Immunomodulatory factors in cerebrospinal fluid of patients with multiple sclerosis and controls

The immunomodulatory effects of cerebrospinal fluid (CSF) from patients with multiple sclerosis (MS) and other neurologic diseases (OND) were determined by measuring their abilities to suppress alloantigen-specific and nonspecific (IL-2 mediated) proliferative responses. An alloantigen primed, IL-2-dependent line of human T-cells (PLT) was used as indicator. CSF from both patient groups significantly suppressed alloantigen-specific and nonspecific PLT proliferative response. However, patterns of suppression differed between the two groups. While alloantigen-specific proliferative responses were suppressed similarly by MS and controls, CSF from MS patients had significantly less suppressing effect on nonspecific lymphocyte proliferation than did control CSF. The degree of suppression of alloantigen-stimulated proliferation by MS CSF correlated with the concentrations of gamma-globulin and myelin basic protein as well as with the Ig index. Suppression of alloantigen-stimulated proliferation by control CSF correlated only with the concentration of alpha 1-globulin. Sera from 3 MS patients and 7 OND patients were also tested in our system. Only MS sera significantly suppressed the alloantigen stimulated proliferative responses of the PLT. Neither serum group affected nonspecific (IL-2 mediated) proliferation. Our data suggest that there are immunomodulatory factors present in both MS and control CSF, but MS CSF may be relatively lacking in a factor controlling nonspecific lymphocyte proliferation. Deficiency of this factor(s) may contribute to the increased numbers of activated lymphocytes in MS CSF.