title: Long term immune responses to pandemic influenza A/H1N1 infection in solid organ transplant recipients.
abstract: In solid organ transplant (SOT) recipients it is unknown if natural infection with influenza confers protection from re-infection with the same strain during the next influenza season. The purpose of this study was to determine if infection with pandemic influenza A/H1N1 (pH1N1) resulted in a long-term immunologic response. Transplant recipients with microbiologically proven pH1N1 infection in 2009/2010 underwent humoral and cell-mediated immunity (CMI) testing for pH1N1 just prior to the next influenza season. Concurrent testing for A/Brisbane/59/2007 was done to rule-out cross-reacting antibody. We enrolled 22 adult transplant patients after pH1N1 infection. Follow up testing was done at a median of 7.4 months (range 5.8-15.4) after infection. After excluding those with cross-reactive antibody, 7/19 (36.8%) patients were seroprotected. Detectable pH1N1-specific CD4+ and CD8+ interferon-γ producing T-cells were found in 11/22 (50%) and 8/22 (36.4%) patients respectively. Humoral immunity had a significant correlation with a CD4 response. This is the first study in transplant patients to evaluate long-term humoral and cellular response after natural influenza infection. We show that a substantial proportion of SOT recipients with previous pH1N1 infection lack long-term humoral and cellular immune responses to pH1N1. These patients most likely are at risk for re-infection.
authors.affiliation: Alberta Institute of Transplant Sciences, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Aliyah
authors.initials: A
authors.lastname: Baluch
authors.forename: Atul
authors.initials: A
authors.lastname: Humar
authors.forename: Adrian
authors.initials: A
authors.lastname: Egli
authors.forename: Jonathan
authors.initials: J
authors.lastname: Gubbay
authors.forename: Luiz
authors.initials: L
authors.lastname: Lisboa
authors.forename: Leticia
authors.initials: L
authors.lastname: Wilson
authors.forename: Deepali
authors.initials: D
authors.lastname: Kumar
mesh_terms: D000328:Adult; D000368:Aged; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D015331:Cohort Studies; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007111:Immunity, Cellular / Q000276:immunology*; D056724:Immunity, Humoral / Q000276:immunology*; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology*; D007251:Influenza, Human / Q000453:epidemiology* / Q000276:immunology* / Q000821:virology; D007371:Interferon-gamma / Q000276:immunology; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D058873:Pandemics; D013045:Species Specificity; D013997:Time Factors; D019737:Transplants / Q000821:virology*
chemical_list: D007371:Interferon-gamma