Effects of thrombopoietin receptor agonists on procoagulant state in patients with immune thrombocytopenia

• DOI: 10.1160/th13-10-0873
• Publication Date: 2014-07-03T07:27:21Z
• Authors: María Teresa Álva...; Ihosvany Fernánde...; Elena G. Arias-Sa...; María Isabel Riva...; Víctor Jiménez Yuste; Mónica Martín Salces; Nora V. Butta
• Keywords: Adult; Blood Platelets; Male; 2. Zero hunger; Purpura, Thrombocytopenic, Idiopathic; Apoptosis; Receptors, Fc; Middle Aged; Platelet Activation; Benzoates; 3. Good health; Plasma; 03 medical and health sciences; Hydrazines; 0302 clinical medicine; Cell-Derived Microparticles; Humans; Pyrazoles; Female; Prospective Studies; Blood Coagulation; Receptors, Thrombopoietin; Aged; Autoantibodies

SummaryThrombopoietin receptor agonists (TPO-RA) have recently been introduced for the treatment of immune thrombocytopenia (ITP), an antiplatelet-antibodies autoimmune disease. The observation of a low frequency of bleeding episodes despite their thrombocytopenia suggests the existence of a compensatory mechanism. This study aimed to evaluate the effect of TPO-RA treatment on platelet function and on the procoagulant state in ITP patients before (ITP-bR) and after responding (ITP-aR) to treatment. Plasma- and microparticle (MP)-associated procoagulant capacity from ITP patients was similar before and after responding to the TPO-RA regimen but higher than the healthy control values. High MP-associated procoagulant activity did not seem to be due to increased platelet activation, since platelet stimulation by agonists was reduced in ITP-bR and ITP-aR patients. It could be related to increased platelet apoptosis, evaluated in terms of surface phosphatidylserine (PS), observed in both ITP groups. In summary, TPO-RA treatment increased platelet count but did not ameliorate their function and did not change plasma- and MP-associated procoagulant state of ITP patient responders to this therapy.