Lymphocyte subsets and interleukin-2 receptors in autistic children.

Blood samples were obtained from 10 male autistic children ages 7-15 years and 10 age-matched, male, healthy controls. Lymphocyte subsets (helper-inducer, suppressor-cytotoxic, total T, and total B cells) were enumerated using monoclonal antibodies and flow cytometry. Bound and soluble interleukin-2 receptors were assayed in unstimulated blood samples and in cell cultures following 72-hour stimulation with phytohemagglutinin. The children with autism had a lower percentage of helper-inducer cells and a lower helper:suppressor ratio, with both measures inversely related to the severity of autistic symptoms (r = - .56 and - .68, respectively). A lower percentage of lymphocytes expressing bound interleukin-2 receptors following mitogenic stimulation was also noted, and this too was inversely related to the severity of autistic symptoms.