MEMBRANOUS GLOMERULONEPHRITIS AND NEPHROSIS POST FACTOR-IX INFUSIONS IN HEMOPHILIA-B

Children with hemophilia B who receive exogenous factor IX infusions m ay rarely develop inhibitors to the exogenous factor IX and require de sensitization. Nephrotic syndrome has recently been described in some of these children. We report the renal clinicopathological findings in a child with severe factor IX deficiency, requiring induction of an i mmune tolerance protocol, who developed nephrotic syndrome. Renal biop sy revealed peripheral capillary wall thickening and a spike appearanc e consistent with membranous glomerulonephritis. Electron microscopy s howed prominent deposits throughout the thickness of the basement memb rane. Factor IX dose reduction was accompanied by reversal of the chil d's nephrotic syndrome without relapses.