title: Diffuse Extent of Peritubular Capillaritis in Late Antibody-Mediated Rejection: Associations With Levels of Donor-Specific Antibodies and Chronic Allograft Injury.
abstract: Recently, diffuse peritubular capillaritis (ptc) has been suggested to independently predict chronic transplant injury and loss, and although the ptc score is a diagnostic criterion for antibody-mediated rejection, the utility of diffuse ptc is under debate.
  
  
  
  We evaluated the diagnostic value of ptc characteristics in this cross-sectional study including 85 biopsies of patients with donor-specific antibodies (DSA). Biopsies were reevaluated for the extent (diffuse vs focal), score and leukocytic composition in relation to DSA binding strength (mean fluorescence intensity [MFI]_max). Chronic allograft injury (transplant chronic glomerulopathy [cg] or chronic lesion score CLS]) were associated with ptc features.
  
  
  
  Peritubular capillaritis was detected in 50% (76% mononuclear ptc). Peritubular capillaritis scores 1, 2, and 3 were present in 36%, 55%, and 9%, and focal or diffuse ptc in 36% or 64%. Diffuse ptc was associated with DSA MFI_max (median: 4407 vs 2419 [focal ptc; P = 0.04] or 1946 [no ptc; P = 0.004]), cg (58% vs no ptc 24% [P = 0.02]), and higher CLS (mean: 6.81 vs 4.67 [focal ptc, P = 0.01] or 5.18 [no ptc, P = 0.001]), respectively. The association of ptc score of 2 or greater with cg was slightly better than with diffuse ptc. Diffuse ptc and ptc score of 2 or greater remained independently related to cg after adjusting for DSA_MFI_max, C4d, or previous rejection episodes, however lost their independent relation after adjusting for total microcirculation scores. Diffuse ptc was the only ptc characteristic independently related to CLS.
  
  
  
  Our results emphasize the clinical relevance of reporting diffuse ptc, which may relate to DSA binding strength and potentially to chronic graft injury.
authors.affiliation: 1 Institute of Clinical Pathology, Medical University Vienna, Vienna, Austria. 2 Division of Nephrology and Dialysis, Department of Medicine III, Medical University Vienna, Vienna, Austria. 3 Department of Emergency Medicine, Medical University Vienna, Vienna, Austria.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Kozakowski
authors.forename: Farsad
authors.initials: F
authors.lastname: Eskandary
authors.forename: Harald
authors.initials: H
authors.lastname: Herkner
authors.forename: Gregor
authors.initials: G
authors.lastname: Bond
authors.forename: Rainer
authors.initials: R
authors.lastname: Oberbauer
authors.forename: Heinz
authors.initials: H
authors.lastname: Regele
authors.forename: Georg A
authors.initials: GA
authors.lastname: Böhmig
authors.forename: Željko
authors.initials: Ž
authors.lastname: Kikić
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000378:metabolism; D001706:Biopsy; D002196:Capillaries / Q000276:immunology / Q000473:pathology*; D003430:Cross-Sectional Studies; D005260:Female; D006084:Graft Rejection / Q000276:immunology* / Q000473:pathology; D006680:HLA Antigens / Q000276:immunology*; D006801:Humans; D007518:Isoantibodies / Q000378:metabolism*; D016030:Kidney Transplantation; D007684:Kidney Tubules / Q000098:blood supply / Q000276:immunology / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D014657:Vasculitis / Q000276:immunology* / Q000473:pathology
chemical_list: D015415:Biomarkers; D006680:HLA Antigens; D007518:Isoantibodies