title: Peritubular capillary basement membrane changes in chronic renal allograft rejection: Comparison of light microscopic and ultrastructural observations.
abstract: Marked peritubular capillary basement membrane (PTCBM) multilayering, the ultrastructural feature of chronic antibody-mediated rejection (ABMR) of kidney allografts, was found to correspond histologically to PTCs with thickened BMs; such PTCs have been suggested as a novel histological marker of chronic rejection. We investigated whether scoring of PTCBM thickening can substitute the ultrastructural search for PTCBM multilayering. The thickening was graded in PAS- and Jones-stained sections in 110 biopsies from recipients with a late dysfunction, all examined ultrastructurally for transplant capillaropathy (≥3 PTCs with ≥5 BM layers). Grade 0 indicated no thickening. Grade 1 and grade 2 were assigned when the PTCBMs were as thick as or thicker than those of the non-atrophic tubules, and duplication/chain-like lamination of the PTCBM was noted in ≤3 or ≥4 high-power fields, respectively. The series was enrolled in subgroups of those with and those without histopathological lesions of chronic rejection. Fifty-six biopsies displayed lesions of chronic ABMR. Transplant capillaropathy was demonstrated in 40 biopsies. Grade 2 thickening furnished a substantial interobserver concordance rate (κ = 0.803) and correlated with the transplant capillaropathy. Jones staining performed somewhat better in scoring than PAS staining. Grade 2 thickening was verified in 35 biopsies involving chronic ABMR, and in one control biopsy (sensitivity 61.4%, specificity 0.98). Grade 1 thickening was not suggestive of chronic ABMR at all. In conclusion, grade 2 thickening can be regarded as the histopathological lesion of chronic ABMR; however, electron microscopy remains the gold standard in the assessment of PTCBM changes.
authors: Department of Pathology, University of Szeged, Allomas u. 2, 6720, Szeged, Hungary. ivanyi@patho.szote.u-szeged.hu
authors: Bela
authors: B
authors: Ivanyi
authors: Eva
authors: E
authors: Kemeny
authors: Peter
authors: P
authors: Rago
authors: Norbert
authors: N
authors: Lazar
authors: Krisztina
authors: K
authors: Boda
authors: Zita
authors: Z
authors: Morvay
authors: Pal
authors: P
authors: Szenohradszky
authors: Edit
authors: E
authors: Szederkenyi
mesh_terms: D001485:Basement Membrane / Q000473:pathology*; D001706:Biopsy; D002196:Capillaries / Q000473:pathology*; D002908:Chronic Disease; D015935:Complement C4b / Q000378:metabolism; D003928:Diabetic Nephropathies / Q000473:pathology; D006084:Graft Rejection / Q000473:pathology*; D006801:Humans; D007668:Kidney / Q000378:metabolism / Q000473:pathology; D016030:Kidney Transplantation; D007684:Kidney Tubules / Q000098:blood supply*; D008854:Microscopy, Electron; D012680:Sensitivity and Specificity; D013194:Staining and Labeling; D014184:Transplantation, Homologous
chemical_list: D015935:Complement C4b