HISTOLOGICAL PREDICTORS OF ACTIVE HELICOBACTER-PYLORI INFECTION

Helicobacter pylori is a common cause of gastritis. No single test is 100% accurate for H. pylori diagnosis. In order to determine whether t he presence of typical histological features of H. pylori gastritis ma y yield diagnostic information, we compared antral histology by H&E st ain to the presence of organisms as detected on Thiazine stain of antr al specimens, CLOtest, urea breath test and anti-H. pylori serology in 50 consecutive patients. Patients were diagnosed as having active H. pylori infection if at least two of these tests were positive, Patient s with only one test positive (N = 5) were considered indeterminate fo r H. pylori and were excluded, resulting in 19 patients (42%) being cl assified as H. pylori positive, All slides were reviewed by a single b linded expert gastrointestinal pathologist and graded 0 (none) to 3 (s evere) for the presence of acute (polymorphonuclear cells) or chronic (lymphocytes, monocytes, plasma cells) inflammation, lymphoid aggregat es, and intestinal metaplasia. Active infection was associated with th e presence of both acute and chronic inflammation (P < 0.0001) but not lymphoid aggregates (P = 0.09) or intestinal metaplasia (P = 0.10), T he best positive predictors of infection were the presence of any acut e inflammation (PPV = 86%) and the combination of any acute and chroni c inflammation (PPV = 92%). The best negative predictor was absence of chronic inflammation (NPV = 100%). The presence of moderate to severe (grade 2 or 3) acute or chronic inflammation were each 100% predictiv e of infection. Moderate to severe chronic inflammation had both 100% sensitivity and specificity for active H. pylori infection, while mode rate to severe acute inflammation was only 26% sensitive but 100% spec ific. The presence of any acute, or the combination of acute and chron ic gastritis, is predictive of active H. pylori infection. Moreover, t he predictive value correlates closely with the severity of the inflam mation. The absence of chronic inflammatory cells rules out active H. pylori infection. These findings support the use of H&E histology-dete rmined features in conjunction with other tests to diagnose H. pylori infection.