Renal Pathology after Haematopoietic Stem Cell Transplantation: A study of 13 patients

Abstract

The ever-growing number and increasing survival of haematopoietic stem cell transplantation (HSCT) allow better recognition of its associated renal injures. We aimed to characterize renal pathology after HSCT by reviewing percutaneous renal biopsies after HSCT. A retrospective clinicopathologic study of all renal biopsies archived to the Department of Pathology, Queen Mary Hospital during the period January 1999 to December 2006 was performed. Biopsies from patients with HSCT were selected. Clinical data on presentation and follow up were retrieved from hospital records and physicians. In the 8-year period, a total of 2,585 renal biopsies were archived. 14 (0.54%) biopsies were from 13 patients with HSCT (11 allogeneic, 2 autologous). All but one patient were male. The age at biopsy ranged from 7-63 year (median: 35 year). The median interval of renal biopsy after HSCT was 18 months (range, 1-134 months). Evidence of graft-versus-host disease (GVHD) was recorded in 9 patients. Presentation of renal disease included significant proteinuria (10 cases) and renal impairment (9 cases). Predominant histological changes were membranous glomerulonephritis (MGN) (n=4) and thrombotic microangiopathy (TMA) (n=3). Four patients died at 0-11 months after renal biopsy. Of the remaining 9 patients with a mean follow up of 39.4 months (range, 6-98 months), chronic renal impairment was found in 4 (44.4%) while proteinuria persisted in 5 patients. Renal involvement investigated by biopsy after HSCT primarily affect male. Among the various renal lesions, two types of glomerulopathy, namely MGN and TMA were the most common. Mechanisms of renal injury include GVHD-associated immune complex (IC) deposition and non-IC injury on endothelial cells, glomerular epithelial cells, mesangium, interstitium and tubular epithelium. Recurrence of paraneoplastic syndrome after HSCT potentially modifies the renal pathology. Pathologists and physicians should attend to the histological and temporal heterogeneities of renal injury when managing patients after HSCT.