The interaction of an anti-phosphorylcholine monoclonal antibody with phosphorylcholine-containing lipids.

Abstract

Of the several types of antibodies described in autoimmune disorders, the anti-phospholipid antibodies have received relatively little attention. These antibodies occur frequently in the sera of patients with a variety of autoimmune diseases, including systemic lupus erythematosus and related connective tissue disorders1. It has been found that antibodies against lipids such as phosphatidylcholine, sphingomyelin, and possibly cholesterol are ubiquitous in normal human sera2. One possible mechanism for the induction and/or pathogenesis of these antibodies involves alterations in the phospholipid architecture of the cell membrane. Such an explanation would seem plausible in the light of the variety of lipid structures that could exist, at least trasiently, in membranes, in addition to the bilayer phase3. In fact, in certain pathological conditions, non-bilayer lipid structures have been demonstrated in vivo4. Although such structures could play a role in antibody induction, this possibility requires a demonstration that anti-lipid antibodies exist which are able to distinguish different polymorphic forms of the same lipid.