Immunodeficiency in Down's syndrome: T-lymphocyte subset imbalance in trisomic children.

In fourteen children with Down's syndrome the percentage of circulating T-cells forming rosettes with sheep erythrocytes, either in the presence or in the absence of foetal calf serum, was significantly lower than in appropriately matched controls. In contrast the percentage of T-cells forming rosettes with human erythrocytes was significantly higher in children with Down's syndrome than in controls. These data support the hypothesis that a defective T-cell maturation is an early integral feature of Down's syndrome.