Quantitation of Salivary, Urinary and Faecal sIgA in Children Living in Different Conditions of Antigenic Exposure

Abstract

A sandwich-type ELISA was developed to quantify salivary, urinary and faecal secretory IgA (sIgA). The assay is based on binding of sIgA to microplates coated with anti-SC antibodies and reaction with peroxidase-labelled anti-IgA. The sensitivity of the technique was approximately 5 micrograms/L. Children, 1-6 years old (n = 142), were divided into two groups. Group 1 (n = 80) was composed of children living in a place with presumably low antigenic exposure conditions. Group 2 (n = 62) was composed of well-nourished (2A, n = 53) and malnourished children (2B, n = 9) living in a São Paulo slum with presumably high antigenic exposure. The subgroup 2A had salivary levels higher than group 1 and the ranges were similar to those found in the literature for older children and adults. The same subgroup presented a high incidence of undetectable faecal sIgA; their levels of urinary sIgA did not differ from group 1. The subgroup 2B did not have levels of salivary, urinary and faecal sIgA different from subgroup 2A. Our results suggest that environmental factors influence the ontogenesis of sIgA system.

Salivary anticandidal activity and saliva composition in an HIV‐infected cohort

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Development and Basic Mechanisms of Human Gut Immunity

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Salivary alterations in type 2 (non‐insulin‐dependent) diabetes mellitus and hypertension

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