CYTOTOXIN GENES OF HELICOBACTER-PYLORI IN CHRONIC GASTRITIS, GASTRODUODENAL ULCER AND GASTRIC-CANCER - AN AGE AND GENDER MATCHED CASE-CONTROLLED STUDY

Helicobacter pylori (H. pylori) infection is involved in many gastroin testinal diseases, such as chronic gastritis (GAG), peptic ulcer and g astric cancer (GCA), Both host factors and H. pylori strain difference s may contribute to differernces in the diseases, Thus, we conducted a n age and gender matched case-control study of 35 patients each with C AG, gastric ulcer (GUL), duodenal ulcer (DUL) and gastric cancer (GCA) to examine the role of strain differences of the H. pylori cytotoxin genes cagA and vacA in these diseases. We employed polymerase chain re action to examine the gastric juice for H. pylori DNA. The test was po sitive for 26 (74.3%) CAG, 29 (82.9%) GUL, 28 (80.0%) DUL and 27 (77.1 %) GCA patients, showing no statistically significant difference among the diseases (P = 0.84). cagA and vacA genes (picked up by using a va cA1 + vacA2 primer pair which detected non-variable regions of the vac A gene) were detected by PCR in the H. pylori DNA-positive cases as fo llows: CAG, 92.3% and 76.9%; GUL, 100% and 86.2%; DUL, 89.3% and 89.3% ; GCA, 92.6% and 85.2%, respectively, No statistically significant dif ferences were found in the frequencies of these cytotoxin genes in H. pylori-positive cases among the various gastric diseases (P = 0.39 for cagA and P = 0.64 for vacA).