Alterations in lymphocyte subpopulations in peripheral blood at manifestation of type 1 diabetes mellitus in childhood.

BACKGROUND Alterations in cellular immunity at manifestation of type 1 diabetes mellitus, as described in publications so far, are equivocal. Moreover, the age of children was usually not taken into account. OBJECTIVES Exact inferentially statistical measures were used to arrive at reliable information. METHODS Thirty four diabetic children and 48 normals were taken randomly according to the established criteria, and scrutinized. Lymphocyte subpopulations counts were measured by flow cytometry using three-color-labelled monoclonal antibodies against cell surface markers. The resulting absolute cell counts as well as percentages from the total lymphocyte count were expressed in terms of univariate and bivariate 95% confidence intervals. They render an illustrative way for defining statistically significant (alpha = 5%) differences between health and disease. RESULTS The CD8, CD16 absolute counts in younger diabetics were significantly decreased in average to 96-58% of the normal subgroup. For older children, CD4, CD8, CD16 and CD19 absolute counts were significantly lowered to 75-61% of the norm. Relative changes in Ly subpopulations were less pronounced. The immunoregulatory index increased significantly to 125-128% of the norm in either age group. The proportion of CD4 memory cells from the total of naive and memory cells was significantly increased to 122-133% of the norm in diabetic children of either age group. CONCLUSION More significant changes of lymphocyte subpopulations than those given in literature were revealed at manifestation of childhood type 1 diabetes. They testify to the autoimmune pathogenesis of the type 1 diabetes mellitus. (Tab. 3, Fig. 4, Ref. 18.)