Immunohistochemical Analysis of MHC Class 2 (HLA-DR / DP), ICAM-1, CD68(+) Macrophage Expression in Gastric Adenocarcinoma

Park, Eon Sub; Kim, Seong Nam; Lee, Tae Jin; Yoon, Im Joong; Shin, Yong Kyoo; Yoo, Jae Hyung

Abstract

PURPOSE
Gastric adenocarcinoma is the most common malignant tumor in Korea and immunochemotherapy can be alternative method of the treatment for it. So we evaluated several immunologic markers, Major Histocomatibility (MHC) Antigen and Intercellular Adhesion Molecule (ICAM)-1 which play an important roles in cellular immune response of the host to the tumar cells, HLA-DR/DP antigens, one of the MHC class II which is expressed in various conditions, CD 68 antigen which are also important factor in immune response to the tumor cells.
MATERIALS AND METHODS
We compared the expression of MHC class II (HLA-DR/DP) antigens, ICAM-1 and the number of tumor-infiltrating macrophages presenting CD68 antigen in formalin-fixed paraffin-embedded tissue sections of 95 gastric adenocarcinomas using immunohistochemistry. In addition to analyze the relationship between expression of these antigens in gastric adenocarcinoma, histolopathologic findings such as tumor invasion, regional lymph node metastasis and histologic differentiation are evaluated.
RESULTS
The rate of HLA-DR/DP expression was 60% and strongly associated with tumor differentiation, invasion and regional lymph node metastasis. ICAM-1 was expressed in 15% and slightly increased in well-differentiated carcinoma. The lack of expression of ICAM-1 was observed in high invasive tumor (T 4). CD 68(+) macrophages counts were significantly increased in around the tumor cells, compared to normal epithelia. HLA-DR/DP expression and infiltrating CD 68(+) macrophage numbers were significantly associated (p<0.05), but there was no correlationship between ICAM-1 and CD 68(+) macrophage numbers.
CONCLUSION
It was considered that enhanced expression of HLA-DR/DP antigens, ICAM-1 and CD68(+) macrophages in gastric adenocarcinomas may be an immunophenotypic deviation. HLA-DR/DP and CD68(+) macrophages infiltration showed correlationship with tumor invasion and regional lymph node metastasis, that they may be used as a prognostic factor of the tumor growth.