MULTIPLE-SCLEROSIS - OCCURRENCE OF MYELIN BASIC-PROTEIN PEPTIDE-REACTIVE T-CELLS IN HEALTHY FAMILY MEMBERS

Genetic factors influence the susceptibility to multiple sclerosis (MS ). This disease is accompanied by augmented T cell responses to CNS my elin components such as myelin basic protein. To evaluate the familial occurrence of such T cell autoreactivity, we have studied 12 MS famil ies including 37 healthy first-degree relatives for occurrence of numb ers of interferon-gamma (IFN-gamma) secreting cells among blood mononu clear after culture in presence of myelin basic protein (MBP), eight s ynthetic MBP peptides and the control antigen acetylcholine receptor ( AChR). There were no differences between MS patients and healthy famil y members regarding frequencies of autoreactive T cells recognizing MB P, the eight different MBP peptides or AChR. None of the MBP peptides predominated as T cell antigen among the MS patients or their unaffect ed family members. In some families the highest number of MBP peptide reactive T cells were found among unaffected family members. No correl ation was observed between numbers of MBP or MBP peptide reactive T ce lls in various subjects and their HLA-DR-DQ phenotypes. In conclusion, this study has revealed the presence of MBP and MBP peptide reactive T cells of similar frequencies in MS patients and their healthy family members.