The efSect of early nifedipine therapy on acute renal allograft rejection was studied in I70 adult cadaveric transplant recipients. Acute rejection occurring in the jirst 3 months after transplantation was diagnosed by Tru-cut biopsy and the severity of each rejection episode assessed histologically. The incidence of acute rejection was signijicantly lower in patients treated with nifedipine (29 of 80; 36 per cent) than in controls (52 of 90; 58 per cent) ( P < 0.01) and there was a higher proportion of histologically mild rejection episodes in the former group ( P < 0.01). Multivariate analysis confirmed that nifedipine exerted a significant independent efSect on the incidence of early acute rejection. Other factors identijied in the multivariate model as influencing rejection were human leucocyte antigen (HLA) matching at the DR locus, blood level of cyclosporin during the jirst week, HLA matching at the B locus, donor age and donor sex. The I-year graft survival rate was 88.6 per cent in patients given nifedipine and 63.8 per cent in controls (P < 0.02). These data suggest that nifedipine therapy has a useful role in human renal transplantation.
The calcium channel blocker nifedipine relaxes vascular smooth muscle and is therefore used extensively as an antihypertensive agent. Cyclosporin therapy is often complicated by sodiumdependent hypertension and nifedipine has commonly been used in renal transplant recipients to treat this condition. Nifedipine also ameliorates cyclosporin nephrotoxicity' and reduces the incidence of delayed graft function after renal transplantation'.
Recent experimental evidence suggests that nifedipine depresses a variety of functions in both the afferent and efferent limbs of the immune response3. The aim of the present study was to determine whether early nifedipine therapy has an effect on acute graft rejection after adult cadaveric renal transplantation. The study was limited to the first 12 weeks after transplantation as this is known to be the period in which rejection is most common.