Antiphospholipid antibodies: clinical significance in systemic lupus erythematosus

A radioimmunoassay using cardiolipin as antigen and labelled SPA, anti-human IgG, anti-human IgM, anti-human IgA as second antibodies in detecting anti-cardiolipin antibody with the sera from 308 patients and 70 normal controls. Among them, 126 patients were of SLE, 27 systemic sclerosis, 40 rheumatoid arthritis, 40 Sj?gren syndrome, 26 other connective tissue diseases, 7 syphilis and 32 with obstetric complications. The positive rate of anticardiolipin antibody were 42.9% (SLE), 29.7% (PSS), 20% (RA), 15% (SS), 26.9% (CTD), 85.7% (syphilis), 3.1% (obstetric complication), 0% (NC). In SLE the anticardiolipin antibody were well correlated with thrombocytopenia, cerebral lupus, thrombosis of vein and spontaneous recurrent abortion. Lupus anticoagulant (APTT) was found in 21.3% of SLE and biological false positive of VDRL test in 4.8%. Both of them correlated with the anticardiolipin antibody detected by the radioimmunoassay. The authors concluded that antiphospholipid antibodies is a group of commonly seen antibodies, which may play a rule in the pathogenesis of SLE. Further study is progressing.