Welcome to the Rare Classroom, a new series from Patient Worthy. Rare Classroom is designed for the curious reader who wants to get informed on some of the rarest, most mysterious diseases and conditions. There are thousands of rare diseases out there, but only a very small number of them have viable treatments and regularly make the news. This series is an opportunity to learn the basics about some of the diseases that almost no one hears much about or that we otherwise haven’t been able to report on very often.
Eyes front and ears open. Class is now in session.
The disease that we will be learning about today is:
Also called bone marrow failure.
What is Aplastic Anemia?
- Aplastic anemia is the medical term for bone marrow failure
- A disease in which the bone marrow, and the blood stem cells that reside there, are damaged causing a deficiency of red blood cells (anemia), white blood cells (leukopenia) and platelets (thrombocytopenia)
- “Aplastic” refers to inability of the stem cells to generate the mature blood cells
- Aplastic anemia is classified as moderate (MAA), severe (SAA), or very severe (VSAA)
- Most prevalent in those in their teens and twenties and in the elderly
- About 600-900 new diagnoses in the US each year. (2-3 people per million)
- Incidence higher in Asia than in the West
- The male-to-female ratio for acquired aplastic anemia is approximately 1:1
How Do You Get It?
- Aplastic anemia is considered an autoimmune illness in which the white blood cells from the immune system attack the bone marrow stem cells.
- The disease can have a genetic or inherited cause or can be acquired later in life.
- More common. Often idiopathic but in 25 out of 100 cases can be linked to the following causes: toxins such as pesticides, arsenic, benzene, radiation and chemotherapy, treatments for lupus or rheumatoid arthritis, pregnancy, hepatitis, Epstein-Barr virus, cytomegalovirus, parvovirus B19, HIV.
What Are The Symptoms?
- Since this illness causes reduced levels of red blood cells, platelets, and white blood cells, symptoms result due to an insufficient number of cells to perform their normal functions.
- Low white blood cells = unexplained infections
- Low platelets = unexpected bleeding, poor clotting/bleeding control
- Low red blood cells = low energy levels, fatigue
- The most frequently reported symptoms include:
- Small red dots on the skin
- Shortness of breath
- Problems controlling bleeds
- Infections, flu-like symptoms
- Easy bruising and bleeding
How Is It Treated?
- Treatment approaches include:
- Blood transfusions
- Platelet transfusions are the first course of treatment for any aplastic anemia patient who is severely deficient in these blood cells
- Transfusions of red blood cells can help combat the fatigue and shortness of breath
- Not a curative therapy
- Bone marrow/stem cell transplant
- When successful is often a cure
- Very serious complications and infections not unusual
- Cure rates decline significantly for those over 40
- Drug therapies
- Immunosuppressive Agents
- Can relieve symptoms and reduce complications. Often used in those who cannot have bone marrow transplant or are waiting for transplant.
- Considered the standard initial treatment for adults and for all patients without a matched related donor for bone marrow or stem cell transplant
- Three medications commonly used: antithymocyte globulin (ATG), cyclosporine, and methylprednisolone
- May require long-term treatment
- Often used in combination
- Blood cell counts can rise high enough to allow people to do their normal activities.
- Antithymocyte globulin (ATG) plus cyclosporine the therapy of choice for older patients
- Hematopoietic Growth Factors
- May help stimulate the bone marrow to produce new blood cells
- Do not replace immunosuppressive therapy
- May work well in combination with each other or with immune-suppressing drugs
- Commonly used: Erythropoietin (EPO) to boost red blood cell production, G-CSF (granulocyte colony-stimulating factor) (Neupogen) and GM-CSF (granulocyte macrophage colony-stimulating factor) (Leukine) to boost white blood cell counts
- Promacta® may be considered in those who have failed immunosuppressive therapy
- Promacta® is the first drug ever approved to treat refractory aplastic anemia
- Promacta® treatment leads to clinically significant responses in approximately 40 percent of patients
- In some patients Promacta® can be discontinued and the responses persist long-term, up to three years or more in some patients treated on the original trial
- Patients begin to show responses after 3-4 months of treatment and maximal responses often take up to 12 months
- Antineoplastic Agent, Antimetabolite (purine)
- Inhibit cell growth and proliferation
- Supportive care to treat infections
- Immunosuppressive Agents
- If untreated, the risk of death is high
- 5 year survival rate of about 70% with drugs or stem cell transplant
- Higher survival rate with younger age
- 25-30% of patients do not respond to immunosuppression treatment
- Relapses are common with immunosuppressive treatment
- 10-15% of SAA evolve into myelodysplastic syndromes (MDS) and leukemia