Abstract

HELICOBACTER PYLORI LABORATORY DIAGNOSES BY COMPAIRING STOOL ANTIGEN TO SERUM ANTIBODY AND PHARMACOLOGICAL TREATMENT

Dr. Maali Ibrahim Younus Al-Hayali*, Dr. Dema Z. Alsaleem and Dr. Haifaa Kadhim Akar

ABSTRACT

To compare the H.pylori positivity between stool antigen and blood antibody test methods and to determine the accuracy, sensitivity, specificity of the stool antigen and IgG serology tests as well as sex, age and geographical area variations with the rate of H. pylori positivity. Helicobacter pylori (H. pylori) infection is highly associated with the occurrence of gastrointestinal diseases, including gastric inflammation, peptic ulcer, gastric cancer, and gastric mucosa-associated lymphoid-tissue lymphoma. Although alternative therapies, including phytomedicines and probiotics, have been used to improve eradication, current treatment still relies on a combination of antimicrobial agents, such as amoxicillin, clarithromycin, metronidazole, and levofloxacin, and antisecretory agents, such as proton pump inhibitors (PPIs). A standard triple therapy consisting of a PPI and two antibiotics (clarithromycin and amoxicillin/metronidazole) is widely used as the first-line regimen for treatment of infection, but the increased resistance of H. pylori to clarithromycin and metronidazole has significantly reduced the eradication rate using this therapy and bismuth-containing therapy or 10-d sequential therapy has therefore been proposed to replace standard triple therapy. Alternatively, levofloxacin-based triple therapy can be used as rescue therapy for H. pylori infection after failure of first-line therapy. The increase in resistance to antibiotics, including levofloxacin, may limit the applicability of such regimens. However, since resistance of H. pylori to amoxicillin is generally low, an optimized high dose dual therapy consisting of a PPI and amoxicillin can be an effective first-line or rescue therapy. In addition, the concomitant use of alternative medicine has the potential to provide additive or synergistic effects against H. pylori infection, though its efficacy needs to be verified in clinical studies. Methods: Stool and serum samples were obtained and assayed quantitatively using the stool antigen Accu-Diag H. pylori Antigen and Accu- Bind antibody ELISA Kits respectively. The stool samples were also assayed qualitatively using the monoclonal fecal H. pylori antigen rapid test kit (Aria H. Pylori Ag Combo Rapid Test. Results: The overall positivity rate of H. pylori stool antigen test (28.2%) was significantly lower (P=0.02) compared to that of the serology test (48.3%). No statistical differences were observed between genders and among age groups and geographical areas in both the stool and serology tests. The positivity in age group of ≥ 60 yrs in the IgG antibody test was significantly (p<0.05) greater compared with age groups 18-39 years and 40-59 years respectively. The stool antigen test had a higher sensitivity (100% vs. 59.8%), specificity (98.7% vs. 57.9%), accuracy (99% vs. 60%) and area under the Receiver Operator Characteristic curve (99.3% vs. 61.4%) compared with the IgG serology test. Conclusion: The present study suggests that H. pylori stool antigen test would be a more appropriate and reliable first-line routine test for diagnosis of H. pylori infection in Delta region of Iraq. The rate of positivity was not affected by sex and geographical areas, but high prevalence rate of H. pylori infection was observed within the oldest population.

Keywords: Helicobacter pylori; Stool sample; Enzyme linked immunosorbent assay; Blood antibody test.