Study of HLA-A, -B and - C specificities in patients with diabetic retinopathy associated with insulin dependent diabetes mellitus

ABSTRACT

The controversy in relation to the presence of a possible association of some HLA specificities with the occurrence of diabetic retinopathy in patients with insulin dependent diabetes, mellitus [IDDM], together with the well established diversity of HLA antigens frequencies associated with IDDM in different populations, raised the importance of determining HLA-A,B and -C specificities in patients with diabetic retinopathy in the Egyptian population. The study has been carried out on twenty patients with IDDM with different stages of diabetic retinopathy, twenty patients with IDDM without retinopathy matched for age, sex and duration of the disease as the previous group and thirty healthy control subjects matched for age, sex and ethnic origins as patients included in the study. Histocompatibility testing by the microlymphocytotoxicity assay was done for determination of HLA-A, -B end -C specificities. The results of the present work showed that insulin dependent diabetics with retinopathy had increased frequency of HLA-B18 antigen which was statistically significant. HLA-Bw35 antigen was absent in patients with retinopathy, suggesting that this allele may confer a protective effect. The diabetics with proliferative retinopathy had significantly increased frequency of HLA-B8 and B18. These findings reinforce the view of the genetic contribution to the pathogenesis of diabetic retinopathy