HETEROGENEOUS REACTIVITY OF HUMAN MONOCLONAL ANTIPHOSPHOLIPID ANTIBODIES (HMA) WITH ENDOTHELIAL CELLS (EC), PLATELETS AND DNA
Antibodies that react with cardiolipin (ACL) and/or have lupus anticoagulant (LA) properties are implicated in the thrombotic diathesis of patients with the antiphospholipid antibody syndromes: recurrent venousand arterial thrombosis, fetal wastage, thrombocytopenia and CNS disease, often associated with systemic lupus erythematosus. We studied a panel of 16 HMA with LA and/or ACL properties (J Biol Chem 261:9672 1986) for their reactivity with platelets (ELISA),DNA (ELISA), with surface antigensonEC (EC-ELISA) and with whole cell EC extracts as detected by western blot and immunoperoxidase (EC-WB). Three control HMA werenonreactive in all assays.Five HMA with LA activity alone did not react with EC. Five of 6 HMA-ACL reacted with EC both on ELISA and WB. All of the HMA-ACL also reacted with DNA and platelets but 4 did not react as LA. Our findings indicate that HMA antiphospholipid antibodies(LA and ACL) appear to be heterogeneous in terms of their spectrum of reactivities, thus, the ACL and LA tests may in some cases recognize antibodies with different properties and perhaps different pathogeneticmechanisms.xs