Use of JAK 2 v617f As a Hypercoagulable Test in a Community Hospital

Introduction: We have anecdotally noticed that hypercoagulable workups are often performed unnecessarily within our community hospital in Orlando Florida. Some providers have a tendency to include JAK2 v617f, a test associated with high cost and one that can take weeks to have results return, as part of their panels. We hypothesize that this test is over utilized and will rarely be helpful in the workup of thrombosis without other reasons to suspect myeloproliferative disorders. We opted to look back at ordering patterns of JAK2 v617f and chart review the reasons it was ordered.

Methods: Using a chart review, we pulled hundreds of charts in which a JAK2 v617f was ordered. We then scrolled through the charts to determine if thrombosis was an ordering reason. If so, we documented a positive or negative result and if the thrombotic event could be explained by other factors.

Results: 120 charts were reviewed. Of the 120, 10 (8%) had JAK 2 v617f as part of a hypercoagulable panel. The remainder of testing was relegated to patients with erythrocytosis, thrombocytosis, or leukocytosis. When the JAK 2 test was used for hypercoagulable workup, it was negative in every case. The thrombosis included:

• Splanchnic vein in two cases

• Splenic infarct in one case

• Single episode of deep vein thrombosis or pulmonary embolism in three cases

• Recurrent deep vein thrombosis or pulmonary embolism in three cases

• Cerebral vascular accident in one case

Risk factors for thrombotic events were documented in seven cases.

Conclusion While the majority of JAK2 v617f testing was done for reasons beyond thrombotic workup, when used of part of a thrombophilia workup, the testing was not useful. While there may be a limited role for testing in clots at unusual sites or unexplainable thrombotic events at a young age, most of the testing done at our institution did not fit this pattern. Routine testing should be looked at and discouraged in inappropriate situations. The cost of the test and the concerns about delaying hospital discharge or raising patient anxiety while awaiting results do not justify the limited utility of this test.

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