title: Assessment of markers of the cell-mediated immune response after influenza virus infection in frail older adults.
abstract: The purpose of this study was to determine whether measures of the cell-mediated immune response to influenza virus could be used as markers of influenza virus infection. We studied 23 subjects who developed upper respiratory, lower respiratory, or systemic symptoms during a small outbreak of influenza in a nursing home population. Influenza virus culture from nasopharyngeal swabs yielded influenza virus isolates from 7 of the 23 subjects. Only three of the subjects had a fourfold rise in antibody titer to the influenza virus antigen positivity after the infection. Granzyme B and cytokine levels were measured in peripheral blood mononuclear cells (PBMC) obtained from all subjects and stimulated with live influenza virus. Elevated granzyme B levels in virus-stimulated PBMC in combination with lower respiratory tract or systemic symptoms in study subjects was a significant predictor of culture-confirmed influenza virus infection compared to those from whom influenza virus could not be identified. Cytokine levels did not distinguish between the two groups in a similar type of analysis. Granzyme B in combination with the clinical profile of symptoms may be a useful retrospective marker for influenza virus infection.
authors.affiliation: Division of Geriatric Medicine, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada. jmcelhan@cha.ab.ca
authors.forename: J E
authors.initials: JE
authors.lastname: McElhaney
authors.forename: S
authors.initials: S
authors.lastname: Gravenstein
authors.forename: P
authors.initials: P
authors.lastname: Krause
authors.forename: J W
authors.initials: JW
authors.lastname: Hooton
authors.forename: C M
authors.initials: CM
authors.lastname: Upshaw
authors.forename: P
authors.initials: P
authors.lastname: Drinka
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000914:Antibodies, Viral / Q000097:blood; D015415:Biomarkers; D016207:Cytokines / Q000097:blood; D004196:Disease Outbreaks; D005260:Female; D016330:Frail Elderly; D053804:Granzymes; D006801:Humans; D007111:Immunity, Cellular; D009980:Influenza A virus / Q000276:immunology* / Q000302:isolation & purification; D009981:Influenza B virus / Q000276:immunology; D007252:Influenza Vaccines / Q000276:immunology; D007251:Influenza, Human / Q000453:epidemiology / Q000276:immunology* / Q000821:virology; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D009305:Nasopharynx / Q000821:virology; D009735:Nursing Homes; D010614:Pharynx / Q000821:virology; D012697:Serine Endopeptidases / Q000097:blood
chemical_list: D000914:Antibodies, Viral; D015415:Biomarkers; D016207:Cytokines; D007252:Influenza Vaccines; C509213:GZMB protein, human; D053804:Granzymes; D012697:Serine Endopeptidases