[Proliferation of large granular lymphocytes in patients with systemic lupus erythematosus]

Large granular T lymphocytes (LGL) make up a small portion of cellular population in peripheral blood. An abnormal proliferation of LGL is detected together with cytopenic and other autoimmune disorders and is often associated with rheumatoid arthritis. The association with other autoimmune diseases, such as systemic lupus erythematosus, is poorly known. The clinical and immunological profile in five patients with SLE and LGL proliferation is here reported.

A clinical follow-up and prospective phenotypic study of mononuclear cells was conducted in patients with SLE for a period of 24 months. LGL were identified on the basis of their shape and analyzed by flow cytometry as cells coexpressing thymic differentiation antigens (CD3 and CD4, or CD8) and NK cells CD16, CD56 or CD57).

Five out of 43 patients with SLE showed recurrent proliferations of LGL (from 2 to 4 per patient) chronologically associated with lupus exacerbations. LGL represented 52 to 78% (mean +/- SD = 56 +/- 8%) from the total of lymphocytes. The phenotype in proliferations was heterogeneous but it was consistent in later relapses in each patient (patient #1 and #2: CD3+CD8-CD4+CD16+CD56+CD57-HLA/D+ patients #3 and #4: CD3+CD8+CD4-CD16+CD56+CD57-HLA/DR+ patient #5: CD3+CD8+CD4- CD16+CD56+CD57-HLA/DR+patient 5:CD3+CD8+CD4-CD16 +/- CD56-CD57+HLA/DR+). These five patients had long term SLE with a greater number of exacerbations and a tendency to develop hemocytopenias, requiring high doses of corticosteroids and even immunosuppressors to control their condition.

Some patients with SLE develop LGL proliferations. The activity, clinical severity and hematological involvement seem to be associated with this immunological disorder, but the pathogenic significance and prognosis of these proliferations are still to be elucidated.