Heme Flashcards
Apt with chronic alcoholism presents with HA, chills, nausea, and dizziness and notes he has been home in his apartment a lot with a gas heater. What abn finding would be on his hgb dissociation curve?
Carbon monoxide poisoning
Decrease in oxygen carrying capacity of hgb
Tx - 100% Oxygen or hyperbaric therapy
Pt presents with hemiparesis, recent history of gum bleeding, LUQ pain, Platelet count 900,000.
Essential thrombocytosis - platelet overproduction
Epistaxis, thrombosis, burising, bleeding, erythromelalgia (buring and redness in hands and fee)
Tx - hydroxyurea - inhibits ribonucleotide reductase preventing dNTP formation
Hodgkin lymphoma is associated with which viral infection?
Epstein Barr (EBV) dsDNA linear
INR increases when warfarin concentration is too
high.
High INR = hypocoaguable
IE when a CYP450 inhibitor is added to the pt regimen (isoniazid, cimetidine, quinidine, quinolones, spironolactone, macrolide, amiodarone, dapsone, ketoconazle
A pt with G6PD deficiency has deficiency in which molecule after taking certain medications (primaquine, sulfonamides, nitrofurantoins) or fava beans?
NADPH (reduced by G6PD)
Pt T cells have a multilobulated nucleus in “cloverleaf” cells. Skin lesions, hepatosplenomegaly, lymphadenopathy.
Adult T cell leukemia
Human T cell leukemia virus (HTLV-1) - rapidly progressive. Death in months
Transplant recipient presents with itching over his palms and soles and recent diarrhea. Maculopapular rash over neck, shoulder, palms, and soles. Elevated ALT/AST alk phos
Acute graft vs host dz
Triad of dermatitis, hepatitis, gastroenteritis
Donor lymphocytes react against host MHC
Occurs weeks after transplantation
In what order do organs begin hematopoiesis during development?
- Yolk sac (3-8 wks)
- Liver (6 wks - birth)
- Spleen (10-28 wks)
- Bone Marrow (~18 wks gestation)
A pt with severe sepsis develops DIC. what changes will be seen in her RBCs?
microangiopathic hemolytic anemia
Schistocytes
A 65 y/o pt has been experiencing pain exacerbation associated with OA for a week and has been brought to the ED with disorientation and lethargy. He is presenting with respiratory alkalosis and anion gap acidosis. What did he over dose on?
Aspiring (salicylate) tox
Would have ringing in the ears prior to disorientation
Combined resp alkalosis and anion gap acidosis
Other AEs = GI discomfort and bleeding
Tx - admin bicarb to alkalinize the urine and promote excretion
What is the result of warfarin exposure in utero?
hemorrhage causing scaring of the organs (optic atrophy, Dandy-walker, developmental delay)
A pt with iron deficiency anemia will have what finding on her labs for: Ferrittin, Iron-binding capacity, MCV
Low Ferrittin, MCV
High Iron binding capacity
What is ferritin?
Binds free iron and stores it intracellularly. Count directly correlates with total body levels of iron
What is give to a pt presenting acutely with a fib to protect from thrombosis? And what is given if they are over anti-coagulated?
Heparin (potentiates antithrombin)
Correct overdose with Protamine sulfate, a cationic molecule that binds the negatively charged heparin
Which drug binds directly to IIb/IIIa on activated platelets to prevent aggregation?
Abciximab
Binds IIb/IIIa to prevent fibrinogen from binding and interfering with aggregation. Used in acute coronary syndrome and angioplasty
Inheritance pattern for G6PD deficiency
X-linked
exposure to oxidant drug -> production of peroxides and free radicals -> GSH (glutathione) absorbs this radicals but fails to regenerate with G6PD is absent because NADPH becomes depleted
In follicular lymphoma these is overexpression of bcl-2. What is its function?
antagonist of apoptosis by preventing cytochrome c from binding APAF
Pt presents with chronic fatigue, pale conjunctivae, decreased cap refill, wide gait, mild parathsia, low hgb, low hct, high MCV, high platelet
Megaloblastic anemia due to B12 deficiency
smear would show macrocytic hypersegmented PMNs and large oval shaped erythrocytes
How do you distinguish folate deficiency from B12?
