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PNH stands for paroxysmal nocturnal haemoglobinuria. It is a rare and debilitating disease of the bone marrow that affects the blood and major organs. PNH is not hereditary, but rather is an acquired illness caused by injury to the bone marrow stem cell. Put very simply, PNH occurs when a gene required for the bone marrow to produce normal blood cells becomes mutated, resulting in defective blood cells. Once affected, the mutated bone marrow gene produces blood cells – red, white and platelets – that do not function as effectively as normal cells. People living with PNH have red blood cells that lack a protein that protects them from being destroyed by complement – a substance in the blood that helps the immune system stave off foreign bodies. Without this protein, red blood cells are destroyed by complement in a process called haemolysis, much more quickly than in healthy individuals. Haemoloysis, or the destruction of red blood cells, can result in a number of health complications. PNH patients can experience symptoms including anaemia (lowered haemoglobin levels), liver and/or kidney failure, heart attack, stroke and blood clots.
Anyone can develop PNH. Though it is a very rare disease affecting around 90 Canadians, it affects individuals of all ages and ethnicities, and occurs equally in males and females. It is most commonly diagnosed in young adults in their 20s or 30s. PNH is not hereditary, but rather is an acquired illness caused by injury to the bone marrow stem cell. Some conditions leave individuals predisposed to developing PNH. For example, according to John Hopkins Medicine, up to 30 per cent of newly diagnosed cases of PNH evolve from a disorder called aplastic anemia.
Symptoms, and the severity of these symptoms, vary widely from patient to patient. Some of the more medically serious physiological symptoms associated with the condition include haemolysis, anaemia and arrhythmia (irregular heartbeat). Other physiological symptoms can include chronic severe fatigue, insomnia, nausea, jaundice and abdominal, esophageal, muscular or joint pain. Psychological symptoms are also seen in patients, and include a lack of mental clarity or motivation, forgetfulness or difficulty concentrating, and difficulty dealing with daily tasks and situations. Daily functioning can also be affected by shortness of breath, headaches, dizziness, loss of appetite, digestive problems or tingling or numbness in the extremities. Erectile dysfunction and dark or unusually coloured urine are also seen in patients. Haemoglobinuria quite literally stands for “haemoglobin in the urine” – a common symptom of PNH. Every case of PNH is different, and patients may experience few or many of these symptoms. If you have PNH and are concerned about symptoms you may be experiencing, see your doctor.
Haemolysis, or the destruction of blood cells, is the defining complication of PNH. It can cause patients to experience a significant drop in haemoglobin levels, as destroyed blood cells cannot be replaced at the rate of destruction. When haemoglobin levels drop low enough, red blood cells may need to be replaced by a blood transfusion. Whether or not a blood transfusion is required, haemolysis places a continuous strain on vital organs – especially the liver, kidneys and heart. This strain increases the risk of serious and life-threatening complications such as liver and/or kidney failure; heart attack; stroke; deep vein thrombosis; Budd-Chiari Syndrome (a clot or clots in the hepatic vein of the liver); or blood clots in other veins or organs. Clots are the most common complication of PNH and the leading cause of death among patients.
PNH often goes unrecognized, and it can take several years for an accurate PNH diagnosis. Due to the gradual manifestation of symptoms, and the possibility of the condition being linked to other potential or existing health issues, delays in diagnosis range from one to more than 10 years. About 90 patients in Canada live with PNH, and delays in diagnosis can also be a product of the extreme rarity of the disease. PNH is diagnosed through a specialized blood test called flow cytometry. A number of other tests – including bone marrow biopsy, blood tests, x-rays, CT scans, ultrasound or specimen tests (i.e. urine) – are often performed during the diagnostic process. During or after the diagnostic process, patients are often referred to haematologists (doctors who specialize in treating blood disorders) or PNH specialists, who have a deeper familiarity with the condition. The more PNH patients the doctor has seen, the more equipped he or she is to recognize symptoms and suggest a personal treatment plan. If you are concerned that you may have PNH, speak with your doctor.
