Advertisement

How I Treat Polycythemia Vera

Jerry L. Spivak

Abstract

Since its discovery 125 years ago, polycythemia vera (PV) has been a challenge to the clinicians responsible for its diagnosis and management, and the scientists attempting to define its molecular basis. As a clonal hematopoietic stem cell disorder, PV is a neoplasm but its driver mutations result in increased production of morphologically and functionally normal blood cells. Although PV arises a pluripotent hematopoietic stem cell, it can present as isolated erythrocytosis, leukocytosis, thrombocytosis, any combination of these and splenomegaly or with myelofibrosis, and it may take years for a true panmyelopathy involving all three myeloid elements to appear. PV shares the same mutations activating Janus Kinase 2 as its companion disorders, essential thrombocytosis and primary myelofibrosis, but erythrocytosis only occurs in PV. From a diagnostic perspective, erythrocytosis provides the basis for recognizing PV, but unlike other causes of erythrocytosis, in PV, the plasma volume is frequently expanded masking the erythrocytosis and making diagnosis a challenge if this essential fact is ignored. Furthermore, PV is not a monolithic disorder: women patients deregulate fewer genes and behave differently clinically than their male counterparts, while some patients are genetically predisposed to a more aggressive clinical course. Nevertheless, based on what we have learned over the past century, most PV patients can lead long and productive lives. In this review, using clinical examples, I describe how I diagnose PV using a validated method and how I manage the disease without relying on chemotherapy while adhering to the dictates of precision medicine.

  • Submitted September 20, 2018.
  • Revision received April 28, 2019.
  • Accepted April 26, 2019.