Total salivary IgA, serum C3c and IgA in obese school children

Studies of the immunologic function in adult obese humans and experimental models indicate that excess adiposity is associated with impairments in host defense mechanisms. The aim of this work was to analyze the secretory and humoral immune system in obese children (n = 105, 55 boys, 50 girls ), between 6 and 13 years of age. Samples of non-stimulated saliva and whole blood were collected from fasting patients. Total salivary IgA (IgAsal), serum C3 complement (C3c) and Immunoglobulin A (IgA) were determined by quantitative radial immunodifussion on agar gel layers ( Diffu-plate, Biocientı́fica SA ). Results, expressed as mg/dl, were compared to laboratory reference values from healthy children of either sex in the same range of age that belong to the same socioeconomic class (n = 60). Data (Mean ± 1 SD) of the whole population were: IgAsal: 11.4 ± 4.8 vs 14.8 ± 6.9; C3c: 190.7 ± 53.1 vs 126.3 ± 45.5; IgA: 194.5 ± 101.5 vs 157.2 ± 19.9. Data distribution showed higher frecuencies near the zone of the highest reference values for serum C3c; when results of IgA and IgAsal were expressed as percentage of the mean reference value, 51% and 48.6% of the whole studied population presented data lower than 100% and 75% respectively. These results show a compromised secretory immune system without incidence of clinical symptoms and infections, whereas humoral immunity might not be profoundly affected.