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Flashcards in RBC Disorders Deck (142):
1

Results of renal papillary necrosis

Results in gross hematuria and proteinuria

2

Main cause of death in paroxysmal nocturnal hemoglobinuria

Thrombosis of the hepatic, portal or cerebral veins

*Destroyed platelts release cytoplasmic contents into circulation, inducing thrombosis

3

_____ inhibits dihydrofolate reductase.

Methotrexate

4

Why do cells sickle in sickle cell anemia?

HbS polymerizes when deoxygenated; polymers aggregate into needle-like structures, resulting in sickle cells

5

Blood smear in Hemoglobin C

HbC crystals in RBCs

6

What type of mutation is seen in B-thalassemia?

Point mutations in promotor or splicing sites

*Seen in individuals of African and Mediterranean descent

7

  • Microcytic, hypochromic RBCs with target cells and nucleated red blood cells
  • HbA2
  • HbF

B-thalassemia major

8

  • Macrocytic RBCs with hypersegmented neutrophils
  • Glossitis
  • Subacute combined degeneration of the spinal cord

B12 deficiency

9

What strain of malaria causes daily fever?

P. falciparum

 

10

  • Severe anemia
  • B chains form tetramers (HbH) 
  • HbH seen on electrophoresis

Three gene delection in a-thalassemia

11

Most common type of anemia in hospitilized patients

Anemia of chronic disease

12

Enterocytes transport iron across the cell membrane into blood via _______. _____ transports iron in the blood. Stored intracellular iron is bound to _________.

Ferroportin; Transferrin; Ferretin

13

Under what conditions does IgG bind to RBCs?

  • In relatively warm temps of the central body

*Membrane of antibody-coated RBC is consumed by splenic macrophages, resulting spherocytes

14

Cause of paroxysmal nocturnal hemoglobinuria

  • Acquired defect in myeloid stem cells resulting in absent glycosylphosphatidylinositol
  • Cells are rendered desctructible by complement

15

Stored iron bound to ferritin prevents iron from forming free radicals via the _______ reaction.

Fenton

16

Presentation of a two gene deletion in a-thalassemia

  • Mild anemia with increase in RBC count
    • Cis: Asians; worse
    • Trans: Africans

17

  • Microcytic, hypochromic RBCs and target cells seen on blood smear
  • Slightly decreased HbA
  • Increased HbA2
  • HbF

B-thalassemia minor

*The mildest form of disease and is usually asymptomatic with an increased RBC count

18

Laboratory findings:

  • Increased ferritin
  • Decreased TIBC
  • Increased serum iron
  • Increased % saturation

Sideroblastic anemia

19

What is the most common congenital defect in sideroblastic anemia?

Defect in aminolevunilic acid synthetase (ALAS)

20

What is the relationship between ferritin and TIBC?

Inverse

21

What causes sickling in the medulla of people with sickle cell trait?

  • Extreme hypoxia and hypertonicity of the medulla
    • Results in microinfarctions leading to microscopic hematuria and, eventually decreased ability to concentrate urine

22

Complications of paroxysmal noctunal hemoglobinuria

  • Iron deficiency anemia
  • Aute myeloid leukemia (develops in 10% of patients)

23

  • Hemoglobinemia
  • Hemoglobinuria
  • Hemosiderinuria
  • Decreased serum haptoglobin

Intravascular hemolysis

24

________ screen causes cells with any amount of HbS to sickle.

Metabisulfite

*;positive in both disease and trait.

25

Most common cause of vitamin B12 deficienct

Pernicious anemia

*Autoimmune destruction of parietal cells leads to intrinsic factor deficiency

26

Which proteins are most commonly affected in hereditary spherocytosis?

Ankyin 

Spectrin

Band 3

27

Aplastic anemia results from damage to ___________ .

Hematopoietic stem cells

*Results in pancytopenia (anemia, thrombocytopenia, and leukopenia)

28

Aside from pernicious anemia. What are some other causes of vitamin B12 deficiency?

  • Pancreatic insufficiency
  • Damage to terminal ileum
    • Crohn's disease
    • Diphyllobothrium latum
  • Dietary deficiency in vegans

29

Causes of aplastic anemia

Drugs or chemicals

Viral infections

Autoimmune damage

30

Absorption of iron occurs in the _______.

