Dynamic of Immune Response induced in Hepatitis B Surface Antigen-transgenic Mice Immunized with a Novel Therapeutic Formulation.

The development of therapeutic vaccines against chronic hepatitis B requires the capacity of the formulation to subvert a tolerated immune response as well as the evaluation of histopathological damage resulting from the treatment. In the present study, the dynamicity of induced immune response to hepatitis B surface antigen (HBsAg) was evaluated in transgenic mice that constitutively express the HBsAg gene (HBsAg-tg mice). After immunization with a vaccine candidate containing both surface (HBsAg) and core (HBcAg) antigens of hepatitis B virus (HBV), the effect of vaccination on clearance of circulating HBsAg and the potential histological alterations were examined. Transgenic (tg) and non-transgenic (Ntg) mice were immunized by intranasal (IN) and subcutaneous (SC) routes simultaneously. A control group received phosphate-buffered saline (PBS) by IN route and aluminum by SC route. Positive responses, at both humoral and cellular levels, were obtained after five immunizations in HBsAg-tg mice. Such responses were delayed and of lower intensity in tg mice, compared to vaccinated Ntg mice. Serum IgG response was characterized by a similar IgG subclass pattern. Even when HBsAg-specific CD8+ T cell responses were clearly detectable by gamma-interferon ELISPOT assay, histopathological alterations were not detected in any organ, including the liver and kidneys. Our study demonstrated, that it is possible to subvert the immune tolerance against HBsAg in tg mice, opening a window for new studies to optimize the schedule, dose, and formulation to improve the immune response to the therapeutic vaccine candidate. These results can be considered a safety proof to support clinical developments for the formulation under study. HOW TO CITE THIS ARTICLE: Freyre FM, Blanco A, Trujillo H, Hernández D, García D, Alba JS, Lopez M, Merino N, Lobaina Y, Aguilar JC. Dynamic of Immune Response induced in Hepatitis B Surface Antigen-transgenic Mice Immunized with a Novel Therapeutic Formulation. Euroasian J Hepato-Gastroenterol 2016;6(1):25-30.

Cuatro métodos de predicción de riesgo de infección bacteriana grave en recién nacidos febriles / Four methods to predict the severe bacterial infection risk in the febrile newborns

INTRODUCCIÓN. El objetivo de esta investigación fue contrastar la efectividad de 4 mÚtodos de evaluación de riesgo de infección bacteriana grave (IBG) en recién nacidos (RN) febriles, uno de los cuales fue desarrollado por los autores del trabajo y los otros son los utilizados en la práctica internacional. MÉTODOS. Se realizó un estudio descriptivo, retrospectivo y aplicado de 1358 RN febriles sin signos de focalización evaluados y clasificados por riesgo de IBG. Fue aplicado el método propuesto por los autores, que comprende: antecedente de ser sano; ausencia de impresión médica de un estado tóxico-infeccioso; ausencia de evidencias de infección focal en el examen físico; fiebre menor de 39 ºC y no persistente o recurrente; recuento de leucocitos sanguíneos > 5,0 x 10(9)/L y < 20,0 x 10(9)/L; velocidad de sedimentación globular < 20 mm/h y recuento de leucocitos en orina < 10 000/mL. Éste y los otros métodos se aplicaron en una evaluación inicial y al término de 48 h evolutivas. Se calcularon los valores predictivos para los distintos métodos y se evaluó también la efectividad mediante la función de ganancia. RESULTADOS. La frecuencia de IBG fue del 20,4 por ciento. La causa más frecuente fue la infección del tracto urinario. De los 652 RN evaluados inicialmente por nuestro método, hubo cambio de categoría evolutiva en 177 (13,0 por ciento); con los otros métodos también ocurrieron cambios, menos notables. Los fallos de los valores predictivos con nuestro método fueron 40 (8,5 por ciento), una proporción significativamente menor (p < 0,001) que con los otros métodos. La función de ganancia tuvo valores aritméticos superiores con los otros métodos. CONCLUSIONES. Existe un mayor margen de seguridad con nuestro método en relación con los otros métodos de evaluación estudiados…

INTRODUCTION. The aim of present research was to contrast the effectiveness of four assessment methods of severe bacterial infection risk (SBI) in febrile newborns (NB) , one of above mentioned methods was developed by paper's authors and the other are used in the international practice. METHODS. A retrospective and descriptive study was conducted and applied in 1358 febrile NB with no focalization signs and classified according to the SBI. The method proposed by authors was applied including a history of be healthy, lack of medical criterion of a infectious-toxic state, lack of evidences of focal infection in physical examination, fever lower than 39ºC and no persistent or recurrent, blood leucocytes count >5,0 x 10(9)/L and < 20,0 x 10(9)/L, globular sedimentation speed <20 mm/h and urine leucocyte count <10 000/mL. This method and the other were applied in a initial assessment and at the end of the evolution 48 h. The predictive values were estimated for the different methods and also the effectiveness was assessed according to the gain function. RESULTS. The SBI was of 20,4 percent. The more frequent cause was the urinary tract infection. From the 652 NB initially assessed by our method there was a change of evolution category in 177 (13,0 percent) with the other methods also there were less marked changes. The failures of predictive values using our method were 40 (8,5 percent), a ratio significantly lower (p<0.001) than with the other methods. The gain function had higher arithmetic values with the other methods. CONCLUSIONS. There is a greater margin of safe with our method in relation to the other study assessment methods. This advantage is attributed to the inclusion of clinical and laboratory assessing parameters (the magnitude and persistence of fever and the toxic-infectious feature) that may to change the febrile NB category in the scale, although we must to point out that all methods had prediction errors due to its own probability nature