People living with PNH can look to several treatment options to help manage their symptoms. PNH has only one known cure – a bone marrow transplant – but other treatments can help patients live a more normal life. Patients can rely on a combination of supportive treatments, including blood transfusions to replace the red blood cells lost through haemolysis; natural therapies including acupuncture, massage or herbal medications; and prescription medications. Some patients benefit from corticosteroids (such as prednisolone or dexamethasone) to reduce the rate of haemolysis, anticoagulants or blood thinners, like warfarin that can decrease the potential for blood clots, folic acid or iron supplements to assist the body’s production of blood cells. One prescription medication approved by Health Canada in 2009 is known as the only treatment to effectively return a patient’s life expectancy to that of a normal person. Eculizumab, or eculizumab, is known to reduce symptoms and decrease the need for blood transfusions in PNH patients. If you have questions about a treatment or dosage, speak with your doctor.
The only known curative treatment is a bone marrow transplant. However, well‐matched donors are often difficult to find, and the procedure carries a significant risk with half the patients dying and at least another third suffering from rejection complications. There is, however, a treatment for PNH that effectively prevents the premature destruction of red blood cells and thereby significantly reduces the development of life‐threatening complications such as blood clots (strokes, heart attacks) and kidney failure. Eculizumab allows a patient’s life expectancy to return to that of a healthy person. eculizumab is administered by infusion every 14 days by a licensed health care professional at a health care clinic, physician’s office or infusion clinic, or even the patient’s own home for the duration of the patient’s life.
To enjoy a better quality of life with PNH, some specialists advise living as healthy a lifestyle as possible, by eating a healthy diet and drinking lots of water. Listen to your body and rest when you need to. Pay attention to your symptoms, and if your condition changes or worsens, contact your physician. One of the best coping mechanisms for patients is talking about your disease. Try not to be afraid of talking about PNH with your family or friends. Once those close to you have a better understanding of the disease, they can provide emotional support, as well as help with your everyday tasks. Dealing with a chronic disease can be difficult – emotionally and physically – and talking about PNH with other patients can also be therapeutic. Though PNH is a rare disease that affects a relatively small number of people, take solace in the fact that you are not alone. By fostering a strong community of individuals living with PNH, be it through meetings, events or online discussion boards, you can share your experiences with patients living with PNH from across Canada and the world.
While there is no special diet that can alleviate your PNH symptoms, experts recommend eating a healthy, well-balanced diet containing lots of fruits and vegetables. Your doctor can help find the best eating plan for you. To ensure your body gets enough folic acid and iron, your specialist will likely recommend a man-made supplement. Folic acid and iron help your body make red blood cells. Always talk to your doctor to see which supplements are right for you, and before taking any supplements, medicines, vitamins or herbs.
The alkaline diet is based on the belief that certain foods can affect the acidity of bodily fluids, including the urine or blood, and can therefore be used to treat or prevent diseases. While there is no documented evidence that shows an alkaline diet (a mostly vegetarian diet consisting of fruits and vegetables) to improve PNH symptoms than a more acidic diet (including meats, dairy, processed foods), your doctor may recommend a diet similar to an alkaline diet to ensure your body’s health is optimal.
A reduction in granulocyte/monocyte clone size is sometimes reported in patients with PNH, but rarely drops below 10 per cent, and seldom occurs alongside a falling platelet count. When a significant spontaneous change is observed in these two test results, it likely reflects a change in the bone marrow that corresponds with a less hospitable environment for PNH stem cells. Speak with your specialist about having a bone marrow exam to check for an associated bone marrow disease.
While it is possible for women with PNH to become pregnant, it can be dangerous for both the mother and infant. If you have PNH and wish to become pregnant, you should discuss this with your partner, your PNH specialist and an obstetrician who specializes in high-risk pregnancies. It is important to understand the risks before you become pregnant. If you do become pregnant, you should be very closely monitored by your doctors.
PNH results from a genetic mutation in a bone marrow stem cell, is not inherited, and therefore it cannot be passed down to children.
This information was prepared by the Canadian Association of PNH Patients and reviewed by:
Dr. Richard A. Wells MD, D.Phil., FRCP(C)
Hematologist, Sunnybrook Health Sciences Centre
Assistant professor, Department of Medical Biophysics, University of Toronto
PLEASE NOTE: This information is intended for general knowledge only and is not to be substituted for medical advice. Please consult with your medical practitioner for further information regarding your personal circumstances.
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