Increased concentrations of milk antibodies in recurrent pulmonary aspiration in infants and young children.

Concentrations of circulating antibodies against bovine serum albumin were significantly increased in six children with recurrent pulmonary aspiration (mean: 5.54 micrograms BSA-N/ml, range: 2.05-12.87 micrograms BSA-N/ml; mean value of 76 control infants: 0.38 microgram BSA-N/ml, 95% confidence interval: 0-0.98 microgram BSA-N/ml, p less than 0.001) as determined by radioimmuno-assay. IgG- and IgA-isotypes against bovine serum albumin, lactalbumin, lactoglobulin, casein and gammaglobulin were determined in four patients by enzyme-linked-immuno-sorbent-assay. Significant differences between patients and controls were found for IgG-antibodies against casein and bovine serum albumin and IgA-antibodies against alpha-lactalbumin and bovine serum albumin. Under certain conditions, stimulation of bronchus-associated lymphoid tissue may lead to a higher immune response than oral immunization. Determination of milk antibodies may be helpful in the diagnosis of recurrent pulmonary aspiration.