If you have been diagnosed with paroxysmal nocturnal hemoglobinuria (PNH), you may also have other health conditions that are more common in people with this blood disorder. In some cases, other conditions may occur first and increase your risk of being diagnosed with PNH.
When someone has more than one disease at the same time, the conditions are known as comorbidities. Other conditions are more likely to occur after PNH has already developed. When a second medical condition develops during an existing disease or after its treatment, it is known as a complication.
Having a comorbidity or complication may make it harder for your health care team to diagnose or treat your PNH. It may even influence your prognosis (the likely course of disease). However, understanding how other conditions are related to PNH can help you talk to your doctor about treatment options. Addressing these related conditions may help you feel better, have a better prognosis, and improve your overall health and quality of life.
Several conditions can occur alongside PNH.
Experts have only identified one risk factor for developing PNH, and that is being diagnosed with aplastic anemia. Between 10 percent and 20 percent of those with aplastic anemia will go on to develop PNH.
Aplastic anemia is a disorder of the bone marrow — the soft, spongy tissue found inside certain bones. Within the bone marrow, stem cells make all of the different types of blood cells found in your body (red blood cells, white blood cells, and platelets). In aplastic anemia, the stem cells develop abnormalities that prevent them from producing enough healthy blood cells. This is known as bone marrow failure.
PNH and aplastic anemia have many similarities. They are both thought to develop when your immune system attacks your stem cells. Additionally, they can lead to some of the same sets of symptoms. PNH may develop before or after aplastic anemia occurs.
Myelodysplastic syndromes (MDS) are a group of bone marrow failure syndromes that occur in about 2 percent to 8 percent of those with PNH.
MDS also occurs due to problems with the bone marrow stem cells. There are multiple forms of MDS that lead to low levels of one or more types of blood cells. MDS is often thought to be caused by gene mutations and things that can damage the genes — such as cancer treatments or being exposed to certain chemicals. In some cases, MDS can progress to leukemia.
Because PNH and MDS both cause a drop in blood cell counts, they can cause some similar symptoms. A diagnosis of PNH may come before or after MDS develops.
About half of people with PNH also have pulmonary hypertension.
Pulmonary hypertension occurs when blood pressure levels rise too high within the blood vessels that connect the heart to the lungs. It can cause chest pain, a fast heart rate, breathing difficulties, dizziness, sleepiness, or blue-tinged skin. Pulmonary hypertension can be serious, and it’s important to get proper treatment for this condition.
For people with PNH, pulmonary hypertension may develop as a complication of hemolysis (the destruction of red blood cells). When red cells break apart, they release a protein called hemoglobin, which can block another substance in the blood called nitric oxide. Nitric oxide is important for keeping your blood pressure levels low, so when you don’t have enough of it due to hemolysis, pressure in your blood vessels may rise.
Blood clots are a complication that occurs in at least one-third of people with PNH.
Usually, blood clotting is a good thing. This process, triggered by platelets, protects you from losing too much blood when you are injured. However, blood clots are a problem if your body makes too many of them, if they occur in parts of the body where they aren’t needed, or if they don’t break down and go away after they initially form.
In general, the most common blood clotting problems are deep vein thrombosis (a clot that forms in the leg or arm) or pulmonary embolism (a clot that forms in the lungs). However, people with PNH are most likely to get blood clots in the brain or abdomen, including in the intestines or spleen. Blood clots typically produce a lot of pain and swelling in the affected area.
PNH may also cause Budd-Chiari syndrome, a condition in which a blood clot forms in a vein within the liver. This can prevent the liver from working normally, leading to abdominal bloating, nausea, and pain or swelling in the upper right side of your abdomen.
Blood clots can cause serious health issues and are sometimes even life-threatening. You should contact emergency services right away if you think you’re experiencing signs of a clot.
Rarely, PNH can occur along with paroxysmal cold hemoglobinuria (PCH), a type of autoimmune hemolytic anemia that also leads to low red blood cell counts.
PCH may develop after an infection. It can lead to symptoms like fever, red or brown urine, abdominal pain, shortness of breath, and jaundice (a yellow tinge to the skin or whites of the eyes).
Both PNH and PCH lead to low levels of red blood cells because these cells are prematurely destroyed. However, they have different causes. PNH occurs when the body makes abnormal red blood cells that aren’t protected from the normal actions of the immune system. PCH occurs when the body produces abnormal immune cells that mistakenly attack healthy red blood cells.
Although it is very rare, PNH can sometimes lead to kidney disease. It’s not clear why, but hemolysis can occasionally cause kidney injury. PNH may also cause blood clots to form in the kidneys’ blood vessels.
Some people with PNH go on to develop acute myeloid leukemia (AML), a form of cancer that causes stem cells in the bone marrow to grow out of control. In AML, stem cells make high amounts of abnormal red blood cells, white blood cells, or platelet-producing cells.
Having AML as a comorbidity is rare — leukemia in general only occurs in 3 percent to 5 percent of those with PNH.
Most cases of PNH are caused by a mutation in the PIGA gene. However, in very rare cases, the condition can be the result of a mutation in a different gene called PIGT. This PIGT mutation leads to inflammatory PNH that causes symptoms like meningitis.
Meningitis is swelling of the tissue that surrounds your brain and spinal cord. It may cause fever, headache, a stiff neck, nausea, confusion, fatigue, or loss of appetite. It requires immediate medical care.
PNH may also lead to inflammatory bowel disease (IBD), although this is also very rare. IBD includes two different conditions, ulcerative colitis and Crohn’s disease, both of which lead to inflammation in the intestines. IBD causes abdominal pain, diarrhea, bloody stool, tiredness, and weight loss.
On myPNHteam, the site for people with paroxysmal nocturnal hemoglobinuria and their loved ones, members come together to ask questions, offer advice, and share their stories with others who understand life with PNH.
Do you have other health conditions besides PNH? Did you find this article helpful?Share your experience in the comments below, or start a conversation on your Activities page.
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