Heme/Onc Flashcards
Bilirubin Stones
- are they radiolucent or radiopaque?
- Are they brown or black?
- What causes them?
1. Radiopaque
2. Black
3. Chronic Hemolysis
What conditions can desmopressin be used for? (4)
1. Central Diabetes Insipidus
2. Nocturnal Enuresis
(Binds V2 –> inc. aquaporins –> increase H2O retention)
3. Hemophilia A (increase factor VIII)
4. Von Willebrand Disease (increases endothelial secretion of VWF)
What is an abnormal Ristocetin Test and what disorder is it indicative of?
von Willebrand Disease
Abnormal Test = failure of platelets to aggregate in a ristocetin assay
Aplastic Anemia
What would the clinical and lab finding look like?
Pancytopenia:
- Decreased erythrocytes –> anemia
- Decreased platelets –> easy bleeding/bruising
- Decreased leukocytes –> recurrent infections
Which drugs can cause Aplastic Anemia?
- carbamezipine
-Methimazole
-NSAIDs
-Benzene
- chrolamphenicol
- Propylthiuracil
“Cant Make New Blood Cells Properly”
How does neonatal vitamin K deficiency present?
A neonate with a:
- intracranial bleed
- GI bleed
- cutaneous bleed
- umbillical bleed
- surgical site bleed
- What cell maintains iron homeostasis?
- How does it do it?
- Where is this cell synthesized?
- Hepcidin
- Binds ferroportin on intestinal mucosa + macrophages
- Liver
What increases Hepcidin?
How would this effect the bodies level of iron?
Hepcidin is increased by:
- Inflammation
- increased levels of Fe
Increased hepcidin —> decreased levels of iron
What decreases Hepcidin?
How would this effect the bodies level of iron?
Hepcidin is decreased by:
- hypoxia
- increased erythropoiesis
decreased hepcidin —> increased levels of iron
(situations when we need more iron for RBC production)
What are 3 classical signs of Megaloblastic anemia?
What causes it?
Classical presentation:
- RBC macrocytosis
- hypersegmented neutrophils
- glossitis
Occurs due to Folate or Vit. B12 deficiency
What is the classical difference is presentation between Folate and Vitamin B12 deficiency? Why?
Vitamin B12 deficiency presents with neurological symptoms
Due to having increased levels of methylmalanoic acid whch impairs spinal cord myelinization
(B12 converts methylmalonic acid to succinyl coA)
What is haptoglobin?
When would it be decreased?
When there is free hemoglobin in blood, Haptoglobin binds it and brings it to the spleen to be reprocessed
Haptoglobin in decreased when there is intravascular hemolysis (releases Hb into blood) since it binds blood and goes to spleen
Is a malnutritoned alcoholic more likely to have Vit.B12 (cobalamin) of folate deficiency?
Folate
since our body has limited stores of folate and plenty of B12
What is the cause of pernicious anemia and why?
Pernicious anemia occurs due to a lack of intrinsic factor from the gastric parietal cells which then prevents absorption of vitamin B12 in the illeum
(Vit. B12 gets absorbed via attachement to intrinsic factor)
What type of anemia does this patient most likely have?
What is the most likely cause of this type of anemia?
Hereditary Spherocytosis
(RBCs lack central pallow)
Due to a cytoskeleton abnormality
(spectrin, ankyrin, band 3)
In which type of anemia would we most commonly find increased mean corpuscular hemoglobin concentration (MCHC)? Why?
Inherited Spherocytosis
Increased MCHC due to amount of Hb in cytoplasm remaining the same while the RBC shrinks
How does a patient with sickle cell trait present?
How much much HbS will they have?
What a good thing about it?
Asymptomatic
Less than 50% HbS
Protection from malaria
What type of infections is someone with Sickle Cell Anemia most at risk for? Why?
Infections by Encapsulated Organisms
(Strep. pneumo, N.Meningitidis, H.Influenza Type B)
Due to the fact their spleen is highly damaged/weakened and the speen produces opsonizing antibodies needed for killing encapsulated bacteria
What mutation results in Paroxysmal Nocturnal Hemoglobinuria?
How does this result in anemia?
PIGA mutation –>
no GPI anchor –>
no DAF/CD55 & MIRL CD59
RBC is now more susceptible to complement-mediated hemolysis
(DAF & MIRL protect RBC from complement)