Studies of intestinal lymphoid tissue. XIII. Immunopathology of the evolving celiac sprue lesion.

Observations, by computerised image-analysis on the evolution of flat mucosae in two celiac sprue patients, are described. Initial immunopathologic features comprised infiltration of epithelium of normal villi by small, non-mitotic lymphocytes, accompanied by crypt hypertrophy and increased crypt cell mitotic activity. The subsequent development, several years later, of flat mucosae was accompanied by mitotic, "immunoblastoid" EL thus fulfilling the diagnostic criteria for celiac sprue. These sequential phases in the evolving flat celiac mucosa parallel experimental graft-versus-host reactions, suggesting that they are fundamentally cell-mediated in type. In becoming flat, it appears obligatory for the mucosa to pass through the early "proliferative-infiltrative" stage in which crypt hypertrophy is a prominent feature.