Detection of the JAK2 V617F Mutation in Urinary Cell-free DNA in Patients with Myeloproliferative Neoplasms

Abstract

Objective Testing for the Janus activating kinase 2 (JAK2) V617F mutation is important for diagnosing and treating myeloproliferative neoplasms (MPNs). Recently, urine cell-free DNA (ucfDNA) was reported to be useful for detecting tumor-specific gene mutations in several solid tumors. However, its utility in detecting such mutations in hematological malignancies has not yet been assessed. In this study, we assessed whether or not the JAK2 V617F mutation could be detected in ucfDNA and whether or not its positivity rate in ucfDNA was associated with the JAK2 V617F allele ratio of peripheral blood cells in patients with MPN. Methods The JAK2 V617F allele ratio of genomic DNA from peripheral blood cells was determined using quantitative polymerase chain reaction (qPCR) or droplet digital PCR (ddPCR). ucfDNA was subjected to ddPCR. The correlation between the JAK2 V617F mutation positivity rates of blood-derived DNA and those of ucfDNA was assessed. Materials Twelve patients with polycythemia vera and 12 patients with essential thrombocythemia were enrolled. Ethylenediaminetetraacetic acid-treated peripheral blood (100 mL) and 15-30 mL of fresh urine were used. Results The JAK2 V617F mutation was detected in the ucfDNA from all 20 JAK2 V617F mutation-positive patients. In addition, the JAK2 V617F mutation positivity rate of ucfDNA was correlated with the JAK2 V617F allele ratio of blood-derived DNA, including in both estimated glomerular filtration rate (eGFR) groups (patients with an eGFR ≥50 or <50 mL/min/1.73 m²). Conclusion Our results indicate that ucfDNA is a valuable tool for diagnosing and monitoring MPN. Given these findings, other disease-specific gene mutations in hematological malignancies may also be detectable in ucfDNA.

Keywords: JAK2 V617F mutation; digital PCR; liquid biopsy; myeloproliferative neoplasm; urinary cell-free DNA.

Figure 1.

(a) Urine cell-free DNA (ucfDNA) concentrations in JAK2 V617F mutation-positive patients with an estimated glomerular filtration rate (eGFR) of <50 or ≥50 mL/min/1.73 m². (b) Representative scatterplots of JAK2 V617F mutation detection in ucfDNA using digital droplet polymerase chain reaction (ddPCR). In this sample, the ucfDNA concentration was 0.9 ng/mL. Although the ucfDNA concentration was <1 ng/mL, the JAK2 V617F mutation was detectable. Blue droplets: JAK2 V617F mutation-positive; green droplets: JAK2 wild-type. (c) Correlation of JAK2 V617F mutation (%) positivity between blood-derived DNA and ucfDNA among all JAK2 V617F mutation-positive patients.

Figure 2.

Correlation of JAK2 V617F mutation (%) positivity between blood-derived DNA and ucfDNA among JAK2 V617F mutation-positive patients with polycythemia vera (PV) (a), essential thrombocythemia (ET) (b), an eGFR of <50 mL/min/1.73 m² (c), or an eGFR of ≥50 mL/min/1.73 m² (d).