Novel diagnostic method of testing for Helicobacter pylori infection using the rapid leukocyte strip test, Leukostix.

BACKGROUND AND AIM

A characteristic of gastric mucosa infected with Helicobacter pylori is infiltration of inflammatory cells, mainly consisting of neutrophils. The present study aimed to detect neutrophils in homogenates of biopsied gastric mucosa semiquantitatively using the rapid leukocyte strip test, Leukostix. The authors then investigated the association of these results with H. pylori status.

METHODS

The authors studied 342 patients undergoing endoscopy. Of these, 160 were treated for eradication of H. pylori infection and were reassessed after treatment. For the definitive diagnosis of H. pylori infection, quantitative culture, the rapid urease test and immunohistostaining were performed. Additionally, serum antibody against H. pylori was determined at the initial examination, and the 13C-urea breath test was performed after treatment. With the use of Leukostix, homogenates of biopsied gastric mucosa were spotted onto strips and judged 2 min later.

RESULTS

There was a significant correlation between the positive reaction of Leukostix and the number of neutrophils in gastric tissues determined by microscopic observation. The sensitivity and specificity of Leukostix at the initial examination were 97.9% and 76.9%, respectively, while those after eradication treatment were 100% and 97.2%, respectively. There was a significant positive correlation between the degree of reaction of Leukostix and the amount of H. pylori determined by quantitative culture.

CONCLUSIONS

The Leukostix test, using biopsied samples of gastric mucosa, was excellent for quantitative determination of neutrophils and useful for diagnosis of H. pylori infection and early assessment of treatment efficacy. Positive gradations of Leukostix results corresponded closely with the amount of H. pylori in gastric tissues.