ABSTRACT
Human leukocyte antigen [LILA] is the most polymorphic genetic system in man. The genes of this region influence susceptibility to certain disease. This study was established to shed light on the possible association of HLA class I and II antigens with RV patients. Lymphocvtotoxicity assay for HLA for class I and II typing had been done for [100] iraqi patients suffering from rheumatic valvulitis [RV] the control groups consisting of [75 healthy individuals and 35 non rheumatic heart disease [NRHD] patients]. The results showed a significant association of A33-Ag with these patients as compared with healthy and cardiac controls [P=0.005][P=0.033] respectively. Another interesting finding was the low frequency of AI in RI patients when compared with heal/he control [p=0.002], suggesting that Al allele may confer protective effect against this disease. In addition significant association between blood group B and RV was evident [p=0.04] An interesting observation was a strong association of blood group B and A33 among those patients [P < 0.001]. The present results are consistent with hypothesis that susceptibility to RV is genetically linked and in turn may be associated mainly with A33 in Iraqi patients