Nephrotic syndrome after allogeneic hematopoietic stem cell transplantation: etiology and pathogenesis.

In this study we investigated the etiology and pathogenesis of nephrotic syndrome (NS) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in 257 patients with hematopoietic malignancies who survived more than 2 months post allo-HSCT. Associations of NS with the conditioning regimen, graft versus host disease (GVHD), and other variables were analyzed. Pathologic features of the kidney, regulatory T cells (Tregs), interferon-γ (IFN-γ), and tumor necrosis factor-α (TNF-α) were studied. NS was identified in 9 patients. The number of Tregs at day+30, 60, 90, and 180 was lower in NS patients than non-NS patients (P=0.001, 0.001, 0.007, 0.003). Serum levels of IFN-γ and TNF-α were higher in NS patients (P=0.032, 0.001, respectively). NS post allo-HSCT was associated with the occurrence of chronic GVHD (P=0.02). NS post-HSCT is an immune disorder that may involve immune complex deposition, Th1 cytokines, and Tregs.