The association of lupus anticoagulant and anti-DNA binding in patients with systemic lupus erythematosus

ABSTRACT

A study was undertaken to ascertain the association of lupus anticoagulant and anti-DNA binding in patients with systemic lupus erythematosus (SLE). The sera of 67 patients who had positive antinuclear factor were studied to determine whether antibodies to DNA are associated with lupus anticoagulant and if so whether anticoagulant and anti-DNA properties reside on the same immunoglobulin. Binding to native DNA was determined by a modified Farr’s assay, and lupus anticoagulant activity was determined by modified kaolin-activated partial thromboplastin time. Of 67 patients, 14 had positive findings for circulating anticoagulant, 37 had antibodies to DNA, and 30 did not. All 14 patients who had circulating anticoagulants had anti-DNA, and conversely, no patient without DNA binding had a lupus anticoagulant. Furthermore, absorption of the test sera with the phospholipid phosphatidyl serine was capable of removing DNA binding in every sera demonstrating lupus anticoagulant and anti-DNA activity. Although it is not clear whether anti-DNA binding and lupus anticoagulant activity coexist in the same immunoglobulin in SLE, lupus anticoagulant and anti-DNA showed a strong positive association in patients with SLE.