GASTRIC-JUICE NEOPTERIN IN HELICOBACTER-PYLORI INFECTION

Neopterin, a pteridine compound produced by macrophages activated by i nterferon-gamma, is widely used to assess the activation of cellular i mmunity. An elevation in serum or urinary neopterin reflects immune ac tivation in many different disorders, including viral infections, canc er, autoimmune diseases or acute myocardial infarction, but less atten tion has been paid to neopterin concentration in other biological flui ds. The aim of the present study was to examine neopterin concentratio n in gastric juice. An association with the presence of Helicobacter p ylori, a bacterium linked to the most common disorders of upper digest ive tract, was also investigated. Gastric juice was obtained at endosc opy from 61 patients. Neopterin was determined by a radioimmunoassay a nd the presence of H. pylori was examined by urease test. The macrosco pic finding of bile in gastric juice was associated with significantly higher neopterin levels compared to patients where no bile was noted (15.5 +/- 15.6 vs. 2.1 +/- 3.0 nmol/l, P < 0.001). However, similar co ncentrations were observed in the H. pylori positive and H. pylori neg ative patients (7.6 +/- 12.0 vs. 11.1 +/- 14.9 nmol/l). Even in the ab sence of macroscopic bile contamination, no significant difference cou ld be found between the infected and uninfected patients (2.3 +/- 3.2 vs. 1.3 +/- 1.9 nmol/l), and the patients with duodenal ulcer and norm al findings (3.8 +/- 4.6 vs 1.6 +/- 1.9 nmol/l). The contamination of gastric juice with bile represents the limitation for the use of neopt erin as a marker of immune activation in the gastric mucosa. Rather th an an index of immune activation, gastric juice neopterin concentratio n represents a marker of duodenogastric reflux.