Purified IgG from Patients with Obstetric but not IgG from Non-obstetric Antiphospholipid Syndrome Inhibit Trophoblast Invasion

ProblemSome patients with antiphospholipid syndrome (APS) suffer pregnancy morbidity (PM) but not vascular thrombosis (VT), whilst others suffer VT only. Therefore, we compared the effects of IgG from VT+/PM- and VT-/PM+ subjects on human first-trimester trophoblast (HTR8) cells. Method of studyHTR-8 cells were incubated with APS VT+/PM-, APS VT-/PM+ or healthy control (HC) IgG. We measured trophoblast invasion by cell invasion assay; mRNA expression of TLR4 and adaptor proteins; phosphorylation of p38 MAPK, NFB and ERK; and expression of interleukin (IL)-8 and IL-6. ResultsVT-/PM+ IgG, but not VT+/PM- IgG significantly reduced HTR-8 invasion. The effects on invasion were blocked by TLR-4 inhibition. Neither VT+/PM- nor VT-/PM+ IgG altered MyD88 mRNA expression, phosphorylation of signalling molecules or cytokine expression. ConclusionsVT-/PM+ IgG exert functionally relevant effects on human trophoblast cells but VT+/PM- IgG do not.