What is Polycythemia Vera?
Polycythemia vera (PV) is a medical condition in which your body makes too many red blood cells. The increase in red blood cells can thicken your blood, causing it to flow slower and clot easier. Sometimes, the body also produces too many white blood cells and platelets, which are cell fragments that help with clotting. This condition is a type of cancer that happens because a specific kind of cell in your body grows and multiplies too much. This strange growth is due to the cells becoming more sensitive to substances that encourage growth. If you have PV, you may experience headaches, dizziness, and problems with blood circulation, like pain when walking, all caused by your blood being thicker than usual. Also, you might have an increased risk of blood clots due to this condition.
What Causes Polycythemia Vera?
The disease we’re talking about has a cause that appears to be related to abnormal cell growth. This means there is a flaw in the signals controlling cell growth, leading to an odd response to growth factors. This abnormal cell line obstructs regular cell development.
In this condition, a gene known as Janus kinase-2 (JAK2), which helps control signals inside the cells, is changed in about 90% of cases of a condition called polycythemia vera (PV), a blood disorder that causes your body to make too many red blood cells.
Studies of cell genetics have also found that about 34% of PV patients display an unusual pattern in the genes in their blood-producing (hematopoietic) mother cells. At PV diagnosis, around 20% of patients have this kind of abnormality, but this number increases to over 80% for those who have been closely followed for more than 10 years.
Risk Factors and Frequency for Polycythemia Vera
Polycythemia vera, also known as PV, is a condition that can impact anyone, regardless of their ethnic group or gender, although it’s slightly more common in men. It can happen at any age, but people are usually diagnosed when they are around 60. In the United States, PV affects between 0.6 to 1.6 people per million. However, it’s less common in Japan compared to the United States or Europe.
- Polycythemia vera (PV) can affect people of all ethnic groups and of both sexes.
- It is slightly more prevalent in men.
- PV can occur at any age, but generally, people are diagnosed around the age of 60.
- In the United States, PV affects between 0.6 to 1.6 people out of a million.
- The condition is less common in Japan compared to the United States and Europe.
Signs and Symptoms of Polycythemia Vera
Polycythemia vera, or PV, is a condition linked to thickened blood that can interfere with how well oxygen is delivered to the body. Physical symptoms of this condition can include inconsistent signs such as being tired, headaches, dizziness, ringing in the ears, changes in vision, sleep issues, leg pain during walking, itching, stomach inflammation, and feeling full early while eating. A specific type of itching known as Aquagenic pruritus, which occurs during or after taking a hot shower, is a complaint in 40% of individuals suffering from this condition. Another characteristic condition, called Erythromelalgia, refers to a burning pain in the hands and feet with redness or paleness. This responds well to low-dose aspirin. Other complications can include both bleeding and blood clot related issues.
- Fatigue
- Headache
- Dizziness
- Ringing in the ears
- Changes in vision
- Issues sleeping
- Leg pain while walking
- Itching
- Stomach inflammation
- Feeling full early
- Bleeding issues such as nosebleeds, gum bleeding, and gastrointestinal bleeding
- Blood clot related issues, including deep vein thrombosis, pulmonary embolism, Budd-Chiari syndrome, splanchnic vein thrombosis, stroke, and arterial thrombosis
- Patients may also have reddening and warming of face and palms, red eyes, and skin abrasions from itching
- Enlarged spleen and liver are also commonly seen
Testing for Polycythemia Vera
In the 1970s, a group of medical researchers established the initial criteria for diagnosing a blood disease called polycythemia vera (PV). According to their guidelines, to get a diagnosis of PV, you either needed to meet all three of the primary (A) criteria, or the first two primary criteria and two additional (B) criteria.
The primary criteria included having a high total amount of red blood cells (36 mL/kg in men or 32 mL/kg in women), having blood oxygen levels of 92% or above, and having an enlarged spleen. As for the additional criteria, they involved high platelet counts (over 400,000/microliter), high white blood cell counts (over 12,000/microliter), high levels of an enzyme called leukocyte alkaline phosphatase (over 100 U/L) and high levels of vitamin B12 (over 900 pg/mL) or vitamin B12 binding capacity (over 2200 pg/mL).
Now, one of the key tests for measuring red blood cell mass involved using a radioactive isotope called Cr-51, which isn’t widely accessible today. As a result, these original guidelines are not widely used anymore. Instead, in 2016, the World Health Organization (WHO) issued updated guidelines for diagnosing PV.
The WHO guidelines comprise three primary and one additional diagnostic criterion. To be diagnosed with PV, you need to meet either all three primary criteria or two primary plus one additional criterion. The primary criteria according to WHO are: high levels of hemoglobin or hematocrit (these are different measures of your red blood cell levels), specific changes in your bone marrow (such as increased cell activity and growth of all three types of marrow cells, including abnormal variations in size), and a specific mutation in a gene called JAK2. The additional criterion is low levels of a hormone called erythropoietin. Erythropoietin usually stimulates the body to make red blood cells, and having a low level is unusual in a person with polycythemia, whose body is overproducing red blood cells.
A crucial point to remember, however, is that these criteria should only be applied after ruling out other potential causes of high red blood cell counts.
Treatment Options for Polycythemia Vera
While there is currently no cure for the condition known as polycythemia vera (PV) – a rare blood disorder that causes your body to produce too many red blood cells – treatment is geared towards relieving symptoms and reducing the risk of complications, such as clot formation, bleeding, and the disease transforming into other conditions. Unfortunately, there is no known method for preventing the disease from transforming into other conditions, such as myelofibrosis – a disorder that disrupts your body’s normal production of blood cells – or acute leukemia, a type of cancer that affects your blood and bone marrow.
