The Diagnostic Usefulness of Stool Antigen Test with Serum Helicobacter pylori Antibody and CLO Test in the Diagnosis of Helicobacter pylori Infection in Dyspeptic Patients

Abstract

Introduction: Helicobacter pylori colonization of the human gastric mucosa potentially leads to chronic gastritis that may progress to peptic ulcer disease. Additionally, this micro-organism has been identified as a risk factor for the development of gastric carcinoma and gastric lymphoma. Its relation with non-ulcer dyspepsia has not been clear. Objective: To assess the diagnostic usefulness of stool antigen test with serum Helicobacter pylori antibody and CLO test in the diagnosis of Helicobacter pylori infection in dyspeptic patients. Materials and Methods: This was a cross sectional study was conducted in the Department of Microbiology, Sylhet M.A.G. Osmani Medical College in collaboration with the Department of Gastroenterology Sylhet M.A.G. Osmani Medical College, Sylhet from July 2012 to June 2013. The calculated sample size was 196 but in this study we took 150 patients due to financial constrain and time limitation. Patients upper GI tract for dyspepsia and whoever fulfilled the inclusion and exclusion criteria were considered as study sample. All the findings, previous history and reports of investigations were recorded in a preformed data collection sheet prepared for this purpose. The patient with clinical features suggestive of dyspepsia was selected for upper GI endoscopy. Results: For this purpose, 150 dyspeptic patients fulfilling the inclusion and exclusion criteria were enrolled. The age of the patients ranged from 18 to 80 years with the mean age of 43.35 (SD ± 16.30) years. There were 32 (21.3%) patients in the age group of 21 to 30 years, 31 (20.7%) patients in the age group of 31 to 40 years, 30 (20.0%) patients in the age group of 41-50 years, 26 (17.3%) patients in the age group of 51-60 years, 21 (14.0%) patients in the age group of above 60 years and 10 (6.7%) patients in the age group up to 20 years. There were 93 (62.0%) male and 57 (38.0%) female with a ratio of male to female was 163:1. Showed the distribution of patients according to endoscopic findings. Endoscopic findings was normal in 85 (56.7%) patients, duodenal ulcer in 26 (17.3%) patients, gastritis in 23 (15.3%) patients, and gastric ulcer in 16 (10.7%) patients. The distribution of patients according to CLO test. CLO test was positive in 97 (64.7%) patients and negative in 53 (35.3%) patients. The patients according to serum Helicobacter pylori antibody by ELISA. Serum Helicobacter pylori antibody was positive in 101 (67.3%) patients and negative in 49 (32.7%) patients. Stool antigen test was positive in 73 (48.7%) patients and negative in 77 (51.3%) patients. Using CLO test as the gold standard the sensitivity and specificity of stool antigen test in the diagnosis of Helicobacter pylori infection was 72.7% and 94.3% respectively. Positive and negative predictive values were 95.9% and 64.9% respectively. The overall accuracy was 80.0%. There was moderate agreement between the two test (Kappa, k=0.603; p<0.001). Using CLO test as the gold standard in the diagnosis of Helicobacter pylori infection the sensitivity and specificity of serum Helicobacter pylori antibody was 89.7% and 82.2% respectively. Positive and negative predictive values were 86.1% and 79.6% respectively. The overall accuracy was 84.0%. There was a substantial agreement between the two test (Kappa, k=0.644; p<0.001). Conclusion: The overall accuracy was 80.0%. There was good agreement between the two test (Kappa, k=0.603). Using CLO test as the gold standard in the diagnosis of Helicobacter pylori infection this study showed that the sensitivity and specificity of serum Helicobacter pylori antibody was 89.7% and 82.2% respectively. Positive and negative predictive values were 88.7% and 100.0% respectively. The overall accuracy was 84.0%. In conclusion comparing CLO test (invasive) is still the superior to stool antigen and serology (non-invasive), both of which is going very close to each other in the diagnosis of Helicobacter pylori infection in dyspeptic patients.