TISSUE IGA ANTIBODY AGAINST HELICOBACTER-PYLORI IN PATIENTS WITH GASTRODUODENAL DISEASES - COMPARISON WITH BACTERIAL CULTURE, SERUM IGG ANTIBODY, AND [C-13]UREA BREATH TEST

Helicobacter pylori infection is often associated with gastrointestina l diseases, such as chronic gastritis, peptic ulcer, and gastric cance r. After total gastrectomy, positive to negative seroconversion of the H. pylori IgG antibody assayed by enzyme-linked immunosorbent assay ( ELISA) was found in 10/15 patients (67%) an average of 8.5 months afte r surgery. Therefore, the IgG antibody persists for a long time after total removal of the stomach in about 30% of patients. Immunoglobulin A (IgA) is a major component of the local immunity of the stomach muco sa and has a short half-life. Therefore, tissue H. pylori IgA antibodi es in biopsy specimens from patients with various gastric diseases wer e assayed by ELISA and compared with the bacterial culture, serum IgG antibody (ELISA), and [C-13]urea breath test results from 144, 170, an d 123 endoscopic examinations, respectively. Positivity and negativity of tissue H. pylori IgA coincided with the culture results in 67% of the examinations, and positive IgA antibody but negative culture resul ts were found in 23%. The coincidence of tissue IgA and serum IgG anti bodies against H, pylori was 64% and that of negative tissue IgA but p ositive serum IgG antibody results was 36%. Positivity and negativity of tissue H. pylori IgA antibody coincided with the [C-13]urea breath test results in 72%. One month after completion of treatment of peptic ulcer patients for H, pylori infection with lansoprazole and benexate HCl betadex plus amoxicillin, 6/9 (67%) patients showed positive to n egative conversion of the tissue IgA antibody, in contrast to no IgG a ntibody seroconversion. In conclusion, the tissue H. pylori IgA antibo dy assay is useful for detection of local immunity against H, pylori i n the stomach and during follow-up after treatment.