Introduction: Alpha-1-antitrypsin (AAT) deficiency is usually associated with lung or liver disease. It is often detected as a qualitative reduction of the alpha-1 band on the serum protein electrophoretic pattern.
Material and methods: We examined the protein electrophoretic pattern in sera of 22980 unselected consecutive patients with neurological disorders and noted a reduced alpha-1 band in 88. Their phenotypes were compared with the clinical disease.
Results: 75 patients had a deficient or non-M and 13 the usual MM phenotype. Contrary to in the general population, PiMZ was four times more common than PiMS. Vascular disease was more common in patients with PiMZ while multiple sclerosis significantly more frequent in patients with PiMS than with other phenotypes, including PiMM.
Conclusions: Other genetic abnormalities have previously been found in AAT associated with multiple sclerosis, but not PiMS. Since PIMS leads to modest reduction of AAT activity, the association may be through other mechanisms than reduced protease activity.