A Study On Relationship Between JAK2 V617F Gene Mutation And Clinical Characteristics Of Classic BCR/ABL Negative Myeloproliferative Neoplasm Patients

Objective:To investigate correlation between JAK2 V617F gene mutation and diagnosis, clinical feature, complication and prognosis of classic BCR/ABL negative myeloproliferative neoplasm patients.Materials and methods:Ninety-six classic BCR/ABL negative myeloproliferative neoplasm patients [42 polycythemia vera(PV) cases, 45 essential thrombocythemia(ET) cases and 9 primary myelofibrosis(PMF) cases] were enrolled as study group and the others [16 secondary polycythemia cases, 26 secondary thrombocythemia cases and 5 secondary myelofibrosis] served as control group. JAK2 V617F gene mutation was detected by allele-specific polymerase chain reaction(AS-PCR) method to appriate whether gene mutation is related with characteristics, complication, prognosis in three groups and analyse the value of it in differential diagnosis.Results: 1. JAK2 V617F gene mutation was detected in 50/96 classic BCR/ABL negative MPN patients, the positive expression rate was 64%(32/50), including 15/19 (78.9%) PV patients, 15/26 (57.7%) ET patients and 2/5 (40%) PMF patients. While 31 patients who were detected in the control group were negative.2. There were significant differences in the expression of JAK2 V617F gene mutation between PV and secondary polycythemia, ET and secondary thrombocythemia, so to detect it has clinical value to discriminate these diseases. However, there was not between PMF and secondary myelofibrosis.3. The incidence of high leucocyte count (P=0.018), high haemoglobin level (P =0.021), high platelet count (P=0.001), splenomegaly (P=0.039), complication (P=0.005) and prognosis (P=0.048) in PV patients was higher than secondary polycythemia; The incidence of great age (P=0.036), high leucocyte count (P=0.040), high haemoglobin level (P = 0.003), high platelet count (P = 0.000), splenomegaly (P=0.015), complication (P=0.004) and prognosis (P=0.042) in ET patients was higher than secondary thrombocythemia; The incidence of high platelet count (P=0.003) in PMF patients was higher than secondary myelofibrosis.4. The incidence of high leucocyte count (P=0.031) in PV patients with JAK2 V617F gene mutation positive was higher than negative; The incidence of high leucocyte count (P=0.032), high haemoglobin level (P=0.044), complication (P=0.002) and prognosis (P=0.024) in ET patients with JAK2 V617F gene mutation positive was higher than negative; The incidence of high leucocyte count (P=0.000) in PMF patients with JAK2 V617F gene mutation positive was higher than negative. Conclusion: 1. AS-PCR can effectively detect JAK2 V617F gene mutation, and can be used in clinic.2. It is extremely important to detect JAK2 V617F gene mutation in PV, ET patients in clinical differential diagnostic value.3. There are many significant clinical differences between classic BCR/ABL negative MPN patients and patients with corresponding secondary diseases.4. There are many significant clinical differences between classic BCR/ABL negative MPN patients with JAK2 V617F gene mutation positive and negative.5. The clinical course of PV, ET and ET patients with JAK2 V617F gene mutation positive is more aggressive than secondary polycythemia, secondary thrombocythemia and ET patients with JAK2 V617F gene mutation negative.