Frequency of γδ T Cells and Invariant Natural Killer T Cells in Helicobacter Pylori-infected Patients with Peptic Ulcer and Gastric Cancer
To clarify the effect of γδ T cells and invariant Natural Killer T (iNKT) cells in pathophysiology of dyspeptic disorders, number of these two cells in patients with non-ulcer dyspepsia (NUD), peptic ulcer disease (PUD), and gastric cancer (GC) were compared.
Patients with dyspepsia were divided into three groups of NUD, PUD, and GC according to their endoscopic and histopathological examinations. Helicobacter pylori infection was diagnosed by rapid urease test and histopathology. The number of peripheral blood CD3+TCRgd+ T cells and CD3+Va24Ja18+ iNKT cells were determined by flow cytometry.
Immunohistochemistry (IHC) was also used for identifying the TCRgd+ cells.
Forty two patients with NUD (31.6%), 44 with PUD (33.1%), and 47 with GC (35.3%) were included in the study. The frequency of CD3+TCRgd+ T cells in peripheral blood of patients with GC (2.71±0.25) was significantly lower than that in NUD (3.97±0.32, p<0.05) and PUD groups (3.87±0.32, p<0.05). However, there was no significant difference in
CD3+TCRgd+ T cell percentage between the NUD and PUD groups. The frequency of TCRgd+ lymphocytes was significantly lower in tissue samples from patients with GC (4.81±0.53) than in NUD (11.09±1.09, p<0.0001) and PUD groups (11.11±1.01, p<0.0001). Also, we could not find any significant difference in the percentage of mucosal TCRgd+ cells between the NUD and PUD groups. The results showed no significant difference in iNKT cells percentage among the three groups of patients.
The results suggest that decreasing number of γδ T cells may be related to development and progression of gastric cancer.