Heme Review

Question 1

Which coagulation factor is deficient in hemophilia A? What’s the inheritance pattern?

Answer 1

factor VIII; X-linked recessive

Question 2

Which coagulation factor is deficiency in hemophilia B? What is the inheritance pattern?

Answer 2

factor IX; X-linked recessive

Question 3

What is the clinical consequence of a deficiency in either protein C or protein S?

Answer 3

increased coagulation

Question 4

What factors are part of the intrinsic pathway?

Answer 4

8,9,11,12

Question 5

What factors are part of the extrinsic pathway?

Answer 5

7

Question 6

What factors are part of the common pathway?

Answer 6

1,2,5,10,13

Question 7

What factors does the PT measure?

Answer 7

1,2,7,10 (extrinsic and common)

Question 8

What factors does the PTT measure?

Answer 8

everything except 7 and 13 (intrinsic and common)

Question 9

What lab test is used to monitor adequate anticoagulation in a patient taking heparin? Warfarin?

Answer 9

heparin - monitor PTT

warfarin - monitor PT and INR

Question 10

What is the treatment for an overdose of heparin? Warfarin?

Answer 10

heparin - protamine sulfate

warfarin - Vit K, FFP, PCC (the last two only if active bleeding)

Question 11

What is the treatment for heparin-induced thrombocytopenia?

Answer 11

stop heparin, switch to a direct thrombin inhibitor

Question 12

What is the presentation of erythroblastosis fetalis?

Answer 12

Clinical features in neonate:

• anemia due to hemolysis of RBCs by maternal antibodies
• jaundice -> possible kernicterus
• hydrops fetalis (generalized fetal edema)
• intrauterine death

Question 13

What allows RBCs to change shape as they pass through vessels?

Answer 13

biconcave shape (anucleate) d/t spectrin

Question 14

Which pathologic form of RBC would you see with lead poisoning?

Answer 14

basophilic stippling

Question 15

Which pathologic form of RBC would you see with G6PD deficiency?

Answer 15

Heinz bodies, bite cells

Question 16

Which pathologic form of RBC would you see with DIC?

Answer 16

schistocytes

Question 17

Which pathologic form of RBC would you see with abetalipoproteinemia?

Answer 17

acathocytes (spur cells)

Question 18

Which pathologic form of RBC would you see with asplenia?

Answer 18

Howell-Jolly bodies, target cells

Question 19

Where does fetal erythropoiesis take place? In which adult bones does erythropoiesis take place?

Answer 19

Fetal - yolk sac, liver, spleen, BM

Adult - axial skeleton (sternum, ribs, pelvis, vertebrae)

Question 20

What are some of the different causes of polycythemia?

Answer 20

decreased plasma volume (dehydration, burns)
decreased O2 - pulmonary problems, heart Dz, high altitude
increased EPO - ectopic tumors (PRHH - pheochromocytoma, renal cell carcinoma, hemangioblastoma, hepatocellular carcinoma)
polycythemia vera

Question 21

What are the hematologic and non-hematologic findings in a patient with lead poisoning?

Answer 21

hematologic - basophilic stippling, microcytic anemia
non-hematologic - encephalopathy, memory loss, HA, wrist/foot drop, lead lines on gingival, lead lines on bones (kids), abdominal colic, renal failure

Question 22

What is the rate-limiting step of heme synthesis? What is required for the reaction?

Answer 22

delta-ALA synthase, Vit B6

Question 23

What inhibits delta-ALA synthase?

Answer 23

glucose and heme

Question 24

What enzyme deficiency causes acute intermittent porphyria?

Answer 24

uroporphyrinogen-1-synthase

Question 25

What enzyme deficiency causes porphyria cutanea tardy?

Answer 25

uroporphyrinogen decarboxylase

Question 26

What enzyme deficiencies can cause lead poisoning?

Answer 26

delta-ALA-dehydratase and ferrochelatase

Question 27

What is the serum iron, TIBC, ferritin, and % transferring saturation (decreased or increased) for iron deficiency anemia?

Answer 27

serum iron - decreased TIBC - increased ferritin - decreased % transferrin saturation - decreased (<12%)

Question 28

What is the serum iron, TIBC, ferritin, and % transferring saturation (decreased or increased) for anemia of chronic disease?

Answer 28

serum iron - decreased TIBC - decreased Ferritin - normal or increased % transferrin saturation - normal (>18%)

Question 29

What is the serum iron, TIBC, ferritin, and % transferring saturation (decreased or increased) for hemochromatosis?

