Agreement between serology and histology for detection of Helicobacter pylori infection

Abstract

Objective: To determine the percentage agreement between serology and histology for detection of Helicobacter (H.) pylori infection.

Study design: Cross-sectional analytical study.

Place and duration of study: Department of Pathology and Microbiology, The Aga Khan University and Hospital, Karachi, from January to December 2009.

Methodology: Fifty subjects were selected by non-probability purposive sampling from laboratory data who had serological testing of H. pylori IgG antibody, prior to histological evaluation of endoscopic gastric or/and duodenal biopsies. Serological Quantification of H. pylori IgG was carried out with HpG screen ELISA kit (Genesis Diagnostics, UK), using an enzyme linked immunosorbent assay for detection of IgG antibodies against H. pylori. Manufacturer's recommended cutoff value was used and results were considered positive when greater than 7 U/ml. For histological diagnosis, an expert histopathologist characterized the presence of spiral bacteria in the mucosal layer or the surface of epithelial cells on microscopic examination, as a positive test.

Results: An agreement of 0.72 was found by Kappa statistics between serology and histopathology results and a good diagnostic accuracy (86%) of serological testing was observed for the diagnosis of H. pylori infection.

Conclusion: A substantial agreement was found between serology and histopathology results to detect the H. pylori infection. Laboratory-based serologic testing using ELISA technology to detect IgG antibodies is inexpensive, noninvasive and convenient method to detect the H. pylori infection in primary care setting.