Neutrophilia and the JAK2 V617F Mutation

[摘要] The JAK2 V617F mutation is the most commonly observed driver mutation in the myeloproliferative neoplasms (MPN), present in greater than 95% of polycythaemia vera patients and in 50–60% of patients with essential thrombocythemia and primary myelofibrosis. This mutation is also present in a smaller but significant proportion of patients with myelodysplastic/myeloproliferative syndromes. The diagnosis of MPN is multifactorial and is dependent upon haematological parameters, clinical presentation, bone marrow morphological features, and increasingly, the underlying molecular genetic signature [1]. While there exists an abundance of literature concerning how to detect the JAK2 V617F and other MPNassociated mutations, there remains a lack of evidence as to which patients not fulfilling the major diagnostic criteria should be screened for this mutation. One of the most frequently observed reasons for JAK2 V617F mutation analysis is the presence of a neutrophilia, either isolated or in association with other haematological features. Given that neutrophilia is one of the most commonly observed haematological abnormalities (causes include infection, inflammation, malignancy, trauma, certain drugs, growth factors, haemorrhage and splenectomy) and the previously documented increase and referral centre variation in JAK2 V617F mutation testing [2], the value of molecular diagnostic screening for this mutation in patients presenting with neutrophilia was assessed.