NEONATAL THROMBOCYTOPENIA COMPLICATING AUTO-IMMUNE THROMBOCYTOPENIA IN PREGNANCY - EVIDENCE FOR TRANSPLACENTAL PASSAGE OF ANTI-PLATELET ANTIBODY

Transient thrombocytopenia may occur in infants born to mothers suffering from autoimmune thrombocytopenic purpura and is believed to result from transplacental passage of maternal immunoglobulin (Ig) G antiplatelet antibody. Although this humoral mechanism generally has been accepted, it has remained unproven, because the antibody has not been shown in either the serum or attached to the platelets of the affected child. A sensitive antiglobin consumption assay, that is capable of measuring amounts of platelet-bound IgG (platelet antibody) has recently been reported. This assay has enabled the authors to show that the thrombocytopenia occurring in a child whose mother had autoimmune thrombocytopenia purpura at the time of its birth was associated with an increased amount of platelet-bound IgG which subsequently fell to normal as the platelet count rose on recovery.