Cuatro métodos de predicción de riesgo de infección bacteriana grave en recién nacidos febriles / Four methods to predict the severe bacterial infection risk in the febrile newborns

INTRODUCCIÓN. El objetivo de esta investigación fue contrastar la efectividad de 4 mÚtodos de evaluación de riesgo de infección bacteriana grave (IBG) en recién nacidos (RN) febriles, uno de los cuales fue desarrollado por los autores del trabajo y los otros son los utilizados en la práctica internacional. MÉTODOS. Se realizó un estudio descriptivo, retrospectivo y aplicado de 1358 RN febriles sin signos de focalización evaluados y clasificados por riesgo de IBG. Fue aplicado el método propuesto por los autores, que comprende: antecedente de ser sano; ausencia de impresión médica de un estado tóxico-infeccioso; ausencia de evidencias de infección focal en el examen físico; fiebre menor de 39 ºC y no persistente o recurrente; recuento de leucocitos sanguíneos > 5,0 x 10(9)/L y < 20,0 x 10(9)/L; velocidad de sedimentación globular < 20 mm/h y recuento de leucocitos en orina < 10 000/mL. Éste y los otros métodos se aplicaron en una evaluación inicial y al término de 48 h evolutivas. Se calcularon los valores predictivos para los distintos métodos y se evaluó también la efectividad mediante la función de ganancia. RESULTADOS. La frecuencia de IBG fue del 20,4 por ciento. La causa más frecuente fue la infección del tracto urinario. De los 652 RN evaluados inicialmente por nuestro método, hubo cambio de categoría evolutiva en 177 (13,0 por ciento); con los otros métodos también ocurrieron cambios, menos notables. Los fallos de los valores predictivos con nuestro método fueron 40 (8,5 por ciento), una proporción significativamente menor (p < 0,001) que con los otros métodos. La función de ganancia tuvo valores aritméticos superiores con los otros métodos. CONCLUSIONES. Existe un mayor margen de seguridad con nuestro método en relación con los otros métodos de evaluación estudiados…(AU)

INTRODUCTION. The aim of present research was to contrast the effectiveness of four assessment methods of severe bacterial infection risk (SBI) in febrile newborns (NB) , one of above mentioned methods was developed by paper's authors and the other are used in the international practice. METHODS. A retrospective and descriptive study was conducted and applied in 1358 febrile NB with no focalization signs and classified according to the SBI. The method proposed by authors was applied including a history of be healthy, lack of medical criterion of a infectious-toxic state, lack of evidences of focal infection in physical examination, fever lower than 39ºC and no persistent or recurrent, blood leucocytes count >5,0 x 10(9)/L and < 20,0 x 10(9)/L, globular sedimentation speed <20 mm/h and urine leucocyte count <10 000/mL. This method and the other were applied in a initial assessment and at the end of the evolution 48 h. The predictive values were estimated for the different methods and also the effectiveness was assessed according to the gain function. RESULTS. The SBI was of 20,4 percent. The more frequent cause was the urinary tract infection. From the 652 NB initially assessed by our method there was a change of evolution category in 177 (13,0 percent) with the other methods also there were less marked changes. The failures of predictive values using our method were 40 (8,5 percent), a ratio significantly lower (p<0.001) than with the other methods. The gain function had higher arithmetic values with the other methods. CONCLUSIONS. There is a greater margin of safe with our method in relation to the other study assessment methods. This advantage is attributed to the inclusion of clinical and laboratory assessing parameters (the magnitude and persistence of fever and the toxic-infectious feature) that may to change the febrile NB category in the scale, although we must to point out that all methods had prediction errors due to its own probability nature (AU)

The effect of the parenteral route of administration on the immune response to simultaneous nasal and parenteral immunizations using a new HBV therapeutic vaccine candidate.

Chronic hepatitis B is a major health problem, with more than 350 million people infected worldwide. Available therapies have limited efficacy and require long-term continuous and expensive treatments, which often lead to the selection of resistant viral variants and rarely eliminate the virus. Immunotherapies have been investigated as a promising new approach. Several vaccine formulations have been clinically tested in chronic patients, none of which have clearly demonstrated efficacy so far. In this study we evaluated a new vaccination strategy comprising the simultaneous co-administration by the nasal and parenteral routes of a multicomponent vaccine formulation in BALB/C and HBsAg-transgenic mice. The formulation under study contains the surface and nucleocapsid antigens of the HBV, and was co-administered by the nasal route and three parenteral routes. For parenteral administration we also evaluated the immunogenicity of the antigenic mixture with alum or without the adjuvant. The immune response was evaluated by ELISA and IFN-γ ELISPOT assays. Our results indicate that all variants generated a strong antibody response in the sera against both antigens, but differed in their capacity to induce cellular immune responses against the surface antigen. Mice immunized by the nasal and subcutaneous routes without alum generated the highest IFN-γ-secreting CD8+ T-cell response, and results in this transgenic mouse model showed that there is no need to include alum. In conclusion, our results indicate that the immunization routes have to be carefully selected before carrying out clinical trials to optimize the immune response and promote further clinical development.