Contemporary concepts for the clinical and laboratory evaluation of systemic lupus erythematosus and "lupus-like" syndromes.

Systemic lupus erythematosus (SLE) is a nonorgan-specific autoimmune disease which affects multiple organ systems and is multifactorial in etiology. SLE is the prototypic systemic rheumatic disease with immune dysregulation characterized by (1) polyclonal activation of B-cells and (2) production of a large spectrum of autoantibodies with a marked preference for nuclear and intracellular antigens. The clinical and laboratory manifestations and criteria for classification and diagnosis of systemic lupus erythematosus, lupus-like syndromes, and various subsets of systemic lupus erythematosus, are reviewed. The differential diagnosis of SLE and related diseases is described with correlation of specific intracellular autoantibodies.