Bone Marrow Failure Syndromes Flashcards
(30 cards)
What is the most common cause of aplastic anemia?
Idiopathic causes
What is a viral cause of Aplastic Anemia?
Parvovirus
If you suspect aplastic anemia what should you be looking for in the bone marrow?
*Look for Hypercellular vs. Hypocellular
What are some conditions that cause bone marrow failure with hypercellular bone marrow?
- Bone Marrow Infiltration via Malignancy
- B12 or Folate Deficiency (Megaloblastic)
- Storage Disorders
What are some conditions that cause bone marrow failure with hypocellular bone marrow?
• Congenital
• Acquired
Congenital
• Fanconi’s Anemia
Acquired • Idiopathic • Myelodysplastic Syndrome • Drugs/Chemicals • Radiation • Viruses
What 2 things Define Aplastic Anemia?
• who gets it?
- Peripheral PANcytopenia
- Hypocellular Bone Marrow
*Can occur in any age group and in both genders
What is the primary mechanism by which cells are killed in aplastic anemia?
*What cell line is killed?
Immune Mediated Destruction of Hematopoietic Stem Cells
**THIS IS WHY YOU GET PANCYTOPENIA
What are some infectious causes of Aplastic Anemia?
- Infectious Mononucleosis
- Hepatitis
- Parovirus
- Cytomegalovirus
- Miliary Tuberculosis
T or F: Paroxysmal Nocturnal Hemoglobinuria is a potential cause of Aplastic Anemia.
True
What drugs are known to causes aplastic anemia?
- Chloramphenicol
- Quinacrine
What lab findings would you expect to see on someone with aplastic anemia?
- explain each of these findings.
- what is the hallmark finding?
RELATIVE lymphocytosis:
• Lymphocytes live much longer than neutrophils
Normochromic, Normocytic RBCs (mild to moderate anisocytosiis and poikilocytosis possible)
• cells ARE NOT neoplastic, they are just getting destroyed
LOW Reticulocytes:
• Hallmark Finding
HYPOcellular Bone Marrow
• more than 70% fat in marrow
What are 3 common treatments of Aplastic Anemias?
- Immunosuppression
- Stem Cell Transplant
- Transfusion
What should be your sequence of treatment for aplastic anemias?
- Withdrawal Offending Agent (drug, chemical, etc)
- Supportive Care (Antibiotics for neutropenia, Transfusion)
- Immunosuppressive Therapies
- Hematopoietic Cell Transplantation (HSCT)
Why has is been hypothesized that Aplastic Anemia is almost certainly an immune mediated phenomenon?
Because Immunosuppressive therapy is so effective at treating it
What defines Pure Red Cell Aplasia?
*Selective Decreases in erythroid precursor cells in the bone marrow while WBCs and Platelets are unaffected
What are some causes of Pure Red Cell Aplasia?
*are these acquired or congenital?
Acquired
Causes:
• Viral (parovirus) or bacterial infections
• Patients with Hemolytic Anemias may halt erythorpoeisis
• Patients with Thyoma - T cell mediated responses against red cells bone marrow EPO or erythroblasts are sometimes produced
How do you treat a Red Cell Aplasia?
- Supportive Care
* Immunosupressives
What is the difference between a myelodysplastic syndrome and an aplastic anemia?
Presence or absence of neoplastic cells in the bone marrow
What are Myelodysplastic Syndromes?
• How do they tend to terminate?
Primary Neoplastic Stem Cell Disorders that tend to Terminate in Acute Leukemia
Do quantitative or qualitative abnormalities causes myelodysplastic syndromes?
QUALITATIVE
• Most of these have defects in differentiation (that’s why they are dysplastic syndromes and not proliferative syndromes)
What are some findings that are characteristic of a peripheral smear in a myelodysplastic syndrome?
- Nucleated RBCs
- Oval Macrocytes
- HYPOsegmented neutrophils, pseudo-Pelger-Heut PMNs
- HYPOgranulated neutrophils
- Hyperchromatin clumping
- Giant Platelets
What finding is characteristic of bone marrow in someone with myelodysplastic changes?
Ringed Sideroblasts
What cell type are myelodysplasias thought to arise from?
Multi-Potent Stem Cells
What do myelodysplasias turn into when more than 20% of peripheral or bone marrow blasts are seen in a patient?
Acute Myelogenous Leukemia (AML)
