Impaired Opsonic Activity but Normal Phagocytosis in Low-Birth-Weight Infants

Abstract

Blood of 19 term and 19 low-birth-weight (LBW) neonates was studied for polymorphonuclear phagocytosis, intracellular killing and serum opsonin activity. Serums from 12 of 13 infants under 1925 gm had inadequate opsonins against Staphylococcus aureus 502A and Serratia marcescens when combined with either autologous or normal adult leukocytes. Serums from adults, term newborn infants and physiologically hypogammaglobulinemic infants did not exhibit this serum abnormality.