Myeloproliferative neoplasms (MPNs, formerly referred to as myeloproliferative disorders) are a group of blood diseases. In each type of MPN, there is an overproduction of one or more blood stem cells in the bone marrow. Red blood cells (RBCs), white blood cells (WBCs) called neutrophils, and platelets may be dysfunctional and excessive in the bone marrow and blood circulation. MPN symptoms are caused by these high levels of abnormal blood cells. Treatment options for MPNs depend on the type of disease.

There are several health conditions that are significantly more common in people with MPNs than in the general population. When someone has more than one health condition at the same time, the conditions are known as comorbidities. Comorbid conditions may be related to MPNs in different ways. When an additional medical issue makes an existing disease harder to treat, it is known as a complication. In people with MPNs, having a comorbidity can complicate cancer treatment and add to the disease burden. Comorbidities are believed to contribute significantly to fatigue in MPNs.

Knowing the common comorbidities of MPNs can help you recognize symptoms and talk to your doctor about treatment. Treating comorbidities may improve quality of life and lower the risk for life-threatening complications.

Some medications can cause dangerous interactions. Always make sure your health care provider is aware of every medication you are taking for every condition, whether it is available over the counter or by prescription, including any vitamins or herbal supplements.

Infections

People with MPNs have a significantly higher risk for developing bacterial, viral, and fungal infections than people of similar ages who have not been diagnosed with MPN. One study found the risk for dying from infections, especially bacterial infections, was higher in people with MPNs than in the general population.

According to one study, people with MPNs have increased risk for infections including:

• Pneumonia
• Urinary tract infections
• Viral hepatitis

The study also found a significantly higher risk in people with MPN for sepsis, a potentially life-threatening immune response to an infection.

Susceptibility to infections may be due both to MPNs themselves and to the effects of MPN treatments. JAK2 inhibitors, a class of medications often used to treat MPNs, can contribute to a higher risk for infections.

Since infections are more likely to become serious in people with MPNs, it’s important to contact your doctor or a nursing advice line if you experience any of the following symptoms:

• Temperature above 99.5 F or below 96.8 F
• Skin feeling hot when touched
• Chills
• Any body pain you did not have before MPN treatment
• Coughing or shortness of breath
• Pain during urination
• Redness, pain, swelling, or discharge at the site of intravenous (IV) lines

Cardiovascular Conditions

Chronic inflammation in MPNs is believed to contribute to the development of cardiovascular complications such as atherosclerosis (also referred to as “hardening of the arteries”) in people with MPNs. Younger people with MPNs have a higher risk for dying from cardiovascular events, such as myocardial infarctions (heart attacks) or strokes, than people of similar ages who have not been diagnosed with MPNs.

Your risk for cardiovascular problems is even higher if these additional risk factors are present:

• Hypertension (high blood pressure)
• Diabetes
• Smoking

You and those you live with should be aware of the symptoms of severe cardiovascular events. Heart attack and pulmonary embolism (blood clot in the lung) can cause chest pain, shortness of breath, and nausea. Strokes can cause severe headaches, disorientation or impaired speech, and weakness in the arms or legs. Call emergency services immediately if you or your loved one experience any of these symptoms.

If you are concerned about your risk for serious cardiovascular complications, your doctor can help you find ways to reduce your risk. These may involve stopping smoking, getting regular exercise, and making changes to your diet, as well as medication. Depending on the specifics of your individual condition, your doctor may recommend taking aspirin, which can help lower the risk for thromboembolisms (blood clots), heart attacks, and strokes in some people. However, aspirin can also raise the risk for bleeding. Always talk to your doctor before making any changes to your treatment regimen.

Blood and Bleeding Disorders

Since MPNs cause overproduction of blood cells, and the blood cells tend to be abnormal and dysfunctional, it is not surprising that blood disorders are a common comorbidity.

