Arias Cabrales, Carlos EnriqueRiera Oliva, MartaPérez-Sáez, María JoséGimeno Beltran, JavierBenito, DavidRedondo Pachón, María DoloresBurballa Tàrrega, Carla, 1988-Crespo Barrio, MartaPascual Santos, JulioRodríguez, Eva2021-09-082021-09-082020Arias-Cabrales CE, Riera M, Pérez-Sáez MJ, Gimeno J, Benito D, Redondo D, Burballa C, Crespo M, Pascual J, Rodríguez E. Activation of final complement components after kidney transplantation as a marker of delayed graft function severity. Clin Kidney J. 2020;14(4):1190-6. DOI: 10.1093/ckj/sfaa1472048-8505http://hdl.handle.net/10230/48410Background: Ischaemia-reperfusion (I/R) damage is a relevant cause of delayed graft function (DGF). Complement activation is involved in experimental I/R injury, but few data are available from kidney transplant (KT) patients. We studied the dynamics of membrane attack complex (C5b-9) as a soluble fraction (SC5b-9) and the histological deposit pattern of C3b, complement Factor H (FH) and C5b-9 in DGF patients. Methods: We evaluated SC5b-9 levels in 59 recipients: 38 with immediate graft function and 21 with DGF. The SC5b-9 was measured at admission for KT and 7 days after KT. DGF-kidney biopsies (n = 12) and a control group of 1-year protocol biopsies without tissue damage (n = 4) were stained for C5b-9, C3b and FH. Results: SC5b-9 increased significantly in DGF patients (Day 0: 6621 ± 2202 mAU/L versus Day 7: 9626 ± 4142 mAU/L; P = 0.006), while it remained stable in non-DGF patients. Days 0-7 increase >5% was the better cut-off associated with DGF versus non-DGF patient discrimination (sensitivity = 81%). In addition, SC5b-9 increase was related to DGF duration and worse graft function, and independently associated with DGF occurrence. SC5b-9, C3b and FH stains were observed in tubular epithelial cells basal membrane. DGF-kidney biopsies showed a more frequently high-intensity stain, a higher number of tubules with positive stain and larger perimeter of tubules with positive stains for SC5b-9, C3b and FH than control patients. Conclusions: Both SC5b-9 levels and SC5b-9, C3b and FH deposits in tubular epithelial cells basal membrane are highly expressed in patients experiencing DGF. SC5b-9 levels increase could be useful as a marker of DGF severity.application/pdfeng© The Author(s) 2020. Published by Oxford University Press on behalf of ERA-EDTA. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact journals.permissions@oup.cominfo:eu-repo/semantics/articlehttp://dx.doi.org/10.1093/ckj/sfaa147BiomarkersComplementDelayed graft functionKidney biopsyKidney transplantationinfo:eu-repo/semantics/openAccess