended the out-patient clinic at Al-Thawra Hospital for treatment were asked for participated in this study. One hundred RHD patients (57 females, 43 males) were freely participated (case group). Gender and age matched healthy subjects aged—18 and 47 years in the same geographical area of the patients were invited to participate in this study (control group). Fifty healthy individuals (28 females, 22 males) were freely participated. Venous blood, 3–4ml was collected from each participant after obtaining the signed consent form. Echocardiogram was done for each patient to confirm the clinical finding of RHD. The healthy subjects were also subjected to echocardiograms to exclude asymptomatic RHD cases.HLA class II genotyping Genomic DNA was extracted from peripheral blood leukocytes using PureLink Genomic DNA kit (invitrogen, USA). HLA class II DRB1 and DQB1 genotypes were carried out using sequence-specific oligonucleotide-probe polymerase chain reaction, Dynal RELI SSOP HLA-DRB1 and HLA-DRB1 kits, respectively (Invitrogen, USA).Statistical analysisFrequency of HLA-DRB1 and HLA-DQB1 alleles were compared between the patients and the controls using the chi-square test. The p value and odds ratio (OR) were calculated using SPSS software, version 12, with 95% confidence intervals and Fisher exact correction for small numbers.ResultsThe results showed that HLA-DRB1∗07 and HLA-DQB1∗0203 allele were risk factors for RHD (P=0.005, OR=4; P=0.02, OR=8.7, respectively). In contrast, the HLA-DRB1∗11, HLA-DQB1∗0305 and HLA-DQB1∗0602 alleles showed a protection against RHD (P=0.01, OR=0.32; P=0.03, OR=0.23; P=0.01, OR=0.24, respectively).ConclusionHLA class II genetic variants were a predisposition factor for developing RHD in Yemeni subjects. This study also replicated the association of HLA-DRB1∗07 with RHD and suggested that HLA-DQB1∗0203 allele as a risk factor for RHD