For patients under 60 years old who haven’t had a history of clotting problems, the risk is considered low. The suggested treatment for these patients includes:
– Phlebotomy: This is a procedure where some blood is removed from your body. It’s done to reduce the concentration of red blood cells in your blood (hematocrit), with a target of less than 45%. This procedure limits the bone marrow’s ability to produce red blood cells and can help prevent heart-related and clotting events. During this procedure, iron supplements should not be taken, as the goal is to create a mild state of iron deficiency, which can help restrict red blood cell production.
– The use of low-dose aspirin once or twice a day, if there are no reasons not to use it (contraindications), helps reduce the risk of clot formation. However, if patients have too many platelets – a type of blood cell that helps form clots – it can increase the risk of bleeding, so aspirin should not be used.
For patients who are 60 years or older or have had clotting problems, they’re considered high risk. In these cases, a treatment called cytoreductive therapy is recommended on top of phlebotomy and aspirin. This type of treatment reduces the number of blood cells in your body, and safe and cost-effective drugs like hydroxyurea are typically used. Other alternatives can be considered if hydroxyurea is unsuccessful or causes side effects.
Itchiness can be managed by using antihistamines and specific types of depression medications known as selective serotonin reuptake inhibitors (SSRIs). If these treatments aren’t effective, certain specialty medications can be used.
In some cases, a surgical procedure to remove the spleen (splenectomy) may be needed, such as in instances when the spleen becomes painfully enlarged or experiences repeated damage from lack of blood supply (infarcts). Certain complications may require other types of surgical interventions as well.
A medication called ruxolitinib, which inhibits a certain protein involved in cell growth, has been approved for use in treating patients with PV who don’t respond well to or cannot tolerate hydroxyurea treatment. It has been found to effectively reduce the number of blood cells in a significant proportion of treated patients.
Please remember to consult with your doctor for advice tailored to your specific situation, as each individual’s health condition can differ.
What else can Polycythemia Vera be?
Polycythemia vera (PV) is a condition where the body produces too many blood cells. To diagnose primary PV, we need to see an increase in production of red blood cells, white blood cells, and platelets – if only the red cell count is high, it’s not enough for a diagnosis. This is because other conditions such as chronic exposure to low oxygen levels and tumors that produce a hormone called erythropoietin can also produce high blood counts. Secondary polycythemia, which happens due to low oxygen levels or smoking, is much more common than primary PV and must be ruled out before we make a diagnosis.
There’s also a rare condition that can seem like PV. In this case, there’s a genetic mutation, leading to an overly sensitive response to erythropoietin which results in an increased red cell number and a decrease in erythropoietin level.
Keep in mind that having a high white cell count could be a response to infections or other conditions that behave like leukemia. A high platelet count alone could result from bleeding or iron deficiency.
To determine if it’s PV, it is necessary to consider possible alternatives diagnoses as:
- Essential thrombocythemia
- Chronic myelogenous leukemia (repeated twice in the original, so we keep it once)
- Agnogenic myeloid metaplasia
- Primary myelofibrosis
- Secondary polycythemia
What to expect with Polycythemia Vera
Polycythemia vera (PV), a health condition characterized by increased red blood cells in the body, has an average survival rate of 18 months if left untreated. Still, with the right treatment, the average lifespan can be considerably higher. On average, someone with PV could expect to live for 14 years with treatment, and up to 24 years if they are under the age of 60.
One study found that mortality, or the death rate, is higher in people with PV compared to those of the same age and gender without the condition. Despite this, the five-year survival rate for those with PV is 79.5%. However, people with PV are at a higher risk of developing other cancers or experiencing a change in their condition that turns it into leukemia. This could impact their chances of long-term survival.
Possible Complications When Diagnosed with Polycythemia Vera
Complications and mortalities from polycythemia vera, a blood disorder, can occur due to blood clots, bleeding, stomach ulcers, myelofibrosis (scarring of bone marrow), acute leukemia (rapidly progressing cancer of blood and bone marrow), or myelodysplastic syndrome (group of disorders caused by poorly formed blood cells).
Blood clotting is a major complication of polycythemia vera, and treatments are targeted at reducing this risk. In the event of a first blood clot, a recommended amount and duration of anticoagulation medication (medication to prevent blood clots) is advised. Current treatment guidelines are the same for patients with underlying polycythemia vera.
Bleeding is also a common complication of this condition, however, serious bleeding is not common. The risk of excessive bleeding is higher in case of severe thrombocytosis (high platelet count) and consumption of high-dose aspirin (over 100 mg/day) or anticoagulation medication.
As the disease progresses, myelofibrosis can worsen. The suggested treatment for myelofibrosis caused by polycythemia vera is identical to the treatment procedure for primary myelofibrosis. If the condition transforms into myelodysplasia and acute leukemia, the prognosis is generally unfavorable. Treatment for such cases is similar to the treatment for primary myelodysplastic syndrome and acute myeloid leukemia.
Common Complications:
- Blood clots
- Bleeding
- Stomach ulcers
- Myelofibrosis
- Acute leukemia
- Myelodysplastic syndrome
Preventing Polycythemia Vera
Polycythemia vera (PV) is a health issue where your bone marrow—which is the sponge-like tissue inside your bones making blood cells—starts working too hard, resulting in an overproduction of red and white blood cells as well as platelets. This excess can lead to serious health risks such as blood clots, which can be life-threatening, excessive bleeding and even specific kinds of blood cancer. Because of these risks, it’s crucial that you collect regular check-ups with a blood specialist, known as a hematologist, to closely track your condition and find the best methods to reduce these risks. The available treatments range from drawing out some of your blood (phlebotomy), taking daily doses of aspirin, to using certain types of medication that tame the overactivity in the bone marrow.
