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)
What is the classical triad of presentation seen in Paraoxysmal Nocturnal Hemoglobinuria?
1. Coombs - hemolytic anemia
2. Pancytopenia
3. Venous Thrombosis
How does Plummer-Vinson Syndrome present?
How can it be treated/resolved?
Dysphagia
Iron Deficiency Anemia (glossitis, spoon nails)
Esophageal Web
Can be resolved with Iron Supplementation
A JAK2 mutation results in a mutation in what kind of receptor?
Non-receptor (Cytoplasmic) Tyrosine Kinase
Hereditaty breast cancer is most associated with BRCA1 / BRCA2 gene mutations. What is the main function of these tumor supressor genes?
DNA Repair
The Retinoblastoma (RB) tumor supressor protein regulates which cell function?
Cell Cycle transition
(G1–>S transition)
To oppose the functions of TXA2 what can be secreted by the endothelium?
Prostacyclin
Liver failure
- How does it affect PT and PTT
- Which factor is most likely to de deficient? Why?
1.
Increased PT
Normall PTT
2.
Factor VII
(shortest half-life)
In a patient end-stage renal disease begins to have uncontrolled bleeding from a catheter exit site.
- Most likely diagnosis
- How would this affect PT, PTT and bleeding time
1.
Uremic Platelet Dysfunction
2.
Normal PT & PTT
Increased bleeding time
Porphyria Cutanea Tarda
- Main symptoms
- Affected Enzyme
- Accumulated Substrate
- What makes it worse?
- Blistering cutaneous photosensitivity + Hyperpigmentation
- Uroporphinogen Decarboxylase
- Uroporphyrin
- Alcohol consumption
Acute Intermittent Porphyria
- Affected Enzyme
- Accumulated Substrate
- Symptoms
- Porphobilinogen Deaminase
- Porphobillinogen
- ‘The 5 Ps’
- Painful abdomen
- Port-wine coloured urine
- Polyneuropathy
- Psychological Disturbances
- Precipated by drugs, alcohol, starvation
What is the treatment for Acute Intermittent Porphyria? Why?
Hemin and Glucose
Since they inhibit ALAS which decreases accumulation of porphobilinogen
Lead Poisoning
- Affected Enzyme
- Accumulated substance
- What type of anemia would this result in?
- ALAD and Ferrochelatase
- Protoporphyrin
(since ferochelatase cannot combine protoporphyrin and iron to make heme)
- Microcytic anemia (more specifically Sideroblastic Anemia)
What are the main symptoms of lead poisining?
“LLEEAAD”
Lead Lines on gingivae and metaphysis of long bones
Encephaloptathy and Erythrocyte Basophilic Stipling
Abdominal Colic and Sideroblastic Anemia
Drop of wrist & foot
What is the main symptom of lead poisining seen in children?
What is used for treatment for children?
Mental Deterioration
(usually language regression)
Succimer
“Succs to be a kid with lead poisining“
What is the 1st line treatment of lead poisoning in adults?
Dimercaprol and EDTA
Cyanide Poisoning
- Main Symptoms
- Treatment and why it works?
- reddish skin discoloration (no cyanosis), tachypnea, headache, confusion
- Nitrites
They work by converting oxidize ferrous iron (Fe2+) into ferric iron (Fe<strong>3</strong>+) inducing methemoglobinemia which then binds the cyanide diminishing its negative effects
During transition from point 1 to point 2 what is hemoglobin molecules are most likely to release what?
H+ and CO2
Haldane Effect: Occurs in the lungs. Hb binds O2 it drives the release of H+ and CO2 from hemoglobin
Bohr Effect: Occurs in peripheral tissues where high CO2 levels increase unloading of O2
Which organelle is esstential for heme synthesis?
Mitochondria
What would the effect of CO poisoning be on:
- Carboxyhemoglobin
- PaO2
- Methemoglobin
- Increased Carboxyhemoglobin
- Normal PaO2
- Normal Methemoglobin
(CO does not induce Fe3+, Nitrites for treatment of cyanide poisining do)
When giving large blood transfusions patients can experience hypocalcemia, why?
Citrate anticoagulants in the transfused blood chelate the calcium
What is the only type of antibody that can cross the placenta?
IgG
Rh Hemolytic Disease of the newborn
- Why/How does it occur?
- Treatment
1.
If an Rh- mother gives birth to an Rh+ child, during birth some of their blood will interact and she will form anti-D(Rh) IgG antibodies. In her next pregnancy anti-D IgG can cross the placenta and cause hemolysis of RBCs in the child
- This can be prevent by giving the Rh- mother anti-D IgG during her 3rth trimester and pospartum if fetus tests + fot Rh
(prevents the mom from mounting a full immune response)
ABO Hemolytic Disease of the Newborn
- How/Why does it occur?
- Presentation
- Treatment
- If a type O mother (who has anti-A and anti-B IgM and IGg) gives birth to a type A or B fetus, the prexisting maternal IgG can cross the placenta and cause hemolysis of RBCs
- Presents as mild jaundice in neonate within 24hrs
(much more mild the Rh hemolytic disease)
- Give newborn phototherapy or blood transfusion
If a patient has anemia with absent erythroid precusor cells but normal WBC and platelet count along with their respective normal precursor cells
What is the most likely diagnosis?
What is it associated with?
Pure Red Cell Aplasia
Thymoma (thymic tumor)
A patient presents with fatigue, easy brusing and frequent epistaxis.
Labs show pancytopenia and a biopsy of his bone marrow is shown below, what is the most likely diagnosis?
Idiopathic Aplastic Anemia
(Pancytopenia with bone marrow hypocellularity that is scattered with fat cells)
Fanconi Anemia
- What is it a type of?
- Main symptoms
- It is a type of aplastic anemia
- Presents as:
- Pancytopenia
- Absent thumbs
- Short stature
- Increase risk of malignancies
A patient with Hemophilia A or B presents to your office.
Treamtent with Factor XII does not work but treatment with thrombin (factor II) does work. Why?
A hemophilliac is deficient in factors 8(A) or 9(b)
Due to the fact that factors activate the factor below them in the cascade giving factor 12 when youre missing 8 or 9 wont help you bypass this deficiency
Giving factor 2 bypasses the intrinsic pathway and activates the common pathway directly resulting in a clot
If a patients RBCs have increased osmotic fragility what is the most likely diagnois?
What is the most likely complication?
Heriditary Spherocytosis
Pigmented Gallstones (as it would be with any hemolytic anemia)
If a patients RBCs have no central pallor what is the most likely diagnois?
What is the most likely complication?
Heriditary Spherocytosis (spherocytes)
Pigmented Gallstones (as it would be with any hemolytic anemia)
