ESSENTIAL THROMBOCYTHEMIA WITH JAK2 V617F OR CALR MUTATION: TWO DIFFERENT PHENOTYPES
(Abstract release date: 05/19/16)
EHA Library. A. 06/09/16; 134927; PB2027
Ms. Alba Sara
Contributions
Contributions
Abstract
Abstract: PB2027
Type: Publication Only
Background
The JAK2 V617F mutation is found in 50-60% of cases of essential thrombocythemia while 30% of cases carry calreticulin gene (CALR) and 5% MPL substitution. Recent studies have analyzed the clinical and hematologic features in essential thrombocythemia and have demonstrated the phenotypically differences between JAK2 V617F and CALR mutations.
Aims
We analyzed a Spanish cohort of 101 cases of essential thrombocythemia with JAK2 V617F or CALR mutations. We studied the hematologic and clinical features, including the thrombotic and hemorrhagic events and we compared both groups in order to study different phenotypes in essential thrombocythemia.
Methods
We retrospectively analyzed a cohort of 101 cases of essential thrombocythemia diagnosed between 1990 and 2015. We examined the frequency of JAK2 V617F and CALR mutations, the clinical (Age, gender, thrombotic and hemorrhagic events) and hematologic features (platelets, leukocytes and hemoglobin counts) and the overall survival in these patients. The mutation load of JAK2 V617F was determinated with real-time quantitative PCR. For the detection of CALR exon 9 mutations, fragment analysis have been used. Statistical analyses were performed with SPSS software.
Results
In our study we identified 80% with JAK2 V617F mutation and 20% with CALR mutation (type 1, 70%; type 2, 25%; and others, 5%). The mean age of patients with CALR mutation was 52 years (range 28-83) and JAK2 patients was 63 years (range 24-90). The CALR group had more males (60%) compared to JAK2 group (40%) and were younger at diagnosis (P=0,007). The CALR group had higher platelet counts (1.006,950 ± 482,2 x109/L versus 707,794 ± 256,3L; p=0,001), lower hemoglobin concentration and lower leukocyte counts, not being statistically significant. Venous and arterial thrombosis were more frequent in JAK2 patients (30%; p=0,030) who had also more cardiovascular risk factors. However, thrombosis in these patients was not related to the platelet counts. Hemorrhages were more frequent in CALR patients (90%; p=0.012) and strongly associated with higher platelet counts (p=0.001) and less with low hemoglobin levels (p=0.227). We also observed that the two groups have similar overall survival.
Conclusion
In our study, we have observed that patients with CALR mutation were younger and they had higher platelet counts compared with JAK2 mutation group. CALR mutation patients showed a higher risk of developing hemorrhagic events while JAK2 mutation-positive showed a higher risk of venous thrombosis. Thrombosis events were also related to higher leukocyte counts and the presence of cardiovascular risk factors, which were more frequent in the JAK2V617F group. However, we did not find differences in overall survival between both groups.In conclusion, this study confirms that essential thrombocythemia with CALR or JAK2 mutations have biological and phenotypical differences. Therefore, it might be useful for a better understanding of the prognosis and treatment in this disease.
Session topic: E-poster
Keyword(s): Essential Thrombocytemia
Type: Publication Only
Background
The JAK2 V617F mutation is found in 50-60% of cases of essential thrombocythemia while 30% of cases carry calreticulin gene (CALR) and 5% MPL substitution. Recent studies have analyzed the clinical and hematologic features in essential thrombocythemia and have demonstrated the phenotypically differences between JAK2 V617F and CALR mutations.
Aims
We analyzed a Spanish cohort of 101 cases of essential thrombocythemia with JAK2 V617F or CALR mutations. We studied the hematologic and clinical features, including the thrombotic and hemorrhagic events and we compared both groups in order to study different phenotypes in essential thrombocythemia.
