RBC pathology

Question 1

What are the typical clinical findings of anemia?

Answer 1

Pale, weak, malaise, easily fatigued, dyspnea on exertion, and SOB

Question 2

How quickly are reticulocytes produced?

Answer 2

5 days

Question 3

What are some long-term effects of chronic anemia and hypoxia?

Answer 3

fatty changes to liver, myocardium and kidneys

Question 4

What are the effects of acute blood loss anemia?

Answer 4

A shift of interstitial fluid to intravascular – this lowers hematocrit
Increased EPO production
Iron deficiency
Leukocytosis (for significant blood loss)
Reticulocytosis and thrombocytosis (days after blood loss)

Question 5

What are the key features of all hemolytic anemias?

Answer 5

Shortened RBC life span (<120 days)
Elevated EPO
Accumulation of hemoglobin degredation products (unconj. bilirubin)

Question 6

Hereditary spherocytosis

Answer 6

RBC vulnerable to splenic destruction due to sphere shape 
AD disorder
increased MCHC
*anemia, splenomegaly and jaundice*
aplastic crisis = parvovirus
hemolytic crisis = mono
tx: splenectomy

Question 7

G6PD deficiency

Answer 7

episodic hemolysis caused by oxidative stress – infections, drugs or food
micro pathology = Heinz bodies and bite cells

Question 8

Sickle cell disease

Answer 8

Glu –> Val mutation

hemolytic anemia, microvascular obstructions and ischemic tissue damage leading to a variety of “crises”

Question 9

SS vaso-occlusive crisis

Answer 9

hypoxic injury and infarction that cause pain in affected region
most severe = acute chest crisis (lungs)

Question 10

SS sequestration crisis

Answer 10

massive entrapment of sickle cells leading to splenic enlargment, hypovolemia and sometimes hypovolemic shock

Question 11

SS aplastic crisis

Answer 11

infection of RBC progenitors by parvovirus B19 causing transient cessation of erythropoiesis and sudden worsening of anemia

Question 12

Hemoglobin C disease

Answer 12

mild hemolytic anemia

mechanism similar to SS but hemoglobin C does not sickle as readily as hemoglobin S

Question 13

Beta-thalassemia major

Answer 13

deficient HbA synthesis resulting in microcytic hypochromic RBC with abnormal O2 transport
ineffective erythropoiesis
RBC prone to splenic destruction
HbF markedly elevated
poor clinical discourse without blood transfusion and iron chelation
hepatosplenomegaly due to extramedullary hematopoiesis
Mediterranean, African and Asian descent

Question 14

Beta-thalassemia minor

Answer 14

patients are asymptomatic
if present, anemia is mild
hypocromic and microcytic (looks like iron deficiency anemia)
increased HbA2 but normal HbF
Mediterranean, African and Asian descent

Question 15

Alpha-thalassemia

Answer 15

reduced or absent synthesis of alpha-globin chains
complete abscence is lethal in-utero
hemolysis and ineffective erythropoiesis less severe than beta-thalassemia
newborns = hemoglobin Barts
children and adults = Hbh

Question 16

paroxysmal nocturnal hemoglobinuria (PNH)

Answer 16

acquired mutation of PIGA gene
susceptible to intravascular hemolysis by complement
typically chronic hemolysis without hemoglobinura despite name
prone to thrombosis

Question 17

Immunohemolytic anemias

Answer 17

caused by antibodies against normal RBC constituents or antigens modified by haptens
results in either extravascular hemolysis or uncommonly complement fixation/intravascular hemolysis

Question 18

hemolytic anemia from trauma to RBC

Answer 18

usually occurs in individuals with cardiac valve prostheses (mechanical) and microangiopathic disorders
vascular changes produce shear stresses than injury circulating RBC

Question 19

megaloblastic anemias

Answer 19

caused by folate or cobalamin deficiency leading to impairment of DNA synthesis
macrocytic morphology

Question 20

pernicious anemia

Answer 20

type of megaloblastic anemia caused by autoimmune gastritis that impairs production of IF required for B12 uptake
autoreactive T-cells initiates gastric mucosal injury and triggers formation of IF autoantibodies
leukopenia, elevated homocysteine and elevated methymalonic acid

Question 21

B12 deficiency

Answer 21

type of megaloblastic anemia caused by impaired absorption of B12 due to loss of pepsin secretion, gastrectomy, ileal resection or certain tapeworms
elevated homocysteine and methymalonic acid

