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Abstract
Background:
Real-time PCR for quantification of JAK2 V617F has recently been introduced and used to evaluate the importance of mutant allele burden in both diagnosis and disease progression in myeloproliferative diseases (MPDs). We evaluated the usefulness of JAK2 MutaScreen™ kit that uses a real-time semiquantitative PCR method and has been designed to screen JAK2 V617F mutant allele burden.
Methods:
Forty MPD patients were included in this study. We screened JAK2 V617F and determined the mutant allele burden using JAK2 MutaScreen™ kit. The mutant allele burden was estimated by six-scaled standards of JAK2 V617F mutant allele (2%, 5%, 12.5%, 31%, 50%, and 78%). For evaluation of test performance, an allele-specific PCR (AS-PCR) was carried out in all samples by using Seeplex JAK2 Genotyping kit. We assessed the clinical differences in distinct disease entities of MPDs according to JAK2 V617F mutant allele burden.
Results:
JAK2 V617F mutation was detected in 30 cases, including 10 of 11 cases (91%) of polycythemia vera (PV), 13 of 20 cases (65%) of essential thrombocythemia (ET), and 2 of 3 cases (67%) of chronic idiopathic myelofibrosis (CIMF). The concordance rate between the two tests was 95% (38/40). JAK2 V617F mutant allele burden was greater than 50% in 17 cases, and 10 of them (59%) were PV. In contrast, mutant allele burden was less than 50% in 13 cases and 11 of them (85%) were ET.
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Fig. 1.
Distribution of JAK2 V617F allele burden determined by JAK2 MutaScreen™ kit in 30 cases of JAK2 V617F positive MPDs. Abbreviations: PV, polycythemia vera; ET, essential thrombocythemia; CIMP, chronic idiopathic myelofibrosis; MPD-U, myeloproliferative disease, unclassifiable.
Table 1.
Clinical characteristics of 40 MPDs patients according to JAK2 V617F mutation status determined by JAK2 MutaScreen™ kit
| Characteristics | JAK2 V617F | |
|---|---|---|
| Present (N=30) | Absent (N=10) | |
| Diagnosis | ||
| PV (N=11) | 10 (91%) | 1 (9%) |
| ET (N=20) | 13 (65%) | 7 (35%) |
| CIMF (N=3) | 2 (67%) | 1 (33%) |
| MPD-U (N=5) | 5 (100%) | 0 (0%) |
| MDS/MPD-U (N=1) | 0 (0%) | 1 (100%) |
| Complications∗ | 8 | 7 |
| Abnormal karyotype | 2 | 1 |
| Palpable spleen | 8 | 0 |
| Cytoreductive treatment | 22 | 5 |
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