White cell function in Down's syndrome.

Neutrophil function was studied in 25 patients with Down's syndrome at a mental subnormality hospital and compared with 26 normal controls. In vitro killing of Candida albicans was significantly lower in the Down's group, but there was no difference in the percentage of cells actively involved in phagocytosis or in the phagocytic index. The spontaneous nitroblue tetrazolium reduction was increased in 10 patients, but no abnormality of peroxidase activity or leucocyte alkaline phosphatase activity was found.