Monoclonal antibody defined T cell subsets and autologous mixed lymphocyte reaction in Down's syndrome.

Peripheral blood from 21 non-institutionalized children with Down's syndrome (DS) and 21 age and sex matched simultaneously studied healthy controls, was analysed for monoclonal antibody defined T cells and T cell subsets, using a fluorescence activated cell sorter, and the autologous (AMLR) and allogeneic mixed lymphocyte reaction (MLR). Total T cells (9.6+), OKT4+ (helper/inducer phenotype) and anti-Tac+ (activated T) cells were present in comparable proportions to that observed in the control group. In contrast, the proportion of OKT8+ (suppressor/cytotoxic phenotype) cells were significantly (P less than 0.05) decreased when compared to healthy controls. The proliferative response in the AMLR and MLR were comparable to control group. The significance of these results are discussed.