Duodenum

*Enterocytes have heme and non-heme (DMT1) transporters. The heme form is more readily absorbed

31

In people with sickle cell trait, RBCs with <50% HbS do not sickle in vivo except in the _________.

Renal medulla

32

Causes of anemia due to underproduction

  • Causes of microcytic and macrocytic anemia
  • Renal failure-decreased EPO production by peritubular interstitial cells
  • Damage of bone marrow presursor cells

33

Where is iron bound to transferrin delivered?

Luver and bone marrow macrophages for storage

34

Mutation in sickle cell anemia

Autosomal recessive mutation in B chain of hemoglobin; a signle amino acid change replaces normal glutamic acid (hydrophilic) with valine (hydrophobic)

35

In hemoglobin C, glutamic acid is replaced by ________.

Lysine

36

Dactylitis

Swollen hands and feet due to vaso-occlussive infarcts in bone (infants)

37

55% HbA, 43% HbS, 2% HbA2

Sickle cell trait

38

treatment for hereditary spherocytosis

Splenectomy

*Anemia resolves but spherocytes persist and Howell Jolly bodies emerge on blood smear

39

  • Macrocytic RBCs and hypersegmented neutrophils
  • Glossitis
  • Decreased serum folate
  • Increased serum homocysteine 
  • Normal methylmalonic acid

Folate deficiency anemia

40

Why are spherocytes consumed by splenic machrophages?

Spherocytes are less able to maneuver through splenic sinusoids 

 

41

In paroxysmal nocturnal hemoglobinuria, why does intravascular hemolysis occur episodically during the night?

Mild respiratory acidosis develops with shallow breathing during sleep and activates complement

*RBCs, WBCs, and platelets are lysed

42

________ confirms the presence and amount of HbS.

Hb electrophoresis

43

alpha2delta2

HbA2

44

What causes the round shape of RBCs in hereditary spherocytosis?

Loss of membrane, due to loss of cytoskeleton-membrane tethering proteins

*These cells are called sperocytes

45

Treatment for aplastic anemia

  • Cessation of any causative drugs and supportive care with transfusions 
  • Marrow-stimulating factors (EPO, GM-CSF, and G-CSF)
  • Immunosuppression may be helpful
  • Bone marrow transplantation as a last resort

 

46

RC <3%

Overproduction, normocytic anemia

47

90% HbS, 8% HbF, 2% HbA2

Sickle cell disease

48

Treatment for hereditary spherocytosis

Splenectomy

49

Role of acid in iron absorption

Acid aids iron absorption by maintaining the Fe 2+ state. which more readily absorbed thatn the Fe 3+ state

50

__________ attaches protoporphyrin to iron to make heme. Where does this occur?

 Ferrochelatase; mitochondria

51

Fanconi anemia can progress to what neoplasm?

AML (>10%)

52

target cells

Decreased Hb in cytoplasm

53

a2B2

HbA

54

  • Anemia with splenomegaly
  • Jaudice 
  • Increased risk for bilirubin gallstones
  • RC count >3%

Extravascular hemolysis

55

Extravascular hemolysis and sickle cell anemia

  • Reticuloendothelial system removes RBCs with damaged membranes, leading to anemia, jaundice with unconjugated hyperbilirubinemia, and increased risk for bilirubin gallstone

*Cells continuously sickle and de-sickle while passing through the microcirculation, resulting in complications related to RBC membrane damage

56

IgG mediated immune hemolytic anemia is associated with which conditions?

  • SLE
  • CLL
  • Certain drugs
    • Penicillin and cephalosporins

57

4 alpha genes are pressent on chromosome _______. Two beta genes are present on chromosome ______.

16;11

58

Normal Hb males/females

Males: 13.5-17.5g/dL

Females: 12.5-16 g/dL

59

Under what conditions does Igm bind to RBCs?

