A 56 year old female is referred to clinic for a RBC count of 6.98 x 1012/L and hemoglobin of 190g/L with a platelet count of 750 x 109/L.
Differentiate between primary (bone marrow) and secondary causes of polycythemia.
Her erythropoietin level is low at 2 IU/L and she has splenomegaly on exam. A JAK2 level is requested on the patient’s peripheral blood as there is suspicion of a myeloproliferative neoplasm.
What does the JAK2 level stand for?