Answer 29

serum iron - increased TIBC - decreased ferritin - increased % transferrin saturation - increased

Question 30

What is the serum iron, TIBC, ferritin, and % transferring saturation (decreased or increased) for sideroblastic anemia?

Answer 30

serum iron - increased TIBC - decreased ferritin - increased % transferrin saturation - normal or increased

Question 31

What test can be used to diagnose beta thalassemia minor?

Answer 31

hemoglobin electrophoresis to look for greater than normal HgA2

Question 32

What should you rule out in a man over 50 with new onset iron deficiency anemia?

Answer 32

colon cancer

Question 33

Causes of hypo chromic, microcytic anemia

Answer 33

``` iron deficiency anemia alpha-thalassemia beta-thalassemia anemia of chronic Dz lead poisoning ```

Question 34

Skull x-ray shows a "hair-on-end" appearance

Answer 34

marrow hyperplasia -> beta thalassemia or sickle cell Dz

Question 35

What are the causes of aplastic anemia?

Answer 35

radiation/drugs -> chloramphenicol and cancer drugs viruses fanconi syndrome idiopathic

Question 36

A patient is diagnosed with a microcytic, megaloblastic anemia. What is the danger of giving folate alone?

Answer 36

will not treat a potential Vit B12 deficiency, but it will mask the anemia

Question 37

microcytic anemia and swallowing difficulty and glossitis

Answer 37

Plummer-Vinson syndrome

Question 38

Microcytic anemia with >3.5% HgA2

Answer 38

beta thalassemia minor

Question 39

macrocytic anemia and hypersegmented neutrophils

Answer 39

folate/B12 def -> megaloblastic anemia

Question 40

megaloblastic anemia not correctable by B12 or folate supplements

Answer 40

oratic aciduria

Question 41

microcytic anemia and basophilic stippling

Answer 41

lead toxicity

Question 42

microcytic anemia reversible with B6 supplements

Answer 42

sideroblastic anemia

Question 43

HIV-positive patient with macrocytic anemia

Answer 43

Zidovudine

Question 44

normocytic anemia and elevated creatinine

Answer 44

chronic kidney disease

Question 45

Acute intermittent porphyria

Answer 45

autosomal dominant porphobilinogen deaminase deficiency (AIA uroporphyrinogen I synthase) Sx - 5P's - painful abdomen, port wine-colored urine, polyneuropathy, psychological disturbances, precipitated by drugs (barbiturates, seizure drugs, rifampin, metoclopramide) Tx 0 glucose and heme, which inhibit ALA synthase

Question 46

Porphyria cutanea tarda

Answer 46

autosomal dominant uroporphyrinogen decarboxylase deficiency Sx - tea-colored urine (uroporphryin build up), blistering cutaneous photosensitivity and hyperpigmentation, hypertrichosis, increased liver function tests; exacerbated by alcohol consumption, and is associated with HepC

Question 47

sideroblastic anemia

Answer 47

causes: genetic, alcohol is most common reversible acquired cause, also Vit B6 deficiency, copper deficiency, and isoniazid Lab findings: increased iron, increased ferritin, ringed sideroblasts (with iron-laden, Prussian blue-stained mitochondria) seen in BM Tx - B6

Question 48

alpha-thalassemia

Answer 48

defect: alpha globin gene deletions -> decreased alpha-globin synthesis prevalent in Asian and African populations 4 allele deletion: Hb Barts, incompatible with life, hydrops fetalis (gamma4 Hgb) 3 allele deletion: HbH disease; very little alpha-globin; beta4 2 allele deletion: less clinically severe anemia 1 allele deletion: no anemia

Question 49

beta-thalassemia

Answer 49

decreased beta globin synthesis; prevalent in mediterranean populations beta-thalassemia minor - beta chain is underproduced; usually asymptomatic, diagnosis is confirmed by increased HbA2 on electrophoresis beta-thalassemia major - beta chain absent -> severe microcytic, hypo chromic anemia with target cells and increased anisopoikilocytosis requiring blood transfusion (secondary hemochromatosis) crew cut on skull x-ray, chipmunk facies; extra medullary hematopoiesis -> hepatosplenomegaly increased risk of parvoB19-induced aplastic crisis increased HbF

Question 50

How do you treat secondary hemochromatosis d/t transfusions in beta-thalassemia major?

Answer 50

deferoxamine (iron chelator)

Question 51

What drugs cause increased oxidative stress in patient with G6PD deficiency?

Answer 51

``` Spleen Purges Nasty Inclusions From Damaged Cells S - sulfonamides P - primaquine N - nitrofurantoin I - isoniazid F - fava beans D - dapsone C - chloroquine ```