What is aplastic anemia?
In simple terms, it is a bone marrow failure. The syndromes are characterized by a drop in all blood counts, including red blood cells, white blood cells (WBCs) and platelets. It is a distinct disease that can vary in its severity and clinical courses, like a fulminant illness marked by a continuous or recurrent hemorrhage and a major infection to an indolent process manageable with transfusion therapy alone.
What Causes aplastic anemia?
It is primarily caused due to exposure to cytotoxic chemotherapy. Aplastic anemia is a major sequel of irradiation, often associated with the use of chemicals, drugs, viral infections and other diseases. However, it is not possible to know the exact reason of this devastating disease.
Who gets aplastic anemia?
This disease is more common in developing countries. Commonly known as a disease of the young, it is mostly present in patients between 15-25 years of age or who are older than 60 years.
What are the symptoms of aplastic anemia?
Most patients with aplastic anemia seek medical attention for symptoms that occur as a result of low blood counts, which can be as follows:
- Bleeding and infection
In a typical case of aplastic anemia, blood counts are depressed. Platelets, WBCs and RBCs are significantly low on a routine blood smear examination. The diagnosis of aplastic anemia requires a bone marrow aspiration and biopsy, and it should always be done whenever this disease is suspected. Bone marrow usually shows ‘empty’ marrow and hardly any blood-forming cells are seen. In addition, routine blood tests like Kidney function, Liver function, reticulocyte counts should also be performed.
Ideally, it should be considered as a medical emergency. Lives are lost mainly because of grave consequences in the drop of blood counts go unrecognized. It is important to start the treatment as soon as possible before the patient succumbs to an early infection. But if the disease is mild and blood count is adequate, only observation and frequent follow-up are required.
This disease can be cured by replacement of stem cells that is bone marrow transplantation or by immunosuppressive therapy.
Immunosuppressive therapy is an effective alternative treatment for patients who are not candidates for bone marrow transplant. Antithymocyte Globulins, which is made from horse, are commonly used for this purpose. It is given over a period of 4 days and is usually tolerated well. However, some patients may develop infusional reactions which can be severe sometimes. Other common side effect is ‘serum sickness’ which develops few days after ATG therapy, and is characterized by mild joint pains. With this therapy 40-70% patients respond with hematological improvement and improved survival.
Bone marrow transplant
Bone marrow transplant from HLA-matched sibling donor provides curative therapy for aplastic anemia patients. It is the treatment of choice for most of the aplastic anemia patients. In the most favorable group, -Untransfused and uninfected patients, survival rates of 80-90% can be expected. Results with BMT have improved over time because of combination of factors, including better supportive care and better pre and post-transplant regimens.