Aplastic anemia

Causes and who gets it

When the stem cells, the source of all blood cells, are damaged, the marrow cannot make enough cells. According to the British Society for Haematology (BSH), no specific cause is found in 70–80 percent of cases (idiopathic); in most of these, the immune system is thought to be attacking the marrow.

Known triggers are:

• Some medicines, such as sulfonamide antibiotics and medicines for epilepsy (seizures)
• Chemicals such as benzene, and pesticides
• Chemotherapy and high-dose radiation
• Some viruses; there is a rare form that develops two to three months after hepatitis (inflammation of the liver that causes jaundice)
• Pregnancy and some autoimmune diseases

Less often, it is inherited, as in Fanconi anemia. In a significant proportion of patients there is a small group of cells belonging to a disease called PNH (paroxysmal nocturnal hemoglobinuria). This group often causes no problems; if it grows, it can lead to destruction of red blood cells and to clots.

Aplastic anemia is not contagious. In Europe it affects 2–3 people per million each year; it is more common between ages 10 and 25 and after age 60.

Symptoms

Symptoms depend on which blood cells are low and by how much; they may be severe from the start or increase over time.

• Low red blood cells (anemia): Tiredness, pale skin, shortness of breath with activity, a fast heartbeat, dizziness when standing up
• Low white blood cells: Frequent, long-lasting or severe infections, and fever
• Low platelets: Bruising easily, nose and gum bleeding, bleeding that lasts a long time, petechiae (pinpoint red-purple spots on the skin)

An enlarged spleen or swollen lymph nodes are usually not seen; if present, your doctor will look for other causes.

Diagnosis and tests

Your doctor will ask in detail about your medicines, chemical exposures, infections you have had and your family history.

• Complete blood count (CBC): Measures hemoglobin, white blood cells (especially neutrophils) and platelets; usually all three are low.
• Reticulocyte count: Counts young red blood cells; a low count shows that the marrow is not producing enough.
• Peripheral blood smear: Blood is examined under a microscope to look for cells that suggest other diseases.
• Bone marrow aspiration and biopsy: Needed for the diagnosis. The marrow has few cells; fat tissue has taken the place of the cells.
• PNH test: Flow cytometry is used to look for PNH cells in the blood.
• Chromosome and gene tests: The marrow is checked for chromosome changes. If an inherited cause is suspected, a chromosome fragility test for Fanconi anemia is done.
• Ruling out other causes: Vitamin B12 and folate, liver tests, and tests for viruses such as hepatitis and HIV
• Tissue typing (HLA): If you are a candidate for a transplant, this is ordered right after diagnosis.

The disease is classified as moderate (non-severe), severe or very severe based on the neutrophil, platelet and reticulocyte counts and the proportion of cells in the marrow. This classification affects the choice of treatment.

Treatment approach

Treatment is chosen based on how severe the disease is, your age, your general health and whether a suitable stem cell donor is available. It is recommended that the decision be made by a team in an experienced center. Any medicine or chemical thought to be a trigger is removed.

• Supportive treatment: Red blood cell and platelet transfusions are given. If the neutrophil count is very low, antibiotics and antifungal medicines may be started to prevent infection; infections that do occur are treated quickly.
• Immunosuppressive treatment: Slows or stops the immune system attack on the marrow; a medicine that stimulates blood production may also be added. It can take months to work; the disease may flare up again later.
• Allogeneic stem cell transplant: Healthy stem cells from a suitable donor are given; it is the only treatment that can bring a lasting cure. In younger patients with severe disease, it is considered as the first option, especially if there is a tissue-matched brother or sister. If no sibling is a match, an unrelated donor is searched for.

In mild or moderate cases without symptoms, treatment may not be needed right away; regular monitoring is done.

Everyday life and follow-up

• Infection: Wash your hands often and well; ask the people around you to do the same. Stay away from sick people and crowds. Cook meat, fish and eggs thoroughly; avoid raw foods and unpasteurized dairy products. Do not take your temperature rectally, and do not use enemas or suppositories.
• Bleeding: Do not take medicines that affect platelets, such as aspirin and ibuprofen, without asking your doctor; they are found in many over-the-counter products. Avoid contact sports such as boxing, soccer and karate.
• Vaccines: If you are receiving treatment that suppresses the immune system, a flu vaccine every year is recommended. Live vaccines are usually not given to people with a weakened immune system; your doctor decides about vaccines. It is recommended that the people you live with be fully vaccinated.
• Check-ups: Blood counts and the PNH test are repeated at regular intervals; if you have frequent transfusions, iron buildup is also monitored.

Living with a long-term illness is hard; do not hesitate to ask for psychological support.

Pregnancy, children and special situations

Pregnancy: Aplastic anemia can start during pregnancy, get worse, or come back after it had improved. According to the BSH, blood counts worsen during pregnancy in about one third of patients. The main approach is supportive treatment; some treatments are not recommended during pregnancy. If you are planning a pregnancy, talk to your hematologist beforehand; care is provided jointly by the hematology, obstetrics and anesthesia teams.

Children: Inherited bone marrow failure syndromes most often appear in childhood; this is why inherited causes such as Fanconi anemia are looked for especially in children. Short height, differences in the structure of the thumb or forearm, café-au-lait (milky coffee-colored) spots on the skin, or kidney abnormalities increase this suspicion. In the inherited form, brothers and sisters are also tested.

In Türkiye

In Türkiye, adults are followed in hematology departments and children in pediatric hematology departments. If there is no matching donor in the family, a patient application is made to TÜRKÖK (the national stem cell coordination center of the Turkish Ministry of Health, Sağlık Bakanlığı); the national bone marrow bank is searched and, if no match is found there, the shared pool of the world’s bone marrow registries.

Hospitals request the blood and platelets they need from the regional blood centers of the Turkish Red Crescent (Türk Kızılay); Kızılay does not charge patients or their relatives for blood components. The public-facing pages of the Türk Hematoloji Derneği (Turkish Society of Hematology) offer advice in Turkish on preventing infection during periods when neutrophils are low.

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