What have we learned from the use of ciclosporin A in the treatment of nephrotic patients with idiopathic membranous nephropathy?

Ciclosporin A (CsA) has been widely used in the treatment of patients with nephrotic syndrome over the last 10 years. Review of the accumulated knowledge from the use of CsA in patients with nephrotic syndrome due to idiopathic membranous nephropathy (IMN). The most important articles concerning the use of CsA in IMN patients have been reviewed. CsA, a potentially nephrotoxic drug, induces remission of nephrotic syndrome in > 80% of IMN patients. Relapses occur after its withdrawal and long-term treatment is necessary. Repeat renal biopsies show no signs of CsA nephrotoxicity, but show deterioration of chronic histological lesions with time, even in cases with remission. Thus, CsA is effective in IMN patients, but its long-term use should be examined with caution.