A MODEL FOR THE ANTIPHOSPHOLIPID ANTIBODY SYNDROME - MONOCLONAL ANTIPHSOPHATIDYLSERINE ANTIBODY INDUCES INTRAUTERINE GROWTH RESTRICTION IN MICE

OBJECTIVE: Antiphospholipid antibodies are associated with clinical in trauterine growth restriction. In this study we investigated whether i mmunoglobulin M monoclonal antibodies against phosphatidylserine or ca rdiolipin or cross-reactive with both phospholipids would induce intra uterine growth restriction in an experimental model of the antiphospho lipid antibody syndrome. STUDY DESIGN: Balb/c or CD-1 mice were inject ed intraperitoneally on day 8 of pregnancy with three immunoglobulin M monoclonal antibodies that differentiated between cardiolipin- and ph osphatidylserine-dependent antigens or with control immunoglobulin M m onoclonal antibodies against irrelevant antigens. The animals were kil led on day 15 of pregnancy and placental and fetal weights were measur ed. RESULTS: Monoclonal antibody 3SB9b, which reacted in enzyme-linked immunosorbent assays with phosphatidylserine but not cardiolipin, ind uced a significant reduction in both fetal and placental weights. Mono clonal antibodies BA3B5C4, which was cross-reactive with cardiolipin a nd phosphatidylserine, and D11A4, which reacted with cardiolipin, did not alter fetoplacental weights. CONCLUSION: An antiphospholipid antib ody that reacts with phosphatidylserine induces significant fetal and placental intrauterine growth restriction in a mouse model for the ant iphospholipid antibody syndrome, but those that react with cardiolipin do not.