ESSENTIAL THROMBOCYTEMIA IN CHILDREN ? CLINICAL, HEMATOLOGICAL, MOLECULAR AND THERAPEUTICAL ASPECTS ? SINGLE CENTER EXPERIENCE
(Abstract release date: 05/21/15)
EHA Library. Colita A. 06/12/15; 102679; PB1913
Disclosure(s): FUNDENI CLINICAL INSTITUEPediatric Hematology & BMT
Assoc. Prof. Anca Colita
Contributions
Contributions
Abstract
Abstract: PB1913
Type: Publication Only
Background
Essential thrombocytemia (ET) is an extremely rare disease in children, with an incidence of 1-4 cases/10 million people/year. ET can be present as sporadic or familial disease and exclusion of secondary thrombocytemia is mandatory. There are few data about ET in children. Some studies showed a lower incidence of JAK2 mutation in children compared to adults.
Aims
The purpose of this study is to evaluate the clinical manifestations and follow-up of children with ET.
Methods
We performed a retrospective study of 5 children with ET, followed between 2008-2014 in the Fundeni Clinical Institute, Bucharest. Diagnosis consisted of: a) tests to exclude secondary thrombocytosis; b) tests to exclude other malignant thrombocytosis and c) specific tests: JAK2V617 PCR analysis, calreticulin, C-MPL, bone marrow examination, cytogenetic analysis. The WHO 2008 criteria for ET were used. Thrombopilia screening was performed with – PC, PS, AT, APC-R analysis; in case of positive screening for thrombophilia, PCR assay for MTHFR 677, FVL, FII was recommended.
Results
Five patients, 4F/1M were diagnosed with ET at ages 7- 15 years (median 8 years). One case was familial ET and 4 were sporadic ET. The platelet count at diagnosis was 700 - 2500 x 109/L. Three cases showed extreme thrombocytemia (>900 x109/L), 2 cases moderate thrombocytemia (700-900x109/L), one case with mild thrombocytemia (450-700x109/L). Clinical manifestations at diagnosis: 2 cases had cephaleea, 1 case cephaleea and severe abdominal pain, 1 with cerebral thrombotic event and hemiparesis and 1 asymptomatic case. Three out of 5 cases were JAK2 positive. BM biopsy revealed in all cases hypercellularity, giant megakaryocytes, absence of reticulin fibrosis. The karyoype was normal in all cases. One case was MTHFR heterozygote. Treatment consisted of α-Interferon followed by anagrelide, due to severe symptoms persistence, in a JAK2 negative case, first-line anagrelide in all 3 JAK2 positive cases and hematologic monitoring in the ET familial case. Anagrelide treatment reduced the platelet count in all cases, and controlled the symptoms, but 1out of 4 patients developed ischemic stroke despite treatment. No secondary effects were recorded.
Summary
We observed severe clinical symptoms in 4/5 pediatric ET cases. Some pediatric studies suggested that JAK2 positive cases have a severe course and could be considered distinct disorders. It is necessary to asses which child with ET really needs cytoreductive therapy, as already defined for adults.
Keyword(s): Anagrelide, Children, Essential Thrombocytemia
Session topic: Publication Only
Type: Publication Only
Background
Essential thrombocytemia (ET) is an extremely rare disease in children, with an incidence of 1-4 cases/10 million people/year. ET can be present as sporadic or familial disease and exclusion of secondary thrombocytemia is mandatory. There are few data about ET in children. Some studies showed a lower incidence of JAK2 mutation in children compared to adults.
Aims
The purpose of this study is to evaluate the clinical manifestations and follow-up of children with ET.
Methods
We performed a retrospective study of 5 children with ET, followed between 2008-2014 in the Fundeni Clinical Institute, Bucharest. Diagnosis consisted of: a) tests to exclude secondary thrombocytosis; b) tests to exclude other malignant thrombocytosis and c) specific tests: JAK2V617 PCR analysis, calreticulin, C-MPL, bone marrow examination, cytogenetic analysis. The WHO 2008 criteria for ET were used. Thrombopilia screening was performed with – PC, PS, AT, APC-R analysis; in case of positive screening for thrombophilia, PCR assay for MTHFR 677, FVL, FII was recommended.
Results
Five patients, 4F/1M were diagnosed with ET at ages 7- 15 years (median 8 years). One case was familial ET and 4 were sporadic ET. The platelet count at diagnosis was 700 - 2500 x 109/L. Three cases showed extreme thrombocytemia (>900 x109/L), 2 cases moderate thrombocytemia (700-900x109/L), one case with mild thrombocytemia (450-700x109/L). Clinical manifestations at diagnosis: 2 cases had cephaleea, 1 case cephaleea and severe abdominal pain, 1 with cerebral thrombotic event and hemiparesis and 1 asymptomatic case. Three out of 5 cases were JAK2 positive. BM biopsy revealed in all cases hypercellularity, giant megakaryocytes, absence of reticulin fibrosis. The karyoype was normal in all cases. One case was MTHFR heterozygote. Treatment consisted of α-Interferon followed by anagrelide, due to severe symptoms persistence, in a JAK2 negative case, first-line anagrelide in all 3 JAK2 positive cases and hematologic monitoring in the ET familial case. Anagrelide treatment reduced the platelet count in all cases, and controlled the symptoms, but 1out of 4 patients developed ischemic stroke despite treatment. No secondary effects were recorded.
