Multipotent hemopoietic progenitor cells in patients with systemic lupus erythematosus.

Hematologic abnormalities in patients with systemic lupus erythematosus (SLE) were studied before treatment, using an in vitro bone marrow progenitor cell assay. In 10 patients with SLE, there was a decrease in the number of multipotent hemopoietic colonies. Multipotent colony formation was suppressed by the addition of T cells from the patients with SLE. The culture supernatant of phytohemagglutinin stimulated SLE leukocytes had diminished activity to support the multipotent colony formation. These results suggest that the hematologic abnormalities in SLE occur at the multipotent stem cell level. The T cell mediated suppression of hemopoietic progenitor cells and the diminished activity of humoral factors released from SLE leukocytes may play some role in the pathogenesis of hematologic abnormalities in SLE.