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.)