Responses of peripheral blood cells and lymphocyte subpopulations to insulin-induced hypoglycaemia in human insulin-dependent (Type 1) diabetes.

Abstract

Changes in counts of peripheral blood cells including lymphocytes and lymphocyte subpopulations were examined in response to acute insulin-induced hypoglycaemia in fourteen insulin-dependent diabetic patients of differing duration, and in eight normal subjects. In patients with a short duration of diabetes (less than 5 years) an initial lymphocytosis preceded a later granulocytosis, similar to changes in the normal group following hypoglycaemia. The lymphocytosis comprised increments in T11 (total), T4 (helper), and T8 (suppressor/cytotoxic) lymphocyte subsets, but B lymphocytes did not rise. In diabetic patients of longer duration (greater than 15 years) the initial lymphocytosis was attenuated, the T4 subset response being absent and the T11 subset response was diminished. The lower lymphocyte responses in the long-term diabetics were unrelated to differences in the hormonal responses to hypoglycaemia or to the rate of blood glucose recovery. Rapid mobilization of specific lymphocyte subpopulations appears to be abnormal in long-term insulin-dependent diabetes, and may indicate underlying immunological dysfunction.