What is Aplastic Anemia?
The blood cells have a limited lifespan. Red blood cells survive 3 months, white cells survive for 24 hours and platelets survive for 5 days. The bone marrow is an amazing organ which produces billions of blood cells every day to keep up with the requirements of our body. When the bone marrow fails, the cell production slows down and often stops. This is called aplastic anemia.
The incidence of Aplastic anemia in Asian countries is 5 times higher than in Europe or USA.
What causes Aplastic Anemia?
Aplastic anemia results from damage to the mother cells or stem cells which are no longer able to produce normal blood cells. This can happen due to the following causes:
- Chemicals and toxins such as benzene and pesticides
- Infections such as hepatitis
- Drugs such as arsenic, gold, painkillers and some antibiotics
- Inherited conditions such as Fanconi’s Anemia
- Most commonly, the cause is not known and thought to be due to an immune mediated attack by the body on its own stem cells.
How do we diagnose Aplastic Anemia?
- The diagnosis of aplastic anemia needs awareness of the condition and a strong index of suspicion. The patient can present with symptoms of anemia such as weakness, shortness of breath on exertion or fatigue, severe or repeated infections or unusual bleeding.
- A routine blood test shall show at least two of the three cell lines of red cells, white cells and platelets to be depressed. The confirmation comes from a bone marrow examination showing bone marrow cells being replaced by fat spaces.
- It is important to look for a causative factor and stop any drug or exposure to chemical that might be causing it.
- The investigations include blood tests to look for infections, autoimmune diseases like lupus and chromosome analysis to rule out Fanconi’s Anemia.
How do we classify aplastic anemia?
- Severe: neutrophil count less than 500 cells /microliter (normal 1500-6000/microliter)
- Very Severe: neutrophil count less than 200 cells /microliter
- Nonsevere: none of the above
Treatment of Aplastic Anemia
- Supportive Therapy: We cannot survive without functioning blood cells. Immediate treatment involves transfusion of red blood cells and platelets as needed and rapid treatment with antibiotics at the earliest sign of infection. However, infection or bleeding kills most patients with severe Aplastic Anemia within one year from diagnosis unless cured
- Curative Treatment:
- Immunosuppressive Treatment: Antithymocyte globulin, a drug produced from horse or rabbit by injecting human lymphocytes in them. This in turn kills lymphocytes in patients suffering from aplastic anemia, which are thought to responsible for killing blood stem cells. Howver, even if it works as it might in 40-60% of patients, this might take upto 6 months.
- Blood and Marrow Transplantation (BMT): BMT cures 90 Other % of the patients with aplastic anemia if carried out early and from a matched family donor. However, only 20% of patients have a matched family donor. BMT from a Matched Unrelated Donor or a Haploidentical (half matched) family donor is a reasonable option.