Complement levels and leucocyte phagocytosis in newborn babies

Abstract

Newborn babies face higher risk of infection than adults, but the immunological basis of this observation is yet to be fully explained particularly in babies of different gestations and birth weights. Sixty-two (62) adults, 55 full-term babies, 18 low birth weight babies and 44 normal birth weight babies were considered for the study. B-lymphocyte s and T-lymphocytes were enumerated by EAC-rosette and E-rosette respectively. Leucocyte migration and intracellular killing were assessed by percentage migration index (% M.I), percentage Candidacidal index (% C.I) and bacterial stimulated nitroblue tetrazolium (NBT) dye reduction index (%NBT) respectively. Also, scrum levels of C3 and C5 were measured by single radial immuno-diffusion method. Percentage T cell, C3, C5, %NB T and %C.I were lowest in low birth weight babies but % B cell was lowest in full term babies while normal birth babies had least %M.I. The present study suggests that gestational age and birth weight affect different aspects of immune response.