Objective: Antiphospholipid antibodies are associated with clinical intrauterine growth restriction. In this study we investigated whether immunoglobulin M monoclonal antibodies against phosphatidylserine or cardiolipin or cross-reactive with both phospholipids would induce intrauterine growth restriction in an experimental model of the antiphospholipid antibody syndrome.
Study design: Balb/c or CD-1 mice were injected intraperitoneally on day 8 of pregnancy with three immunoglobulin M monoclonal antibodies that differentiated between cardiolipin- and phosphatidylserine-dependent antigens or with control immunoglobulin M monoclonal antibodies against irrelevant antigens. The animals were killed on day 15 of pregnancy and placental and fetal weights were measured.
Results: Monoclonal antibody 3SB9b, which reacted in enzyme-linked immunosorbent assays with phosphatidylserine but not cardiolipin, induced a significant reduction in both fetal and placental weights. Monoclonal antibodies BA3B5C4, which was cross-reactive with cardiolipin and phosphatidylserine, and D11A4, which reacted with cardiolipin, did not alter fetoplacental weights.
Conclusion: An antiphospholipid antibody that reacts with phosphatidylserine induces significant fetal and placental intrauterine growth restriction in a mouse model for the antiphospholipid antibody syndrome, but those that react with cardiolipin do not.