title: Pathology of fatal human infection associated with avian influenza A H5N1 virus.
abstract: Eighteen cases of human influenza A H5N1 infection were identified in Hong Kong from May to December 1997. Two of the six fatal cases had undergone a full post-mortem which showed reactive hemophagocytic syndrome as the most prominent feature. Other findings included organizing diffuse alveolar damage with interstitial fibrosis, extensive hepatic central lobular necrosis, acute renal tubular necrosis and lymphoid depletion. Elevation of soluble interleukin-2 receptor, interleukin-6 and interferon-gamma was demonstrated in both patients, whereas secondary bacterial pneumonia was not observed. Virus detection using isolation, reverse transcription-polymerase chain reaction and immunostaining were all negative. It is postulated that in fatal human infections with this avian subtype, initial virus replication in the respiratory tract triggers hypercytokinemia complicated by the reactive hemophagocytic syndrome. These findings suggest that the pathogenesis of influenza A H5N1 infection might be different from that of the usual human subtypes H1-H3.
authors.affiliation: Department of Anatomical and Cellular Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong SAR, China.
authors.forename: K F
authors.initials: KF
authors.lastname: To
authors.forename: P K
authors.initials: PK
authors.lastname: Chan
authors.forename: K F
authors.initials: KF
authors.lastname: Chan
authors.forename: W K
authors.initials: WK
authors.lastname: Lee
authors.forename: W Y
authors.initials: WY
authors.lastname: Lam
authors.forename: K F
authors.initials: KF
authors.lastname: Wong
authors.forename: N L
authors.initials: NL
authors.lastname: Tang
authors.forename: D N
authors.initials: DN
authors.lastname: Tsang
authors.forename: R Y
authors.initials: RY
authors.lastname: Sung
authors.forename: T A
authors.initials: TA
authors.lastname: Buckley
authors.forename: J S
authors.initials: JS
authors.lastname: Tam
authors.forename: A F
authors.initials: AF
authors.lastname: Cheng
mesh_terms: D000293:Adolescent; D000328:Adult; D001853:Bone Marrow / Q000473:pathology; D016207:Cytokines / Q000097:blood; D004196:Disease Outbreaks; D017809:Fatal Outcome; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D053124:Influenza A Virus, H5N1 Subtype; D009980:Influenza A virus / Q000302:isolation & purification; D007251:Influenza, Human / Q000453:epidemiology / Q000473:pathology* / Q000821:virology*; D008168:Lung / Q000473:pathology; D008221:Lymphoid Tissue / Q000473:pathology; D011180:Postmortem Changes
chemical_list: D016207:Cytokines