title: Pathological study of archival lung tissues from five fatal cases of avian H5N1 influenza in Vietnam.
abstract: Highly pathogenic avian H5N1 influenza virus (H5N1) infection in humans causes acute respiratory distress syndrome, leading to multiple organ failure. Five fatal cases of H5N1 infection in Vietnam were analyzed pathologically to reveal virus distribution, and local proinflammatory cytokine and chemokine expression profiles in formalin-fixed, paraffin-embedded lung tissues. Our main histopathological findings showed diffuse alveolar damage in the lungs. The infiltration of myeloperoxidase-positive and/or CD68 (clone KP-1)-positive neutrophils and monocytes/macrophages was remarkable in the alveolar septa and alveolar spaces. Immunohistochemistry revealed that H5N1 mainly infected alveolar epithelial cells and monocytes/macrophages in lungs. H5N1 replication was confirmed by detecting H5N1 mRNA in epithelial cells using in situ hybridization. Quantitation of H5N1 RNA using quantitative reverse transcription PCR assays revealed that the level of H5N1 RNA was increased in cases during early phases of the disease. We quantified the expression of tumor necrosis factor-alpha (TNF-α), interleukin (IL)-6, IL-8, regulated on activation normal T-cell expressed and secreted (commonly known as RANTES), and interferon-gamma-inducible protein of 10 kDa (IP-10) in formalin-fixed, paraffin-embedded lung sections. Their expression levels correlated with H5N1 RNA copy numbers detected in the same lung region. Double immunofluorescence staining revealed that TNF-α, IL-6, IL-8 and IP-10 were expressed in epithelial cells and/or monocytes/macrophages. In particular, IL-6 was also expressed in endothelial cells. The dissemination of H5N1 beyond respiratory organs was not confirmed in two cases examined in this study.
authors.affiliation: Department of Pathology, National Institute of Infectious Diseases, Shinjuku, Tokyo, Japan. tenko@nih.go.jp
authors.forename: Noriko
authors.initials: N
authors.lastname: Nakajima
authors.forename: Ngo
authors.initials: N
authors.lastname: Van Tin
authors.forename: Yuko
authors.initials: Y
authors.lastname: Sato
authors.forename: Hoang Ngoc
authors.initials: HN
authors.lastname: Thach
authors.forename: Harutaka
authors.initials: H
authors.lastname: Katano
authors.forename: Pho Hong
authors.initials: PH
authors.lastname: Diep
authors.forename: Toshio
authors.initials: T
authors.lastname: Kumasaka
authors.forename: Nguyen Trung
authors.initials: NT
authors.lastname: Thuy
authors.forename: Hideki
authors.initials: H
authors.lastname: Hasegawa
authors.forename: Luong Thi
authors.initials: LT
authors.lastname: San
authors.forename: Shoji
authors.initials: S
authors.lastname: Kawachi
authors.forename: Nguyen Thanh
authors.initials: NT
authors.lastname: Liem
authors.forename: Kazuo
authors.initials: K
authors.lastname: Suzuki
authors.forename: Tetsutaro
authors.initials: T
authors.lastname: Sata
mesh_terms: D056809:Alveolar Epithelial Cells / Q000276:immunology / Q000473:pathology / Q000821:virology; D015703:Antigens, CD / Q000032:analysis; D015214:Antigens, Differentiation, Myelomonocytic / Q000032:analysis; D015415:Biomarkers / Q000032:analysis; D018925:Chemokines / Q000032:analysis / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D016207:Cytokines / Q000032:analysis / Q000235:genetics; D017809:Fatal Outcome; D005260:Female; D005404:Fixatives; D005455:Fluorescent Antibody Technique; D005557:Formaldehyde; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D018836:Inflammation Mediators / Q000032:analysis; D053124:Influenza A Virus, H5N1 Subtype / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity; D007251:Influenza, Human / Q000235:genetics / Q000276:immunology / Q000473:pathology* / Q000821:virology; D008168:Lung / Q000276:immunology / Q000473:pathology* / Q000821:virology; D008264:Macrophages / Q000276:immunology / Q000473:pathology / Q000821:virology; D008297:Male; D009504:Neutrophils / Q000276:immunology / Q000473:pathology / Q000821:virology; D016612:Paraffin Embedding; D009195:Peroxidase / Q000032:analysis; D012333:RNA, Messenger / Q000032:analysis; D012367:RNA, Viral / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016707:Tissue Fixation / Q000379:methods; D014744:Vietnam; D019562:Viral Load; D000097382:CD68 Molecule
chemical_list: D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D015415:Biomarkers; D018925:Chemokines; D016207:Cytokines; D005404:Fixatives; D005557:Formaldehyde; D018836:Inflammation Mediators; D009195:Peroxidase; D012333:RNA, Messenger; D012367:RNA, Viral; C067980:CD68 antigen, human; D000097382:CD68 Molecule