真性红细胞增多症和原发性血小板增多症JAK2 V617F基因纯合突变克隆分析

A Higher JAK2 V617F Homozygous Mutated Clone is Observed in Polycythemia Vera than in Primary Thrombocytosis

目的定量检测并分析JAK2V617F突变等位基因在真性红细胞增多症(polycythemia vera,PV)和原发性血小板增多症(essential thrombocythemia,ET)中的分布情况。方法分别建立位点特异性PCR和荧光实时定量PCR检测JAK2V617F突变的方法,对40例PV、31例ET标本和对照标本(急性白血病和正常人标本各40例)进行检测,统计分析2种方法的突变检出率、突变等位基因比例在2种疾病中的差异及其与年龄、性别的相关性。结果位点特异性PCR法和荧光实时定量PCR法在PV患者中检测阳性率分别为87.5%和92.5%,在ET患者中检测阳性率分别为51.6%和64.5%,在急性白血病和正常对照标本中均未检测到突变。突变阳性的PV患者突变型等位基因比例为0.436±0.261,其中携带纯合突变者占PV患者总数的40.54%。突变阳性的ET患者中突变型等位基因比例为0.216±0.207,其中携带纯合突变者占ET患者总数的10%。统计分析表明在PV和ET患者中突变型等位基因比例和患者性别无关(P值分别为0.342和0.154)。突变阳性的PV和ET患者中突变等位基因比例和年龄无相关性(PV:r=0.161,P=0.342;ET:r=0.331,P=0.154)。结论PV患者较ET患者携带更多突变的等位基因,PV患者携带纯合突变的比例是ET患者的4倍。采用较高灵敏度的检测方法有助于提高JAK2V617F突变的检出率。

Objective To analyze the mutation allele ratio in polycythemia vera （PV） and essential thrombocythemia （ET） samples. Methods SB-ASA and real-time PCR assays were developed and performed for JAK2 V617F detection on 40 PV samples, 31 ET samples and control samples（40 acute leukemias and 40 normal samples）. Difference between detection rates of the two assays was analyzed. Ratio between mutation alleles in PV and ET samples and their relevance with biological characters were also analyzed. Results More mutation positive samples were detected with real-time PCR than with SB-ASA assay. The detection rates in PV and ET were 87.5% and 51.6% with SB-ASA PCR but 92.5% and 64.5% with real-time PCR respectively. No mutation was detected in control samples. The mutation allele ratio was 0.436±0. 261 in PV and 0.216±0. 207 in ET respectively. Percent age of homozygous mutation in PV was 40.54% and in ET was 10%. Statistical analysis showed no relevance between mutation allele ratio and sex and age. Conclusion The JAK2 V617F mutated allele ratio is higher in PV than in ET; The ratio of homozygous mutated clone in PV is 4 times of that in ET. The pathogenesis of PV or ET has relationship with the mutation allele ratio of JAK2.