title: The accumulation of regulatory T cells in the hepatic hilar lymph nodes in biliary atresia.
abstract: OBJECTIVE
  A proposed etiopathogenesis of biliary atresia (BA) involves T-cell-mediated inflammatory bile duct damage and progressive hepatic fibrosis. Pediatric surgeons often observe swelling of the hepatic hilar lymph nodes during the Kasai procedure. Given the importance of regulatory mechanisms in immune responses, the present study was designed to analyze the quantitative changes of regulatory T cells (Tregcells) in the hepatic hilar lymph nodes (hepatic hilar LNs) and peripheral blood (PB) in BA.
  
  
  METHODS
  The hepatic hilar LNs and PB obtained during the Kasai procedure were analyzed by flow cytometry. The ratios of total and active Tregs to the total CD4+cells in the PB and the hepatic hilar LNs were compared.
  
  
  RESULTS
  In patients with BA, the ratios of both the total and active Tregcells in the hepatic hilar LNs were higher than those in the PB (total Tregcells: PB vs. LN; P < 0.001; active Tregcells: PB vs. LN; P = 0.001). In BA patients, the increase in the ratio of active Tregcells to the CD4 + cells in the LNs in comparison to the PB was greater than that in control patients. The ratio observed in the BA patients was almost double the ratio observed in the control patients. The median LN/PB ratio in the BA patients was 3.1, while that in controls was 1.6 (P = 0.03).
  
  
  CONCLUSIONS
  The present study showed that the ratios of both total Tregcells and active Tregcells were higher in the hepatic hilar lymph nodes of BA patients. This finding could shed light on the pathogenesis of BA.
authors.affiliation: Department of Pediatric Surgery, University of Tsukuba, 2-1-1 Amakubo, Tsukuba, Ibaraki, 305-8576, Japan. nsakamoto1125@yahoo.co.jp.
authors.forename: Naoya
authors.identifier: http://orcid.org/0000-0001-6423-6918
authors.initials: N
authors.lastname: Sakamoto
authors.affiliation: Department of Pediatric Surgery, Ibaraki Children's Hospital, 3-1-1 Futabadai, Mito, Ibaraki, 311-4145, Japan.|, 3320 Hayato-cho Matsunaga, Kirishima, Kagoshima, 899-5112, Japan.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Muraji
authors.affiliation: Department of Pathology, Mito Saiseikai General Hospital, 3-3-10 Futabadai, Mito, Ibaraki, 311-4198, Japan.|Department of Pathology, Ibaraki Children's Hospital, Mito, Japan.
authors.forename: Haruo
authors.initials: H
authors.lastname: Ohtani
authors.affiliation: Department of Pediatric Surgery, University of Tsukuba, 2-1-1 Amakubo, Tsukuba, Ibaraki, 305-8576, Japan.
authors.forename: Kouji
authors.initials: K
authors.lastname: Masumoto
mesh_terms: D000293:Adolescent; D001652:Bile Ducts / Q000276:immunology / Q000473:pathology; D001656:Biliary Atresia / Q000097:blood / Q000209:etiology* / Q000276:immunology / Q000473:pathology; D015496:CD4-Positive T-Lymphocytes; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008099:Liver / Q000276:immunology* / Q000473:pathology*; D008198:Lymph Nodes / Q000276:immunology* / Q000473:pathology*; D008297:Male; D011171:Portoenterostomy, Hepatic; D011446:Prospective Studies; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000473:pathology*
keywords: Biliary atresia; Hepatic hilar lymph nodes; Lymphadenopathy; Regulatory T cell