Renal tissue specimens

Kidney biopsies collected during and after renal transplantation between 2015 and 2020 from the Department of Nephrology at the FAU Erlangen-Nürnberg, Germany were included and did not contain tissues from prisoners. In total 28 FFPE carefully selected specimens of archived kidney biopsies (from the Department of Nephropathology, University Hospital, Erlangen, Germany) were used to evaluate the relevance of complement activation in patients with DGF (n = 6), ABMR (n = 7) and TCMR (n = 8) within the first 2.5 years. Biopsies from patients with borderline diagnosis or other co-morbidities like viral infection were excluded. Protocol biopsies from kidneys without signs of renal dysfunction or rejection, collected 12–14 months after renal transplantation, served as controls (n = 7). DGF was defined as impaired renal function necessitating dialysis within the first 10 days post transplantation and lack of rejection. The study groups and patients´ characteristics are described in Table 1 and BANFF scores are provided in details in a supplemental Table ¹.

Patient characteristics.

Ctrl = control, DGF = delayed graft function, TCMR = T-cell mediated rejection, ABMR = antibody-mediated rejection, eGFR = estimated glomerular filtration ratio (according to CKD-EPI equation), CAD = coronary artery disease, CIT = cold ischemia time, WIT = warm ischemia time, HLA = human leucocyte antigen; Ranges are stated as mean ± SD.