Decreased expression of MMP-9 in CD8+ cells in placenta with severe preeclampsia
Abstract We compared the number of CD4-positive (CD4+) and CD8-positive (CD8+) cells in severe and non-severe preeclampsia (PE), and in normal pregnancy. We also evaluated the expression of matrix metalloproteinase 9 (MMP-9) in CD4+ and CD8+ cells. Immunohistochemistry for CD4+ and CD8+ was performed on the decidua basalis of 15 severe and 13 non-severe PE women and compared to decidual tissue of 19 normal pregnancies (control group). Co-expression of MMP-9 with CD8+ and CD4+ cells was determined by double immunofluorescence staining. The median number of CD8+ cells/mm2 was significantly lower for the severe PE group than for the normal pregnancy group, as was the number of CD4+ cells and MMP-9+CD8+ cells. No statistical difference was found between the non-severe PE group and the normal pregnancy group. The significant decrease of CD4+, CD8+ and MMP-9+CD8+ cells at the fetal-maternal interface only in the severe PE group suggests that immunological disorders play a role in the pathophysiology of severe PE.