Disordered Immune Regulation in Autoimmune Rheumatic Diseases

ABSTRACT

Polymyositis/dermatomyositis (PM/DM) and systemic lupus erythematosus (SLE) are autoimmune disorders of unknown etiology. In order to study whether immunoregulatory abnormalities might be involved in these autoimmune states, the autologous mixed lymphocyte reaction (AMLR) was investigated in patients with either adult PM/DM, childhood DM (CDM), or SLE. The AMLR was found to be significantly depressed in adult PM/DM regardless of disease activity. By contrast, in CDM the AMLR was normal. In SLE, the AMLR was depressed in patients with both active and inactive disease and the responding T cell population appeared to be defective, as shown in a study on a pair of identical twins. These studies thus underscore the existence of a primary immunoregulatory dysfunction in these two autoimmune diseases.