单中心1648例Ph染色体阴性慢性骨髓增殖性肿瘤患者JAK2、CALR及MPL基因突变的临床分析

Clinical significance of JAK2, CALR and MPL gene mutations in 1 648 Philadelphia chromosomenegative myeloproliferative neoplasms patients from a single center

目的研究Ph染色体阴性的慢性骨髓增殖性肿瘤（MPN）患者JAK2、CALR及MPL基因突变情况，比较不同类型基因突变及突变阴性患者部分临床参数的差异。 方法采用基因测序法分别检测1 648例Ph阴性MPN患者JAK2V617F、JAK2基因12号外显子、CALR基因9号外显子及MPL基因10号外显子突变情况。 结果①JAK2V617F突变总检出率为82.8%（1 364/1 648），其中真性红细胞增多症（PV）为92.7%（471/508），原发性血小板增多症（ET）为78.1%（819/1 049），原发性骨髓纤维化（PMF）为81.3%（74/91）；JAK2基因12号外显子突变总检出率为0.5%（9/1 648），均为PV患者[1.7%（9/508）]；CALR基因突变总检出率为8.7%（143/1 648）,其中ET为12.6%（132/1 049），PMF为12.1%（11/91）；MPL基因突变总检出率为0.6%（10/1 648）,其中ET为0.9%（9/1 049），PMF为1.1%（1/91）。未发现两种及以上基因突变共存病例。②JAK2V617F突变组中位年龄[61（15-95）岁]高于JAK2 12号外显子突变组[49（33-62）岁]及突变阴性组[42（3-78）岁]（P值均〈0.001），与CALR突变组[57（17-89）岁]、MPL突变组[59（22-71）岁]比较差异无统计学意义（P〉0.05）。JAK2V617F突变阳性组白细胞计数、血红蛋白浓度均高于CALR突变阳性及阴性组（P〈0.05），而与MPL突变阳性组比较仅表现为高白细胞计数（P=0.013）；CALR突变组血小板计数高于JAK2V617F突变组[966（400-2 069）×109/L对800（198-3 730）×109/L，P〈0.001]。③共1 160例患者进行了有效染色体核型分析，CALR基因突变阳性、阴性患者异常核型检出率差异无统计学意义[9.8%（8/82）对7.4%（80/1 078），P=0.441]；JAK2V617F突变阳性、阴性患者异常核型检出率差异无统计学意义[7.7%（75/971）对6.9%（13/189），P=0.688]。CALR突变阳性组与JAK2V617F突变阳性组的异常核型检出率差异无统计学意义[9.8%（8/82）对7.7%（75/971），P=0.512]。7例JAK2基因12号外显子突变阳性及6例MPL基因突变阳性患者均未发现异常核型。 结论基因检测使MPN的诊断及预后判断有了更可靠的依据，不同MPN亚型基因突变的发生频率、分布情况不同，不同基因突变导致独特的临床表型。

Objective To explore the prevalences of JAK2, CALR and MPL gene mutations and the mutation types in patients with Philadelphia chromosome negative myeloproliferative neoplasms （MPNs）, and to compare their clinical characteristics of different mutation types with each other and mutation negative group. Methods The mutations ofJAK2 V617F, JAK2 gene at exon 12, CALR gene at exon 9 and MPL gene at exon 10 in 1 648 Ph negative MPNs patients were detected by direct sequencing.Results @The JAK2V617F mutation was found in 471 （92.7%） of 508 PV patients, 819 （78.1%） of 1 049 ET patients and 74 （81.3% ） of 91 PMF patients respectively, with the total mutation rate as 82.8% （ 1 364/1 648）. The JAK2 exonl2 mutation was found in 9 （ 1.7% ） of 508 PV patients, none was found in ET or PMF patients, with the total mutation rate as 0.5%（9/1 648）. The CALR mutation was found in 132 （12.6%） of 1 049 ET patients and 11 （12.1%） of 91 PMF patients respectively, with the total mutation rate as 8.7% （ 143/1 648）; the MPL mutation was found in 9（0.9%）of 1 049 ET patients and 1 （ 1.1%）of91 PMF patients respectively, with the total mutation rate as 0.6% （10/1 648）. The co-occurrence of any two types of driver gene mutations was not detected by direct sequencing. @The median onset age of patients with JAK2V617F [61 （ 15-95）yl was significant higher than of with JAK2 exonl2 mutationE49（33-62）y] or without mutations [42 （3- 78） yl （P〈0.001）, but not for patients with CALR [57 （ 17- 89） y] or MPL mutation [59 （22-71）y （P〉0.05）. Patients with JAK2V617F had higher white blood cell count and hemoglobin level （P〈0.05） when compared with patients with CALR mutation or without mutations, or only significantly higher white blood cell count when compared with patients with MPL mutation （P= 0.013）. The platelet count of patients with CALR mutation was significantly higher than of with JAK2V617F [966 （400-2 069） x 109/L vs 800 （ 198-3 730） x 109/L, P〈0.0011. @Karyotype analysis was conducted in 1 160 patients with MPNs, the rates of karyotype abnormality of patients with and without CALR mutation were 9.8% （8/82） and 7.4% （80/1 078） （P=0.441） respectively; The rates of karyotype abnormality of patients with and without JAK2V617F mutation were 7.7% （75/971） and 6.9% （13/189） （P=0.688） respectively. The incidence of karyotype abnormality of patients with CALR mutation was higher than of with JAK2V617F [ 9.8% （8/82） vs 7.7% （75/971 ） without statistically significant difference （P=0.512）. The karyotype analysis of 7 cases of JAK2 exonl2 mutation and 6 ones with MPL gene mutation revealed normal karyotype. Conclusions Driver gene mutations detection could ensure the diagnosis and prognosis judgment of MPN more reliable, different subtypes of MPNs had different profiles of driver gene mutations, the latter lead to unique clinical phenotype.