Renal function after long-term low-dose cyclosporin for psoriasis.

Two groups of patients receiving cyclosporin A (CyA) for psoriasis had their renal function assessed by measurement of glomerular filtration rate (GFR) and effective renal plasma flow (ERPF). The first group comprised 13 patients who had taken low dose (average 3 mg/kg per day) CyA for an average period of 2.5 years. Seven of the 13 had a normal GFR of 108 (77-121) ml/min (median; range). In the other six patients the GFR was low at 63 (50-77) ml/min and CyA was discontinued for periods ranging from 3 to 17 weeks. The GFR rose in all six patients, to 79 (60-91) ml/min; this change was significant (P less than 0.05). The six patients restarted CyA because their psoriasis recurred and after a mean interval of 15 weeks the GFR had fallen in all six to 63 (46-80) ml/min (P less than 0.05) and the ERPF decreased from 339 (231-414) ml/min to 244 (177-321) ml/min (P less than 0.05). In the second group of 11 patients measurements were made prior to starting CyA and after taking CyA for a mean of 9 weeks. The GFR fell in eight out of 11 subjects, the GFR for the 11 patients being 117 (72-128) ml/min before taking CyA and 97 (51-122) ml/min after CyA (P less than 0.02). The ERPF was measured in nine of the 11 patients and fell in seven of the nine. The ERPF for the nine patients before CyA was 490 (296-642) ml/min and for the 11 patients after CyA was 410 (195-543) ml/min (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)