Antigens of the major histocompatibility system in ischemic heart disease and idiopathic dilated cardiomyopathy

Background: Although dilated cardiomyopathy (DCM) is a disease of unknown a nd probably multifactorial etiology, a change in immune mechanisms is presu mably significant, with many abnormalities in humoral and cellular response s having been reported. The heart thus becomes the target organ for an init ial episode of myocardial damage that triggers an autoimmune response. Hypothesis: The purpose of this study was to analyze the frequency of diffe rent human leukocyte antigens in patients with a diagnosis of well-advanced DCM and ischemic heart failure, comparing them with a control group of pre sumably healthy subjects. Methods: The group with dilated cardiomyopathy consisted of 50 patients (7 women and 43 men), aged from 14 to 64 years. The group with ischemic heart disease included 76 patients (4 women and 72 men): with ages ranging from 3 4 to 64. The control group, consisting of 1,337 presumably healthy subjects from the Spanish Mediterranean area, was recruited based on paternity stud ies. Results: Compared with the control group, we found in DCM a greater inciden ce of B15 (20 vs. 6%) and DQ 3 (83 vs. 50%) antigens. In ischemic heart dis ease we found a lower incidence of Al (3 vs. 22%), B8 (5 vs. 12%), and DQ2 (16 vs. 50%) in comparison with the control group. Conclusions: In the Spanish Mediterranean area, the presence of antigens B- 15 and DQ3 would be associated with advanced DCM. The absence of antigens A l, B8, and DQ2 would be associated with the occurrence of severe ischemic h eart disease.