Treatment with candesartan combined with angiotensin-converting enzyme inhibitor for immunosuppressive treatment-resistant nephrotic syndrome after allogeneic stem cell transplantation

Most cases of nephrotic syndrome following stem cell transplantation (SCT) occur 6 months after SCT. The patients are treated with immunosuppressive therapies; however, in some cases treatment is not effective. We used enalapril, an angiotensin-converting enzyme inhibitor (ACEI) and candesartan, an angiotensin II receptor blocker (ARB), for the control of proteinuria in a case of immunosuppressive treatment (IST)-resistant nephrotic syndrome. A 15-year-old boy with acute lymphoblastic leukemia underwent allogeneic peripheral blood SCT from a completely HLA-matched sibling after completion of a conditioning regimen composed of 12-Gy doses of total-body irradiation, 600 mg/m(2) thiotepa, and 140 mg/m(2) melphalan. Twenty-eight months after SCT, minimal-change nephrotic syndrome was diagnosed on the basis of biopsy findings. Although neither cyclosporine (trough level, 100-150 ng/mL) nor corticosteroid was effective, proteinuria disappeared 2 months after the beginning of treatment with tacrolimus (trough level, 13-20 ng/mL), and remission was maintained for 23 months. Nephrotic syndrome recurred, however, and was resistant to tacrolimus. Findings at the second renal biopsy revealed membranous nephropathy. An ARB (candesartan, 4 mg/ day) in combination with an ACEI (enalapril, 5 mg/day) was started. Proteinuria improved within 2 weeks. We suggest that ARB combined with ACEI can be used to control proteinuria in patients with IST-resistant nephrotic syndrome after SCT.