Systemic lupus erythematosus. Some contemporary laboratory aspects.

A summary of some of the important laboratory features of systemic lupus erythematosus (SLE) is presented. Emphasis is given to the sensitivity and specificity of the antinuclear antibody test, the relevance of particular antinuclear antibody patterns, and the status of testing for antibodies to DNA. Serum complement abnormalities in the patient with SLE are briefly reviewed, and the utility of the total hemolytic complement assay is stressed. The increasing evidence for disordered immune regulation in SLE is considered. Particular attention is given to the role of antilymphocyte antibodies and in vitro assays that permit an assessment of functional lymphocyte subsets. The heterogeneity of the SLE patient population and the influence of treatment and/or disease activity on laboratory results is repeatedly emphasized.