DETECTION OF HELICOBACTER-PYLORI DNA IN GASTRIC-JUICE BY THE POLYMERASE CHAIN-REACTION - COMPARISON WITH FINDINGS IN BACTERIAL CULTURE AND THE DETECTION OF TISSUE IGA AND SERUM IGG ANTIBODIES AGAINST HELICOBACTER-PYLORI

The detection of Helicobacter pylori in gastric juice by the polymeras e chain reaction (PCR) was undertaken in 124 patients with peptic ulce r or chronic gastritis. PCR products were evaluated by agarose gel ele ctrophoresis and Southern hybridization of H. pylori-specific DNA sequ ences. Positive and negative results of the PCR analysis in 72 examina tions were compared with those from bacterial culture, and with the de tection of tissue IgA antibody against H. pylori by enzyme-linked immu nosorbent assay ELISA; Serion, Wuerzburg, Germany, and detection of se rum IgG antibody against H. pylori by ELISA; Radim Pomezia, Italy. Thi rty-four PCR-positive samples evaluated by electrophoresis and hybridi zation coincided with positive samples in 56% of bacterial cultures, 5 9% of tissue IgA antibody identifications, and 94% of serum IgG antibo dy evaluations; 26 PCR-negative samples coincided with negative sample s in 96% of bacterial cultures, 81% of tissue IgA antibody evaluations , and 38% of serum IgG assessments. We compared the detection achieved with the H. pylori PCR assay in gastric juice with that in biopsies t aken from the antrum and upper corpus in 90 examinations, and found th em to be both positive in 34 (38%) and 36 (40%) of specimens, both neg ative in 37 (41%) and 30 (33%) specimens, gastric juice-positive but b iopsy-negative in 10 (11%) and 12 (13%) specimens, and vice versa in 9 (10%) and 12 (13%) specimens, when detected by electrophoresis and hy bridization, respectively, showing equivalent detection rates. In rela tion to the type of disease, the positive PCR assay results with gastr ic juice, evaluated by electrophoresis and hybridization, respectively , were: gastric ulcer 34/53 (64%) and 39/53 (74%), duodenal ulcer 23/3 8 (61%) and 25/38 (66%), and chronic gastritis 20/33 (61%) and 23/33 ( 70%), showing no significant difference in positive rates between pept ic ulcer and chronic gastritis. Of the samples of 16 patients with H, pylori-positive gastric juice by the PCR assay, 7 were negative by PCR assay analyzed by electrophoresis and hybridization after the complet ion of treatment H. pylori. However, after treatment, 3 were negative on electrophoresis but still had positive results with hybridization, indicating that a minimal number of bacilli may have still remained. D etection of H. pylori in gastric juice has potential advantages for ex amining H. pylori infection in the entire stomach and for follow up af ter treatment for the eradication of H. pylori.