Post-transplant hypertension and chronic renal allograft failure

Chronic renal allograft dysfunction is often associated with hypertension, but it is unknown to what extent this affects graft structure and function. We investigated the effect of antihypertensive drug treatments on the course and histopathology of chronic renal allograft rejection in a rat model. Recipient animals were treated with a combination of reserpine, hydralazine and hydrochlorothiazide, the angiotensin converting enzyme inhibitor cilazapril, or the angiotensin II receptor blocker L158,809. Systemic blood pressures and tubular stop-flow pressures were measured on day 50 after transplantation; the histopathology was assessed semiquantitatively in kidneys not used for micropuncture studies. Grafts removed from untreated recipients showed inflammation and structural vascular and glomerular lesions consistent with chronic rejection. All treatment regimens decreased the systemic and glomerular capillary pressures and were associated with improved graft survival, decreased proteinuria and a tendency to improved graft function; the histopathology showed a significant amelioration of glomerular mesangiolysis and glomerulosclerosis but no effect was found on the tubulointerstitial lesions; the angiotensin receptor blocker also inhibited graft atherosclerosis. We conclude that hemodynamic and angiotensin II-mediated processes may play a pivotal role in the expression of immune-mediated glomerular lesions of chronic allograft dysfunction.