Does differential HLA-E and -F expression cause an aberrant immune tolerance in preeclampsia and HELLP?

The non-classical HLA-groups (E, F, G), representing Minor Histocompatibility antigens (miHA) are essential for fetal-maternal immune tolerance and normal placental development. Reduced HLA-G expression on extravillous trophoblasts is linked to pregnancy disorders like preeclampsia (PE) due to weak trophoblast invasion in the maternal decidua. We measured the RNA-expression level of HLA-F and -E in placental tissue by SYBRgreen based qPCR. We examined PE (n = 19), PE/SGA (n = 10), HELLP (n = 10), HELLP/SGA (n = 6), SGA (n = 18) and control (n = 25) tissues to determine a possible linkage of HLA-E and -F to place…