Long chain polyunsaturated fatty acids and immunity in infants.

An infant is usually born with a deficient immune system, and the long chain polyunsaturated fatty acids (LC-PUFA) in breast milk plays an important role in the development and maturation of infant’s immune system. This article reviews the role of LC-PUFA in breast milk in the development of immunity and prevention of atopic manifestations in infants. The review also attempts to assess the correct proportion of these nutrients that needs to be present in infant formulae for babies in whom breast milk is unavailable and formula milk is unavoidable. It was concluded that LC-PUFA plays a vital role in overall development of immunity in the infant. Clinicians should ensure that LC-PUFA are supplied to the term and preterm infant in the form of breastmilk or provided in right proportions in formula, if breast milk is unavailable.

Diferencias en la activación del factor de crecimiento transormante beta-1 (TGF-b1) por el ácido y el calor

El factor de crecimiento transformante beta-1 (TGF-alfa1) es una citoquina con diversas funciones en procesos inflamatorios y el sistema inmune. Un método comercial comúnmente usado para la determinación de TGF-alfa1 es el ensayo de inmunoadsorción enzimática (ELISA), que detecta directamente la forma activa, o la forma inactiva (latente), después de activarla por acidificación o por tratamiento con urea. Este método constituye la mejor opción debido a su simplicidad, especificidad y sensibilidad, sin embargo, existen algunas discrepancias en la literatura científica relacionadas con los factores que activan el TGF-alfa1 latente in vitro e in vivo. Por este motivo decidimos comparar los efectos del calor y de la acidificación en la activación del complejo inactivo. Los resultados muestran que aunque ambos tratamientos activan el TGF-alfa1 latente, la activación térmica es más eficiente que la acidificación. Estos resultados sugieren que los datos publicados reportando valores absolutos de TGF-alfa1, basados sólo en ELISA, se deben interpretar cautelosamente. Asimismo, para la detección de TGF-alfa1 por este método es recomendable usar como control positivo tanto la activación térmica, como la acidificación.

HIV and children: the developing immune system fights back

Children infected with HIV display great variability in their clinical outcome and rate of progression to AIDS. The reasons for this variability are largely unknown. Increasing evidence from adult studies suggests that the cellular immune response is a critical determinant of viral containment, and likely accounts for much of the observed variability in clinical progression. Detailed studies of the HIV-specific immune responses generated by adults with long-term nonprogressive infection have revealed elements of the host immune response that correlate with effective viral control. However, much less is known about the HIV-specific immune responses generated by perinatally infected children. Recent studies have revealed that elements of both the HIV-specific cytotoxic T lymphocyte response (mediated by CD8+ lymphocytes) and the T-helper response (mediated by CD4+ lymphocytes) differ between adults and children, and these differences could have important implications for the ability to control HIV viraemia. Identification of the precise correlates of viral containment in children could provide important insights into the pathogenesis of vertical infection, and will greatly assist the rational design of HIV vaccines and immunotherapies