Demonstration of gastrin cell autoantibodies in antral gastritis with avidin-biotin complex antibody technique

In the present study we used the highly sensitive avidin-biotin complex technique (ABC) for detection of gastrin cell (G cell) autoantibodies. Serum samples were studied from 56 patients with histologically proven antral gastritis, 20 adult subjects with histologically proven normal antral and fundal mucosa and from 25 healthy children. The presence of G cell autoantibodies was assessed by both immunofluorescence (IFL) and the ABC-peroxidase method, using sections from paraformaldehyde-lysine-periodate fixed and paraffin embedded human antral mucosa as antigen. Other organ specific and non-organ specific autoantibodies were demonstrated with IFL. Using the ABC method, G cell autoantibodies were found at a dilution of 1:100 in nine of 56 sera with antral gastritis. One of the control sera was positive. The ABC method was considered superior to IFL in demonstrating G cell antibodies, since positively stained G cells could be easily distinguished from the histiocytic cells in lamina propria which sometimes give false positive staining. Furthermore, higher antibody titres results in the ABC method. Thus it is suggested that by analogy to fundal gastritis, some cases of antral gastritis may have autoimmune aetiology.