Lipoprotein(a) and HLA-DRB1 and -DQB1 genes in coronary artery disease.

In some respects, atherosclerosis resembles autoimmune disease. Since many autoimmune diseases are associated with certain histocompatibility leukocyte antigen (HLA) class II alleles, we have looked for a similar HLA association with atherosclerosis. In the first phase, genomic typing was performed in 52 men with coronary artery disease. In the second phase, 50 men with early onset (before 50 years of age) coronary artery disease were studied. 12 DRB1 and 4 DQB1 alleles were determined by restriction fragment length polymorphism analysis. No significant difference in frequency of the examined alleles was observed in any of the patient groups compared to healthy controls. The plasma level of lipoprotein(a) (Lp(a)) is considered an important risk factor for early coronary heart disease. A linkage between inherited high levels of Lp(a) and certain HLA class II genotypes has been suggested. In the present study, Lp(a) levels were measured in men with early onset of coronary artery disease. 11 (23%) Study patients and 3 (7%) control subjects had Lp(a) levels above 450 mg/l. However, no correlation between high Lp(a) levels and certain HLA genotypes was found. Summarized, these findings indicate that atherosclerosis, especially early onset coronary atherosclerosis, is not a disease associated with particular HLA alleles.