Incidence of gastric parietal cell antibody in families of patients with iron-deficiency anaemia.

One hundred and forty-eight relatives of eleven achlorhydric, iron-deficiency anaemic patients, with gastric parietal cell antibody, have been tested for the presence of gastric antibody. The propositi were divided into two groups, six with latent pernicious anaemia and five without latent pernicious anaemia. Ten out of the seventy-six relatives of the propositi with latent pernicious anaemia possessed the antibody but only two of the seventy-two relatives without pernicious anaemia had the antibody. This difference is statistically significant (<0·05). Five out of the six propositi with latent pernicious anaemia had no history of excessive blood loss while four out of the five propositi without latent pernicious anaemia had such a history. In the first group of propositi it is suggested that the antibody is genetically determined while in the second group the antibody may have resulted from gastric mucosal damage due to iron-deficiency anaemia.