What is Aplastic Anemia?
Aplastic anemia is a Bone Marrow Failure disorder characterised by pancytopenia with bone marrow hypoplasia due to loss of hematopoeitic stem cells .
When the bone marrow fails to produce different types of blood cells RBCA WBCS AND PLATELETS it’s called APLASTIC ANEMIA .
EVERTHING YOU NEED TO KNOW ABOUT APLASTIC ANEMIA
Aplastic anemia | causes |Symptoms | when to see your HEMATOLOGIST |Risks | Tests needed |Treatments | what to expect | lifestyle
What is Aplastic Anemia ?
- Aplastic anemia (AA) is a bone marrow failure (BMF) disorder characterized by pancytopenia with bone marrow hypoplasia/aplasia due to loss of hematopoietic stem cells (HSCs).
- Aplastic anemia can be moderate, severe or very severe.
- People with severe or very severe aplastic anemia are at risk for life-threatening infections or bleeding.
- With prompt and proper care, most people who have aplastic anemia can be successfully treated.
- The only cure for aplastic anemia is a BONE MARROW TRANSPLANT.
- Aplastic anemia can strike at any age regardless of race or gender.
- However, it is diagnosed more often in children, young adults and older adults. It also appears more often in Asian-Americans.
WHAT IS HAPPENING TO YOUR BLOOD IN APLASTIC ANEMIA?
- Blood consists of blood cells floating in plasma. Plasma is mostly made of water.
- It also includes salts, proteins, hormones, minerals, vitamins and other nutrients and chemicals your body needs.
WHAT ARE THE THREE BASIC TYPES OF BLOOD CELLS?
1)Red blood cells (RBCs) are also called erythrocytes. They make up almost half of blood. Red blood cells are filled with the protein hemoglobin that picks up oxygen in the lungs and brings it to cells all around the body.
2)White blood cells (WBCs) are also called leukocytes. They fight disease and infection by attacking and killing germs that get into the body. There are several kinds of white blood cells, each of which fights a different kind of germ.
3)Platelets are also called thrombocytes. They are small pieces of cells that help blood clot and stop bleeding.
HOW ARE THE BLOOD CELLS FORMED?
- The process of making blood cells is called hematopoiesis.
- Blood cells are made in the bone marrow, a spongy tissue located inside certain bones.
- Marrow contains blood-forming stem cells that make copies of themselves to create all three types of blood cells.
- When blood cells are fully mature and functional, they leave the bone marrow and enter the bloodstream.
- Healthy people have enough stem cells to make all the blood cells they need.
WHAT IS BONE MARROW FAILURE?
- Bone marrow failure happens when the marrow doesn't produce enough red cells, white cells or platelets, or the blood cells that are produced are damaged or defective.
- This means the body can not supply itself with the blood it needs.
- Aplastic anemia, MDS and PNH are bone marrow failure diseases.
WHAT HAPPENS WHEN YOU HAVE APLASTIC ANEMIA ?
- Aplastic anemia is caused by the destruction of blood-forming stem cells in bone marrow.
- These stem cells normally develop into three types of blood cells: Red blood cells, White blood cells and Platelets.
- The symptoms of aplastic anemia vary depending on how severe it is and how low blood counts are.
Some typical symptoms include:
WHAT ARE THE SYMPTOMS IN APLASTIC ANEMIA?
- Feeling tired and out of breath after only a little exercise
- The tendency to bruise and bleed easily
- The tendency to catch infection easily
- Bleeding that won't stop
- Infections and an associated fever
WHAT CAUSES APLASTIC ANEMIA ?
- Loss of hematopoietic stem cells (HSC) is a defining feature of Aplastic Anemia .
- Hematopoietic stem cells ( HSCs )in the bone marrow are the source of all mature cells in the peripheral blood and tissues.
- HSCs are multipotent (ie, can give rise to diverse cellular lineages) and generally quiescent.
- HSCs have the capacity for self-renewal (thereby sustaining a lifelong store of HSCs) and give rise to committed progenitor cells, which have reduced lineage potential but high proliferative capacity.
- Through successive mitotic divisions, progenitor cells ultimately produce fully mature blood cells.
- HSCs are not morphologically identifiable but they can be recognized and isolated based on their characteristic immunophenotype.
- HSCs constitute a small population within the CD34+/CD38–
fraction of bone marrow cells.
- HSCs can also be detected in the peripheral blood, from which they can be isolated for use in hematopoietic cell transplantation.
Pathogenic mechanisms — 👉Aplastic Anemia is associated with loss of HSCs and the resultant decrease in mature blood cells.
- When the HSC pool falls below a critical mass, the conflicting demands of self-renewal and differentiation can lead to pancytopenia.
