The growing problem of chronic renal failure after transplantation of a nonrenal organ.

The clinical introduction of the immunosuppressive drug cyclosporine in the early 1980s revolutionized the field of organ transplantation. The adoption of cyclosporine-based immunosuppressive regimens dramatically improved survival among patients who received nonrenal allografts. Twenty years later, cyclosporine and tacrolimus (another inhibitor of calcineurin — a key enzyme involved in T-cell activation) 1 remain the cornerstone of immunosuppressive therapy for most patients who receive nonrenal transplants. Not surprisingly, given the procedures involved, transplantation of nonrenal organs can be associated with acute renal failure. During the past two decades, however, it has become apparent that chronic renal failure is also an important complication. Whatever type of organ is transplanted, the clinical features are quite similar: a decrease in the glomerular filtration rate — by 30 to 50 percent during the first six months after transplantation — followed by stabilization or a slower rate of loss of renal function. 2 Hypertension is present in the majority of affected patients. The urine sediment is usually unremarkable, although proteinuria may be present. Laboratory studies may show evidence of low-grade thrombotic microangiopathy. 3 Renal biopsies (rarely performed unless the clinical presentation is atypical) usually demonstrate interstitial fibrosis and tubular atrophy, arteriolar hyalinosis, and sclerosis or collapse of glomeruli. 4