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◉ What is aplastic anemia?
Aplastic anemia (AA) is a rare, non-cancerous, and serious condition in which the stem cells in the bone marrow, responsible for producing all types of blood cells, are unable to produce a sufficient number of normal blood cells.
Aplastic anemia can result from either inherited or acquired factors that contribute to the damage of the stem cells in your bone marrow. Consequently, the bone marrow produces fewer red blood cells, white blood cells, and platelets, leading to the condition known as pancytopenia.
Patients with this condition can present across a spectrum, which ranges from being asymptomatic with incidental findings on peripheral blood testing to experiencing life-threatening neutropenic infections or bleeding.
A few decades ago, aplastic anemia was often fatal, but now it can be treated effectively with stem-cell transplantation or immunosuppressive drugs.
◉ Who Is at Risk for Aplastic Anemia?
People of all ages can develop aplastic anemia. However, it's most common in adolescents (15 to 20 years of age) , and the elderly (over 60 years old). The incidence of AA is similar in men and women
◉ Types and Classification of Aplastic Anemia
Aplastic anemia is primarily classified into inherited, which is often linked to genetic factors, and acquired. The acquired pattern can be further classified into three major types based on disease severity and accompanying clinical signs, as follows:
◉ 1. Moderate Aplastic Anemia (MAA)
MAA, or Non-severe aplastic anemia (NSAA), is characterized by chronically low blood counts without clinical evidence of progression. Patients may have lower blood cell counts than normal, but not as low as in severe aplastic anemia. Symptoms are generally rare or absent in this type of aplastic anemia.
characterized by chronic moderately depressed blood counts without clinical evidence of progression.◉ 2. Severe Aplastic Anemia (SAA)
In this type, symptoms intensify and the patient's condition becomes somewhat serious. The most important indicators of entry into this type are a hypocellular bone marrow and any two of the following criteria:
- Reticulocyte count: less than 60,000 cells per microliter (< 60 x 109/L).
- Absolute neutrophil count: less than 500 cells per microliter (< 0.5 x 109/L).
- Platelet count: less than 20,000 cells per microliter (< 20 x 109/L).
◉ 3. Very Severe Aplastic Anemia (VSAA)
Very severe aplastic anemia, is the most dangerous type of this disease. Laboratory test values are similar to those of the previous type, but the differentiating factor is the extremely low count of neutrophils:
- Reticulocyte count: less than 60,000 cells per microliter (< 60 x 109/L).
- Absolute neutrophil count: less than 200 cells per microliter (< 0.2 x 109/L).
- Platelet count: less than 20,000 cells per microliter (< 20 x 109/L).
◉ What causes aplastic anemia?
Aplastic anemia is caused by damage to stem cells, and various factors may be involved in this damage.
◉ 1. Causes of inherited aplastic anemia
- Fanconi anemia (FA)
- Dyskeratosis congenita.
- Shwachman-Diamond syndrome (SDS).
- Myelodysplasia.
- Pearson marrow-pancreas syndrome.
- Reticular dysgenesis.
- Familial aplastic anemia.
◉ 2. Causes of acquired aplastic anemia
- Autoimmune disorders are the most common cause of bone marrow damage, and the exact reason for this autoimmune reaction is not known in more than half of cases.
- Exposure to radiation.
- Chemotherapy.
- Hepatitis.
- Exposure to chemical toxins such as pesticides and complex compounds.
- Side effects of taking certain types of medications such as broad-spectrum antibiotics, immunosuppressants, nonsteroidal anti-inflammatory drugs, antiseizure medications or gold salts.
- Pregnancy.
- Viral diseases such as HIV, Epstein-Barr virus (EBV) and cytomegalovirus (CMV).
◉ Symptoms
In the early stages of aplastic anemia, patients may not initially notice any symptoms or signs, but gradually experience fatigue and weakness, often accompanied by other symptoms that help confirm the diagnosis. Some of the most significant signs:
- Severe fatigue and weakness.
- Infections that last a long time.
- Sudden appearance of bruises.
- Nosebleeds and gum bleeding.
- Accelerated heart rate.
- Pale and dull skin.
- Shortness of breath.
- Delayed wound healing.
- Chronic dizziness.
- Headaches and fever.
◉ Diagnosis
The supervising physician diagnoses aplastic anemia by considering the clinical signs mentioned above, along with conducting a series of tests and examinations, which include
- Complete blood count (CBC) test: The CBC checks the number of red blood cells, white blood cells, platelets, hemoglobin and hematocrit levels.
- Peripheral blood smear.
- Reticulocyte count test (measuring immature red blood cells).
- Bone marrow biopsy (sample can be taken from the hip bone under local anaesthetic).
- Tests for gene mutations (PIGA, ASXL1, BCOR)
- Liver function tests (ALT test, AST test, ALP test).
- Virus testing (HIV, Cytomegalovirus, Epstein-Barr virus. etc)
The diagnosis of aplastic anemia should be suspected in any patient presenting with pancytopenia. The results that can orient the doctor to the diagnosis of aplastic anemia include:
- Bone marrow show hypocellularity cellularity (< 25%) without evidence of significant dysplasia, blasts, fibrosis, or other abnormal infiltrate.
- At least two of the following peripheral cytopenias must be present: hemoglobin < 10 g/dL, platelets < 50 x 10⁹/L, absolute neutrophil count < 1.5 x 10⁹/L.
- All alternative causes of bone marrow failure must be excluded as part of the diagnostic evaluation.
◉ Treatment
There are several treatment options for aplastic anemia that depend on the patient's health status and the severity of their disease. However, the main treatment methods can be summarized into 3 types, which are:
- Dietary Changes and Supplements.
- Bone marrow transplantation through surgery.
- Blood transfusion from a healthy individual.
- Drug therapy to help your body make more red blood cells or to treat an underlying cause of anemia.
◉ Conclusion
Aplastic anemia is a rare and serious condition that can result from various factors, including autoimmune disorders, toxins, medications, and viral infections. Diagnosing it often involves blood tests like the complete blood count (CBC)
Early diagnosis and appropriate treatment can significantly improve outcomes for aplastic anemia patients.
