BackgroundA better understanding of the quality of cellular immune responses directed against molecularly defined targets will guide the development of TB diagnostics and identification of molecularly defined, clinically relevant M.tb vaccine candidates.MethodsRecombinant proteins (n = 8) and peptide pools (n = 14) from M. tuberculosis (M.tb) targets were used to compare cellular immune responses defined by IFN-γ and IL-17 production using a Whole Blood Assay (WBA) in a cohort of 148 individuals, i.e. patients with TB + (n = 38), TB- individuals with other pulmonary diseases (n = 81) and individuals exposed to TB without evidence of clinical TB (health care workers, n = 29).ResultsM.tb antigens Rv2958c (glycosyltransferase), Rv2962c (mycolyltransferase), Rv1886c (Ag85B), Rv3804c (Ag85A), and the PPE family member Rv3347c were frequently recognized, defined by IFN-γ production, in blood from healthy individuals exposed to M.tb (health care workers). A different recognition pattern was found for IL-17 production in blood from M.tb exposed individuals responding to TB10.4 (Rv0288), Ag85B (Rv1886c) and the PPE family members Rv0978c and Rv1917c.ConclusionsThe pattern of immune target recognition is different in regard to IFN-γ and IL-17 production to defined molecular M.tb targets in PBMCs from individuals frequently exposed to M.tb. The data represent the first mapping of cellular immune responses against M.tb targets in TB patients from Honduras.

BackgroundPrevious exposures to flu and subsequent immune responses may impact on 2009/2010 pandemic flu vaccine responses and clinical symptoms upon infection with the 2009 pandemic H1N1 influenza strain. Qualitative and quantitative differences in humoral and cellular immune responses associated with the flu vaccination in 2009/2010 (pandemic H1N1 vaccine) and natural infection have not yet been described in detail. We designed a longitudinal study to examine influenza- (flu-) specific immune responses and the association between pre-existing flu responses, symptoms of influenza-like illness (ILI), impact of pandemic flu infection, and pandemic flu vaccination in a cohort of 2,040 individuals in Sweden in 2009–2010.MethodsCellular flu-specific immune responses were assessed by whole-blood antigen stimulation assay, and humoral responses by a single radial hemolysis test.ResultsPrevious seasonal flu vaccination was associated with significantly lower flu-specific IFN-γ responses (using a whole-blood assay) at study entry. Pandemic flu vaccination induced long-lived T-cell responses (measured by IFN-γ production) to influenza A strains, influenza B strains, and the matrix (M1) antigen. In contrast, individuals with pandemic flu infection (PCR positive) exhibited increased flu-specific T-cell responses shortly after onset of ILI symptoms but the immune response decreased after the flu season (spring 2010). We identified non-pandemic-flu vaccinated participants without ILI symptoms who showed an IFN-γ production profile similar to pandemic-flu infected participants, suggesting exposure without experiencing clinical symptoms.ConclusionsStrong and long-lived flu-M1 specific immune responses, defined by IFN-γ production, in individuals after vaccination suggest that M1-responses may contribute to protective cellular immune responses. Silent flu infections appeared to be frequent in 2009/2010. The pandemic flu vaccine induced qualitatively and quantitatively different humoral and cellular immune responses as compared to infection with the 2009 H1N1 pandemic H1N1 influenza strain.

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Helicobacter pylori es un colonizador ávido de la mucosa gástrica del ser humano. Las infecciones por H. pylori son usualmente asintomáticas y adquiridas en la niñez por lo cual tienden a progresar hacia cronicidad generando un daño tisular severo; por ello es relevante caracterizar diversos grupos poblacionales y vigilar epidemiológicamente la distribución de casos. Se realizó un proceso educativo de prevención de enfermedades gastrointestinales enlistando 60 niños entre 8 y 12 años en una escuela de la ciudad de Tegucigalpa, Honduras. Previo asentimiento informado, 45 escolares respondieron una encuesta para obtener datos demográficos, clínicos, ambientales y sociales. Asimismo, accedieron a colectar y entregar una muestra fecal. Se realizó un método inmunocromatográfico para determinar coproantígenos de H. pylori y se analizó estadísticamente la asociación entre infección por H. pylori, variables socioeconómicas y clínicas. Se detectaron coproantígenos de H. pylori en 29% de la población escolar estudiada, los cuales no mostraron sintomatología gastrointestinal severa o complicaciones. La prevalencia de infección aumenta con la edad de los escolares. No se encontró ninguna asociación estadística significativa entre la infección y las variables analizadas; no obstante, la prevalencia de portadores asintomáticos entre escolares pone en perspectiva el desarrollo de programas de vigilancia, así como estudios prospectivos con intervalos de seguimiento diagnóstico y clínico para prevenir oportunamente complicaciones tempranas y tardías. Palabras clave: H. pylori, Diagnostico, Epidemiología, Escolares