C0184: Lupus Anticoagulant in Patients without Thrombotic or Obstetric Complications

Abstract

Background: Despite lupus anticoagulant (LA) is one of the laboratory criteria for antiphospholipid syndrome (APS), it can be present in asymptomatic subjects or it can be associated with other clinical conditions like bleeding symptoms. We present a retrospective analysis (May 2011-July 2013) of LA positive tests not associated with APS. Methods: The results of 2000 consecutive LA assays, including both sensitive APTT and dRVVT, were analysed; 1501 of them were performed in patients with clinical criteria for APS and 499 in patients without criteria for APS. Results: At least a positive LA test, according to ISTH criteria, was found in 410/1501 (27.3%) and 216/499 (43.3%) of assays in the group with or without APS criteria respectively. The analysis of the clinical background in patients with positive LA but without APS showed that 18% (39/216) of cases were asymptomatic, 34.3% (74/216) had bleeding symptoms (epistaxis, gingivorrhagia, bruising, spontaneous hematomas) and 47.7% (103/216) had other clinical settings (infertility, chronic kidney disease, autoimmune disorders, haematological diseases, IHD, ITP, TIA, among others). Patients with bleeding symptoms showed platelet dysfunction (n =15); low VWF:RCo (not detectable-50 UI/dL) and/or VWF:Ag (9–50 UI/dL) (n = 9); 3 patients showed low Fibrinogen (one of them with low platelet count and one with low FX); hypoprothrombinemia (n =1); low FV (n =1); low FVII (n = 1); low FVIII (n = 6); low FXI (n = 1);a-FVinhibitor (n = 1); hyperfibrinolysis (n = 3) one of them with VWF:Ag and VWF:RCo in the normal limit; the other patients had normal laboratory phenotypes (n =33). Among the four patients with no detectable ristocetin cofactor, one of them had a severe von Willebrand disease. The other three displayed inhibitory effect against VWF:RCo; in these cases of acquired (AVWS) the alteration was associated with MGUS, MGUS and platelet associated immunoglobulins and Waldestrom macroglobulinemia. The patient with a-FV had multiple myeloma. Conclusions: These results showed that LA can be present not only in asymptomatic subjects without APS criteria, but also in patients with bleeding symptoms or other clinical settings. In those cases positive for LA and bleeding, an underlying bleeding defect should be suspected. A careful analysis of laboratory results should be done in order to achieve accurate diagnosis, essential for therapeutic decisions. C0360 CORRELATION OF CHEMILUMINESCENT AND ELISA METHOD FOR DETERMINATION OF ANTI-CARDIOLIPIN ANTIBODIES L. Slavik, J. Prochazkova, D. Janek, J. Ulehlova, M. Wijova, V. Krcova, A. Hlusi. University Hospital. Olomuc, Czech Republic