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.

A group of 37 patients with nonactive multiple sclerosis and 20 healthy individuals (HI) were examined by the standard lymphocyte transformation test for their blastogenic response to a wide range of concentrations of human myelin basic protein (BP), purified protein derivative of tubercle bacilli and phytohemagglutinin. The group with multiple sclerosis (MS) showed a lower blastogenic response than the group of HI. The suppressed response was dose dependent; the highest suppressor activity was found at a BP concentration of 0.5 μg/ml, lower suppression was noted at a BP concentration of 50 μg/ml and no suppression could be detected when 5 × 10––7μg of BP/ml was employed. The suppressed response was confirmed using a two-stage procedure based on the concanavalin-A (Con-A) stimulation of the BP-pretreated lymphocytes. In the second-stage cultures, Con-A seemed to induce a clonal expansion of the BP-activated cells. The degree of blastogenic response could be similarly detected with a wide range of concentrations of Con-A. Phytohemagglutinin was not as effective as Con-A in detecting the BP-induced activity. Cultured lymphocytes were as good responders to the BP-induced activity as fresh autologous lymphocytes. The results of comparative studies using both procedures and their effectiveness in detecting the cellular response to BP are discussed.

Peripheral blood lymphocytes from forty-nine patients with multiple sclerosis (MS), twelve patients with other neurological diseases and twenty-seven healthy individuals were examined by a two-stage procedure based on the Con A stimulation of the basic protein (BP) pre-treated lymphocytes. Enhanced BP-induced blastogenic stimulation (BS) (90--220% was observed in MS individual classified as active (A-MS), whereas suppressed BS (27--120%) was observed in MS patients classified as non-active (NA-MS). The difference was statistically significant (P less than 0.01). The results obtained with the MS patients' lymphocytes also differed significantly (P less than 0.05) from those of the two control groups. Either response obtained with MS lymphocytes could be elicited with a similar concentration of BP. The enhanced or suppressed response to BP did not correlate with the cellular response to common antigens such as candida and streptokinase-streptodornase. Most lymphocytes of individuals from the two control groups showed BS values of 100 +/- 20% in response to BP. However, some degree of stimulation or suppression was also obtained with lymphocytes from a few individuals of both control groups. The potential value and application of the two-stage procedure is discussed.