THE EFFECT OF INTRAVENOUS CYCLOPHOSPHAMIDE PULSE ON PERIPHERAL-BLOOD LYMPHOCYTES IN LUPUS-ERYTHEMATOSUS PATIENTS

In the present study we investigated the longterm effect of intravenou s pulse cyclophosphamide (CY) on lymphocyte surface antigens in system ic lupus erythematosus (SLE) patients. Blood samples derived from 17 l upus erythematosus patients were analysed using two-and three-colour f low cytometry. During the CY therapy, the total number of T lymphocyte s (CD3+) was reduced by 31.4%, B lymphocytes (CD19+) by 67.4% and NK c ells (CD16+) by 27.4%. Six months after the end of the CY regimen, the se values recovered to entry levels. At the onset of the study we obse rved increased percentages of CD3+ CD25+, CD3+ CD4-CD8-, CD4+ CD29+, C D19+ and CD19+ CD5+ cells. The CY treatment regimen decreased the CD3 CD25+, CD3+ CD4-CD8-, CD19+ and CD19+ CD5+ cells, but increased the C D3+ CD8+ subpopulation. Taken together, a deficiency of CD8+ T cells a ssociated with CD4+ CD29+ predominance may imply an immune regulatory imbalance leading to abnormal CD4+ cell activation and in consequence to autoimmunity. Depletion of CD19+ cells combined with an enlargement of CD8 cells as a result of CY therapy may reduce the enhanced immune response in SLE patients.