Time of onset, folate occurs in months. B12 takes years
Following a mono infection a college student presents with fatigue, scleral icterus, cervical lymphadenopathy and splenomegaly. Finger tips are purple. Low hgb, high reticulocyte, + heterophile testing. Dx?
IgM-mediated hemolytic anemia (cold agglutin)
Manifests shortly after EBV, acute HIV, mycoplasma, leukemia
heterophile test = sens and spec to cold agglutins
pt presents with RLQ pain, diarrhea, fever x 10 years. Low hgb, large MCV. Hypersegmented PMNs and oval macrocytes on smear. Dx?
Crohn’s dz
Decreased abs of B12 causing megaloblastic anemia
Elevated methylmalonic acid level b/c B12 is an essential cofactor to convert it to succinyl-CoA
Pt presents with anemia, jaundice, and splenomegaly with spheroids on smear
Hereditary spherocytosis
defect in cytoskeletal proteins (ankyrin, band 3, spectrin)
Tx - splenectomy
A college student reports seeing blood in her urine but only first thing in the morning
Paroxysmal nocturnal hemoglobinuria (PNH)
abn PIG-A gene which produces the glycophosphatidylinositol (GPI) anchors on the cell surface
Without these anchors, MAC complexes attach to the RBC and cause hemolytic anemia
hematuria happens all day but most noticable in the morning because urine is concentrated
When do you see the Taut form of hemoglobin?
It is the deoxygenated form, low oxygen affinity, favors offloading. See it in the venous system.
Relaxed form has greater oxygen affinity
What findings (demographic and labs) would be seen in Beta-Thalassemia?
hypochromic microcytic RBC
Elevated RBC count, nl to low hematocrit
Target cells
Mediterranean and North African descent
What hematologic changes may be found in a HCV pt that is taking ribavirin?
Ribavirin inhibits inosine monophosphate dehydrogenase (nucleotide formation)
Assoc with hemolytic anemia (low serum haptoglobin (b/c they are sopping up free hgb in the blood), high lactate dehydrogenase, indirect hyperbilirubinemia (intravascular hemolysis)
MOA of Cyclophosphamide?
Alkylating agent that covalently bonds DNA to guanine N-7
Cell-cycle independent
MOA of vincristine?
Blocks polymerization of microtubules by binding tubulin and inhibits mitotic spindle formation. M-phase specific
A pt taking cyclophosphamide for non-Hodgkin’s lymphoma. 2 months later she presents with a urinalysis finding: 1+ protein, 1+ leukocyte esterase, WBC, TMTC RBCs. This would have been prevented is she was also given which drug?
Mesna
AE’s assoc with cyclophosphamide incl. myelosuppression and hemorrhagic cystitis
Mesna prevents hemorrhagic cystitis by binding cyclophosphamide metabolites in the urine and neutralizing them
When would you coadminister a treatment with diphenhydramine?
Along with a drug that may cause an allergic rxn (vanco) or alleviate dystonic rxns (haloperidol)
Pt presents with slow-onset, bizzare, paranoid behavior, jerky uncoordinated gait, weight loss. PE beefy red tongue, hyperreflexia, extensor plantar reflexes, + Romberg. What would be seen on smear?
Increased nuclear lobulations in PMNs, macrocytic RBC’s
Dx = pernicious anemia. autoimmune Ab causing atrophic gastritis and IF deficiency which reduces B12 absorption
Tx - B12 injections
A pt with RA presents with fatigue and bruising. CBC shows decreased RBCs, WBCs, and platelets. He RA tx inhibits dihydrofolate reductase. Co-administration with what would have reduced these effects?
Pt is taking Methotrexate for R and it prevents thymidine synthesis.
Co-admin with leucovorin or folinic acid (tetrahydrofolate derivative) mitigates the myelosuppression
leucovorin rescue
pt presents with recurrent gum bleeding, severe menorrhagia. Notes her mom and gma had similar syx but not her dad. Labs:platelet 250,000, increased bleeding time, increased PTT, nl PT. Dx?
