Antiphosphatidylethanolamine antibodies in systemic lupus erythematosus

Antiphosphatidylethanolamine antibodies (aPEA) were investigated in a population of 78 systemic lupus erythematosus (SLE) patients, by means of an enzyme-linked immunosorbent assay method. These antibodies are specifically directed against phosphatidylethanolamine, one of the zwitterionic phospholipids present in cell membranes. Antiphosphatidylethanolamine antibodies were found in 13 patients (16.6%). They were generally associated with lupus anticoagulant (two patients), antiphospholipid antibodies directed against anionic phospholipids (six patients), or both (four patients). In only one case, aPEA were the sole detectable antiphospholipid antibodies. Thrombosis, recurrent fetal loss, valvular disease or neurological involvement was present in most (11 of 13) of the patients with aPEA. It seems valuable to carry on further searches for these antibodies in SLE, since patients with aPEA are at higher risk of thrombosis and/or recurrent fetal losses than are patients with antiphospholipid antibodies (anticardiolipin, anti-anionic phospholipid and/or lupus anticoagulant) other than aPEA. Moreover, since aPEA can be the sole detectable antiphospholipid antibodies, they should be investigated in SLE with thrombosis when neither lupus anticoagulant nor anticardiolipin antibodies can be demonstrated.