Abstract
We reported a case of 3 year-old-boy Hurler syndrome, who developed nephrotic syndrome 7 months after the second allogenic bone marrow transplantation (BMT). After BMT he had been treated by immunosuppressive drug (Tacrolimus) for prophylaxis of graft-versus-host disease. He had been suffered from autoimmune hemolytic anemia and thrombocytopenic purpura at 5 months later from second BMT, which had been treated with steroid hormone. While the steroid hormone dosage was decreasing, he showed severe hypoproteinemia and oliguria abruptly.
Renal biopsy revealed one cellular crescent and one glomerular thrombosis, several mild mesangial cell proliferation, increase of mesangial matrix and swelling of epithelial cells among 24 glomeruli. Vacuolization of medial smooth muscle cells of afferent arterioles was prominent. Electron microscopic findings showed severe swelling and degeneration of subendothelial cell and no electron dense deposits. These findings suggested thrombotic microangiopathy (TMA) after BMT.
Because the arteriolopathy of this case was considered to be induced by cell toxicity of tacrolimus, this drug was discontinued. Instead, methylprednisolone pulse therapy, oral prednisolone with dipyridamole therapy were employed. Proteinuria disappeared in two weeks, and prednisolone therapy discontinued at 8 months later without any recurrence.
The glomerulopathy is suspected to be attributed to not only tacrolimus but also total body irradiation and chronic graft-versus-host disease.
