Age-related reactivity of lymphocytes from multiple sclerosis patients to myelin basic protein.

Peripheral blood lymphocytes from 51 multiple sclerosis (MS) patients and 23 healthy individuals were examined for their response to human myelin basic protein at three concentrations. Cells from active-MS patients responded in most cases with definitely enhanced blastogenic stimulation (BS), whereas those of the nonactive-MS patients or of patients in remission showed values of BS similar to or below those of the control group. Patients and control individuals were divided in two groups according to their age. The younger group included individuals from 20 to 40 years of age, the older those from 41 to 68 years. The lowest and highest values obtained using the three doses of basic protein was selected and the results compared. The higher values of BS and the greater frequency of active blood samples were observed in the younger than in the older active-MS patients. On the other hand, a larger number of samples obtained from the older patients showed the lowest values of BS. The relevance of age to the suppressor activity induced by the basic protein in the lymphocytes of MS patients is discussed.