Publication
Effects of antioxidant supplementation on blood cyclosporin A and glomerular filtration rate in renal transplant recipients
Publisher:
Oxford University Press (OUP)
Date:
05-07-2005
DOI:
10.1093/NDT/GFH875
Abstract: Transplant recipients have elevated oxidative stress, which has prompted suggestions that supplementary antioxidants may be beneficial. However, only a small number of clinical trials have investigated antioxidant supplementation in transplant recipients, with very few data on their effects on patients' immunosuppressive therapy. A randomized placebo-controlled single-blind crossover trial was conducted in 10 renal transplant recipients (RTRs) taking cyclosporin A (CsA) as part of their immunosuppressive therapy. Each phase of the trial lasted 6 months, with a 6 month wash-out period in between. During one of the phases, patients consumed a tablet twice per day which delivered 400 IU/day of vitamin E, 500 mg/day of vitamin C and 6 mg/day of beta-carotene. During antioxidant supplementation, there was no change in CsA dose. Antioxidant supplementation resulted in a significant decrease (P<0.05) in blood trough CsA by 24% (mean+/-SD, pre- 127.3+/-38.9, post- 97.2+/-30.7 microg/ml) compared with no change while taking the placebo (pre- 132.2+/-50.6, post- 138.6+/-56.0 microg/ml). The glomerular filtration rate was significantly (P 0.05) in markers of oxidative stress (malondialdehyde, susceptibility of plasma to oxidation) or plasma antioxidant enzymes. In CsA-treated RTRs, antioxidant supplementation decreased blood CsA, which may affect adequacy of immunosuppression.