title: Antibody-mediated rejection in pediatric liver transplant recipients.
abstract: BACKGROUND
  Antibody-mediated rejection (AMR), associated with the presence of C4d deposits, is well-defined in kidney transplantation but much less documented in liver transplantation (LTx). The aim of our study was to retrospectively analyze a group of pediatric liver transplant recipients who experienced episodes of acute rejection in the past, for the signs of AMR and its impact on liver histology.
  
  
  METHODS
  Our study population consisted of 18 patients after living related donor liver transplantation with a history of acute cellular rejection (1-5/patient). In all of them, actual liver function was good at almost 2-year median follow-up after transplantation. We reassessed all liver biopsies taken from these children between 5 days to 5.7 years after transplantation for signs of acute cellular rejection and antibody-mediated rejection. In all patients, anti-HLA antibodies were also assessed at least 2 years after transplantation (2.18-12.27 years, median 6.795 years).
  
  
  RESULTS
  There were 27 episodes of acute rejection proved by liver biopsy. Signs of AMR were found in 6 of 18 patients (33.3%). In 5 of these patients, donor-specific (DSA) and non-specific anti-HLA antibodies were also identified. In the group of 12 patients with acute rejection without histochemical signs of AMR, anti-HLA antibodies were found in sera of only 5 of 12 patients after transplantation.
  
  
  CONCLUSIONS
  Our study shows some correlation between C4d-positive reaction in liver biopsies with acute cellular rejection and presence of anti-HLA antibodies, particularly against HLA class II. We did not find any difference in the late graft function, which could be correlated with the presence of AMR. Further studies on larger groups of patients are necessary.
authors.affiliation: Department of Pediatric Surgery and Organ Transplantation, Children's Memorial Health Institute, Warsaw, Poland.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Markiewicz-Kijewska
authors.affiliation: Department of Pediatric Surgery and Organ Transplantation, Children's Memorial Health Institute, Warsaw, Poland.
authors.forename: Piotr
authors.initials: P
authors.lastname: Kaliciński
authors.affiliation: Department of Pathology, Children's Memorial Health Institute, Warsaw, Poland.
authors.forename: Przemysław
authors.initials: P
authors.lastname: Kluge
authors.affiliation: Histocompatibility Laboratory, Children's Memorial Health Institute, Warsaw, Poland.
authors.forename: Barbara
authors.initials: B
authors.lastname: Piątosa
authors.affiliation: Histocompatibility Laboratory, Children's Memorial Health Institute, Warsaw, Poland.
authors.forename: Aneta
authors.initials: A
authors.lastname: Rękawek
authors.affiliation: Department of Gastroenterology, Hepatology and Feeding Disorder, Children's Memorial Health Institute, Warsaw, Poland.
authors.forename: Irena
authors.initials: I
authors.lastname: Jankowska
authors.affiliation: Histocompatibility Laboratory, Children's Memorial Health Institute, Warsaw, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Kostecka
authors.affiliation: Histocompatibility Laboratory, Children's Memorial Health Institute, Warsaw, Poland.
authors.forename: Przemysław Norbert
authors.initials: PN
authors.lastname: Kurowski
mesh_terms: D000208:Acute Disease; D001706:Biopsy; D002675:Child, Preschool; D015935:Complement C4b / Q000276:immunology; D005500:Follow-Up Studies; D006084:Graft Rejection / Q000188:drug therapy / Q000276:immunology* / Q000473:pathology; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D006801:Humans; D056724:Immunity, Humoral / Q000276:immunology*; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D007223:Infant; D007231:Infant, Newborn; D007518:Isoantibodies / Q000276:immunology*; D016031:Liver Transplantation / Q000009:adverse effects*; D019520:Living Donors; D010446:Peptide Fragments / Q000276:immunology; D012189:Retrospective Studies
chemical_list: D000949:Histocompatibility Antigens Class II; D007166:Immunosuppressive Agents; D007518:Isoantibodies; D010446:Peptide Fragments; D015935:Complement C4b; C032261:complement C4d