Von Willebrand dz (vWD)
AD
mucocutaneous bleeding and menorrhagia in women
Defect in platelet aggregation and factor VIII delivery (nl PT)
A pt with RA presents with fatigue, palpitations, and increased SOB. PE pallor and tachycardia. low hgb, low serum iron, high ferritin level, decreased TIBC. Smear shows decreased number of normal sized RBCs
Anemia of chronic dz
normochromic, hypoproliferative anemia, decreased Fe, decreased TIBC
Elevated ferritin demonstrates that Fe isn’t so low that the stores are depleted
A pt is treated for N. meningitides in Guatemala. 5 days post therapy her labs show: WBC 2400 Hgb 5.3 Platelet 25,000 Ret 0.1% What abx was she given?
Chloramphenicol
Causes aplastic anemia (pancytopenia, low Ret), gray baby syndrome
Rarely used in the US
Which type of transplant is the most effective and least likely to be rejected?
Autogenic (self-graft)
Skin, coronary a. bypass, cartilage
NO need for immunosuppresion
Option in Hodgkin lymphoma since stem cells are not affected and can be harvested
What is an allograft?
Graft from a genetically different member of the same species.
Require immunosuppresion to prevent T cell mediated organ rejection
Second line in Hodgkins if autogeneic graft fails
A pt with breast cancer was started on a chemo regimen and the masses have been shrinking. However, the masses have returned to their original size and have been found to have a mutation in beta tubulin. What drug was given?
Paclitaxel - prevents microtubule disassembly
Vincristine, vinblastine - inhibit microtubule formation
What is the MOA of doxorubicin?
Generates free radicals and causes ds DNA breaks.
MOA of busulfan
DNA alkylating agent.
MOA of Ciplatin
DNA crosslinking agent
MOA of etoposide
inhibit type II topoisomerase.
A pt with sickle-cell may have what findings would be on their blood smear?
Normocytic RBCs, Sickle shaped RBCs, increased reticulocytes, and Howell-Jolly bodies
Also predisposed to calcium bilirubinate gallstones (radiopaque)
What does external validity mean in a study?
extent to which study results are applicable to a population outside of the study population. Randomization is one way to help ensure appropriate external validity
Measure of accuracy
A pt presents with dizziness, fatigue, megaloblastic anemia following abx use for UTI’s. Which abx was used?
Trimethoprim-sulfamethoxazole
AE’s of Bactrim = Stevens-Johnson syndrome, nausea, megaloblastic anemia, leukopenia, and granulocytopenia. These are reduced with a folinic acid supplement
When is Chloramphenicol given and what are it’s AEs?
Used in bacterial meningitis
AE’s = aplastic anemia, gray baby syndrome.
Can lead to death if unable to metabolize the drug
What should a pt with von Willebrand’s dz (Increased PTT, Bleeding time) be given as a preventative prior to undergoing a procedure?
Desmopressin
ADH analog, increases the release of vWF from storage sites and increase factor VIII activity
a pt with lead poisoning (fatigue, peripheral neuropathy) inhibits what enzyme?
Gamma-aminolevulinic acid
Involved in heme synthesis
What lab findings are consistent with Iron deficiency anemia?
Decreased MCV (microcytic) Low ferritin (hypochromic)
A pt with anemia symptoms and labs also have a positive direct coomb’s test. Dx?
Autoimmune hemolytic anemia
Idiopathic, viral induced, SLE-induced, lymphomas
Rank HCV, HBV, and HIV in order from highest infectability to lowest
HBV
HCV
HIV
What is the prominent protein in eosinophils?
Major basic protein
They also produce histaminase and arylsulfatase which degrade histamine and slow-releasing substance of anaphylaxis
A vegan presents with macrocytic anemia and multilobed PMNs. What lab test will definitively determine the deficiency?
Methylmalonic acid level. Methylmalonyl CoA is converted to succinyl CoA with B12 as a cofactor. If B12 is deficient methylmalonic acid will accumulate
Don’t want to measure B12 directly because most will be bound to a protein and won’t tell you how much of the B12 content is bioactive
Folate deficiency will have normal methylmalonic acid levels
A pt has irregular bruising/bleeding and peripheral smear shows few platelets and large WBC’s with azurophilic granular needles in the cytoplasm. Dx and Tx?
