小児期インスリン依存性糖尿病におけるNatural killer活性の検討

抄録

Natural killer (NK) cell activities were measured in 16 IDDM children with insulin-dependent diabetes mellitus (IDDM) to assess the involvement of immune dysfunction in this chronic metabolic disorder.
No significant difference was found between average NK cell activities in 16 IDDM children and 20 healthy children, however, in IDDM children, NK cell activities were significantly lower in the group with a longer disease duration (L group) than in that with a shorter duration (S group). There were no correlation between NK cell activity and either sex, age, age of onset, or control of the disease, defined by blood glucose level and HbAlc. The responsiveness of NK cells to the exogenous addition of recombinant IL 2 was also determined, and NK cell activity was shown to increase in IDDM children in the S group but not in the L group. NK cell activity was independent of the expression of surface phenotype of NK cells, defined by CD 16 or Leu 7. These results suggest that functional disability but not decreased number of NK cells is responsible for the decreased NK cell activity in the L group IDDM children, and imply the presence of a secondary mechanism in suppression of the immune function in long-term treated IDDM children.