Serum immunoglobulin levels in multiple sclerosis in Orkney.

Serum levels of immunoglobulins A, G and M in the population of multiple sclerosis patients in Orkney were generally similar to those in series of contiguous and discontiguous controls, and in the normal first-degree relatives both of patients and controls. There is a slight elevation of mean log IgE in patients, and this is due mainly to elevation in the rural patients. Factors possibly responsible are sought, but none can be clearly identified.