Acute DIC due to Acute promyelocytic leukemia (auer rod, t(15;17))
Tx - all-trans retinoic acid which promotes the differentiation of immature tumor cells
A pt with a hx of weakness of weightloss has hepatosplenomegaly and general lymphadenopathy. Peripheral smear shows lymphocytes that are destroyed during slide preperation. This dz involves clonal expansion of which cell type?
B lymphocyte
This is chronic lymphocyte leukemia (CLL)
Smudge cells are seen on the smear which are clonal B lymphocytes arrested in the B cell differentiation pathway between pre-B cells and mature B cells
4 y/o presents with fatigue, loss of appetite, and bruising. Smear shows abundant lymphoblasts. Dx?
Acute lymphocytic leukemia (ALL)
Neoplasm from a single B or T progenitor cell. Blast accumulates in the marrow crowding out the other cells lines and suppressing hematopoiesis.
Syx = anemia, thrombocytopenia, neutropenia
Following a UTI a pt has an elevated INR. Why?
Loss of gut bacteria (bit K deficiency)
A child has jaundice following a viral infection. Peripheral smear and osmotic fragility test are diagnostic. Dx?
Hereditary spherocytosis (defect in spectrin, ankyrin) Spherocytes are fragile and pt is more prone to heolysis with stress. Difficult for spherocytes to filter through spleen and splenectomy ameliorates the condition
What is heaprin-induced thrombocytopenia (HIT)?
Low platelet state 5-14 days post heparin therapy
Ab form against heparin-platelet factor 4 complex causing stroke, MI, DVT etc. Occurs when platelets fall to 50% and more common in pts that have received heparin before
A teenager has a nosebleed lasting 1 hr after a URI. PE shows small nonblanching petechiae on the legs. Labs: 25,000 platelet, aPTT and PT are WNL. Dx and additional lab findings?
Idiopathic thrombocytopenic purpura (ITP)
autoimmune dz triggered by viral infection
dx of exclusion
Ab against GPIIb/IIIa
80% of childhood cases are self limiting
Adults - tx with steroids, IVIG, plasmapheresis, rituximab
A newborn (3 days) presents with an umbilical stump oozing blood and black malodorous stool. Dx and lab findings?
Vitamin K deficiency
NL platelet count, bleeding time, d-dimer
Elevated PT and PTT
Pt presents with B symptoms, nontender cervical and supraclavicular lymphadenopathy. Bx = large cells with lobed nuclei and prominent eosinophilic inclusion like nucleoli. Dx?
Hodgkin’s lymphoma
Bx describes a reed-sternberg cell. These cells are CD15/CD30 +
RF’s 15-40 y/o male and 55+ y/o male, EBV infection, immunodeficiency, prolonged HGH use
What molecule does fetal Hgb have lower affinity for and contributes to the left shift seen on the oxygen-hgb dissociation curve?
2,3-bisphosphoglycerate
Lower 2,3-BP affinity = higher oxygen affinity = left shift
After a long flight a pt has a DVT and then experiences a PE in the middle of the night. Dx?
Factor V Leiden
Most common inherited hypercoagulability.
Arg to glut substitution in residue 506 of Factor V makes the protein resistant to cleavage by protein C
A cancer pt is presenting with aplastic anemia (anemia, neutropenia, thrombocytopenia). What drug could have prevented this and what is its MOA?
G-CSF is given during chemo to prevent neutropenic fever
It binds a transmembrane receptor to stimulate immature PMN differentiation in the marrow
Can also use bone marrow transplant and transfusion but these are infrequently used
What is neutropenic fever?
PMN count 38 for at least an hour or one temp at >38.3
Assumed to have an infection and initiate broad spectrum abx
Translocation of 15;17. Dx and tx?