Methods
We retrospectively analyzed a cohort of 101 cases of essential thrombocythemia diagnosed between 1990 and 2015. We examined the frequency of JAK2 V617F and CALR mutations, the clinical (Age, gender, thrombotic and hemorrhagic events) and hematologic features (platelets, leukocytes and hemoglobin counts) and the overall survival in these patients. The mutation load of JAK2 V617F was determinated with real-time quantitative PCR. For the detection of CALR exon 9 mutations, fragment analysis have been used. Statistical analyses were performed with SPSS software.
Results
In our study we identified 80% with JAK2 V617F mutation and 20% with CALR mutation (type 1, 70%; type 2, 25%; and others, 5%). The mean age of patients with CALR mutation was 52 years (range 28-83) and JAK2 patients was 63 years (range 24-90). The CALR group had more males (60%) compared to JAK2 group (40%) and were younger at diagnosis (P=0,007). The CALR group had higher platelet counts (1.006,950 ± 482,2 x109/L versus 707,794 ± 256,3L; p=0,001), lower hemoglobin concentration and lower leukocyte counts, not being statistically significant. Venous and arterial thrombosis were more frequent in JAK2 patients (30%; p=0,030) who had also more cardiovascular risk factors. However, thrombosis in these patients was not related to the platelet counts. Hemorrhages were more frequent in CALR patients (90%; p=0.012) and strongly associated with higher platelet counts (p=0.001) and less with low hemoglobin levels (p=0.227). We also observed that the two groups have similar overall survival.
Conclusion
In our study, we have observed that patients with CALR mutation were younger and they had higher platelet counts compared with JAK2 mutation group. CALR mutation patients showed a higher risk of developing hemorrhagic events while JAK2 mutation-positive showed a higher risk of venous thrombosis. Thrombosis events were also related to higher leukocyte counts and the presence of cardiovascular risk factors, which were more frequent in the JAK2V617F group. However, we did not find differences in overall survival between both groups.In conclusion, this study confirms that essential thrombocythemia with CALR or JAK2 mutations have biological and phenotypical differences. Therefore, it might be useful for a better understanding of the prognosis and treatment in this disease.
Session topic: E-poster
Keyword(s): Essential Thrombocytemia
Abstract: PB2027
Type: Publication Only
Background
The JAK2 V617F mutation is found in 50-60% of cases of essential thrombocythemia while 30% of cases carry calreticulin gene (CALR) and 5% MPL substitution. Recent studies have analyzed the clinical and hematologic features in essential thrombocythemia and have demonstrated the phenotypically differences between JAK2 V617F and CALR mutations.
Aims
We analyzed a Spanish cohort of 101 cases of essential thrombocythemia with JAK2 V617F or CALR mutations. We studied the hematologic and clinical features, including the thrombotic and hemorrhagic events and we compared both groups in order to study different phenotypes in essential thrombocythemia.
Methods
We retrospectively analyzed a cohort of 101 cases of essential thrombocythemia diagnosed between 1990 and 2015. We examined the frequency of JAK2 V617F and CALR mutations, the clinical (Age, gender, thrombotic and hemorrhagic events) and hematologic features (platelets, leukocytes and hemoglobin counts) and the overall survival in these patients. The mutation load of JAK2 V617F was determinated with real-time quantitative PCR. For the detection of CALR exon 9 mutations, fragment analysis have been used. Statistical analyses were performed with SPSS software.
Results
In our study we identified 80% with JAK2 V617F mutation and 20% with CALR mutation (type 1, 70%; type 2, 25%; and others, 5%). The mean age of patients with CALR mutation was 52 years (range 28-83) and JAK2 patients was 63 years (range 24-90). The CALR group had more males (60%) compared to JAK2 group (40%) and were younger at diagnosis (P=0,007). The CALR group had higher platelet counts (1.006,950 ± 482,2 x109/L versus 707,794 ± 256,3L; p=0,001), lower hemoglobin concentration and lower leukocyte counts, not being statistically significant. Venous and arterial thrombosis were more frequent in JAK2 patients (30%; p=0,030) who had also more cardiovascular risk factors. However, thrombosis in these patients was not related to the platelet counts. Hemorrhages were more frequent in CALR patients (90%; p=0.012) and strongly associated with higher platelet counts (p=0.001) and less with low hemoglobin levels (p=0.227). We also observed that the two groups have similar overall survival.
