HL-A histocompatibility antigens in optic neuritis.

HL-A and MLC typing in 54 patients with optic neruitis showed increased frequencies of the HL-A3, 7 and LD-7a determinants of approximately the same magnitude as in patients with multiple sclerosis. The frequencies of the same three determinants were not different in the 11 patients who developed multiple sclerosis during the period of follow-up compared to the remaining patients. There was a significant increase in the frequency of the HL-A3 determinant in patients with oligoclonal IgG of the cerebrospinal fluid at the onset of disease. The connection between this determinant and the occurrence of cerebrospinal fluid changes is not clear. The results suggest that optic neuritis and multiple sclerosis represent different aspects of the same disease entity, rather than two distinct diseases. HL-A and MLC typing did not seem to offer prognostic information as to the later development of multiple sclerosis in these patients, but the observation period is still short.