Acute promyelocytic leukemia (APL)
Tx - all-trans retinoic acid (vit A derivative, bind nuclear receptors to upregulate genes to allow maturation of myeloid cells)
Auer rods = pathognomonic
A child presents with B symptoms x 1 week. Lymphoblasts are seen on smear are seen on smear. Dx?
Acute lymphocyte leukemia
Presents with sudden onset of syx associated with bone marrow suppression.
How do you distinguish lymphoblasts from myeloblasts?
Lymphoblast - large blue cell
Myeloblast - more nucleoli, more granules, auer rods
A child presents with jaundice. Labs: anemia, increased ret count, + warm agglutinin test
Warm-reactive autoimmune hemolytic anemia (AIHA)
Tx - corticosteroids
Corticosteroids inhibit the Fc receptor mediated clearance of sensitized RBCs
How does the diptheria vaccine work?
Cross-reactivity of toxoid
Toxoid = toxin that has been modified so that it is no longer toxic but antigenicly similar
Toxid cross-reacts with the toxin.
A 12 y/o develops hemorrhagic cystitis following use of cyclophosphamid for juvenile RA. She also develops petechiae. What is likely to manifest with these symptoms?
Fanconi’s anemia
ar, marrow hypofunction and eventual pancytopenia
Presents early in life
Hallmark = increased chromosolmal breakage in response to DNA-damagin agents due to a defect in homologous recombination repair.
More sensitve to cyclophosphamide and other chemo’s
A pt with colon cancer is have dark colored stools WBC - 10,200 Hgb 8.8 HCT 26.5% Platelet 231,000
Microcytic anemia
Blood loss = Fe loss = hypochromic microcytic anemia
What is the MOA of mesna?
free thiol compound that reacts with urotoxic products of cyclophasphamide. Prevents hemorrhagic cystitis associated with cyclophosphamide usage
A pt presents with a single (painless) large mass. Bx shows many large cells resemblind lymphocytes. B symptoms
Diffuse large B-cell lymphoma (DLBCL), most common type of Non-Hodgkin lymphoma
RF’s immunosuppresion (esp HIV, HH8). Increasing age
A pt presents with megaloblastic anemia due to folate deficiency. What process will the pt have a defect in?
One-Carbon unit transfers
Tetrahydrofolate is an intermediate that transfers 1 unit of C in purine synthesis.
NO neuro symptoms
A dz is characterized by lytic bone lesions, hypercalcemia, renal insufficiency, anemia, susceptibility to infection. Monoclonal spike on protein electrophoresis.
Multiple myeloma
Proliferation of plasma cells
Spike = monoclonal M
Produces great quantities of Bence Jones proteins (Ab light chains)
Renal insufficiency due to production of large, tubular casts obstructing the tubular lumina
How do you treat hemochromatosis?
Regular phlebotolmy
Iron-chelating agent (deferoxamine)
Following a blood transfusion pt develops fever, tachycardia, dyspneanausea, tight chest, flank pain and diffuse ECG changes. What is the mechanism of the rxn?
Type II HS (complement mediated cytotoxic) due to ABO incompatibility
Massive hemolysis leads to hyperkalemia (spiked T waves on ECG)
Vinca alkaloids and paclitaxel have what common feature?
Specific mitotic phase inhibitors of the cell cycle (microtuble assembly and disassembly)
Vinca alkaloids = vincristin and vinblastine, inhibit spindle formation
Paclitaxel = hyperstabilizes microtubules, prevents spindle breakdown
A pt presents with tingling that has progressed over months. No travel hx. Mildly jaundiced, tongue is glazed in appearance, decreased vibration sense and muscle strength in lower extremities. Hypersegmented PMNs on smear
Pernicious anemia
Syx resemble B12 deficiency (pallow, jaundice, low RBC, fissures at the cornors of the mouth, glossitis, motor and sensory loss (abn myelin))
Pernicious anemia = most common cause of B12 deficiency. Ab against IF decreases B12 absorption despite normal intake
A pt presents with labs showing abn monoclonal serum Ig levels. Bone scan, abd CT, 24 hr urine collection are all normal. What is the next step?
Repeat labs in 6 mo
pt likely has monoclonal gammopathy of undetermined significance (MGUS). Premalignant dysproteinemia