Therapy of focal segmental glomerulosclerosis with cyclosporine A.

Six patients with biopsy-documented focal segmental glomerulosclerosis were treated with cyclosporine A (CyA) a new and potent T-cell suppressant. Dosage was adjusted to maintain trough levels between 100 and 300 ng/ml (whole blood radioimmunoassay). Patients were treated for 6 weeks or until unacceptable drug toxicity occurred. In one patient proteinuria was significantly reduced. This same individual was the only patient treated within 6 months of diagnosis. Therapy was discontinued in two patients at week 4, one because of worsening renal failure and one because of hypertension. These complications occurred despite trough CyA blood levels of less than 300 ng/ml. The results suggest that further and controlled studies of CyA are warranted in the therapy of nephrotic syndrome associated with focal segmental glomerulosclerosis, especially when used early in the course of disease. The data also suggest enhanced toxicity of CyA in patients with active nephrotic syndrome.