Anemia is defined as having low levels of red blood cells. Anemia may be included as part of the criteria for diagnosing MPNs. Anemia can be caused directly by the MPN, or it may occur as a side effect of cancer treatment. It can also be caused by nutritional deficiencies of iron or vitamin B12 or by unrelated conditions. Symptoms of anemia include fatigue, weakness, pale skin, cold hands and feet, and shortness of breath. Anemia may be accompanied by feelings of pain, fullness, or pressure in the abdomen resulting from splenomegaly (enlarged spleen). Most MPN treatment regimens address anemia. Therapies may include red blood cell transfusion, nutrition, hormonal medication such as danazol, or angiogenesis inhibitors such as Thalomid (thalidomide) or Revlimid (lenalidomide).

People living with an MPN are more likely to experience both blood clots and bleeding problems. Blood clots can block arteries and cause life-threatening events such as stroke or pulmonary embolism. Bleeding may be minor or severe.

People with MPNs may develop acquired von Willebrand disease. Von Willebrand disease (VWD) is a bleeding disorder that can cause nosebleeds, excessive bleeding during dental and medical procedures, easy bruising, and heavy periods in women. In most cases, VWD is a genetic disorder, but it can sometimes be caused by MPNs, lupus, heart disease, or certain medications. In one study of 116 people with essential thrombocythemia (ET) and 57 people with polycythemia vera (PV), 55 percent of those with ET and 49 percent of those with PV developed acquired von Willebrand disease. There are several therapies available to treat VWD.

Autoimmune Disorders

There is evidence that people with MPNs may be predisposed to develop autoimmune (AI) disorders — chronic conditions in which the immune system mistakenly attacks one’s own tissues. Inflammation is a major aspect of autoimmunity and the direct cause of pain and tissue damage. In people with MPNs, AI conditions may worsen the symptom burden and even cause cancer cells to grow faster, contributing to disease progression.

These are the autoimmune conditions most commonly seen in those with MPNs, along with their major effects:

• Crohn’s disease can cause sores and damage anywhere in the gastrointestinal system, from the mouth to the anus.
• Lupus can affect any tissues, but often attacks the skin, kidneys, and nervous system.
• Psoriasis causes painful, itchy patches of skin with scales.
• Scleroderma causes skin to harden and develop sores. Joints can also be affected.
• Autoimmune hemolytic anemia destroys red blood cells.
• Aplastic anemia, also known as bone marrow failure, causes the body to stop making all types of blood cells.
• Polymyalgia rheumatica results in stiffness and pain in the muscles and joints.
• Reiter’s syndrome is a type of chronic arthritis.
• Giant cell arteritis causes inflammation in the arteries. Symptoms include headaches and vision changes.

Autoimmune conditions are chronic and may have a cycle of disease flares (when symptoms are intense) and remissions (when symptoms subside). Most AI conditions can be managed with medications that modify the immune system.

Secondary Cancers

People diagnosed with MPNs have a significantly increased risk for developing a secondary cancer — whether another type of blood cancer or different type of cancer altogether. Cancers that have been shown to develop more commonly in those with MPN than in other people include:

• Nonmelanoma skin cancer
• Kidney cancer
• Brain cancer
• Endocrine cancer
• Malignant melanoma
• Pancreatic cancer
• Lung cancer
• Head and neck cancer

MPNs can transform into acute blood cancers such as acute myeloid leukemia (AML) or lymphoma. Essential thrombocythemia and polycythemia vera can transform into myelofibrosis.

Your doctor can help you better understand your individual risk for developing related conditions and recommend steps to lower your risk.

MPN Condition Guide

• Myeloproliferative Neoplasms (MPNs) — An Overview
• Types of Myeloproliferative Neoplasms (MPNs)
• Diagnosing Myeloproliferative Neoplasms (MPNs)
• Symptoms of Myeloproliferative Neoplasms (MPNs)
• Treatments for Myeloproliferative Neoplasms (MPNs)
• What Causes Myeloproliferative Neoplasms (MPNs)?