Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 14 5 2015 10 20 493 501 EN Mojtaba Shadman Department of Immunology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran. Zeinab Rajabian Department of Immunology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran. Abolghasem Ajami Department of Immunology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran AND Molecular and Cell Biology Research Center, Mazandaran University of Medical Sciences, Sari, Iran. Hadi Hussein-Nattaj Department of Immunology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran. Alireza Rafiei Department of Immunology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran AND Molecular and Cell Biology Research Center, Mazandaran University of Medical Sciences, Sari, Iran. Vahid Hosseini Inflammatory Diseases of Upper GI Tract Research Center, Imam Hospital, Mazandaran University of Medical Sciences, Sari, Iran. Tarang Taghvaei Inflammatory Diseases of Upper GI Tract Research Center, Imam Hospital, Mazandaran University of Medical Sciences, Sari, Iran. Ali Abbasi Department of pathology, Islamic Azad University, Sari Branch, Sari, Iran. Mohsen Tehrani Department of Immunology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran AND Molecular and Cell Biology Research Center, Mazandaran University of Medical Sciences, Sari, Iran. 2015 10 19 2015 10 19 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. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/599 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/599/564