Production of anticardiolipin antibodies by cultured human lymphocytes.

Antibodies against negatively charged phospholipids, such as those to cardiolipin, can often be detected in the serum of patients with autoimmune related conditions, chronic infections and in patients treated with phenothiazines. In the present study, peripheral blood lymphocytes from nine healthy controls and eight patients with phenothiazine-induced IgM anticardiolipin antibodies (ACA) and the lupus anticoagulant were placed in vitro. Culture supernatants were assayed for ACA by measurement of optical densities using an ELISA. A significant difference (p less than 0.05) was demonstrated between the mean concentration of culture supernatant ACA from the patients as compared to healthy controls. The concentration of ACA in culture supernatants strongly correlated (r = 0.85) with that from the serum. There was a weak correlation between serum and culture supernatant ACA concentration and the lupus anticoagulant activity as measured by prolongation of the partial thromboplastin time. This technique uses readily accessible peripheral blood lymphocytes and should permit dissection of cytokine and cellular immune pathways regulating APA production.