Immunoglobulin and anti-Escherichia coli antibody in lower respiratory tract secretions from infants weighing less than 1500 g at birth.

Abstract

Concentrations of immunoglobulins and antiEscherichia coli antibody were studied longitudinally in tracheobronchial aspirates from 33 premature intubated neonates, median gestational age 27 weeks. Aspirates collected at birth contained IgG, IgA, and IgM in 100%, 93%, and 79% of samples, respectively. The median IgA concentration at birth was 0-7 ig/ mg total protein and increased to 5-8 rig/mg protein by the sixth week. IgG and IgM antibodies to E coli were present in 90% and 30%, respectively, of tracheobronchial aspirates collected at birth. Samples from three of 28 neonates (11%) contained IgA anti-E coli antibody at birth, and the proportion with IgA antibody rose to 50% during the sixth week. Secretory component associated IgA and IgM were detectable in samples tested at birth and at 4 weeks of age, and secretory component associated anti-E coli antibody was present in aspirates from three of nine neonates studied at 4 weeks of age, but had not been detectable at birth.

Immunoglobulin and ?2-microglobulin concentrations in bronchoalveolar lavage of children and adults

“…Limited evidence suggests that IgA and IgG can be detected in airway secretions of newborn children as well as premature infants weighing less than 1,000 [4,19]. These studies have been performed using tracheal aspirates, and they are therefore not representative for the characterization of the epithelial lining fluid.…”

Ontogeny of Mucosal Immunity and Aging

“…IgA antibodies secreted at extraintestinal mucosal sites begin to increase during the first few weeks of life Fitzsimmons et al, 1994;Gleeson et al, 1982Gleeson et al, , 1986Hanson et al, 1980;Sennhauser et al, 1990;Taylor and Toms, 1984). Salivary IgA levels increase rapidly in the neonatal period to peak levels between four and six weeks of age (Gleeson et al, 1986;Weemaes et al, 2003).…”

“…In a cohort of normal Australian children, S-IgA antibodies to E. coli O antigen were not detected in saliva until one to two months of age and gradually increased with age (Gleeson et al, 1987a). Bronchial aspirates from premature neonates showed a similar pattern of appearance of S-IgA anti-E. coli antibodies (Sennhauser et al, 1990). These studies indicate a tightly controlled mucosal immune response to a major colonizing antigen.…”

“…There is increasing evidence to suggest that the integrity of the mucosal epithelium is an important factor in mucosal immunity. The loss of IgG from mucosal secretions (Sennhauser et al, 1990;Taylor and Toms, 1984;Gleeson et al, 1986) in the immediate postnatal period is indicative of membrane closure. Subsequent detection of IgG in saliva, with the exception of IgA-deficiency states, provides a marker for disrupted epithelial integrity (Gleeson et al, 1995).…”

“…These levels are initially low, have a transient peak at three to four months, and decline until higher secretion rates are observed at six years of age (Weemaes et al, 2003). The concentration of IgM in bronchial washings also increases during the first week of life (Sennhauser et al, 1990).…”