The Frequency of Human Leukocyte Class II Antigens in Patients with Rheumatic Heart Disease in an Iranian Population

Background- With respect to the high incidence of rheumatic heart disease (RHD) and the almost identical racial background of the western population of Iran and the importance of investigation on HLA typing as a new research tool, this study was conducted with the aim of better understanding the mechanisms involved. Methods- The frequencies of class II HLA antigens (DQ, DR) in 35 patients with a diagnosis of RHD were studied and compared with a control group of 36 healthy individuals. Results- An increase was found in the frequency of HLA-DR53 (57.1% in the patient group versus 16.7% in the control group: P=0.00099, RR=6.66), HLA-DR2 (31.4% in the patient group versus 2.8% in the control group: P=0.0037, RR=16.04) and HLA-DR15 (28.6% versus 2.8%: P=0.007, RR=14). The increased frequency of HLA-DQ2 and HLA-DQ5 in the patients compared with the control group was also significant (P<0.05); however, frequency differences for other antigens was not significant. Conclusion- HLA-DR53, HLA-DR2 and HLA-DR15 may be markers for susceptibility to RHD in our patients. These results could be explained by genetic differences resulting from racial or geographical diversity