Influence of cyclophosphamide and other immunosuppressive drugs on immune disorders and neoplasia in NZB/NZW mice.

NZB/NZW mice were treated with various immunosuppressive drugs used in human SLE. Cyclophosphamide (5 mg/kg 6 days out of 7), alone or with prednisolone, was better than azathioprine, prednisolone, or azathioprine-plus-prednisolone, in prolonging survival and/or reducing proteinuria, Coomb's antibodies, antinuclear antibodies, and glomerular deposits of gamma-globulin. Intermittent bolus therapy with cyclophosphamide (59 mg/kg/10 days) was as effective as daily therapy. However, 61% of the mice receiving any cyclophosphamide regimen developed malignant tumors compared to none in the other groups.