Levels of secretory immunoglobulin A in the saliva of children with acute upper respiratory infections

The purpose of this study was to investigate the level of secretory immunoglobulin A in the saliva of children with acute upper respiratory infections. A comparison between their disease state sample and a repeat sample collected 14 days later was made. Amounts of Salivary Secretory IgA were determined by radial immunodiffusion. A standard of secretory IgA was obtained from colostrums by ammonium sulfate precipitation and gel filtration chromatography and used as the control. The mean amounts of secretory IgG in mixed unstimulated saliva collected from subjects raging in age from ? 1 to 10 years appeared to increase with age: .063 mg/ml, .085 mg/ml, .087 mg/ml, .09 mg/ml, .22 mg/ml, .224 mg/ml, .46 mg/ml, and .405 mg/ml. A great deal of individual variance in amounts within age groups, during illness, and after illness was noted. A t-test of the difference between the sample means of the initial state of illness and repeat sample means 14 days later revealed no significant difference. A comparison of sex, method of feeding, probable causative agent, social-economic level, race and available laboratory data with levels of Salivary S-IgA revealed interesting differences. In conclusion, this study seems to indicate more resistance to vital infections and less allergies in breast-fed infants and children.