THE EFFECT OF IMMUNOGLOBULIN-G FRACTIONS FROM PATIENTS WITH LUPUS ANTICOAGULANT ON PLACENTAL PROSTACYCLIN AND THROMBOXANE PRODUCTION

OBJECTIVE: We evaluated whether the production of prostacyclin and thr omboxane by normal human placental tissue is consistently altered by i ncubation with immunoglobulin G fractions prepared from plasma of pati ents with lupus anticoagulant. STUDY DESIGN: The immunoglobulin G frac tions were prepared from eight patients with lupus anticoagulant and e ight control patients. Doses of these fractions (3 mg, 7.5 mg, and 12 mg) were incubated with placental explants obtained from normal pregna ncies, and prostacyclin and thromboxane production was assessed over 4 8 hours. RESULTS: Prostacyclin production was similar for placental ti ssue incubated with immunoglobulin fractions from control and lupus an ticoagulant patients at all of the doses tested. Placental production of thromboxane was significantly increased with immunoglobulin fractio ns from lupus anticoagulant patients for all three doses (p = 0.02). C ONCLUSIONS: The immunoglobulin G fraction from patients with lupus ant icoagulant consistently alters placental thromboxane production withou t affecting prostacyclin production. Increases in placental thromboxan e production may contribute to antiphospholipid antibody-mediated preg nancy loss.