Peritubular capillary basement membrane multilayering in early and advanced transplant glomerulopathy: quantitative parameters and diagnostic aspects.
The ultrastructural quantitative aspects of peritubular capillary basement membrane multilayering (PTCBML) were examined in 57 kidney transplant biopsies with transplant glomerulopathy (TG). The measurements included three cutoffs [permissive: 1 PTC with 5 basement membrane (BM) layers, intermediate: 3 PTCs with 5 layers or 1 PTC with 7 layers, strict: 1 PTC with 7 layers and 2 PTCs with 5 layers] and the mean number of BM layers (PTCcirc). Two groups were assigned, namely patients with mild TG (Banff cg1a and cg1b) and those with moderate-to-severe TG (cg2 and cg3). Their respective clinical, serological, and morphological characteristics were then compared. The clinical data revealed that mild TG corresponded to early chronic antibody-mediated rejection (cABMR), while moderate-to-severe TG corresponded to the advanced stage of the disease. The permissive threshold displayed the lowest specificity (73 %) and the highest sensitivity (83 %) for moderate-to-severe TG, and its corresponding PTCcircvalue was 3 layers. In contrast, the strict threshold-adopted by the Banff 2013 classification-displayed a specificity and sensitivity of 93 and 52 %, respectively, and the corresponding PTCcircwas 4 layers. In mild TG, 26 % of the cases met the permissive cutoff and 6 % the strict cutoff. Mild TG was associated with a lower PTCcirc(2.6 layers vs 4.5 layers in moderate-to-severe TG; p < 0.0001). Amongst the various criteria, the permissive criterion was associated most frequently with mild TG, and had prognostic relevance. Because of this, we propose its usage as a marker of early cABMR-induced PTCBML if non-alloimmune causes of PTCBML can be ruled out.
Department of Pathology, Faculty of Medicine, University of Szeged, Állomás utca 1, Szeged, H-6725, Hungary. dobi.dejan@med.u-szeged.hu.
Deján
D
Dobi
Department of Pathology, Faculty of Medicine, University of Szeged, Állomás utca 1, Szeged, H-6725, Hungary.
Zsolt
Z
Bodó
Department of Pathology, Faculty of Medicine, University of Szeged, Állomás utca 1, Szeged, H-6725, Hungary.
Éva
É
Kemény
Department of Pathology, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98, Debrecen, H-4012, Hungary.
László
L
Bidiga
Department of Surgery, Faculty of Medicine, University of Szeged, Szőkefalvi-Nagy u. 6, Szeged, H-6720, Hungary.
Zoltán
Z
Hódi
Department of Surgery, Faculty of Medicine, University of Szeged, Szőkefalvi-Nagy u. 6, Szeged, H-6720, Hungary.
Pál
P
Szenohradszky
Department of Surgery, Faculty of Medicine, University of Szeged, Szőkefalvi-Nagy u. 6, Szeged, H-6720, Hungary.
Edit
E
Szederkényi
Transplantation Immunogenetics Laboratory, Hungarian National Blood Transfusion Service, Karolina út 19-21, Budapest, H-1113, Hungary.
Anikó
A
Szilvási
Department of Pathology, Faculty of Medicine, University of Szeged, Állomás utca 1, Szeged, H-6725, Hungary.
Béla
B
Iványi
D001485:Basement Membrane / Q000473:pathology*; D001706:Biopsy; D002196:Capillaries / Q000473:pathology; D002908:Chronic Disease; D015935:Complement C4b / Q000378:metabolism; D005260:Female; D006084:Graft Rejection / Q000175:diagnosis / Q000473:pathology*; D006801:Humans; D007674:Kidney Diseases / Q000473:pathology* / Q000628:therapy; D016030:Kidney Transplantation / Q000379:methods; D008297:Male; D014184:Transplantation, Homologous
D015935:Complement C4b
Chronic antibody-mediated rejection; Peritubular capillaries; Renal transplantation