Aplastic Anemia Flashcards
What is Aplastic Anemia?
Bone marrow is unable to produce enough blood cells
What blood cells are affected by aplastic anemia?
- White blood cells (leukopenia)
- Red blood cells (anemia)
- Platelets (thrombocytopenia)
What is the primary cause of Aplastic Anemia?
It usually has an autoimmune origin involving the T lymphocytes
- The T cells target and destroy the patient’s own stem cells.
What branch of the immune system is responsible for Aplastic Anemia?
Cell-mediated (adaptive) immunity
Clinical manifestations related to changes in the RBCs?
- Fatigue (↓ O2 to brain)
- Shortness of breath (↓ O2 to lungs)
- Decreased activity tolerance
- Glossitis – swollen, smooth tongue
- Tachycardia (compensatory mechanism to ↑ blood flow and O2)
- Pallor (↓ O2 to skin)
Not enough O2 to the tissues!
Clinical manifestations related to changes in the white blood cells?
- Patients will be at risk for developing an infection due to the leukopenia (<5,000)
- Normal WBC (5,000-10,000)
- Greater risk of developing any infection because ALL the walls are down
- Bacterial, viral, fungal
Clinical manifestations related to changes in the platelets?
Thrombocytopenia:
- Increased risk for bleeding
- Petechiae
- Bruising
- Nosebleeds
- Hematuria
- Bleeding from injection sites, etc.
Diagnostic changes expected with Aplastic Anemia?
Decreased:
- RBCs
- WBC (<5,000)
- Platelets
- Hemoglobin
- Hematocrit
Definitive diagnostic test for the diagnosis of aplastic anemia?
Bone marrow biopsy
- The marrow in aplastic anemia is hypocellular with an increased amount of yellow marrow (fat content)
How is treatment determined based on the 55 years of age cut-off?
- In patients ↓ 55 years of age who have a matched sibling donor, stem cell transplant is the definitive treatment and is considered curative.
- In patients ↑ 55 years of age or those with no matched sibling, immunosuppressive therapy (IST) is the primary treatment.
What is a stem cell transplant?
- The goal is to replace the damaged or non-functioning bone marrow with healthy stem cells that can regenerate and produce normal blood cells.
- The process is similar to a blood transfusion (usually through a central line)
How does immunosuppressant therapy (IST) work for AA?
- Suppresses overactive immune system that is attacking the bone marrow
- Allows bone marrow to recover and produce healthy blood cells again
What is ATG (Anti-thymocyte globulin)? Mechanism of Action?
- Immunosuppressant therapy
- An infusion of horse or rabbit-derived antibodies against human T cells and their precursors (thymocytes)
Calms down the T cells that have gotten out of control
What is serum sickness?
- Fancy word for allergic reaction
- Symptoms:
- Fever
- Rash
- Polyarthritis
- Polyarthralgias
- The symptoms typically occur one to two weeks after exposure to an offending agent (e.g., ATG) and usually resolve within several weeks of discontinuation.
What type of drug is cyclosporine? What is the intended action?
- Immunosuppressant
- Usually used to prevent transplant rejection. Also used for rheumatoid arthritis.
What are the side effects of cyclosporine?
- Hypertension
- Hirsutism = hair growing in places it shouldn’t be growing
- Gingival hyperplasia = overgrowth of the gum tissue
- Nephrotoxicity = kidney function (elevated BUN, creatinine)
What type of drugs are corticosteroids? What is the intended action?
- Anti-inflammatory
- Suffix: -one
- Eg. Prednisone
- Corticosteroids are useful and effective as immunosuppressive agents
What are the side effects of corticosteroids?
- Hyperglycemia
- Hypertension
- Fluid retention
- Sodium retention
- Osteoporosis
Do not stop abruptly!
Why are growth factors given to treat AA?
- May be given to stimulate the bone marrow to produce more blood cells.
- Erythropoetin (RBCs)
- Thrombopoetin (Platelets)
What is the significance of aspirin and AA?
Aspirin is avoided in patients with thrombocytopenia because of its anti-platelet effect.
- risk of bleeding
Under what conditions would a patient be prescribed an anti-fungal drug?
- If patients have a low neutrophil count and receive IST, prolonged neutropenia increases the risk for mold (fungal) infections
- high mortality rate
- Anti-fungal suffix: -nazole
- Eg. voriconazole
