Stratégie diagnostique dans le syndrome des anticorps anti-phospholipides: le “ plus ” des anticorps anti-β2glycoprotéine 1

A lot of reports show the association of anti-β2glycoprotein 1 anti-bodies with the anti-phospholipid syndrome and some reports show that anti-β2glycoprotein 1 antibodies can be found without anti-phospholipid antibodies.We aimed at (a) defining specificity and predictive values of anti-β2glycoprotein 1 in patients without knowledge of their anti-cardiolipin status and compare them with anti-cardiolipin specificity and predictive values ; (b) searching if anti-β2glycoprotein 1 antibodies could be found in the absence of anti-cardiolipin ; (c) proposing an approach for biological diagnosis of anti-phospholipid syndrome.We showed that anti-β2glycoprotein 1 specificity (90–100 %) is better than anti-cardiolipin one (80–84 %). We clearly improved the positive predictive value which is 16–19 % for anti-cardiolipin, 58–67 % for anti-β2glycoprotein 1 and 70–100 % for anti-cardiolipin + anti-β2glycoprotein 1. On the other hand, our patients anti-β2glycoprotein 1 positive and anti-cardiolipin negative were free of clinical manifestations. These data allowed us to propose an approach for anti-phospholipid syndrome diagnosis.