The association of early neonatal feeding on clinical outcomes and cytotoxic T lymphocyte (CTL) responses in HIV exposed low birth weight infants.

Abstract

BACKGROUND Sub-saharan Africa remains to date at the forefront of the HIV/AIDS epidemic. Despite breastfeeding being a significant mode of postnatal HIV transmission it remains the main nutritional source and pillar of child survival for the majority of infants born in Africa. It is therefore, not surprising that considerable research has centred on making breastfeeding safer in terms of HIV transmission. The flash heat treatment method (HTEBM) provides a unique opportunity to safely breastfeed infants but prevent mother-to-child transmission of HIV. Cytotoxic T lymphocyte (CTL) responses have been well documented in HIVinfected adults and children. However, there is a lack of literature on CTL responses in HIV exposed low birth weight infants. This pilot study attempted to examine the association of early neonatal feeding on the clinical outcomes and CTL responses in HIV exposed low birth weight infants. METHODS Seventy-seven patients that fulfilled inclusion and exclusion criteria were enrolled. The clinical outcomes of these patients were evaluated over a 9 month period. Fifty-five of these patients were also investigated for cytotoxic T lymphocyte (CTL) responses by means of the IFNγ ELISpot (megamatrix and confirmation) assays at the 6 weeks, 3, 6,and 9 months follow-up. RESULTS Two HIV-1 infected infants generated a CTL response at a single time point using the ELISPOT matrix screening assay. These responses could not be confirmed and were undetectable at any of the consecutive visits. At the time of detection of responses the infants were fed unheated breastmilk. HIV-1 exposed uninfected infants were unable to elicit a HIV-1-specific CTL response irrespective of feed. With regards to clinical outcomes, infants born o HIV infected mothers with a CD4 count < 500cells/μl were 2x more likely to acquire other infections at birth compared to those infants born to HIV infected mothers with a CD4 count >500cells/μl. Also, infants born to HIV infected mothers with advanced disease (CD4 count 0-200 cells/μl) had a lower birth weight compared to infants born to HIV-1 infected mothers with a CD4 count > 350 cells/μl. We also investigated the feasibility of the flash heat treatment method at birth. While inhospital, 38 HIV-1 infected women fed their infants HTEBM after receiving counseling and support from the nursing staff at the King Edward VIII hospital. The numbers decreased rapidly post hospital discharge, mainly due to mixed feeding. DISCUSSION In conclusion we have shown that it is feasible for HIV infected mothers to heat treat their expressed breastmilk during hospital admission. Furthermore, we were able to demonstrate in this small cohort of patients that the clinical outcomes and growth parameters of infants fed HTEBM were similar to that of infants fed either formula or unheated breastmilk. We were unable to demonstrate HIV-specific responses in the infected infants or the uninfected infants who had been exposed to heat inactivated virus in HTEBM. Our findings indicate that this pilot study was limited in its ability to detect CTL responses in HIV exposed low birth weight infants and further studies are warranted.