Immunoglobulin profile of tracheal aspirate fluid in intubated children

Pulmonary lavage immunoglobulins IgG, IgA and IgM were measured in intubated ventilated neonates during their period of intubation (range 1-64 days, mean 12). The neonates were divided into two groups based on gestational age (group 1 26-32 weeks, group 2 33-40 weeks). IgG levels were high at birth, and decreased exponentially throughout the period of intubation. There was no statistical difference in IgG levels between the two groups. IgA and IgM levels were low at birth, and increased linearly, there being a significantly greater increase with age in Group 2 (the more mature gestationally) for both immunoglobulins. Two groups of older children were also studied (2-4 year olds, and 8-10 year olds). In the 2-4 year age group, IgG levels were similar to those seen in the immediate newborn period, were quantitatively greater than IgA and IgM, and were not significantly different from levels in the 8-10 year olds. IgA and IgM levels were also not significantly different between the two groups.