Association between HLA B7, DR2 and dysfunction of natural- and antibody-mediated cytotoxicity without connection with the deficient interferon production in multiple sclerosis.

In this study, 133 patients with MS were investigated for HLA-A,B,C,DR antigens, natural killer (NK) cell activity, and antibody-mediated cytotoxicity (ADCC). A higher frequency of HLA B7 and DR2 was found in this group of patients than in the healthy control group, as can be observed in other caucasoid populations as well. In Gypsies living in the same geographic area, almost a complete absence of the disease was observed, corresponding to a lack of B7; however, HLA DR2 was present in 56% of this population. NK activity and ADCC measured against the K-562 tumor cell line was found to be significantly lower in MS patients, most pronounced in the group of male patients. Interferon augmentation of NK activity showed similar impairment in the patient group, and their lymphocytes produced a significantly lower amount of interferon. A correlation was demonstrated between both killer cell function and HLA B7, DR2 in MS patients, however, it was significant only in the case of ADCC and DR2. No other correlations were found in relation to interferon augmentation, interferon production, and HLA antigens. The above finding underscores a possible HLA-linked pathogenetic role of NK and K cell dysfunction in MS. This is consistent with other, similar observations that a possible defect in virus immunity may exist in MS patients.