Immature platelet count: A simple parameter for distinguishing thrombocytopenia in pediatric acute lymphocytic leukemia from immune thrombocytopenia

• Published in: Pediatric blood & cancer Vol. 57; no. 4; pp. 641 - 647
• Main Authors: Strauß, Gabriele, Vollert, Cora, von Stackelberg, Arend, Weimann, Andreas, Gaedicke, Gerhard, Schulze, Harald
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.10.2011
• Subjects: Adolescent; Blood cells; Blood Platelets - cytology; Bone marrow; Cancer; Child; Child, Preschool; Children; Diagnosis, Differential; Female; Humans; immature platelets; immune thrombocytopenia; Infant; Infant, Newborn; leukemia; Lymphatic leukemia; Male; Osteoprogenitor cells; Pediatrics; Platelet Count; Platelets; Precursor Cell Lymphoblastic Leukemia-Lymphoma - blood; Precursor Cell Lymphoblastic Leukemia-Lymphoma - complications; Purpura, Thrombocytopenic, Idiopathic - blood; Purpura, Thrombocytopenic, Idiopathic - diagnosis; reticulated platelets; Thrombocytopenia; Thrombocytopenia - blood; Thrombocytopenia - diagnosis; Thrombocytopenia - etiology; thrombopoiesis
• ISSN: 1545-5009; 1545-5017; 1545-5017
• DOI: 10.1002/pbc.22907

Background Platelet counts below normal values define thrombocytopenia. However, platelet counts alone do not reveal the underlying pathomechanism. New blood cell counters provide additional information on platelet size and volume, and enable the distinction of sub‐populations. In this preliminary study, we evaluate whether one of these markers can be used for diagnosis of isolated thrombocytopenia in children. Procedure We provide normal values for mean platelet volume (MPV), platelet distribution width (PDW), plateletcrit (PCT), platelet large cell ratio (P‐LCR), platelet mean‐frequent volume (P‐MFV), relative immature platelet fraction (IPF%), and absolute IPF (IPF#) for 100 healthy children and analyzed 87 children with thrombocytopenia. Results In children with platelet production defects, IPF% was low, while in acute immune thrombocytopenia (ITP), IPF% was markedly increased (median 25.2%, P < 0.01), representing accelerated platelet turnover. Interestingly, children diagnosed with acute lymphocytic leukemia (ALL) also had elevated IPF% (median 10%, P < 0.01), suggesting that thrombopoiesis is stimulated despite virtual absence of bone marrow progenitors. Low IPF# was only found in patients with acute ITP. Conclusions IPF% is a marker for thrombocytopenia due to defective platelet production while IPF#, representing the immature platelet count, might become a practical parameter to distinguish acute ITP from thrombocytopenia in children with newly diagnosed ALL (P < 0.01). Pediatr Blood Cancer 2011; 57: 641–647. © 2010 Wiley‐Liss, Inc.