Proliferating cells in demyelinating states.

Proliferation of mononuclear cells was examined with an autoradiography method in the CSF and peripheral blood of 13 patients with multiple sclerosis (MS), serially during activation of disease in one patient with subacute sclerosis panencephalitis (SSPE), and in some control patients with various neurological conditions. High cerebrospinal fluid (CSF) cell labelling indices, up to 1.7%, which could not be directly related to the clinical activity of the disease, were found in some MS patients. During activation of SSPE there was marked increase in labelled cells of CSF, up to 4.3%. In controls, corresponding CSF indices ranged from less than 0.1% to 0.4%. Mononuclear cells in CSF and peripheral blood behaved as clearly different cell populations.