Lymphocyte subpopulations in the cerebrospinal fluid and peripheral blood in patients with multiple sclerosis.

The cerebrospinal fluid (CSF) and blood of patients with multiple sclerosis (MS) were studied with respect to the frequency of lymphocytes with intracellular immunoblobulins of different Ig classes as well as the relative frequency of B and T lymphocytes. An increased number of Ig-postive cells were found in CSF (mean, 0.52%) when compared with blood (mean 0.18%). In CSF there was a striking dominance of IgG-postive cells, very few IgA-postive cells, and almost no IgM-postive cells. The distribution in blood was approximately normal. The ratios between chi- and lambda-postive cells in CSF were all outside the range in blood. In CSF there were fewer B cells (mean, 4.7%) and more T cells (mean 74.2%) when compared with blood (mean, 11.5%) and 61.8%, respectively). The values for MS blood were approximately the same as for normal controls. The increased number of IgG-containing cells in the CSF are in agreement with earlier studies, which showed a local immunoglobulin synthesis. The increased proportion of T lymphocytes in CSF of MS patients may indicate that these cells play a role in the pathogenesis of MS.