Genetic studies of immunological markers in diabetes: prediction of insulin dependence

The classification based on the physiopathological criteria distinguishes type I diabetes, observed in patients with stigmata of anti-islet of Langerhans autoimmunity, from type II diabetes without these autoimmune changes. Type I diabetes is subdivided into classes la and Ib, class Ib comprising those cases associated with other autoimmune diseases. Yet, in the present work, serological analysis of 76 patients with clinical type la diabetes and 215 healthy, first degree relatives was not clear cut and revealed that at least some patients that are classified clinically as la were in fact intra-clinical Ib subjects. Forty one percent of patients with class la diabetes had anti-gastric, anti-adrenal or anti-thyroid antibodies, and 28% of their healthy relatives also had the same types of antibodies, several prospective studies of the families of patients with type I diabetes have shown that anti-islet of Langerhans antibodies were associated with a high risk of diabetes. similarly, the presence of these antibodies in patients apparently with Type II diabetes [266 NIDD patients] has been associated with an increased risk of developing insulin dependence. These results illustrate the value of immunological investigation in diabetic patients; as this may influence the choice of treatment in the future

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

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