Letters to the Editor
To the Editor: We conducted a study of the use of polymerase chain reaction (PCR) to detect Helicobacter pylori in pediatric gastric biopsies, traditionally diagnosed by Warthin-Starry or immunostain (1). Previous biopsies of active and nonactive gastritis, all using negative Warthin-Starry stains, were obtained. Patient age was restricted to 18 years or younger. Normal biopsies and cases of chronic active gastritis that were positive for H pylori on Warthin-Starry were used as negative and positive controls, respectively. H pylori PCR was then performed on each block as previously described (2).
Of the cases of chronic nonactive gastritis negative for H pylori on the Warthin-Starry, 24% were positive by PCR (27/112). Of those with chronic active gastritis, 31% were positve (13/42). Of the normal controls, 22% were positive (13/59). None of these differences was statistically significant, with P > 0.05 by Pearson χ2 test. Of the positive controls, 96% were positive (22/23).
PCR did detect a surprisingly high number of new cases with H pylori both in the normal biopsies and test cases. The similar prevalence of PCR-detected H pylori in the normal cases suggests that the H pylori is not causing the gastritis, but rather is coincidental. Many patients are asymptomatically colonized by H pylori, and we suspect that host immunological factors influence whether a person with H pylori colonization is asymptomatic or develops gastritis. If PCR was instituted as the standard means of detection, then it would likely lead to finding numerous cases of asymptomatic colonization in which the usefulness of treatment would be debatable.
1. Gisbert JP, Blanco M, Cruzado AI, et al. Helicobacter pylori
infection, gastric metaplasia in the duodenum and the relationship with ulcer recurrence. Eur J Gastroenterol Hepatol
2. Lu JJ, Perng CL, Shyu RY, et al. Comparison of five PCR methods for detection of Helicobacter pylori
DNA in gastric tissues. J Clin Microbiol