Contributions
Abstract: PB2062
Type: Publication Only
Background
Polycythemia vera (PV), essential thrombocytosis (ET, and primary myelofibrosis (PMF) are Philadelphia chromosome negative myeloproliferative neoplasms (MPN) characterized by the expression of an aquired activated JAK2V617F mutation. Up to date, it remains controversial how one mutation can lead to expression of three different clinical MPN phenotypes. However, several studies have shown that the JAK2V617F allele burden may correlate with specific MPN entity.
Aims
In order to further clarify these observations, we evaluated the JAK2 mutational status and its clinical implications in 233 JAK2 V617F + patients with different MPNs from the Republic of Macedonia.
Methods
We conducted a single center retrospective study which included 233 patients with JAK2V617F + MNP diagnosed according to WHO criteria, with median follow up period of 4 years. Quantification of the JAK2V617F mutation was analized with the Real Time PCR method using the Larsen protocol. Based on the mutational load patients were divided in three groups: first with <10% mutational load, second with 10-50% load and third with >50% mutational load. The correation of the allele burden with various clinical parameters was done by Mann-Whitney and student's tests using Statgraphics 4.3 software.
Results
Our study showe that median allele burden was lowest in patients with ET (22.8%), followe by PV patients (37.1%) and PMF pts (49.6%) (p<0.01). A higher mutation burden (>50% vs <10%) was associated with advanced age (67.5 vs 58,5 years and 65 vs 58 years in ET and PMF pts respectively), with higher leucocyte count (103 /μL) (9,87 vs 8,87, 13.8 vs 12.4, and 18.99 vs 14,8 in ET, PV and PMF pts respectively), with elevated erytrocyte count (5.76 vs 4.85 and 5.59 vs 4.52 in ET and PMF pts respectively), and with higher hemoglobin level (g/dL) and platelet count 103 /μL (15.45 vs 14.35 and 1071.5 vs 860.5 in ET patients respectively) (p<0.05 for all comaprisions)
Conclusion
Our study confirmed that higher allele burden is associated with advanced age, polycythemic features, and increased leucocytes and platelets counts regardless of the diagnosed MPN entity and suggests that implementation of JAK2V617F allele burden in the diagnostic workup of MPN pts could help for choosing the optimal treatment option in this group of patients.
Session topic: 16. Myeloproliferative neoplasms - Clinical
Keyword(s): Phenotype, Mutation
Abstract: PB2062
Type: Publication Only
Background
Polycythemia vera (PV), essential thrombocytosis (ET, and primary myelofibrosis (PMF) are Philadelphia chromosome negative myeloproliferative neoplasms (MPN) characterized by the expression of an aquired activated JAK2V617F mutation. Up to date, it remains controversial how one mutation can lead to expression of three different clinical MPN phenotypes. However, several studies have shown that the JAK2V617F allele burden may correlate with specific MPN entity.
Aims
In order to further clarify these observations, we evaluated the JAK2 mutational status and its clinical implications in 233 JAK2 V617F + patients with different MPNs from the Republic of Macedonia.
Methods
We conducted a single center retrospective study which included 233 patients with JAK2V617F + MNP diagnosed according to WHO criteria, with median follow up period of 4 years. Quantification of the JAK2V617F mutation was analized with the Real Time PCR method using the Larsen protocol. Based on the mutational load patients were divided in three groups: first with <10% mutational load, second with 10-50% load and third with >50% mutational load. The correation of the allele burden with various clinical parameters was done by Mann-Whitney and student's tests using Statgraphics 4.3 software.
Results
Our study showe that median allele burden was lowest in patients with ET (22.8%), followe by PV patients (37.1%) and PMF pts (49.6%) (p<0.01). A higher mutation burden (>50% vs <10%) was associated with advanced age (67.5 vs 58,5 years and 65 vs 58 years in ET and PMF pts respectively), with higher leucocyte count (103 /μL) (9,87 vs 8,87, 13.8 vs 12.4, and 18.99 vs 14,8 in ET, PV and PMF pts respectively), with elevated erytrocyte count (5.76 vs 4.85 and 5.59 vs 4.52 in ET and PMF pts respectively), and with higher hemoglobin level (g/dL) and platelet count 103 /μL (15.45 vs 14.35 and 1071.5 vs 860.5 in ET patients respectively) (p<0.05 for all comaprisions)
Conclusion
Our study confirmed that higher allele burden is associated with advanced age, polycythemic features, and increased leucocytes and platelets counts regardless of the diagnosed MPN entity and suggests that implementation of JAK2V617F allele burden in the diagnostic workup of MPN pts could help for choosing the optimal treatment option in this group of patients.
Session topic: 16. Myeloproliferative neoplasms - Clinical
Keyword(s): Phenotype, Mutation