The most common cause of isolated thrombocytopenia is primary immune thrombocytopenia (ITP). For patients failing initial corticosteroid-based treatment and with refractory ITP post-splenectomy, thrombopoietin receptor agonists are indicated. Two of this thrombopoiesis-stimulating agents have been approved for use in ITP - eltrombopag, formulated for oral administration, once a day and romiplostim, which is administered weekly as a subcutaneous injection. (C) 2013 Polskie Towarzystwo Hematologow i Transfuzjologow, Instytut Hematologii i Transfuzjologii. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

Protein Z (PZ) deficiency may induce bleeding as well as thrombosis. The aim of our study was to estimate the concentration of PZ in patients with acute leukemia. Plasma levels of PZ were determined in 76 patients with newly diagnosed acute leukemia ([AML], n =3D 50; acute lymphoblastic leukemia [ALL], n =3D 26) and 62 healthy participants. In the patients, mean plasma concentrations of PZ were statistically lower than in healthy individuals: AML (1.24 =C2=B1 0.11 mug/mL vs 1.58 =C2=B1 0.05 mug/mL P =3D .01) and ALL (1.19 =C2=B1 0.16 mug/mL vs 1.58 =C2=B1 0.05 mug/mL P =3D .01). Levels of PZ below the fifth percentile (0.873 mug/mL) of normal value distribution in control participants were found in 30% of patients with AML and ALL and in 3% of controls (P < .0001). In this AML subgroup, we found statistically significant correlation between episodes of bleeding and PZ level (P =3D .01). There was no such correlation in ALL group. The results suggest that PZ can be a cofactor associated with an increased bleeding tendency in patients with AML.=20