Immunoregulation by alpha 1 antitrypsin.

alpha 1 antitrypsin (alpha 1 AT) deficiency is a common genetic disorder seen in about 10% of the population. It predisposes to the development of a large number of inflammatory and immunologic disorders including rheumatoid arthritis, systemic lupus erythematosus, juvenile chronic arthritis, anterior uveitis, ankylosing spondylitis, fibrosing alveolitis and emphysema. We have investigated immunologic function in subjects with severe alpha 1 AT deficiency and demonstrated serum mediated enhancement of lymphocyte response to PHA and increased zymosan activation of mononuclear cells and neutrophils as measured by their chemiluminescence. These patients also have accelerated delayed hypersensitivity responses and increased levels of factor B, C3 and C5 but normal levels of immunoglobulin and other complement components. Such abnormalities in immunoregulation demonstrate a tendency to hyperreactivity that may contribute to disease predisposition.