Conversion from cyclosporine to azathioprine in renal graft recipients.

Only one of six patients in whom a clinical diagnosis of rejection was confirmed by both biopsy and FNA benefited from a switch from cyclosporine to azathioprine. Nine patients, in whom nephrotoxicity and rejection could not be separated and in whom the biopsy was positive but the FNA negative, improved when converted to cyclosporine. This improvement was, however, followed by subsequent rejection episodes in four of these patients. This study suggests caution in changing from CsA therapy in patients with unstable function.