Cell mediated immunity in patients with subacute sclerosing panencephalitis.

Cell mediated immunity was assessed on the basis of total lymphocytes (TL), total T lymphocytes (TTL) counts, delayed skin test responses and in vitro leucocyte migration inhibition test (LIF) production in 25 patients with SSPE, classified according to the clinical stages of the disease. The patients in stage I of the disease did not show any defect in cellular immunity while the patients in stage II showed decreased TL and TTL counts, more negative skin test responses to PHA, SKSD and PPD, and unresponsiveness to SKSD of LIF production. When the patient group was evaluated as a whole, only the TL counts and the skin test responses against SKSD differed from those in the controls. These results suggest that the defects in cellular immunity demonstrated in the patients with SSPE may be due to SSPE or the measles virus itself rather than to a genetic factor predisposing patients to SSPE.