A comparative study of clinicopathological features between chronic cholecystitis patients with and without Helicobacter pylori infection in gallbladder mucosa

Abstract

Background: Helicobacter pylori has been isolated from 10%-20% of human chronic cholecystitis specimens but the characteristics of "Helicobacter pylori positive cholecystitis" remains unclear. This study aims to compare the clinicopathological features between chronic cholecystitis patients with and without Helicobacter pylori infection in gallbladder mucosa.

Methods: Three hundred and twenty-six chronic cholecystitis patients were divided into two groups according to whether Helicobacter pylori could be detected by culture, staining or PCR for Helicobacter 16s rRNA gene in gallbladder mucosa. Positive samples were sequenced for Helicobacter pylori-specific identification. Clinical parameters as well as pathological characteristics including some premalignant lesions and the expression levels of iNOS and ROS in gallbladder were compared between the two groups.

Results: Helicobacter pylori infection in gallbladder mucosa was detected in 20.55% of cholecystitis patients. These patients had a higher prevalence of acid regurgitation symptoms (p = 0.001), more histories of chronic gastritis (p = 0.005), gastric ulcer (p = 0.042), duodenal ulcer (p = 0.026) and higher presence of Helicobacter pylori in the stomach as compared to patients without Helicobacter pylori infection in the gallbladder mucosa. Helicobacter pylori 16s rRNA in gallbladder and gastric-duodenal mucosa from the same individual patient had identical sequences. Also, higher incidences of adenomyomatosis (p = 0.012), metaplasia (p = 0.022) and higher enhanced expressions of iNOS and ROS were detected in Helicobacter pylori infected gallbladder mucosa (p<0.05).

Conclusions: Helicobacter pylori infection in gallbladder mucosa is strongly associated with Helicobacter pylori existed in stomach. Helicobacter pylori is also correlated with gallbladder premalignant lesions including metaplasia and adenomyomatosis. The potential mechanism might be related with higher ROS/RNS production but needs further investigation.

Figure 1. H.pylori infection in metaplastic gallbladder mucosa (oil immersion lens,×1000, red arrow indicates H.pylori).

Figure 2. PCR products of Helicobacter specific 16s rRNA gene from gallbladder and gastric mucosa samples.

(lanes M: step-ladder marker; 1: positive control of gastric biopsy-derived H. pylori DNA; 2: negative control of gastric biopsy; 3: negative 16s rRNA gene in gallbladder; 4 and 5: negative 16s rRNA gene in gallbladder and gastric mucosa acquired from one individual patient; 6 and 7: positive 16s rRNA gene in gallbladder and gastric mucosa acquired from another individual patient).

Figure 3. Comparison of complete sequence data of H. pylori 16s rRNA gene tested in gallbladder mucosa sample from published GenBank data: sequence ID ref|NR_044761.1|.

(nucleotides 263–695 were listed).

Figure 4. BLAST showed H. pylori 16s rRNA gene in gallbladder and gastric mucosa from the same individual patient had completely identical sequences.

(sequence ID50661: H. pylori 16s rRNA tested in gallbladder mucosa; sequence ID50659: H. pylori 16s rRNA tested in gastric mucosa).

Figure 5. Metaplasia of Chronic Cholecystitis (hematoxylin-eosin stain,×100).

Figure 6. iNOS expression in gallbladder mucosa of chronic cholecystitis with H. pylori infection (A) and without H. pylori infection (B) (×100).

Figure 7. ROS expression in gallbladder mucosa of chronic cholecystitis with H. pylori infection (A) and without H. pylori infection (B) (×100).