Association between HLA-DRB1, HLA-DRQB1 alleles, and CD4(+)CD28(null) T cells in a Chinese population with coronary heart disease.

CD4(+)CD28(null) T cells are present in increased numbers in the peripheral blood of patients with acute coronary syndrome. However, the triggers of expansion of these cells are unclear. Susceptibility to coronary heart disease (CHD) is strongly associated with alleles of human leukocyte antigen (HLA), but it is not equally strong in different human populations. The objective of the study was to investigate association between CD4(+)CD28(null) T cells and HLA-DRB1 alleles. The HLA alleles were determined by polymerase chain reaction with sequence-specific primers (PCR-SSP) method, in a group of CHD patients and control subjects from the same area. The number of CD4(+)CD28(null) T cells was measured using the flow cytometry technique. The HLA-DRB1*01 (RR = 4.705, P < 0.005) and DRB1*04 (RR = 3.554, P < 0.005) alleles showed the strongest association with CHD in the Chinese population, and increased numbers of CD4(+)CD28(null) T cells were found in association with HLA-DRB1*04 (17.1%) and DRB*01 (12.9%), while decreased numbers of CD4(+)CD28(null) T cells were present in subjects with DRB1*15 (0.8%). CHD in Chinese population is strongly associated with HLA-DRB1*01 and DRB1*04 haplotypes, and formation of CD4(+)CD28(null) T cells was related to HLA-DRB1*01, DRB1*04, and DRB1*15 alleles.