伴JAK2 exon12突变与JAK2 V617F突变真性红细胞增多症患者的临床与实验室特征比较

OBJECTIVE: To compare clinical and laboratory features between JAK2 exon12 and JAK2 V617F mutated polycythemia vera (PV). METHODS: We collected data from 570 consecutive newly-diagnosed subjects with PV and JAK2 mutation, and compared clinical and laboratory features between patients with JAK2 exon12 and JAK2 V617F mutation. RESULTS: 543（95.3％）subjects harboured JAK2 V617F mutation (JAK2 V617F cohort), 24（4.2％）harboured JAK2 exon12 mutations (JAK2 exon12 cohort), and 3（0.5％）harboured JAK2 exon12 and JAK2 V617F mutations. The mutations in JAK2 exon12 including deletion (n＝10, 37.0％), deletion accompanied insertion (n＝10, 37.0％), and missense mutations (n＝7, 25.9％). Comparing with JAK2 V617F cohort, subjects in JAK2 exon12 cohort were younger［median age 50（20–73）years versus 59（25–91）years, P＝0.040］, had higher RBC counts［8.19（5.88–10.94）×10(12)/L versus 7.14（4.11–10.64）×10(12)/L, P<0.001］and hematocrit［64.1％（53.7–79.0％）versus 59.6％（47.2％–77.1％）, P＝0.001］, but lower WBC counts［8.29（3.2–18.99）×10(9)/L versus 12.91（3.24–38.3）×10(9)/L, P<0.001］, platelet counts［313（83–1433）×10(9)/L versus 470（61–2169）×10(9)/L, P<0.001] and epoetin［0.70（0.06–3.27）versus 1.14（0.01–10.16）IU/L, P＝0.002］levels. We reviewed bone marrow histology at diagnosis in 20 subjects with each type of mutation matched for age and sex. Subjects with JAK2 exon12 mutations had fewer loose megakaryocyte cluster (40％ versus 80％, P＝0.022) compared with subjects with JAK2 V617F. The median follow-ups were 30 months (range 4–83) and 37 months (range 1–84) for cohorts with JAK2 V617F and JAK2 exon12, respectively. There was no difference in overall survival (P＝0.422) and thrombosis-free survival (P＝0.900). CONCLUSION: Compared with patients with JAK2 V617F mutation, patients with JAK2 exon12 mutation were younger, and had more obvious erythrocytosis and less loose cluster of megakaryocytes.