Pregnancy and antiphospholipid antibody

Summary

The antiphospholipid antibody syndrome is defined by anticardiolipin antibody or lupus anticoagulant and recurrent pregnancy loss or recurrent thrombosis. Approximately one-third of patients with systemic lupus erythematosus, 10-15% of women with recurrent fetal loss, and 1-2% of normal women have one or both of these antibodies. The true antigen is a phospholipid-binding protein, β₂-glycoprotein I, not cardiolipin. Risk for pregnancy loss is determined by IgG isotype titer, and prior pregnancy history. Early pregnancy is often normal, but placental insufficiency produces slowed fetal growth and second trimester fetal demise. The most likely mechanism is unimpeded thrombosis within the placental circulation, possibly because antiphospholipid antibody competes with placental anticoagulant I. Heparin in subanticoagulant doses plus low dose aspirin results in fetal survival rates of over 90%. Post partum, the long-term risk of maternal arterial or venous thrombosis is high.

Zusammenfassung

Das Antiphospholipid-Antikörpersyndrom ist durch Antikardiolipin-Antikörper oder Lupus-Antikoagulans und rezidivierende Aborte oder rezidivierende Thrombosen definiert. Etwa ein Drittel der Patientinnen mit systemischem Lupus erythematosus, 10-15% der Frauen mit rezidivierenden Aborten, und 1-2% der gesunden Frauen besitzen einen oder beide dieser Antikörper. Bei dem eigentlichen Antigen handelt es sich um ein Phospholipid-bindendes Protein, nämlich β2-Glykoprotein I und nicht um Kardiolipin. Das Risiko für einen Abort wird durch den IgG-Isotyptiter und einen früheren Schwangerschaftsverlauf bestimmt. Eine Frühschwangerschaft verläuft häufig normal, doch führt eine Plazentainsuffizienz zu einem verlangsamten fetalen Wachstum und dem Absterben des Fetus im zweiten Trimenon. Die wahrscheinlichste Ursache ist eine unerkannte Thrombose innerhalb des Plazentarkreislaufs, die möglicherweise darauf zurückzuführen ist, dass Antiphospholipid-Antikörper mit dem plazentaren Antikoagulans I konkurrieren. Die Gabe von Heparin in niedrig antikoagulatorischen Dosen sowie niedrig dosiertem Aspirin führt zu fetalen Überlebensraten von mehr als 90%. Das postpartale Langzeitrisiko für eine mütterliche arterielle oder venöse Thrombose liegt hoch.

Keywords

Antiphospholipid antibody - lupus anticoagulant - pregnancy loss - lupus

Schlüsselwörter

Antiphospholipid-Antikörper - Lupus-Antikoagulans - Abort - Lupus

• References

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