Cardiac transplantation and cyclosporine nephrotoxicity

CASE PRESENTATION A 26-year-old Caucasian man with a history of viral myocarditis and subsequent heart transplant at age 13 underwent a kidney biopsy for rapidly deteriorating renal function. The patient’s baseline serum creatinine was 2.2–3.0 mg/dl (194–264 mmol/l) with 3þ albuminuria by dipstick, but had recently increased to 4.8 mg/dl (422 mmol/l) over a 5-month period. His immunosuppressive regimen included azathioprine, prednisone, and cyclosporine (CsA); the latter was changed to sirolimus 6 months before presentation without improvement in renal function. Treatment with sirolimus led to the development of acne, which was treated with a 5-month course of cephalexin. Empiric therapy with prednisone for presumed allergic interstitial nephritis was ineffective after 2 weeks of therapy. Past history was otherwise remarkable for hypertension and hyperlipidemia. Physical examination revealed a well-appearing man. His blood pressure was 156/96, heart rate was 92, and he was afebrile. His jugular venous pressure was not elevated and there was trace peripheral edema. The remainder of the examination was unremarkable. Laboratory values are shown in Table 1. The serological work-up for a secondary cause for his nephrotic-range proteinuria was negative. He subsequently underwent renal biopsy to guide therapy.