Immunofluorescence studies of anti-T cell antibodies and T cells in systemic lupus erythematosus. Selective loss of brightly staining T cells in active disease.

Peripheral blood T cells from patients with systemic lupus erythematosus (SLE) and age- and sex-matched controls were studied by flow microfluorometry by using SLE anti-cell antibodies and fluorescein conjugated antibody to human IgM. Brightly staining cells were reduced in a number of patients with active SLE. Analysis of SLE T cells separated on a discontinuous stractin gradient indicated a preferential loss of cells, especially brightly staining cells, from one fraction. Quantitation of this phenomenon indicated that an average of greater than 90% of the brightly staining T cells from that fraction was lost in active SLE. This preferential loss of a subpopulation of T cells in patients with active SLE may be responsible for many of their immunologic abnormalities.