Immunohistochemical Study On Dendritic Cells In Human Normal Endometrium

PurposeImmunohistochemical methods and image analysis technique were used to investigate the number and distribution of CD la and HLA-DR positive dentritic cells in normal human endometrium. It might be helpful for further study of the pathological changes of endometrium.MethodsThe HLA-DR monoclonal antibody and CD la protein antibody were used to detect the dendritic cells in normal human endometrium in 60 samples (proliferative phase n=26, secretory phase n=24, postmenopause n=10). The expression and staining intensity of HLA-DR and CD la of dentritic cells were evaluated via image analysis technique.Results1. The dendritic cells expressing MHC-II were found in normal human endometrium. Brown-yellowish staining was observed in cell plasma. HLA-DR+ and CDla+ DCs in the proliferative phase and the secretory phase were mostly located in the stroma of zona functionalis. They displayed irregular shape with delicate processes. While HLA-DR+ DCs in the postmenopause were round or ellipsoid shaped and had fewer and short processes.2. HLA-DR positive DCs were found in 18 cases (69.2%) during the proliferative phase, in 8 cases (33.3%) during the secretory phase and only in 1 case (10%) during postmenopause phase. CD la positive DCs were found in 16 cases (61.5%) during the proliferative phase, in 8 cases (33.3%) during the secretory phase and none during the postmenopause phase. Compared with proliferative phase, the number of DCs during the secretory phase was significantly lower (p<0.05). The number of DCs during the postmenopause was the lowest.3. No significant difference of expression intensity of HLA-DR could be seen between the endometrium of proliferative phase and secretory phase (p>0.05). But there was a statistical difference of expression intensity of CDla between the endometrium of proliferative phase and that of secretory phase (p<0.05).Conclusion1. The dendritic cells expressing class II molecules exist in normal human endometrium during menstrual cycle.2. Compared with secretory phase, both positive rate and number of HLA-DR+ and CD1a+ cells were higher in the proliferative phase, indicating that the number and distribution of dendritic cells may be regulated by the ovarian hormones.3. The incidence of endometrial carcinoma is high in the postmenopausal age. Our study shows that the lack of DCs in the postmenopausal endometrium may provide a chance for the cancer cells to escape from the immune surveillance.4. No significant difference of the expression intensity of HLA-DR could be seen between the endometrium of proliferative phase and secretory phase (p>0.05), suggesting that there is no statistical difference about the capability of presenting antigen between the DCs of both groups.5. There is a statistical difference of the expression intensity of CD la between the endometrium of proliferative phase and secretory phase (p<0.05), suggesting that DCs in the two groups might be at the different stages of differentiation and development.