title: Post-transplant recurrent hepatitis C: immunohistochemical detection of hepatitis C virus core antigen and possible pathogenic implications.
abstract: BACKGROUND
  The mechanisms by which severe cholestatic hepatitis develops after liver transplantation are not fully understood. Reports on immunohistochemical distribution of hepatitis C virus (HCV) antigens are still scarce, but recently, HCV immunostaining was suggested for early diagnosis of cholestatic forms of recurrent hepatitis C in liver grafts. After purification, Rb246 pab anticore (aa1-68) yielded specific, granular cytoplasmic staining in hepatocytes. Signal amplification through the Envision-Alkaline Phosphatase System avoided endogenous biotin and peroxidase.
  
  
  OBJECTIVE
  Rb246 was applied to liver samples of explants of 12 transplant recipients, six with the most severe form of post-transplantation recurrence, severe cholestatic hepatitis (group 1) and six with mild recurrence (group 2). We also assessed immuno-reactivity at two time-points post-transplantation (median 4 and 22 months) in both groups. HCV-core Ag was semiquantified from 0 to 3+ in each time point. Serum HCV-RNA was also measured on the different time points by branched DNA.
  
  
  RESULTS
  In the early post-transplant time point, one patient had a mild staining (1+), two patients had a moderate staining (2+) and the other three had no staining in group 1, compared with five patients with no staining (0) and one patient with mild staining (1+) in group 2. Late post-transplant liver samples were available in nine patients, and two out of four samples in group 1 showed a mild staining, compared with no staining patients in five patients in group 2. Strikingly, on the explant samples, HCV immunostaining was strongly positive in group 1, and mildly positive in group 2. Two out of five samples showed 3+ staining, and three samples showed 2+ staining in group 1; two out of five samples showed no staining, two samples showed 1+ staining and one sample showed 2+ staining in group 2. Serum HCV-RNA was significantly higher in group 1, on both time-points post-transplantation. HCV-core Ag was not directly associated with serum HCV-RNA on the different time points.
  
  
  CONCLUSIONS
  These preliminary results suggest that strong HCV immunostaining in the explant is predictive of more severe disease recurrence.
authors.affiliation: Department of Pathology, São Paulo University School of Medicine, São Paulo, Brazil. mgpessoa@uol.com.br
authors.forename: Mário G
authors.initials: MG
authors.lastname: Pessôa
authors.forename: Venancio A F
authors.initials: VA
authors.lastname: Alves
authors.forename: Alda
authors.initials: A
authors.lastname: Wakamatsu
authors.forename: Joaquim G
authors.initials: JG
authors.lastname: Gomes
authors.forename: Geert
authors.initials: G
authors.lastname: Maertens
authors.forename: Bart
authors.initials: B
authors.lastname: van der Borght
authors.forename: Michael
authors.initials: M
authors.lastname: Kim
authors.forename: Linda
authors.initials: L
authors.lastname: Ferrell
authors.forename: Teresa L
authors.initials: TL
authors.lastname: Wright
mesh_terms: D002780:Cholestasis, Intrahepatic / Q000473:pathology / Q000821:virology*; D016174:Hepacivirus / Q000235:genetics / Q000276:immunology / Q000472:pathogenicity*; D006526:Hepatitis C / Q000473:pathology / Q000821:virology*; D018936:Hepatitis C Antigens / Q000032:analysis; D006801:Humans; D007124:Immunoenzyme Techniques; D008099:Liver / Q000737:chemistry / Q000473:pathology / Q000821:virology; D017093:Liver Failure / Q000601:surgery / Q000821:virology; D016031:Liver Transplantation; D011183:Postoperative Complications; D012367:RNA, Viral / Q000097:blood; D012008:Recurrence; D014758:Viral Core Proteins / Q000032:analysis
chemical_list: D018936:Hepatitis C Antigens; D012367:RNA, Viral; D014758:Viral Core Proteins