Summary
We observed severe clinical symptoms in 4/5 pediatric ET cases. Some pediatric studies suggested that JAK2 positive cases have a severe course and could be considered distinct disorders. It is necessary to asses which child with ET really needs cytoreductive therapy, as already defined for adults.
Keyword(s): Anagrelide, Children, Essential Thrombocytemia
Session topic: Publication Only
Abstract: PB1913
Type: Publication Only
Background
Essential thrombocytemia (ET) is an extremely rare disease in children, with an incidence of 1-4 cases/10 million people/year. ET can be present as sporadic or familial disease and exclusion of secondary thrombocytemia is mandatory. There are few data about ET in children. Some studies showed a lower incidence of JAK2 mutation in children compared to adults.
Aims
The purpose of this study is to evaluate the clinical manifestations and follow-up of children with ET.
Methods
We performed a retrospective study of 5 children with ET, followed between 2008-2014 in the Fundeni Clinical Institute, Bucharest. Diagnosis consisted of: a) tests to exclude secondary thrombocytosis; b) tests to exclude other malignant thrombocytosis and c) specific tests: JAK2V617 PCR analysis, calreticulin, C-MPL, bone marrow examination, cytogenetic analysis. The WHO 2008 criteria for ET were used. Thrombopilia screening was performed with – PC, PS, AT, APC-R analysis; in case of positive screening for thrombophilia, PCR assay for MTHFR 677, FVL, FII was recommended.
Results
Five patients, 4F/1M were diagnosed with ET at ages 7- 15 years (median 8 years). One case was familial ET and 4 were sporadic ET. The platelet count at diagnosis was 700 - 2500 x 109/L. Three cases showed extreme thrombocytemia (>900 x109/L), 2 cases moderate thrombocytemia (700-900x109/L), one case with mild thrombocytemia (450-700x109/L). Clinical manifestations at diagnosis: 2 cases had cephaleea, 1 case cephaleea and severe abdominal pain, 1 with cerebral thrombotic event and hemiparesis and 1 asymptomatic case. Three out of 5 cases were JAK2 positive. BM biopsy revealed in all cases hypercellularity, giant megakaryocytes, absence of reticulin fibrosis. The karyoype was normal in all cases. One case was MTHFR heterozygote. Treatment consisted of α-Interferon followed by anagrelide, due to severe symptoms persistence, in a JAK2 negative case, first-line anagrelide in all 3 JAK2 positive cases and hematologic monitoring in the ET familial case. Anagrelide treatment reduced the platelet count in all cases, and controlled the symptoms, but 1out of 4 patients developed ischemic stroke despite treatment. No secondary effects were recorded.
Summary
We observed severe clinical symptoms in 4/5 pediatric ET cases. Some pediatric studies suggested that JAK2 positive cases have a severe course and could be considered distinct disorders. It is necessary to asses which child with ET really needs cytoreductive therapy, as already defined for adults.
Keyword(s): Anagrelide, Children, Essential Thrombocytemia
Session topic: Publication Only
Type: Publication Only
Background
Essential thrombocytemia (ET) is an extremely rare disease in children, with an incidence of 1-4 cases/10 million people/year. ET can be present as sporadic or familial disease and exclusion of secondary thrombocytemia is mandatory. There are few data about ET in children. Some studies showed a lower incidence of JAK2 mutation in children compared to adults.
Aims
The purpose of this study is to evaluate the clinical manifestations and follow-up of children with ET.
Methods
We performed a retrospective study of 5 children with ET, followed between 2008-2014 in the Fundeni Clinical Institute, Bucharest. Diagnosis consisted of: a) tests to exclude secondary thrombocytosis; b) tests to exclude other malignant thrombocytosis and c) specific tests: JAK2V617 PCR analysis, calreticulin, C-MPL, bone marrow examination, cytogenetic analysis. The WHO 2008 criteria for ET were used. Thrombopilia screening was performed with – PC, PS, AT, APC-R analysis; in case of positive screening for thrombophilia, PCR assay for MTHFR 677, FVL, FII was recommended.
Results
Five patients, 4F/1M were diagnosed with ET at ages 7- 15 years (median 8 years). One case was familial ET and 4 were sporadic ET. The platelet count at diagnosis was 700 - 2500 x 109/L. Three cases showed extreme thrombocytemia (>900 x109/L), 2 cases moderate thrombocytemia (700-900x109/L), one case with mild thrombocytemia (450-700x109/L). Clinical manifestations at diagnosis: 2 cases had cephaleea, 1 case cephaleea and severe abdominal pain, 1 with cerebral thrombotic event and hemiparesis and 1 asymptomatic case. Three out of 5 cases were JAK2 positive. BM biopsy revealed in all cases hypercellularity, giant megakaryocytes, absence of reticulin fibrosis. The karyoype was normal in all cases. One case was MTHFR heterozygote. Treatment consisted of α-Interferon followed by anagrelide, due to severe symptoms persistence, in a JAK2 negative case, first-line anagrelide in all 3 JAK2 positive cases and hematologic monitoring in the ET familial case. Anagrelide treatment reduced the platelet count in all cases, and controlled the symptoms, but 1out of 4 patients developed ischemic stroke despite treatment. No secondary effects were recorded.
Summary
We observed severe clinical symptoms in 4/5 pediatric ET cases. Some pediatric studies suggested that JAK2 positive cases have a severe course and could be considered distinct disorders. It is necessary to asses which child with ET really needs cytoreductive therapy, as already defined for adults.
Keyword(s): Anagrelide, Children, Essential Thrombocytemia
Session topic: Publication Only
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