Immuno-epidemiologic correlates of pandemic H1N1 surveillance observations: higher antibody and lower cell-mediated immune responses with advanced age.
J Infect Dis
; 203(2): 158-67, 2011 Jan 15.
Article
em En
| MEDLINE
| ID: mdl-21288814
ABSTRACT
BACKGROUND:
Pandemic H1N1 (pH1N1) surveillance data showed lower attack rates but higher risk of severe outcomes with advanced age. We explored immuno-epidemiologic correlates of surveillance findings including humoral and cell-mediated immunity (CMI).METHODS:
In an age-based design, â¼100 banked/residual sera per 10-year age stratum were assessed by hemagglutination inhibition (HI) and microneutralization (MN) assays for preexisting antibody to pH1N1 and recent seasonal H1N1 and H3N2 strains. In a separate birth cohort design defined by childhood influenza A/subtype priming (1919-1929 H1N1; 1945-1949 H1N1; 1958-1960 H2N2; 1969-1970 H3N2; 1978-1989 H3N2/H1N1), whole blood was collected from up to 50 volunteers per birth cohort. The ratio of Th1(IFN-γ)Th2(IL-10) cytokine responses was evaluated in vitro.RESULTS:
Antibody to seasonal viruses was highest in school-age children. Cross-reactive HI/MN antibody to pH1N1 was low among participants <70 years of age (yoa; 6%/4% ≥ 40), but seroprevalence increased at 70-79 yoa (27%/6%), increased even more at 80-89 yoa (65%/47%), and was highest at ≥90 yoa (88%/76%). CMI to pH1N1 was evident in all 5 birth cohorts but was lower compared with seasonal strains. There was little differentiation by subtype priming, but the Th1Th2 ratio for all viruses dropped significantly in the 2 oldest cohorts.CONCLUSIONS:
Preexisting antibody may have protected the very old from pH1N1 infection, while diminished CMI may have contributed to greater severity once infected. In the young, cross-reactive pH1N1 antibody was mostly absent, while more intact CMI may have protected against severe outcomes.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Linfócitos
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Influenza Humana
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Vírus da Influenza A Subtipo H1N1
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Anticorpos Antivirais
Tipo de estudo:
Screening_studies
Limite:
Adolescent
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Adult
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Aged
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Aged80
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Child
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Child, preschool
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Female
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Humans
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Infant
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Male
Idioma:
En
Revista:
J Infect Dis
Ano de publicação:
2011
Tipo de documento:
Article