Heme Flashcards
(95 cards)
If on blood smear, you see round RBCs that lack the normal biconcave shape and the normal central pallor, what should you suspect?
Spherocytosis - defect in structural proteins (usually spectrin or ankyrin)
What is the difference between FDP (fibrin degradation products) and d-dimer?
FDP - can be generated from the degradation of fibrin or fibrinogen
D-dimer - derived exclusively from fibrin, making d dimer a more informative test for diagnosing clots/DIC
When treating jaundice with phototherapy, what vitamin do you need to supplement?
Riboflavin (B2) because it breaks down when it absorbs light
Which enzymes can be inhibited in lead poisoning?
Aminolevulinate dehydratase (ALAD) and ferrochelatase
What lab values are affected by fibrinolytics? Why?
PT and PTT because tPA lead to degradation of both fibrinogen and fibrin. By breaking down fibrinogen, the common pathway will be partially inhibited (increasing both PT and PTT)
Platelet count is unaffected
How does uterine leiomyoma lead to anemia?
Increased blood loss during menstruation –> iron deficiency –> microcytic anemia
How does ketoconazole interact with warfarin?
Ketoconazole potentiates warfarin’s effects because it inhibits cytochrome P450 (thus decreasing the metabolism of warfarin)
Describe what a Reed-Sternberg cell looks like.
Large binucleate eosinophilic cells
Why is TIBC low in anemia of chronic disease?
TIBC measures blood’s capacity to bind iron with transferrin. Transferrin and relatedly TIBC are low in ACD because even though the serum Fe levels are low, the body senses high iron in its intracellular stores (ferritin) because it’s storing iron there.
What five cancers should you suspect when you see polycythemia (i.e. to see if it’s a paraneoplastic syndrome).
- Hepatocellular carcinoma
- Renal cell carcinoma
- Hemangioblastoma
- Pheochromocytoma
- Uterine myomata
Describe the characteristic histologic findings in a benign reactive lymphadenitis.
- Tingible body macrophages (macrophages that have ingested lymphocytes - filled with debris)
- Multiple large germinal centers
- Frequent mitoses
- Recognizable light and dark zones
Does warfarin affect PT, PTT, or both? Compare normal therapeutic doses vs. overdose.
In normal therapeutic dose - just PT (because it’s mainly the effect of Factor VII)
In overdose - both (because of the effects of all the factors in the common pathway)
What cranial X ray finding is typical of sickle cell anemia?
Sickle cell anemia
Why would a sickle cell patient have shortened digits?
Result of past crises damaging bone growth
What cells are classically found in EBV mononucleosis?
Downey cells - atypical reactive CD8+ lymphocytes
What are two side effects of chloroquine?
- Worsen psoriasis
2. Retinopathy
What should you give with ALL chemo to prevent uric acid stones?
Xanthine oxidase inhibitor - e.g. febuxostat, allopurinol
How do macrolides interact with warfarin?
Potentiate the effects of warfarin - macrolides inhibit CYP450 so they inhibit the metabolism of warfarin
What are Heinz bodies composed of?
Denatured hemoglobin
What lab test is used to monitor the effects of heparin?
PTT
Lymph node biopsy shows “follicle formation with predominantly small lymphocytes containing scanty cytoplasm and irregular, twisted, and indented nuclei”. What is the likely diagnosis and what genetic translocation is associated with it.
Follicular lymphoma
t(14:18)
immunoglobulin heavy chain and bcl-2
Which cells found in small number on skin are perivascular, have darkly stained ovoid nuclei on H&E, and demonstrate metachromasia of cytoplasm when stained with Giemsa?
Mast cells
What drug, commonly given with aspirin to lower risk for MI after stent placement, has a potential toxicity of neutropenia? How does this drug work?
Ticlopidine - irreversibly blocks ADP from binding platelets
Why does placental abruption increase risk of DIC?
The placenta contains massive amounts of tissue factor, which is the primary initiator of the clotting cascade (found in subendothelial tissue) through thrombin generation