HpSS: a new silver staining method for Helicobacter pylori.

AIMS To verify whether the proposed new silver staining method compares favourably with other well established methods in the detection of Helicobacter pylori in gastric biopsies. METHODS One hundred and forty pairs of antral and fundic biopsies, routinely formalin fixed and paraffin wax embedded, from 70 consecutive unselected patients were stained with haematoxylin and eosin, modified Giemsa, and the proposed H pylori silver stain (HpSS). H pylori immunodetection was performed in the same material with a polyclonal antiserum against H pylori. RESULTS H pylori was detected in 89 biopsies from 48 patients with haematoxylin and eosin; in a further five biopsies (one antral and four fundic) with Giemsa stain, thereby identifying one more H pylori infected patient. The new silver staining method was positive in all the cases detected by these two methods and detected three extra infected patients (five more positive biopsies). Immunohistochemistry detected one more positive case (two positive biopsies) not identified by any of the other methods. CONCLUSIONS The HpSS method proposed is highly sensitive in detecting H pylori; it is simple and it compares well with other methods used routinely for evaluating gastric biopsies for H pylori.