Kannim Supattra, Thongnoppakhun Wanna, Auewarakul Chirayu U
Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
Clin Chim Acta. 2009 Mar;401(1-2):148-51. doi: 10.1016/j.cca.2008.12.010. Epub 2008 Dec 14.
Philadelphia chromosome (Ph(1))-negative myeloproliferative disorders (MPD) are hematopoietic stem cell disorders characterized by extensive proliferation of myeloid blood cells. JAK2V617F has recently been identified in the majority of Ph(1)-negative MPD and becomes an essential diagnostic marker.
To screen for JAK2V617F, a two-round allele specific-polymerase chain reaction (AS-PCR) was developed and compared to PCR-restriction fragment length polymorphism (PCR-RFLP), denaturing high performance liquid chromatography (DHPLC), and DNA sequencing. A primary AS-PCR was performed followed by a secondary AS-PCR, which was an amplification of the primary AS-PCR products using the same set of primers under alternative conditions.
By primary AS-PCR, a strong mutant-DNA band was seen in the DNA mixture containing as low as 2.5% of mutant allele. An ambiguous band was seen in 1% dilution while being totally absent in 0.1% dilution. After secondary AS-PCR, a mutant DNA band was clearly detected at 0.01% dilution. The detection sensitivity of PCR-RFLP and DHPLC was 2.5% while sequencing analysis was unable to detect below 5% dilution.
Two-round AS-PCR is simple and inexpensive, making it a suitable method for JAK2V617F mutation screening. Moreover, monitoring of minimal residual disease after specific treatment of Ph(1)-negative MPD patients should be feasible with this highly sensitive method.
费城染色体(Ph(1))阴性骨髓增殖性疾病(MPD)是造血干细胞疾病,其特征为髓系血细胞广泛增殖。JAK2V617F最近在大多数Ph(1)阴性MPD中被发现,并成为一项重要的诊断标志物。
为筛查JAK2V617F,开发了一种两轮等位基因特异性聚合酶链反应(AS-PCR),并与聚合酶链反应-限制性片段长度多态性(PCR-RFLP)、变性高效液相色谱(DHPLC)和DNA测序进行比较。先进行一轮AS-PCR,然后进行二轮AS-PCR,二轮AS-PCR是在不同条件下使用同一组引物对一轮AS-PCR产物进行扩增。
通过一轮AS-PCR,在含有低至2.5%突变等位基因的DNA混合物中可见一条强的突变DNA条带。在1%稀释度时可见一条模糊条带,而在0.1%稀释度时完全没有。二轮AS-PCR后,在0.01%稀释度时可清晰检测到突变DNA条带。PCR-RFLP和DHPLC的检测灵敏度为2.5%,而测序分析在低于5%稀释度时无法检测到。
两轮AS-PCR简单且成本低廉,使其成为JAK2V617F突变筛查的合适方法。此外,用这种高灵敏度方法对Ph(1)阴性MPD患者进行特异性治疗后监测微小残留病应该是可行的。