Sustained renal function loss in psoriasis patients after withdrawal of low-dose cyclosporin therapy.

Eight patients with psoriasis received low-dose cyclosporin (CyA) treatment for an average period of 12 months (range 4-16 months). There was great variability in minimal effective CyA dose. In 50% of the patients long-term treatment was limited by dose reductions necessitated by side-effects. A considerable impairment of renal function during CyA therapy was found. Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were measured with 125I-iothalamate and 131I-hippuran, respectively. Both at the end of the active treatment period (GFR-CyA and ERPF-CyA), and 4 months after withdrawal of CyA (GFR-4mo and ERPF-4mo), there was sustained renal impairment: GFR-BL = 97 (64-117), GFR-CyA reduction 17.8% (2.2-31.9%) [P < 0.02], GFR-4mo reduction = 9.8% (5.5-21.5%) ml/min/1.73 m2 (P < 0.05 vs. BL); ERPF-BL = 401 (232-607), ERPF-CyA reduction = 10.1% (7.4-27.3%) [P < 0.05], ERPF-4mo reduction = 13.5% (3.0-32.9%) ml/min/1.73 m2 (P < 0.02). Further studies of the effects on renal function during, and after, long-term therapy of psoriasis with low-dose CyA are warranted.