Nephrotoxicity in bone marrow transplant recipients treated with cyclosporin A.

Cyclosporin A(CyA) is a valuable post graft immunosuppressive agent in allogeneic bone marrow transplantation. The use of CyA is associated with a reduction in severity of graft versus host disease and improved marrow engraftment. A major side effect of CyA is nephrotoxicity. In 33 patients studied during the first 4 weeks of therapy there is a close correlation between trough (12 h) serum cyclosporin A concentrations and plasma creatinine (r = 0.93, P less than 0.001) and urea (r = 0.88, P less than 0.001). Trough CyA serum concentrations of greater than 500 ng/ml are potentially nephrotoxic. Other risk factors for early nephrotoxicity in cyclosporin therapy are the concurrent use of aminoglycoside antibiotics (P = 0.01) and hyperbilirubinaemia (P = 0.01). Early nephrotoxicity can be prevented by maintaining trough CyA levels in the range 100-400 ng/ml. During prolonged CyA therapy, cumulative renal impairment can occur and nephrotoxic episodes associated with microangiopathic peripheral blood changes and hypertension are seen in a minority of patients.