Unit 17 - Bone marrow failure Flashcards
What is aplastic anemia?
A bone marrow failure syndrome caused by damaged or destroyed stem cells
Does BM failure cause pancytopenia?
Yes
Are most cases of aplastic anemia acquired or inherited?
80% to 85% acquired
What are the three examples of inherited aplastic anemia?
Fanconi anemia, Dyskeratosis congenita, and Shwachman-Bodian-Diamond syndrome
What is the acquired pure red cell aplasia disease called?
Diamond Blackfan anemia
What is the term to describe the bone marrow in patients with aplastic anemia?
Hypocellular
Are most acquired aplastic anemias idiopathic or secondary?
70% idiopathic
What are the common age ranges for patients with acquired aplastic anemia?
Ages 15-25 and older than 60
How do we classify aplastic anemia when the BM does not recover after withdrawal of the toxic agent?
Idiosyncratic - dose independent
What viruses can cause secondary acquired aplastic anemia?
EBV, Hepatitis and HIV
What is PNH?
Paroxysmal nocturnal hemoglobinuria
What happens to the growth factors, EPO, TPO, and CSF during aplastic anemia?
They are increased
What is a possible treatment for people with aplastic anemia? Who is excluded from this treatment?
Immunosuppressive medication, this does not work for patients who have issues with shortening of telomeres
What fraction of patients with aplastic anemia have shortened telomeres?
1/3
What do telomeres do?
Protect the ends of the chromosomes
What happens to retics in aplastic anemia?
They are decreased - the bone marrow is failing to produce cells, even immature cells
What happens to the MCV in a patient with aplastic anemia?
The MCV is normal or increased
Is there hepatosplenomegaly as a symptom of aplastic anemia?
Nope
Is there poikilocytosis as a result of aplastic anemia
Nope again
What does the decrease in RBCs in aplastic anemia usually cause?
Pallor, fatigue and shortness of breath
What does the decrease in WBCs in aplastic anemia usually cause for the patient?
Reoccurring infections
What does the low platelet count usually cause as a result of aplastic anemia?
Bleeding and bruising
What is the most common inherited aplastic anemia?
Fanconi anemia
What chromosomal defect is indicative of Fanconi anemia?
Fragile chromosomes that break easily
What happens to the telomeres of a patients with Fanconi anemia?
Accelerated shortening
The lab findings of Fanconi anemia are similar to that of aplastic anemia. T or F?
True
What are some of the common physical abnormalities of Fanconi anemia?
2/3 have skeletal abnormalities, hyperpigmentation and/or cafe-au lait spots, and short stature
When are patients most symptomatic with Fanconi anemia?
Ages 5 to 10
Patients with Fanconi anemia have a high risk of developing solid tumors. T or F?
True
Patients with Fanconi anemia have high hgb F and alpha-fetoprotein. T or F?
True
Getting a BMT lowers the risk of cancer for patients with Fanconi. T or F?
False, the secondary risks are still high
In a patient with Fanconi anemia the platelets will be the last to decrease. T or F?
False, they are the first to decrease
What is the general prognosis for Fanconi anemia?
Greater than 90% of patients have BM failure by age 40, 1/4 of patients have solid tumors by 26, death by the age of 20 is common
Is Fanconi amemia autosomal recessive or dominant?
Recessive
Is dyskaratosis congenita caused by a dominant or recessive mutation?
Both
What chromosomal abnormality is indicative of dyskaratosis congenita?
A decrease in telomerase complex and telomere maintenance resulting in extremely shortened telomeres
What are the common clinical findings of dyskaratosis congenita?
Abnormal skin pigmentation, dystrophic nails, oral leukoplasia, multisystem abnormalities and a 40% risk of developing cancer by 50
What is one of the most diagnostic tests for dyskaratosis congenita?
FISH showing shortened telomeres in multiple WBC subsets (including T and B cells)
What are the common lab findings for dyskaratosis congenita?
Pancytopenia, macrocytes and possibly increased Hgb F
What is the general prognosis for dyskaratosis congenita?
60-70% death due to BM failure, 10-15% pulmonary disease, and median survival of 42 years
BMT is recommended for patients with dyskaratosis congenita. T or F?
False, it is not optimal due to complications
Shwachman-Bodian-Diamond Syndrome is due to an autosomal recessive mutation. T or F?
True
What is the genetic cause of Shwachman-Bodian-Diamond Syndrome?
Gene involved in ribosome metabolisms and mitotic spindle stability is mutated
What happens to pancreatic enzyme secretions in Shwachman-Bodian-Diamond Syndrome?
They are decreased leading to pancreatic insufficiency (show symptoms early on in infancy)
What are three clinical findings of Shwachman-Bodian-Diamond Syndrome?
Neutropenia, delayed bone maturation, and short stature in 50% of patients
What happens to the RBCs and Plts in 50% if patients with Shwachman-Bodian-Diamond Syndrome?
They are decreased
What does pancreatic insufficiency cause in the patient’s stool with Shwachman-Bodian-Diamond Syndrome?
An increase excretion of fat in the feces (can do a 72 hour fecal fat test)
Shwachman-Bodian-Diamond Syndrome can cause an increased risk of…
AML and MDS
How can Shwachman-Bodian-Diamond Syndrome be treated?
BMT, transfusions, granulocyte transfusion (last resort, rarely used), and pancreatic enzyme replacement
What are the lab findings of pure red cell aplasia?
Severely decreased RBC precursors, low retic count, severe anemia, normal WBC and Plt counts
What is the name of the inherited form of pure red cell aplasia?
Diamond-Blackfan Anemia
What is TEC?
Transient erythroblastopenia of early childhood
What gene is affected in DIamond-Blackfan anemia?
Gene coding for ribosomal proteins
What are the physical abnormalities in patients with DIamond-Blackfan anemia?
Short stature, craniofacial dysmorphism, neck and thumb malformations
What are the lab findings for DIamond-Blackfan anemia?
Severely low Hgb levels and macrocytes
What are the symptoms of secondary hemosiderosis and what disorder is this associated with?
Iron overload, jaundice, and splenomegaly; Congenital dyserythropoietic anemia
What is a common lab finding in all of these types of anemias?
Retics are low because the bone marrow is not responding
In what disorder is nuclear bridging between cells seen?
Congenital dyserythropoietic anemia