Conclusion
In our study, we have observed that patients with CALR mutation were younger and they had higher platelet counts compared with JAK2 mutation group. CALR mutation patients showed a higher risk of developing hemorrhagic events while JAK2 mutation-positive showed a higher risk of venous thrombosis. Thrombosis events were also related to higher leukocyte counts and the presence of cardiovascular risk factors, which were more frequent in the JAK2V617F group. However, we did not find differences in overall survival between both groups.In conclusion, this study confirms that essential thrombocythemia with CALR or JAK2 mutations have biological and phenotypical differences. Therefore, it might be useful for a better understanding of the prognosis and treatment in this disease.
Session topic: E-poster
Keyword(s): Essential Thrombocytemia
Type: Publication Only
Background
The JAK2 V617F mutation is found in 50-60% of cases of essential thrombocythemia while 30% of cases carry calreticulin gene (CALR) and 5% MPL substitution. Recent studies have analyzed the clinical and hematologic features in essential thrombocythemia and have demonstrated the phenotypically differences between JAK2 V617F and CALR mutations.
Aims
We analyzed a Spanish cohort of 101 cases of essential thrombocythemia with JAK2 V617F or CALR mutations. We studied the hematologic and clinical features, including the thrombotic and hemorrhagic events and we compared both groups in order to study different phenotypes in essential thrombocythemia.
Methods
We retrospectively analyzed a cohort of 101 cases of essential thrombocythemia diagnosed between 1990 and 2015. We examined the frequency of JAK2 V617F and CALR mutations, the clinical (Age, gender, thrombotic and hemorrhagic events) and hematologic features (platelets, leukocytes and hemoglobin counts) and the overall survival in these patients. The mutation load of JAK2 V617F was determinated with real-time quantitative PCR. For the detection of CALR exon 9 mutations, fragment analysis have been used. Statistical analyses were performed with SPSS software.
Results
In our study we identified 80% with JAK2 V617F mutation and 20% with CALR mutation (type 1, 70%; type 2, 25%; and others, 5%). The mean age of patients with CALR mutation was 52 years (range 28-83) and JAK2 patients was 63 years (range 24-90). The CALR group had more males (60%) compared to JAK2 group (40%) and were younger at diagnosis (P=0,007). The CALR group had higher platelet counts (1.006,950 ± 482,2 x109/L versus 707,794 ± 256,3L; p=0,001), lower hemoglobin concentration and lower leukocyte counts, not being statistically significant. Venous and arterial thrombosis were more frequent in JAK2 patients (30%; p=0,030) who had also more cardiovascular risk factors. However, thrombosis in these patients was not related to the platelet counts. Hemorrhages were more frequent in CALR patients (90%; p=0.012) and strongly associated with higher platelet counts (p=0.001) and less with low hemoglobin levels (p=0.227). We also observed that the two groups have similar overall survival.
Conclusion
In our study, we have observed that patients with CALR mutation were younger and they had higher platelet counts compared with JAK2 mutation group. CALR mutation patients showed a higher risk of developing hemorrhagic events while JAK2 mutation-positive showed a higher risk of venous thrombosis. Thrombosis events were also related to higher leukocyte counts and the presence of cardiovascular risk factors, which were more frequent in the JAK2V617F group. However, we did not find differences in overall survival between both groups.In conclusion, this study confirms that essential thrombocythemia with CALR or JAK2 mutations have biological and phenotypical differences. Therefore, it might be useful for a better understanding of the prognosis and treatment in this disease.
Session topic: E-poster
Keyword(s): Essential Thrombocytemia
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