Gastric antigens in health and disease. Behaviour in early development, senescence, metaplasia, and cancer.

Immunofluorescence studies of the behaviour of gastric antigens in health and disease have shown that during foetal development both gastric and intestinal antigens are present in the gastric superficial mucous epithelium. The intestinal component disappears soon after birth; it re-emerges in senescence and in metaplasia and neoplasia, while the gastric antigen, which normally persists in adult life, is depleted in these circumstances. The loss of adult and the re-emergence of foetal antigen in both metaplasia and neoplasia suggest a possible fundamental relationship between these conditions; the phenotypic variation may reflect cytogenetic liability, which has malignant transformation as a final irreversible step.