1. What cell maintains _iron homeostasis_? 2. How does it do it? 3. Where is this cell synthesized?

1. _Hepcidin_ 2. Binds _ferroportin_ on intestinal mucosa + macrophages 3. Liver

Heme/Onc Flashcards by Josh Cohen

Bilirubin Stones

are they radiolucent or radiopaque?
Are they brown or black?
What causes them?

1. Radiopaque

2. Black

3. Chronic Hemolysis

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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)

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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

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Aplastic Anemia

What would the clinical and lab finding look like?

Pancytopenia:

Decreased erythrocytes –> anemia
Decreased platelets –> easy bleeding/bruising
Decreased leukocytes –> recurrent infections

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Which drugs can cause Aplastic Anemia?

- carbamezipine

-Methimazole

-NSAIDs

-Benzene

- chrolamphenicol

- Propylthiuracil

“Cant Make New Blood Cells Properly”

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How does neonatal vitamin K deficiency present?

A neonate with a:

- intracranial bleed

- GI bleed

- cutaneous bleed

- umbillical bleed

- surgical site bleed

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What cell maintains iron homeostasis?
How does it do it?
Where is this cell synthesized?

Hepcidin
Binds ferroportin on intestinal mucosa + macrophages
Liver

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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

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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)

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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

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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)

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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

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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

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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)

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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)

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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

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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

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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

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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)

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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_** 1. How does it affect PT and PTT 2. 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. 1. Most likely diagnosis 2. How would this affect PT, PTT and bleeding time

1. **_Uremic Platelet Dysfunction_** 2. **Normal PT & PTT** **Increased bleeding time**

**_Porphyria Cutanea Tarda_** 1. Main symptoms 2. Affected Enzyme 3. Accumulated Substrate 4. What makes it worse?

1. Blistering cutaneous photosensitivity + Hyperpigmentation 2. **_Uroporphinogen Decarboxylase_** 3. **Uroporphyrin** 4. Alcohol consumption

**_Acute Intermittent Porphyria_** 1. Affected Enzyme 2. Accumulated Substrate 3. Symptoms

1. **_Porphobilinogen Deaminase_** 2. Porphobillinogen 3. 'The 5 Ps' * **P**ainful abdomen * **P**ort-wine coloured urine * **P**olyneuropathy * **P**sychological Disturbances * **P**recipated 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_** 1. Affected Enzyme 2. Accumulated substance 3. What type of anemia would this result in?

1. **ALAD and Ferrochelatase** 2. **Protoporphyrin** (since ferochelatase cannot combine protoporphyrin and iron to make heme) 3. **Micro**cytic anemia (more specifically Sideroblastic Anemia)

What are the main symptoms of lead poisining?

"**_LLEEAAD_**" **_L_**ead **_L_**ines on gingivae and metaphysis of long bones **_E_**ncephaloptathy and **_E_**rythrocyte Basophilic Stipling **_A_**bdominal Colic and Sideroblastic **_A_**nemia **_D_**rop 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_** 1. Main Symptoms 2. Treatment and why it works?

1. **reddish skin discoloration (no cyanosis)**, tachypnea, headache, confusion 2. **_Nitrites_** They work by converting oxidize ferrous iron (**Fe²⁺**) into ferric iron (**Fe**³⁺) 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: 1. Carboxyhemoglobin 2. PaO2 3. Methemoglobin

1. **Increased Carboxyhemoglobin** 2. **Normal** PaO2 3. **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_** 1. Why/How does it occur? 2. 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 2. 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_** 1. How/Why does it occur? 2. Presentation 3. Treatment

1. 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 2. Presents as **mild jaundice** in neonate within 24hrs (much more mild the Rh hemolytic disease) 3. 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_** 1. What is it a type of? 2. Main symptoms

1. It is a type of aplastic anemia 2. _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)