Immunofluorescence studies of anti‐t cell antibodies and t cells in systemic lupus erythematosus

Peripheral blood T cells from patients with systemic lupus erythematosus (SLE) and age‐ and sexmatched 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 >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.