title: Rethinking peritubular capillary basement membrane multilayering in renal transplant pathology: a case report.
abstract: Severe multilayering (ML) of the peritubular capillary basement membranes in kidney allografts is considered to be an ultrastructural hallmark of chronic antibody-mediated rejection (CAMR). We describe here the unexpected findings in a young male adolescent with underlying focal segmental glomerulosclerosis who underwent a living-related donor transplant procedure, a case which brought into question the specificity of ML.
  
  
  
  The patient received a kidney from his mother, whose donor screening was unremarkable. He developed nephrotic-range proteinuria shortly after the procedure. Biopsies performed within the first 6 months after transplantation demonstrated ML (5-6 layers).
  
  
  
  Since there were no other criteria for CAMR, electron microscopic analysis of the baseline biopsy was performed, which in retrospect also demonstrated ML. The donor is still asymptomatic after 7 years of follow-up, with normal renal function and no proteinuria.
  
  
  
  We discuss the phenomenon of ML in renal disease and together with the findings in our case would like to draw attention to the fact that ML in the setting of renal transplantation is not specific to CAMR, as it can exist in several kidney diseases and even in asymptomatic donors.
authors.affiliation: University of Barcelona, Barcelona, Spain. dlopategui@gmail.com.|Department of Pediatric Nephrology and Solid Organ Transplantation, University Hospitals Leuven, Leuven, Belgium. dlopategui@gmail.com.
authors.forename: Diana Maria
authors.initials: DM
authors.lastname: Lopategui
authors.affiliation: Department of Morphology and Molecular Pathology, University Hospitals Leuven, Leuven, Belgium.
authors.forename: Evelyne
authors.initials: E
authors.lastname: Lerut
authors.affiliation: Department of Microbiology and Immunology, KU Leuven, Leuven, Belgium.|Department of Nephrology, University Hospitals Leuven, Leuven, Belgium.
authors.forename: Maarten
authors.initials: M
authors.lastname: Naesens
authors.affiliation: Department of Pediatric Nephrology and Solid Organ Transplantation, University Hospitals Leuven, Leuven, Belgium.
authors.forename: Rita
authors.initials: R
authors.lastname: Van Damme-Lombaerts
authors.affiliation: Department of Pediatric Nephrology and Solid Organ Transplantation, University Hospitals Leuven, Leuven, Belgium.
authors.forename: Elena
authors.initials: E
authors.lastname: Levtchenko
authors.affiliation: Department of Pediatric Nephrology and Solid Organ Transplantation, University Hospitals Leuven, Leuven, Belgium.
authors.forename: Noël
authors.initials: N
authors.lastname: Knops
mesh_terms: D001485:Basement Membrane / Q000473:pathology*; D001706:Biopsy; D002648:Child; D005923:Glomerulosclerosis, Focal Segmental / Q000601:surgery; D006084:Graft Rejection / Q000473:pathology*; D006650:Histocompatibility Testing; D006801:Humans; D016030:Kidney Transplantation / Q000009:adverse effects*; D007684:Kidney Tubules / Q000473:pathology*; D019520:Living Donors; D008297:Male; D008854:Microscopy, Electron; D011507:Proteinuria / Q000378:metabolism
keywords: Focal segmental glomerulosclerosis; Multilayering; Rejection; Transplant