De novo postallogeneic hematopoietic stem cell transplant membranous nephropathy.

We report membranous nephropathy in a 61-year-old man after allogeneic hematopoietic stem cell transplant without chronic graft-versus-host disease. A diagnosis of acute myeloid leukemia was made, and the patient received hematopoietic stem cell transplants, twice, from different donors. The first donor was his brother and the second donor was an unrelated man. Human leukocyte antigens between donors and recipient were fully matched. His clinical course was stable without acute or chronic graft-versus-host disease or relapse of acute myeloid leukemia with tacrolimus after the second hematopoietic stem cell transplant. Six months after the second hematopoietic stem cell transplant, tacrolimus was decreased gradually and discontinued because of tacrolimus-induced liver dysfunction. Three months after discontinuing the tacrolimus, the patient developed edema in his leg. The results of a blood analysis showed that plasma albumin level was 21 g/L and plasma total cholesterol level was 11.5 mmol/L, while results from a urinalysis showed proteinuria of 5.6 g/d without hematuria. No abnormalities in the skin, mucosal tissues, and other organs suggestive of chronic graft-versus-host disease were seen. A renal biopsy was done to investigate the cause, which revealed renal disease. Electron microscopic analysis showed dense deposits in the subepithelial region in all glomeruli. Immunofluorescence analysis showed the deposition of IgG4 and C3c in the subepithelial space of all glomeruli. Membranous nephropathy was diagnosed. He then was administered prednisolone at a dosage of 45 mg/d (0.7 mg/kg/d). After prednisolone treatment, urine protein and hypoalbuminemia were markedly improved, and his leg edema disappeared. These results suggest that this membranous nephropathy may have been de novo membranous nephropathy after hematopoietic stem cell transplant because it developed after hematopoietic stem cell transplants without chronic graft-versus-host disease.