title: The prevalence and clinical significance of C1q-binding donor-specific anti-HLA antibodies early and late after kidney transplantation.
abstract: We aimed to determine the prevalence and clinical significance of complement-binding donor-specific antibodies (DSA) detected up to 30 years after kidney transplantation. Group 1 patients included 284 consecutive DSA negative patients who underwent kidney transplantation after 1 May 2009. Group 2 included 405 patients transplanted before this date and followed at our center with functioning allografts. DSA were tested using Luminex Single Antigen and the C1q assay. In Group 1 patients, who were monitored prospectively, 31 (11%) developed de novo DSA during a median follow-up of 2.5 (1.9, 3.6) years. Of these, 11 (4%) had C1q+ and 20 (7%) had C1q negative DSA. In Group 2 patients, 77 (19%) displayed DSA. Among these, 33 (8%) had C1q+ and 44 (11%) had C1q negative DSA. The incidence of acute antibody-mediated rejection (AMR) was significantly higher in C1q+DSA patients in both Group 1 (45%) and Group 2 (15%) compared with C1q negative DSA (5% and 2%) and DSA negative patients (1% and 3%; P < 0.001 and P = 0.001). The incidence of chronic AMR was 36% (Group 1) and 51% (Group 2) in patients with C1q+DSA. In contrast, chronic AMR occurred in 5% and 25% of C1q negative DSA, and 2% and 6% of DSA negative Group 1 and 2 patients, respectively (P < 0.001). Although the graft survival was lower in Group 1 C1q+DSA patients (73%) compared with C1q negative DSA (95%) and DSA negative (94%) patients, the difference was not statistically significant by Kaplan-Meier survival analysis (P = 0.21). Our results indicated that the presence of C1q+ DSA was associated with acute and chronic AMR.
authors.affiliation: Division of Nephrology, Albert Einstein College of Medicine, Bronx, New York, USA.
authors.forename: Sumeyye
authors.initials: S
authors.lastname: Calp-Inal
authors.affiliation: Division of Nephrology, Albert Einstein College of Medicine, Bronx, New York, USA; Montefiore-Einstein Center for Transplantation, Montefiore Medical Center, the University Hospital for Albert Einstein College of Medicine, Albert Einstein College of Medicine, Bronx, New York, USA.
authors.forename: Maria
authors.initials: M
authors.lastname: Ajaimy
authors.affiliation: Division of Nephrology, Albert Einstein College of Medicine, Bronx, New York, USA.
authors.forename: Michal L
authors.initials: ML
authors.lastname: Melamed
authors.affiliation: Montefiore-Einstein Center for Transplantation, Montefiore Medical Center, the University Hospital for Albert Einstein College of Medicine, Albert Einstein College of Medicine, Bronx, New York, USA; Transplant Immunology Laboratory, Albert Einstein College of Medicine, Bronx, New York, USA.
authors.forename: Christina
authors.initials: C
authors.lastname: Savchik
authors.affiliation: Montefiore-Einstein Center for Transplantation, Montefiore Medical Center, the University Hospital for Albert Einstein College of Medicine, Albert Einstein College of Medicine, Bronx, New York, USA; Transplant Immunology Laboratory, Albert Einstein College of Medicine, Bronx, New York, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Masiakos
authors.affiliation: Montefiore-Einstein Center for Transplantation, Montefiore Medical Center, the University Hospital for Albert Einstein College of Medicine, Albert Einstein College of Medicine, Bronx, New York, USA; Transplant Immunology Laboratory, Albert Einstein College of Medicine, Bronx, New York, USA.
authors.forename: Adriana
authors.initials: A
authors.lastname: Colovai
authors.affiliation: Division of Nephrology, Albert Einstein College of Medicine, Bronx, New York, USA; Montefiore-Einstein Center for Transplantation, Montefiore Medical Center, the University Hospital for Albert Einstein College of Medicine, Albert Einstein College of Medicine, Bronx, New York, USA. Electronic address: eakalin@montefiore.org.
authors.forename: Enver
authors.initials: E
authors.lastname: Akalin
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D064591:Allografts / Q000276:immunology*; D000906:Antibodies / Q000097:blood*; D002908:Chronic Disease; D015922:Complement C1q / Q000276:immunology*; D005260:Female; D005500:Follow-Up Studies; D006084:Graft Rejection / Q000453:epidemiology* / Q000276:immunology*; D006085:Graft Survival / Q000276:immunology; D006680:HLA Antigens / Q000276:immunology*; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D013997:Time Factors
chemical_list: D000906:Antibodies; D006680:HLA Antigens; D015922:Complement C1q
keywords: acute rejection; chronic allograft nephropathy; transplantation