In pooled bile, obtained by cannulating the common bile duct of normal rats, the immunoglobulins were mainly of the IgA class but the total immunoglobulin concentration was 20 times less than in the blood. Paired samples of blood serum and bile were collected from rats at various times after antigens had been injected into the Peyer’s patches, the spleen, or the subcuticulum. Between 5 and 10 days after killed bacteria had been injected into the Peyer’s patches, specific agglutinins appeared in the bile in titres that often were as high as those in the blood, and much higher than those in the bile of rats that had been immunized by other routes. By using specifically purified, radiolabelled antiglobulin reagents it was shown that the antibodies in the bile were mainly of the IgA class, whilst those in the blood were of the IgG and IgM classes. A similar distribution of antibody isotypes was found after allogeneic white cells had been injected. Substantial amounts of alloantibodies of the IgA class were found in the bile but not in the blood; in addition, the bile contained significant amounts of antibody associated with IgM. Thus, by injecting antigens into Peyer’s patches and collecting the bile it is easy to obtain specific, secretory antibodies in the amounts needed for the investigation of their functions in vitro and in vivo.

No abstract

A healthy 38-year-old white woman had two abortions and three live children. Red cells from each of her living children at birth had a strongly positive direct antiglobulin test. Detailed studies on the third child showed that the cells were sensitized by IgG. Maternal serum, tested by a range of techniques against reagent red cells and the husband's cells, showed no unusual antibody. Maternal serum and eluates prepared from red cells of the third child did not react with fresh cells from the older siblings (aged 7 and 10 years). Follow-up on the third child showed that the direct antiglobulin test was positive at 2 months, weakly positive at 4 months, and negative at 8 months. Red cells collected at 8 months of age did not react with the stored eluate prepared from the baby's sensitized red cells at birth. The most likely explanation of these data is that the children inherited a paternal antigen that is only present as a red cell surface-active structure during fetal development.