Prevalence, diversity and disease association of Helicobacter pylori in dyspeptic patients from Pakistan

Adnan Khan,Faisal Rasheed,Hamid Manzoor,Muhammad Saeed Quraishy,Shahana U Kazmi,Amber Farooqui,Yasir Raza,Bianca Paglietti,Syed Shakeel Akhtar,Salvatore Rubino

doi:10.3855/jidc.2942

Abstract

The etiological association of Helicobacter pylori with gastric ulcer (GU), gastric cancer (GC), and duodenal ulcer (DU) is well-known. Understanding the epidemiology of H. pylori facilitates the estimation of disease burden in a certain population. This study presents the diversity of H. pylori genotypes and their association with different clinical outcomes among dyspeptic patients in Pakistan over a period of four years. Gastric biopsy samples from a total of 450 dyspeptic individualswere subjected to PCR, genotypingand histology. A total of 201 (45%) cases were found positive for H. pylori. The detection rate was high in GU (91%), DU (86%) and GC (83%) cases compared with those cases who had intact gastric mucosa (18%). Histology revealed the presence of infection in 68% of cases of mild/chronic nonspecific gastritis with others belonging to the GU sequel. cagA gene carriage was observed in 104 (51%) cases or mostly from DU, GU and GC groups, of which 97 were Western type strains while 3 were East-Asian type strains that are rarely observed in South Asia. vacA allelic variant s1am1 was most commonly observed, followed by s1am2, and s1bm1, with direct correlation in diseased cases (gastritis, GU, DU and GC). Prevalent genotypic combinations were s1am1/cagA- in gastritis and s1am1/cagA+ in DU, GU, and GC. Our study indicates the predominant circulation of Western type cagA and vacAs1am1 type H. pylori strains in Pakistan.

Highlights

The etiological association of Helicobacter pylori with gastric ulcer (GU), gastric cancer (GC), and duodenal ulcer (DU) is well-known
Each subtype is prevalent in its respective geographical location; i.e., East Asian type cytotoxin associated gene A (cagA) is prevalent in East Asia and Western types are prevalent in North America and Europe [17]
In Asia, the prevalence of H. pylori infection differs widely in different countries; for example, Pacific Asians such as Chinese, Korean and Japanese populations are considered to be highly susceptible groups due to the highestprevalence of H. pylori infection and GC cases in those countries compared to rest of the world

Summary

Introduction

The etiological association of Helicobacter pylori with gastric ulcer (GU), gastric cancer (GC), and duodenal ulcer (DU) is well-known. CagA gene carriage was observed in 104 (51%) cases or mostly from DU, GU and GC groups, of which 97 were Western type strains while 3 were East-Asian type strains that are rarely observed in South Asia. Helicobacter pylori are associated with various gastrointestinal disorders such as gastritis, gastric ulcer (GU), and duodenal ulcer (DU) [1,2]. H. pylori strains can be grouped as Western and East Asian subtypes on the basis of polymorphism in the 3′ repeat region of the cagA gene [12]. The East Asian subtype of the cagA gene is more commonly associated with severe histological damage, e.g., acute gastritis and gastric cancer, than Western subtypes [13,14,15,16]. Prevalence is considered both as an effective assessment tool to analyze the epidemiology

Methods

Results

Conclusion