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66 Cards in this Set
- Front
- Back
What's the lifespan of a platelet?
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8-10 days
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What are in platelet dense granules? and alpha granules?
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Dense granules: ADP, calcium, 5-HT
Alpha granules: vWF, fibrinogen, factors V and VIII, plasminogen, plasminogen activator inhibitor |
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What are some causes of eosinophilia?
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NAACP:
Neoplastic Asthma Allergic processes Collagen vascular diseases Parasites (invasive) |
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What disease are hypersegmented PMNs typical of?
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Megaloblastic anemia (vit B12 or folate deficiency)
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What are in neutrophil granules?
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Hydrolytic enzymes
Lysozyme Myeloperoxidase (responsible for green color in pus/mucus) Lactoferrin (antimicrobial activity) |
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CD3, CD4, CD8, CD19, CD20... what cells are they in?
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CD3- all T cells
CD4- Th cells CD8- Tc cells CD19- B cells & follicular dendritic cells CD20- all B cells (but not on pro-B cells and plasma cells) |
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What drugs block the ADP receptor on platelets, and what does this do?
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Clopidogrel and ticlopidine (more side effects)
- ADP binding to platelets causes expression of Gp-IIb/IIIa on platelet surface, which can then bind fibrinogen --> block of ADP binding inhibits platelet aggregation |
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What is Bernard-Soulier syndrome?
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Deficiency of Gp-Ib (mediates binding of platelets to vWF at high shear stress) --> bleeding
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What is Glanzmann's thrombasthenia?
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Deficiency of Gp-IIb/IIIa (on platelets; binds fibrinogen) --> bleeding
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How does warfarin work?
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Inhibits epoxide reductase, which is needed to reduce (activate) vitamin K to serve as a cofactor for factor synthesis (II, VII, IX, X, proteins C & S)
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What does protein C do?
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It's activated by protein S + thrombomodulin --> activated protein C cleaves and inactivates factors Va and VIIIa
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When might you see acanthocytes?
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Liver disease, abetalipoproteinemia
- Acanthocytes = spur cells |
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When might you see basophilic stippling of RBC?
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TAIL: Thalassemias, Anemia of chronic disease, Iron deficiency, and Lead poisoning
"Baste" (Basophilic Stippling) the ox TAIL |
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When do you see bite cells?
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G6PD deficiency
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When do you see macro-ovalocytes?
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Megaloblastic anemia (also would see hypersegmented PMNs), marrow failure
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When do you see ringed sideroblasts?
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Sideroblastic anemia (seen in myelodysplastic syndrome)
- Ringed sideroblasts have accumulated granules of iron in mitochondria in ring around nucleus of developing RBC; due to impaired heme synthesis |
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When do you see schistocytes or helmet cells?
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DIC, TTP/HUS, traumatic hemolysis (microangiopathic hemolytic anemias)
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When do you see spherocytes, aside from hereditary spherocytosis?
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Autoimmune hemolysis
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When do you see teardrop cells?
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Myelofibrosis (bone marrow infiltration)
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When do you see target cells?
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HALT: HbC disease (incl. HbSC disease), Asplenia, Liver disease, Thalassemia
"HALT," said the hunter to his TARGET |
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What are Heinz bodies, and when do you see them?
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Oxidized iron (ferrous --> ferric) leads to denatured Hb --> precipitation in cell --> damage to RBC membrane
- Leads to bite cells - Seen in G6PD deficiency and alpha-thalassemia |
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What are Howell-Jolly bodies, and when do you see them?
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Basophilic nuclear remnants found in RBCs
- Seen in pts w/ functional hyposplenia or asplenia, since they would normally be removed by the spleen |
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What pts do you see alpha-thalassemia in? And beta-thalassemia?
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Alpha- Asians, Africans
Beta- Mediterranean populations |
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What is Hb Barts?
