Peritubular capillary basement membrane changes in chronic renal allograft rejection

• Published in: Virchows Archiv : an international journal of pathology Vol. 459; no. 3; p. 321
• Main Authors: Ivanyi, Bela, Kemeny, Eva, Rago, Peter, Lazar, Norbert, Boda, Krisztina, Morvay, Zita, Szenohradszky, Pal, Szederkenyi, Edit
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer Nature B.V 01.09.2011
• Subjects: Lesions
• ISSN: 0945-6317; 1432-2307
• DOI: 10.1007/s00428-011-1114-x

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.[PUBLICATION ABSTRACT]