Cell-mediated immunity to measles virus in subacute sclerosing panencephalitis

Evaluation of lymphocyte subgroups in children with subacute sclerosing panencephalitis

The aetiology of subacute sclerosing panencephalitis (SSPE) remains to be fully elucidated, although it follows infection with a hypermutant defective M-protein measles virus. This study analysed peripheral blood lymphocyte subgroups to determine their role in the pathophysiology of SSPE. It included 22 children with SSPE aged 2 - 15 years (patient group) and 22 age- and gender-matched healthy children (control group). In children < 6 years old, there were no statistically significant differences between the two groups in the proportions of lymphocytes expressing the surface markers CD3, CD8, CD19 or CD16/56, or in CD4/CD8 ratio. The proportion of CD4(+) lymphocytes in SSPE patients < 6 years of age was significantly lower compared with the control group. In children >or= 6 years old, there were no significant differences in the lymphocyte subgroups. In conclusion, these findings suggest that a low CD4(+) lymphocyte count might be responsible for SSPE in younger children.

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.