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Hb made of 4 γ chains (γ4)
- Results from alpha-thalassemia with deletion of all 4 alpha genes--pts can't make alpha chains, so make Hb Barts --> hydrops fetalis |
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What is Hb H?
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Hb made of 4 β chains (β4)
- Seen in alpha-thalassemia with deletion of 3/4 alpha genes - Deletion of 1/4 or 2/4 alpha genes is not associated with anemia |
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Pt with increased levels of HbA2 (>3.5%)... what is it?
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Beta-thalassemia minor (heterozygote)
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What happens to HbF in pts with beta-thalassemia major and minor?
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Both have increased HbF (α2γ2)
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What does lead poisoning do?
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Inhibits ferrochelatase and ALA dehydratase --> decreased heme synthesis
- Also inhibits RNA degradation --> basophilic stippling |
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What causes hereditary sideroblastic anemia?
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X-linked defect in ALA synthase gene --> impaired heme synthesis --> ringed sideroblasts (iron-laden mitochondria)
- ALA synthase is the rate limiting enzyme in heme synthesis |
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What causes non-hereditary sideroblastic anemia?
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Alcohol, lead poisoning (things that inhibit heme synthesis)
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How do you treat sideroblastic anemia?
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Pyridoxine (B6) therapy (B6 is a cofactor in heme synthesis)
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What is megaloblastic anemia and what causes it?
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Big cells due to nuclear:cytoplasmic asynchrony in erythropoiesis (slowed/impaired DNA synthesis means that nuclear maturation is retarded as cytoplasmic production of Hb continues)
- Caused by folate or B12 deficiency, certain drugs (5-FU, nucleoside analogues, hydroxyurea), liver disease, metabolic disorders, etc. |
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What causes anemia of chronic disease?
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Inflammation --> ↑ IL-1 and TNF-α --> ↑ hepcidin and ferritin --> limits the Fe that can be freed to transferrin, which is required to get Fe to bone marrow for erythropoiesis
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Anemia with decreased serum Fe, decreased TIBC, increased ferritin... what is it?
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Anemia of chronic disease
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Anemia with decreased serum Fe, increased TIBC, decreased ferritin... what is it?
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Iron deficiency anemia
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Peripheral blood smear with normal cell morphology, bone marrow with fatty infiltration and few cells... what is it and what causes it?
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Aplastic anemia
- Caused by XRT, drugs (chemo), viral agents (parvovirus B19, EBV, HIV), Fanconi's anemia (defect in DNA repair), idiopathic |
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What mutation causes sickle cell anemia?
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Single amino acid replacement in beta chain gene (glu --> val: substitution of normal glutamic acid with valine)
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What happens to serum transferrin and transferrin saturation in pregnancy/OCP use?
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Serum transferrin goes up
Transferrin saturation goes down Ferritin and serum iron don't change |
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Blistering cutaneous photosensitivity, tea-colored urine that contains uroporphyrin... what is it and what's deficient?
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Porphyria cutanea tarda
- Deficiency of uroporphyrinogen decarboxylase --> uroporphyrinogen accumulates - Most common porphyria |
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Severe abdominal pain, muscle weakness, mental disturbances, uroporphyrin in urine... what is it and what's deficient?
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Acute intermittent porphyria
- Deficiency of porphobilinogen deaminase (= uroporphyrinogen-I-synthase) --> porphobilinogen and δ-ALA accumulate (uroporphyrin shows up in urine) - Can be asymptomatic |
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What are the symptoms of acute intermittent porphyria?
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5 P's:
Painful abdomen Pink urine (contains uroporphyrin) Polyneuropathy (muscle weakness) Psychological disturbances Precipitated by drugs |
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How do you treat acute intermittent porphyria?
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Glucose and heme, which inhibit ALA synthase
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Headache, memory loss, inability to concentrate, wrist and foot drop, basophilic stippling in peripheral RBC... what is it?
