Thyroid Auto-antibodies in Pernicious Anaemia.

precipitation. These three methods correlate well. The electrophoretic method was found to be the most suitable for the study of this antibody. Antibodies to gastric mucosa were demonstrated by complement fixation and immunofluorescence. The two methods gave good correlation, the latter being more sensitive. The antigen was localized in the cytoplasm of the parietal cells and was recovered in the particulate fraction of gastric mucosal homogenates. The complement-fixing antibody is a 7S y-globulin, which is specific for parietal cells and cross-reacts with gastric mucosal extracts of other species. The parietal-cell antibody is distinct from anti-I.F. Of patients with pernicious anaemia, 44% had autoantibodies to I.F. The incidence of parietal-cell antibodies was 86%. This compares with 1 1 % in controls matched for age and sex. The immunofluorescent test may have important diagnostic applications, particularly for pernicious anaemia patients under the age of 60, where the incidence of positive reactions was 93%. Close parallels between pernicious anaemia and autoimmune thyroiditis are drawn on the basis of clinical and immunological features.