ИСТИНА

Background & Objectives: The assessment of tumour immune microenvironment in AAUM isn’t enough studied. This is an important direction in gastric cancer research because immune cells in AAUM may contribute in epithelial-mesenchymal transition and tumour metastasis. CD4+ and CD8+ lymphocytes are the main component of antitumour immunity which controls all other cellular reactions. It is known that high density of intratumour CD4+ and CD8+ infiltration is associated with better prognosis in gastric cancer patients but it is not well known in AAUM. Methods: 55 cases of gastric cancer (surgical material) were included in our study. Lymphocytes identification was performed by immunohistochemical staining on markers CD4 (clone 4B12) and CD8 (clone C8/144B). Cell counting was performed in three fields of view (magn. x200) separately in TT and AAUM. These results were compared with classic tumour characteristics: depth of invasion (T), number of nodes metastases (N), distant metastases (M), grade (G). Results: CD4+ infiltration in TT (median=37,8 cells) was higher than in AAUM (median=19,5 cells) in samples with N3 tumours (p=0,6148); CD4+ infiltration in AAUM in samples with N3 tumours was significantly higher than in samples with N2 tumours (median=11,33). CD8+ infiltration in TT (median=105,79 cells) was higher than in AAUM (median=72,21 cells) in samples with T4a tumours (p=0,7123); CD8+ infiltration in AAUM (median=74,33 cells) in samples with T4a/T4b tumours was significantly higher than in samples with T1a/T1b tumours (median=48,33). Conclusion: High density of CD4+ and CD8+ infiltration in AAUM in gastric cancer is associated with greater depth of invasion and large number of lymph modes metastases which is opposite to intratumour infiltration. This indirectly confirms the hypothesis that CD4+ and CD8+ in AAUM may be involved in tissue restructuring that conduct to the tumour progression.