Assaf Arie Barg1,2,3, Amos Toren1,3, Hannah Tamary1,4, Joanne Yacobovich1,4, Orna Steinberg-Shemer1,4, Oded Gilad1,4, Gal Goldstein1,3, Hagit Miskin5,6, Shoshana Revel-Vilk5,6, Nurit Rosenbeg1,2, Gili Kenet1,2, Vered Shkalim Zemer1,7. 1. Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel. 2. The Israeli National Hemophilia Center, Thrombosis Unit and Amalia Biron Research Institute of Thrombosis and Hemostasis, Sheba Medical Center, Tel Hashomer, Israel. 3. Department of Pediatric Hematology, Oncology & BMT, The Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Ramat-Gan, Israel. 4. Department of Pediatric Hematology-Oncology, Schneider Children's Medical Center of Israel, Petach Tikva, Israel. 5. Pediatric Hematology Oncology Unit, Shaare Zedek Medical Center, Jerusalem, Israel. 6. Faculty of Medicine, Hebrew University, Jerusalem, Israel. 7. Clalit Health Services, Petach Tikva, Israel.
Abstract
BACKGROUND: Essential thrombocythemia (ET) is rare in children, and pediatric guidelines are lacking. Therefore, we aimed to evaluate ET diagnosis and treatment in a pediatric cohort. PROCEDURE: Data of patients with ET from three hospitals were reviewed. Molecular diagnosis included JAK2V617F, CALR, and MPL mutations. Patients were evaluated for acquired von Willebrand syndrome (AVWS). Follow-up included clinical symptoms, adverse events, and treatment. RESULTS: Twelve children (median age: 8 years, range 1-14.5) were included. Mean lag period between the first documentation of thrombocytosis until ET diagnosis was 36 months. Six patients were positive for JAK2V617F and two for CALR mutations. In six of nine patients, AVWS was diagnosed. At diagnosis, only 33% of patients started therapy with aspirin (n = 4) and hydroxyurea (n = 2). In three of eight untreated patients, therapy was added during follow-up. The cohort was followed for a median of 32.5 months (range: 4-108 months). Clinical follow-up disclosed vascular complications in 4 of 12 patients (deep vein thrombosis, n = 1; transient ischemic attack, n = 3). Two females experienced excessive bleeding; both were diagnosed with AVWS. Neither leukemia nor myelofibrosis evolved in our cohort. CONCLUSION: Increased awareness to pediatric ET is warranted, as delayed diagnosis is common. Compared to adults, AVWS may be more prevalent among children with ET.
BACKGROUND:Essential thrombocythemia (ET) is rare in children, and pediatric guidelines are lacking. Therefore, we aimed to evaluate ET diagnosis and treatment in a pediatric cohort. PROCEDURE: Data of patients with ET from three hospitals were reviewed. Molecular diagnosis included JAK2V617F, CALR, and MPL mutations. Patients were evaluated for acquired von Willebrand syndrome (AVWS). Follow-up included clinical symptoms, adverse events, and treatment. RESULTS: Twelve children (median age: 8 years, range 1-14.5) were included. Mean lag period between the first documentation of thrombocytosis until ET diagnosis was 36 months. Six patients were positive for JAK2V617F and two for CALR mutations. In six of nine patients, AVWS was diagnosed. At diagnosis, only 33% of patients started therapy with aspirin (n = 4) and hydroxyurea (n = 2). In three of eight untreated patients, therapy was added during follow-up. The cohort was followed for a median of 32.5 months (range: 4-108 months). Clinical follow-up disclosed vascular complications in 4 of 12 patients (deep vein thrombosis, n = 1; transient ischemic attack, n = 3). Two females experienced excessive bleeding; both were diagnosed with AVWS. Neither leukemia nor myelofibrosis evolved in our cohort. CONCLUSION: Increased awareness to pediatric ET is warranted, as delayed diagnosis is common. Compared to adults, AVWS may be more prevalent among children with ET.