Myeloproliferative disorders are a group of conditions characterized by overactivity in the bone marrow. Many of these conditions are driven by mutations in the JAK-2 gene (Janus Kinase 2 gene), which plays a crucial role in regulating the growth and production of cells in the bone marrow. While there are other mutations involved, JAK-2 mutations are among the most common.
Polycythemia Vera
Polycythemia vera is a condition in which the bone marrow produces an excessive number of red blood cells. Red blood cells are responsible for carrying oxygen throughout the body. Too few red blood cells result in anemia, leading to fatigue and weakness. Conversely, an excess of red blood cells, known as erythrocytosis or polycythemia, thickens the blood and increases the risk of headaches, flushing, stroke, and heart attacks.
Common Factors Leading to Elevated Red Blood Cells
Several factors can cause an increase in red blood cell production:
- Smoking: Smoking exposes the body to carbon monoxide, which poisons red blood cells. In response, the body produces more red blood cells to compensate for the damaged ones.
- Supplements like Testosterone: Testosterone, an androgen, stimulates red blood cell production.
- Sleep Apnea/Snoring: Sleep apnea and snoring result in reduced oxygen intake. The body compensates by producing more red blood cells to counteract the oxygen deficiency.
- Heart or Lung Conditions: When the heart or lungs can’t oxygenate properly, the bone marrow increases red blood cell production to compensate.
- Kidney Cysts: Kidneys produce erythropoietin, an enzyme that stimulates red blood cell production. Sometimes, this enzyme is overproduced, leading to excessive red blood cell production.
- Polycythemia Vera: Typically, a mutation in the JAK-2 gene causes the bone marrow to produce an excessive number of red blood cells, even when the body doesn’t require them.
Diagnosis and Treatment
To determine if polycythemia vera is the likely cause, a simple blood test can check for the JAK-2 mutation. If the mutation is present, polycythemia vera is likely. If the mutation is absent, other causes become more probable.
Treatment for polycythemia vera typically involves phlebotomies (removing blood). The frequency varies, with some patients requiring blood removal a few times a year and others more frequently. Other treatment options include hydroxyurea (a medication that suppresses a portion of the bone marrow), pegylated interferon alpha-2a (an injectable therapy that lowers hemoglobin levels), and JAKIFI (a medication that targets the mutant JAK-2 gene).
If the issue isn’t due to a JAK-2-driven disease but is related to sleep apnea or smoking, the best course of action is smoking cessation or addressing the underlying sleep apnea.
About the author
Dr. Daniel Landau is a distinguished board-certified hematologist/oncologist renowned for his exceptional contributions in the field. With an illustrious career spanning across esteemed institutions like the Orlando Health Cancer Institute and the Medical University of South Carolina, Dr. Landau’s expertise shines in both genitourinary oncology and hematology.
Engage with Dr. Landau’s expertise and ignite your curiosity on “Ask MedOnCMD” as he invites you to explore the vast landscape of oncology with a fresh outlook.