Cyclosporin A (CsA) and azathioprine (AZA) combination in renal allografts with CsA nephrotoxicity.

Cyclosporin A (CsA) is a potent immunosuppressive drug whose effect is well known in the organ transplantation field. Treatment with CsA reduces the incidence of rejection and improves graft survival after renal transplantation (RT). However, to set against the clear advantages of CsA, a most important problem is nephrotoxicity. Scientists are therefore seeking new non-nephrotoxic Cs derivatives, but the search has not yet borne fruit. Teams working in organ transplantation attempt to avoid nephrotoxicity by switching to conventional treatment with azathioprine (AZA), starting 1, 3 or 6 months after transplantation. Conversion from CsA to AZA has not always been successful due to the high incidence of rejection. AZA has also been started immediately after transplantation in combination with CsA at low doses, and in some instances no CsA is administered when oliguric acute tubular necrosis is present. In a previous report, we presented the short-term results of the treatment with a CsA-AZA combination, reducing the CsA dose and giving a moderate dose of AZA in 21 transplanted patients not achieving acceptable graft function. In the present study we analysed the long-term results in a group of patients whose kidney biopsy examination results were compatible with CsA nephrotoxicity.