We measured salivary, urinary and fecal
secretory IgA (
sIgA) levels in 11 children with total
IgA deficiency and in 6 children with partial
IgA deficiency using an ELISA technique. This was based on flexible microplates coated with antisecretory component (SC) and
peroxidase-conjugated
anti-IgA as a second antibody. Selective
IgA deficiency is diagnosed as a serum
IgA concentration < or = 0.05 g/l; partial
IgA deficiency is diagnosed as a serum concentration of
IgA > 0.05 g/l but 2 SD below normal levels. No salivary or fecal
sIgA, and only low levels of urinary
sIgA, were detected in the selective
IgA-deficient group. The partial
IgA-deficient children presented with low levels of salivary, urinary and fecal
sIgA. Fecal
sIgA levels correlated with salivary
sIgA levels (p < 0.01) but not with urinary
sIgA levels (p > 0.05) in the
IgA-deficient patients. We found that all the children with partial
IgA deficiency, except one, had detectable, but low values of
secretory IgA. Our data suggest that these patients also have a partial mucosal
IgA deficiency.