IgG subclass concentrations in absolute, partial and transient IgA deficiency in childhood.

Sixty-seven children with symptomatic IgA deficiency were studied on two separate occasions. Eighteen had aIgAd at presentation, and 49 had pIgAd. IgA concentrations had risen to the normal range for age in 22.

Comparison of rotavirus immunoglobulin A coproconversion with other indices of rotavirus infection in a longitudinal study in childhood.

In order to determine the sensitivity and reliability of antirotaviral fecal immunoglobulin A (IgA) as an indicator of rotavirus reinfection, the antibody responses to rotavirus of 44 infants with severe rotavirus gastroenteritis recruited on admission to a hospital were studied. Feces were collected daily during hospitalization and weekly thereafter, and sera were obtained every 4 months, for 6 to 32 months (median, 17 months). Antirotaviral IgG, IgA, and IgM were measured by enzyme immunoassay in all samples.

Anti-IgA antibodies in IgA-deficient children.

IgG and IgM isotype antibodies to polyclonal human IgA, myeloma IgA1, and myeloma IgA2 were estimated in 38 IgA-deficient children aged between 0.9 and 15 years. All children had IgM anti-IgA antibodies.

Quantitation of human serum polymeric IgA, IgA1 and IgA2 immunoglobulin by enzyme immunoassay.

This report concerns the relative quantitation of serum polymeric IgA and polymeric IgA subclass concentrations by enzyme immunoassay (EIA). The assay relies on the specific binding of polymeric IgA to secretory component. Competition between pentameric IgM and polymeric IgA for binding to secretory component was observed.