Is Low Positive JAK2 V617F Mutation Test Result Clinically Significant?: Multi-Institutional Study.

Area of Science:

• Hematology
• Molecular Diagnostics
• Oncology

Background:

• The Janus kinase 2 (JAK2) V617F mutation is a key marker in myeloproliferative neoplasms (MPN).
• The clinical significance of low-level JAK2 V617F positivity, often detected by allele-specific real-time polymerase chain reaction, remains unclear.

Purpose of the Study:

• To investigate the clinical significance of low positivity JAK2 V617F mutations.
• To determine if low positive JAK2 V617F results are indicative of MPN or other conditions.

Main Methods:

• Retrospective analysis of 1697 JAK2 V617F mutation tests performed between 2010-2012.
• Defined low positive JAK2 V617F as 0.2% to 5% mutant allele.
• Conducted chart reviews for clinical correlation of low positive cases.

Main Results:

• Forty-five cases (2.65%) showed low positive JAK2 V617F (average 1.45%), with 62% having <1% mutant allele.
• Eight cases had a history of MPN; the rest were associated with reactive conditions.
• Low positivity of JAK2 V617F was observed in both MPN and non-clonal reactive conditions.

Conclusions:

• Arbitrary cutoffs for JAK2 V617F interpretation are not recommended.
• All low positive JAK2 V617F results should be reported.
• Clinical information is crucial for the accurate interpretation of low positive JAK2 V617F findings.