Adult immunodeficiency and rheumatic disease.

Several rheumatic illnesses may develop in adults with primary or acquired immunologic defects. Individuals with primary defects in B-cell antibody production, such as common variable immunodeficiency of selective IgA deficiency, and those with defects of complement components, have an increased prevalence of systemic lupus erythematosus--like syndromes or other autoimmune diseases. Defects in immunoglobulin production may be complicated by inflammatory or infectious arthritis. Infection with HIV-1 may be associated with diverse rheumatic conditions, including diffuse infiltrative lymphocytosis syndrome, myopathies, vasculitides, inflammatory arthritides, and infectious musculoskeletal complications. An approach to these disorders that takes into consideration the underlying mechanism of disease is presented. Appropriate strategies aimed at treatment of the underlying immunodeficiency may improve the clinical course of the associated rheumatic disorder.