Demonstration of IgA-containing cells in the small intestine of lambs infected with Nematodirus battus.

A peroxidase anti-peroxidase immunohistochemical technique was used to demonstrate IgA-containing cells in the small intestine of lambs infected with Nematodirus battus. These cells were more numerous in the infected lambs than in the uninfected animals. The difference was greatest for the first three sites, 1 to 3 m distal to the pylorus, where the preponderance of the N battus infection is found. It is suggested that future immunohistochemical studies on the relationships between IgA and resistance to N battus should be directed to this area.