Histopathological Changes in Helicobacter pylori Associated Gastritis and Scope of Special Stain and Immunohistochemistry as Diagnostic Aids

BACKGROUND Helicobacter pylori associated chronic gastritis plays a vital role in the development of majority of gastric adenocarcinomas and most gastric MALT (Mucosa Associated Lymphoid Tissue) lymphomas. Many diagnostic methods are available for the identification of this organism. However, in gastroenterology practice, histopathological examination of biopsy samples provides visual identification of the pathogen and the associated mucosal changes with special stains like Giemsa. The aim of this study was to evaluate the efficacy of three stains H & E- (Haematoxylin and Eosin), Giemsa and IHC (Immunohistochemistry) in the identification of H. pylori. Associated histologic changes were noted and the relationship between the degree of colonisation and the activity and chronicity of gastritis were analysed. METHODS 585 gastric biopsies taken from dyspeptic patients were evaluated for gastritis, based on updated Sydney System. In 250 randomly selected cases, three staining methods were used. RESULTS Out of 585 cases, 413 (70.60 %) had features of chronic gastritis. Mild chronic gastritis was the commonest finding and is seen in most cases of mild H. pylori colonisation. When activity was monitored, mild activity was the most frequent finding [225 (38.46 %)]. Majority of the severe activity cases showed severe H. pylori colonisation. 13.16 %, 4.79 % and 7.35 % showed intestinal metaplasia, atrophy and dysplastic changes respectively. Out of 250 cases, H & E and Giemsa stains showed 45.6 % and 57.2 % positivity while IHC demonstrated maximum number of positivity (156 cases - 62.4 %). Sensitivity and specificity of H & E was found to be 77.90 % and 98.95 %, positive predictive value was 99.13 % and negative predictive value was 69.18 %. For Giemsa stain, sensitivity was 91.67 %, specificity was 100 %, positive predictive value was 100 % and negative predictive value was 87.85 %. DISCUSSION H. pylori gastritis was a frequent finding in dyspeptic patients in southern part of India. When chi-square test was done, a significant statistical relationship between the severity of H. pylori colonisation, activity and chronicity of gastritis was noted. P value was < 0.001. With the use of special stain, Giemsa and ancillary techniques like IHC, the detection rate of H. pylori was enhanced considerably. CONCLUSIONS With increasing number of H. pylori in the mucosa, there was increase in the chronicity and activity of gastritis. Although immunohistochemistry revealed more cases of H. pylori, Giemsa can be a cost-effective substitute, because of its high specificity and positive predictive value. KEYWORDS H. pylori Gastritis, Giemsa, Haematoxylin and Eosin Stain, Immunohistochemistry