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Lead poisoning
- Inhibits ferrochelatase (adds Fe to protoporphyrin to make heme) and ALA dehydratase --> impaired heme synthesis, protoporphyrin accumulation |
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How do you treat lead poisoning?
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Adults- dimercaprol, EDTA
Kids- succimer |
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What causes idiopathic thrombocytopenic purpura?
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Anti-Gp-IIb/IIIa antibodies --> peripheral platelet destruction
- Increased megakaryocytes, but decreased platelet survival --> thrombocytopenia --> purpura |
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What causes thrombotic thrombocytopenic purpura?
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Deficiency of ADAMTS 13 (vWF metalloprotease) --> decreased degradation of vWF multimers --> increased thrombosis
- Labs: schistocytes, elevated LDH |
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What is ADAMTS 13?
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vWF metalloprotease (degrades vWF multimers)
- Deficiency --> TTP (increased thrombosis) |
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Neurologic and renal symptoms, fever, thrombocytopenia, microangiopathic hemolytic anemia, schistocytes, elevated LDH... what is it?
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Thrombotic thrombocytopenic purpura (TTP)
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What is prothrombin time (PT) a test of?
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Extrinsic pathway function (factors I, II, V, VII, X)
- Defects in above factors --> increased PT - PT used to derive INR |
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What is partial thromboplastin time (PTT) a test of?
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Intrinsic pathway function (all factors except VII and XIII)
- Defects --> increased PTT |
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What happens to the PT and PTT in pts with hemophilia?
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PT doesn't change, PTT increases
- Due to intrinsic pathway coagulation defect |
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What happens to the PT and PTT in pts with von Willebrand's disease?
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PT doesn't change, PTT increases (this is because vWF binds and stabilizes factor VIII; so deficient vWF --> functional factor VIII deficiency)
- Other platelet disorders have normal PT and PTT |
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What things can cause DIC?
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"STOP Making New Thrombi":
Sepsis (gram negative) Trauma Obstetric complications Pancreatitis (acute) Malignancy Nephrotic syndrome Transfusions |
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Pts with hereditary thrombosis syndrome due to mutated prothrombin gene--what is the causative mutation?
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Mutation in 3' untranslated region of the prothrombin gene
- Assoc. with increased risk of DVT |
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What causes the hemorrhagic skin necrosis seen with warfarin admin?
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Deficiency of protein C or S (decreased inability to inactivate factors V and VIII)
- Proteins C and S have shorter half-lives than the vitamin K-dependent coagulation factors --> initial prothrombotic effect seen with warfarin admin |
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When might you see an increased leukocyte alkaline phosphatase (LAP)? What about a decreased LAP?
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- Increased LAP in benign myeloproliferative disorders, like leukemoid reaction
- Decreased LAP in CML |
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Erythrocytosis, leukocytosis, thrombocytosis, decreased erythropoietin, JAK2 mutation... what is it?
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Polycythemia vera
- JAK2 = signaling protein that's mutated in many benign myeloproliferative disorders |
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Platelet counts >1,000,000... what is it?
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Essential thrombocytosis
- Like polycythemia vera, but for platelets |
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Teardrop-shaped erythrocytes, thrombocytosis... what is it?
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Myelofibrosis
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Bcr/abl transformation... what is it?
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CML
- Negative for JAK2 mutations, which are seen in benign myeloproliferative disorders |
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How do you monitor pts on heparin tx?
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Follow PTT (measure of intrinsic pathway)
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How do you monitor pts on warfarin tx?
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Follow PT/INR (measure of extrinsic pathway)
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How do you treat heparin overdose?
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Protamine sulfate (doesn't work as well on LMWH/enoxaparin)
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How do you treat warfarin overdose?
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IV vitamin K and fresh frozen plasma
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How do you treat tPA overdose?
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Aminocaproic acid (inhibitor of fibrinolysis)
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When might you see a decreased ESR?
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Sickle cell anemia (due to altered shape), polycythemia vera, and CHF (unknown why)
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