Pathophysiologic processes that lead to loss of HSCs and cause AA include
- Autoimmune mechanisms
- Direct injury to HSCs (eg, by drugs, chemicals, irradiation)
- Viral infection
- Clonal and genetic disorders
HOW WILL YOUR HEMATOLOGIST IN MUMBAI DIAGNOSE AND CONFIRM APLASTIC ANEMIA ?
- History, examination, laboratory studies
1)The history may provide clues to an underlying etiology (eg, exposure to drugs/chemicals, hepatitis, or other viral infections).
2)Family history (in both children and ad adults) may reveal other family members with cytopenias and/or somatic findings suggestive of an inherited disorder.
3)Physical findings are generally consistent with pancytopenia, especially pallor and petechiae.
4)The liver, spleen, and lymph nodes are not typically enlarged in Aplastic Anemia .
5) Serum chemistries, including electrolytes, liver function tests (including lactate dehydrogenase [LDH]), and renal function tests should be performed to identify associated conditions and complications (eg, hemolysis), and help to distinguish Aplastic Anemia from other causes of pancytopenia.
6)Serum vitamin B12 and red blood cell folate levels should be performed to exclude those causes of megaloblastic anemia.
7) Bone marrow examination — Bone marrow aspiration and biopsy is required to establish the diagnosis of Aplastic Anemia and exclude other causes of pancytopenia.
8)The biopsy should be performed at a site that has not suffered prior direct damage (eg, radiation, trauma, infection).
Diagnostic findings from bone marrow examination include:
- The bone marrow is profoundly hypocellular with a decrease in all elements; the marrow space is composed mostly of fat cells and marrow stroma .
- Residual hematopoietic cells are morphologically normal, and hematopoiesis is not megaloblastic.
- Infiltration of the bone marrow with malignant cells or fibrosis is not present.
Bone marrow specimens should undergo cytogenetic, molecular, and other specialized testing, as described below.
Diagnostic criteria — Aplastic Anemia is defined as pancytopenia with a hypocellular bone marrow in the absence of an abnormal infiltrate or marrow fibrosis.
There is no required duration of cytopenias to establish a diagnosis of Aplastic anemia .However, if a specific cause of cytopenias is identified (eg, cytotoxic chemotherapy, viral infection), the blood counts may be monitored for days to several weeks to permit recovery and determine if the insult is reversible.
For purposes of risk stratification and selection of therapy, Aplastic Anemia is classified according to the following criteria:
Severe — Diagnosis of severe aplastic anemia (SAA) requires both of the following criteria.
- Bone marrow cellularity <25 percent (or 25 to 50 percent if <30 percent of residual cells are hematopoietic)
- At least two of the following:
- Peripheral blood absolute neutrophil count (ANC) <500/microL (<0.5 X 109/L)
- Peripheral blood platelet count <20,000/microL
- Peripheral blood reticulocyte count <60,000/microL .
Very severe — Diagnosis of very severe aplastic anemia (vSAA) include the criteria for SAA (above) and ANC is <200/microL.
Non-severe — Criteria for non-severe Aplastic anemia are:
- Hypocellular bone marrow (as described for SAA)
- Peripheral blood cytopenias not fulfilling criteria for SAA or vSAA (see above)
Specialized testing — The decision to perform specialized testing is influenced by the clinical setting (eg, adult versus child, findings consistent with an inherited syndrome).
In all adults with Aplastic Anemia the following specialized testing should be performed to detect coexistent disorders, such as paroxysmal nocturnal hemoglobinuria, myelodysplastic syndrome, or acute leukemia:
- Flow cytometry for assessment of cell surface CD59 on peripheral blood red blood cells or neutrophils.
- Cytogenetic and molecular testing of bone marrow.
In all children with AA we suggest genetic testing .
CONSULT YOUR HEMATOLOGIST IN MUMBAI FOR FURTHER QUERIES AND DETAILS .
HOW IS APLASTIC ANEMIA TREATED ?
The treatment depends on the cause of your aplastic anemia. Treatment can include:
- Stopping medicines that might have caused the problem
- Medicines – These can include:
Antibiotics and antiviral medicines – These are used to prevent and treat infections.
- Transfusion of red blood cells or platelets – During a transfusion, you get blood that has been donated by someone else after proper screening and testing in Blood Banks.
Hematologist also try to avoid using blood from family members who might donate bone marrow later.
- "Immunosuppressive" medicines – Aplastic anemia is sometimes caused by an "overactive" immune system. This means that your immune system attacks healthy cells in your bone marrow. If this is the case, you might get medicines that prevent your immune system from doing this. There are also other medicines that help your bone marrow make more blood cells.
- Bone marrow transplant (also called a "stem cell transplant") – This procedure replaces abnormal or missing cells in the bone marrow with healthy cells from a donor.
Dr.Suraj and his team is extremely popular across the country for treating Aplastic anemia and performing a very high volume of BONE MARROW / STEM CELL TRANSPLANTS ..
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