Primary and secondary antiphospholipid syndrome -: Comparative study of diagnostic antibodies

The antiphospholipid syndrome is known as the association of arterial and/or venous thrombosis, recurrent abortion and/or thrombocytopenia together with antiphospholipid antibodies. It may be primary or secondary. It is primary when there are no associated pathologies and it is secondary when it is related to other autoimmune disease. The objective of this work was to compare the prevalence of antiphospholipid antibodies: VDRL, lupus anticoagulant, IgG anticardiolipin antibodies and anti-beta2-glycoprotein I antibodies in patients with primary (PAPS) and secondary antiphospholipid syndrome (SAPS) to evaluate the relevance of each antibody in the diagnosis of antiphospholipid syndrome. In patients with SAPS associated to sistemic lupus erythematosus (SLE) a correlation between anti-cardiolipin antibodies and anti-DNAds antibodies was determined. 100 patients (1degreesPAPS: n = 40, 2degreesSAPS: n = 50) and 79 healthy controls were studied. VDRL was performed by indirect aglutination, anti-cardiolipin antibodies and anti-beta2glyprotein I antibodies were measured by ELISA, lupus anticoagulant by screening and confirmatory methods and anti-DNAds antibodies by indirect immunofluorescence tests. A high prevalence of anti-cardiolipin antibodies was found: PAPS (97.5%) and SAPS (83.3%). Prevalence of anti-beta2glyprotein I in PAPS was significantly different from SAPS (90% vs 61.6%) (p < 0.01). The association between anti-DNAds antibodies and anti-cardiolipin antibodies was 89,7%. It was concluded that anti-cardiolipin antibodies are the most frecuent marker found in patients with primary or secondary antiphospholipid syndrome, but anti-beta2glyprotein I antibodies would be more especific. In patients with SAPS and SLE, anti-cardiolipin antibodies could be more frecuent in those with active disease.