title: Intragraft expression of recipient-type ABO blood group antigens: long-term follow-up and histological features after liver transplantation.
abstract: Several reports have shown detection of recipient-type ABO histo-blood group antigens (r-ABOAg) in the liver allograft, which may represent either true intragraft chimerism or other events such as cell injury. Little is known about factors that affect the timing and extent of r-ABOAg expression in the graft. We examined 65 recipients who underwent ABO nonidentical living donor liver transplantation (61 compatible, 4 incompatible). Ninety-seven postoperative specimens (71 episode biopsies, 16 protocol biopsies, and 10 explanted allografts) were available for evaluation with immunohistochemistry of ABH blood type antigens. The expression of r-ABOAg was assessed in relation to histological and clinical factors. Capillaries in the portal tracts were the primary sites of r-ABOAg expression. The percentage of specimens showing r-ABOAg expression increased with lengthening of the post-transplantation period. Only 1 (4%) of 28 specimens showed endothelium with r-ABOAg within 1 year after the procedure, but 10 (29%) of 35 did between 1 and 5 years after transplantation and 21 (62%) of 34 after more than 5 years. Proportional analysis found that chronic rejection was a significant factor (P = 0.006) for any r-ABOAg expression in the capillaries, and allograft portal fibrosis was a significant predictive factor for extensive r-ABOAg expression (seen in more than one third of the portal tracts) in the capillaries (P = 0.017). Sex mismatch, age of recipients, age of donors, graft/recipient body weight ratio, and histology other than chronic rejection and fibrosis did not correlate with the expression of r-ABOAg. In conclusion, these observations suggest that portal capillaries with r-ABOAg are the results of graft injury and repair, and some of them may be neovessels of recipient origin.
authors.affiliation: Laboratory of Anatomic Pathology, Kyoto University Hospital, Kyoto, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Hironori
authors.initials: H
authors.lastname: Haga
authors.forename: Hiroto
authors.initials: H
authors.lastname: Egawa
authors.forename: Tomoko
authors.initials: T
authors.lastname: Okuno
authors.forename: Aya
authors.initials: A
authors.lastname: Miyagawa-Hayashino
authors.forename: Tatsuaki
authors.initials: T
authors.lastname: Tsuruyama
authors.forename: Michiyo
authors.initials: M
authors.lastname: Kambe
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Marusawa
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Chiba
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Manabe
mesh_terms: D000017:ABO Blood-Group System / Q000276:immunology*; D000293:Adolescent; D000328:Adult; D001706:Biopsy; D001788:Blood Grouping and Crossmatching; D002648:Child; D002675:Child, Preschool; D041322:Chromosomes, Human, Y; D004730:Endothelium, Vascular / Q000276:immunology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D007223:Infant; D007231:Infant, Newborn; D008099:Liver / Q000166:cytology* / Q000276:immunology*; D016031:Liver Transplantation / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D014184:Transplantation, Homologous
chemical_list: D000017:ABO Blood-Group System