Background and study aim: Gastritis linked to Helicobacter pylori is characterized by its high frequency, drug resistance and development to gastric cancer. We aimed to examine the role that endoscopic nodule appearance and expression of programmed death ligand 1 (PD-L1) have in diagnosis of gastric cancer and H. pylori-associated gastritis.
Patients and Methods: Three groups participated in this prospective case-control study: Twenty patients with gastric cancer were in group II, twenty patients with positive H. Pylori infection were in group III, and twenty patients with seemingly normal gastric tissue were in group I. Of these, eighteen cases had mucosal nodularity and twenty-two instances did not. A research using PDL-1 primary antibody immunohistochemistry was carried out on all groups.
Results: Gastric mucosal nodularity was a significant finding in H. pylori infection; however, it did not affect clinical disease severity when compared to those without nodularity (p> 0.05). PDL-1 expression was found in 27.5% of H. pylori patients and 50% of gastric carcinoma cases, respectively.  PDL1 combined positive score (cps) was statistically higher in H. pylori group than in control group (p =0.015). However, there was no statistically significant difference in PDL-1 levels based on illness severity (p> 0.05). Furthermore, PDL1 cps in gastric cancer group was significantly higher than in control and H. pylori groups (p < 0.001 and p = 0.041, respectively).
Conclusions: Although it is a worrying sign of H. Pylori infection, gastric mucosal nodularity is not very predictive. From H. pylori infection to stomach cancer, PDL-1 expression rose gradually.