Similarities of antiphospholipid antibodies in HIT and APS patients with heparin-platelet factor 4 antibodies

Thrombosis Update

Imene Hocine¹ 

[1] University Hospital of Bab El Oued - Laboratory of Hemobiology and Blood Transfusion- Hemostasis Unit, 16008, Algiers, Algeria;

关键词: Heparin induced thrombocytopenia;    Anti-heparin-PF4;    Antiphospholipid antibodies;    Antiphospholipid syndrome;    Heparin neutralization assay;    4Ts score;   

DOI  :  

来源: DOAJ

【 摘 要 】

Heparin-induced thrombocytopenia (HIT) is a prothrombotic autoimmune disorder confirmed by the existence of Heparin-Platelet Factor 4 (HPF4) antibodies. The aim of this work is to study the possible relationship between anti-HPF4 and antiphospholipid antibodies (aPLs) that may explain the discrepancies observed in patients with a suspected HIT (HIT group) with positive immunoassay (HPF4-Elisa) and negative functional assay (heparin-induced platelet aggregation test). So, we performed H-PF4 antibodies research in 31 APS confirmed patients (APL group). All tests performed have been compared to normal controls (n = 34). We found anti-H-PF4 in 7/31 patients of APL group. In parallel, we search for aPLs in 9/34 patients tested positive for anti-HPF4 in HIT group, all of them were positive. All specificities were observed in the two anti-HPF4 positive groups (aβ2GP1 IgM/IgG/IgA, aCL (IgM/IgG/IgA, aPS-PT IgM/IgG). The most associated antibodies with anti-HPF4 are the anti ß2Glycoprotein1 (Odds ratio = 50.1). We suggest that the presence of aPLs in HIT group with anti-HPF4 could be the cause of the discrepancies. In addition, we performed the Heparin Neutralization Assay (HNA) which is specific for anti-HPF4, neutralization was obtained for patients exposed to heparin. Furthermore, we suggest that we should performed a larger cohort to confirm the causal relationship of aPLs and also to expand the tests allowing the differentiation between these autoantibodies.

【 授权许可】

Unknown