Question 22

Folate deficiency

Answer 22

type of megaloblastic anemia caused by insufficient diet

elevated homocysteine but normal MMA

Question 23

porphyria

Answer 23

a deficiency in the pigments involved in the formation of heme (porphyrins) which causes anemia and/or splenomegaly
abnormal reaction to sunlight, abnormal hair growth, teeth staining, seizures, hallucinations, and general psychosis
vampires and werewolves

Question 24

iron deficiency anemia

Answer 24

most commonly due to chronic blood loss
morphologically microcytic and hypochromic 
Low HCT
Low Hgb
Low iron
Low ferritin
Low hepcidin

Question 25

Plummer-Vinson syndrome

Answer 25

microcytic hypochromic anemia esophageal webs atrophic glossitis

Question 26

aplastic anemia

Answer 26

syndrome of chronic primary hematopoietic failure and subsequent pancytopenia causes include aquired, chemical agents, physical agents and inherited typical anemia sx *reticulocytopenia; NO splenomegaly*

Question 27

pure red cell aplasia

Answer 27

primary marrow disorder with only RBC precurors affected | causes include thymoma, autoimmune or parvovirus B19

Question 28

PTT measures which clotting pathway?

Answer 28

Intrinsic | XII, XI, IX, VIII

Question 29

PT meaures which clotting pathway?

Answer 29

Extrinsic | VII

Question 30

Henoch-Schonlein purpura

Answer 30

systemic immune disorder characterized by purpuric rash, colicky abdominal pain, polyarthralgia, and acute glomerulonephritis due to deposition of immune complexes

Question 31

Hereditary hemorrhagic telangiectasia

Answer 31

AD disorder caused by mutations of genes that modulate TFG-B signaling dilated, tortuous blodd vessels bleeding common under mucous membranes

Question 32

perivascular amyloidosis

Answer 32

amyloid light chain amyloidosis | mucocutaneous petechiae

Question 33

chronic immune thrombocytopenic purpura

Answer 33

caused by autoantibody (IgG) destruction of platelets can occur secondarily to SLE, HIV or B-cell neoplasms tx: splenectomy micro shows megathrombocytes sx include petechiae, ecchymosis, mucosal bleeding, and hemorrhages NO splenomegaly or lymphadenopathy PT and PTT are normal

Question 34

acute immune thrombocytopenic purpura

Answer 34

similar to chronic but mainly a disease of childhood sx appear 1-2 weeks after a viral illness resolves spontaneously

Question 35

drug induced thrombocytopenia

Answer 35

typically caused by quinine, quinidine, and vancomycin

Question 36

heparin-induced thrombocytopenia

Answer 36

causes severe life threatening venous and arterial thromboses

Question 37

HIV-associated thrombocytopenia

Answer 37

HIV can infect megakaryocytes since they contain CD4 and CKCR4 receptor and coreceptor infected megakaryocytes are prone to apoptosis and opsonization by immune complexes or splenic destruction

Question 38

thrombotic thrombocytopenic purpura

Answer 38

deficiency in plasma enzyme ADAMTS13 causes thrombotic microangiopathies widespread organ dysfunction

Question 39

hemolytic-uremic syndrome

Answer 39

triggered by E. coli Shiga-like toxin which alters endothelial function and platelete aggregation causing thrombotic microangiopathies widespread organ dysfunction

Question 40

Bernard-Soulier syndrome

Answer 40

deficiency in endothelial platelet membrane complex Ib-IX (vWF receptor) generally a pediatric disease with giant platelets in peripheral blood severe bleeding tendency

Question 41

Glanzmann thrombasthenia

Answer 41

deficiency in glycoprotein IIb-IIIa which aids in binding platelets to fibrinogen mild to severe bleeding tendency

Question 42

Hemophilia A

Answer 42

deficiency in factor VIII, which normally binds to vWF once in circulation prolonged PTT with normal PT easy bruising, massive hemorrhage after trauma, and spontaneous hemorrhage (hemarthroses) tx: factor VIII infusions

Question 43

von Willebrand disease

Answer 43

deficiency in vWF only types 1 and 3 are clinically detected by prolonged PTT *type 2 is most common*

Question 44

Hemophilia B

Answer 44

factor IX deficiency clinically indistinguishable from Hem A prolonged PTT with normal PT tx: factor IX infusions

Question 45

Disseminated intravascular coaguation (DIC)

Answer 45

acute, subacute or chronic thrombohemorrhagic disorder characterized by excessive activation of coagulation and foration of thrombi in microvasulature not a primary disease – complication of a variety of disorders sx include microangiopathic hemolytic anemia, dyspnea, cyanosis, respiratory failure, subacute renal failure, circulatory failure/shock tx: treat the underlying cause