Relatively cold temps of the extremities 

*Also fixes complement

60

Stepwise synthesis of protoporphyrin

1. Aminolevulinic acid synthesae converts succinyl CoA to aminolevulinic acid using vitamin B6 as a cofactor

2. Aminolevulinic acid dehydratase converts aminolevulinc acid to porphobilinogen

3. Porphobilongen to protoporphyrin

61

Percentage of HbS in sickle cell anemia

>90%

62

Treatment for anemia of chronic disease

  • Treat underlying condition
  • Exogenous EPO is useful in patients with cancer

63

Plummer-Vinson syndrome

Iron deficiency anemia with esophageal web and atrophic glottis; presents with anemia, dysphagia, and beefy-red tongue

64

Igm mediated immune hemolytic anemia is associated with what conditions?

Mycoplasma pneumoniae

Infectious mononucleosis

65

a2y2

HbF

66

Normocytic anemias predominantly associated with intravascular hemolysis

  • Paroxysmal nocturnal hemoglobinuria
  • Glucose-6-phosphate dehydrogenase deficiency
  • Immune hemolytic anemia
  • Microangiopathic hemolytic anemia
  • Malaria

67

Causes of normocytic anemia

  • Increased peripheral destruction 
  • Underproduction

68

process by which B12 is absorbed

  • Salivary gland enyzymes liberate vitaming B12
  • B12 then bound to R-binder and carried to the stomach
  • Pancreatic proteases in the duodenum detach vitamin B12 from R-binder
  • Vitamin B12 binds intrinsic factor
  • Vitamin B12-intrinsic factor complex is absorbed in the ileum

69

How is hereditary spherocytosis diagnosed?

by osmotic fragility test, which reveals increased spherocyte fragility in hypotonic solution

70

Treatment for IgG mediated immune hemolytic anemia

Cessation of offending drug

Steroids

IVIG

Splenectomy (if necessary)

71

Causes of macrocytic anemia without megaloblastic change?

Alcoholism

Liver disease

Drugs

72

  • X-linked recessive disorder 
  • Renders cells susceptible to oxidative stress

Gucose-6-Phosphate dehydrogenase deficiency

73

Total iron binding capacity

Measure of transferrin molecules in the blood

74

RC >3%

Peripheral destruction, normocytic anemia

*Marrow response (to increase RC in response to anemia) is good

75

  • Hydrops fetalis
  • Hb Barts seen on electrophoresis

Four genes deleted causing a-thalassemia

76

  • Increased serum homocysteine
  • Increased methylmalonic acids
  • Decreased serum vitamin B12

Anemia due to B-12 deficiency

77

Which strain of malaria results in fevers every other day?

P.vivax and Povale

78

Treatment for B-thalassemia major

  • Chronic transfusions 
    • Leads to risk for secondary hemochromatosis

79

Percentage of HbS in sickle cell trait

<50%

80

Subacute combined degeneration

–Demyelination lateral and dorsal columns

–Paraesthesia, loss of vibration and position, gait, spasticity

*Seen in B12 deficiency

81

malaria is transmitted by _________

Female anopheles mosquito

82

MCV >100

Macrocytic

83

a-thalassemia is usually due to ______________. B-thalessemia is due to _________.

Gene deletion; gene mutation

84

Which conditions are predominantly associated with extravascular hemolysis?

  • Hereditary spherocytosis
  • Sickle cell anemia
  • Hemoglobin C

85

Stages of iron deficiency

  • Storage iron deficiency
  • Serum iron is depleted
  • Normocytic anemia
  • Microcytic, hypochromic anemia

86

Complications of extensive sickling

Vaso-occlusion

  • Dactylitis
  • Autosplenectomy
  • Acute chest syndrome 
  • Pain crisis
  • Renal papillary necrosis

87

Vitamin B6 deficiency can caused acquired sideroblastic anemia. When is this most commonly seen?

As a side effect of isoniazid treatment for TB

88

Aquired caused of sideoblastic anemia

  • Alcoholism-mitochondrial poison
  • Lead poisoning- inhibits ALAD and ferrochelatase
  • Vitamin B6 deficiency

89

_________ is needed to regenerate reduced glutathione

NADPH

*By-product of G6PD

90

Biochem of folate B12, and methionine

  • Methylytetrahydrofolate donates a methyl group to B12 and becomes folate
  • B12 donates methyl grouo to homocysteine and becomes methionine

91

Clinical findings of B-thalassemia major

  • Crewcut appearance on X-ray
    • erythroid hyperplasia 
    • Expansion of hematopoiesis into the skull
  • Chipmuck facies
    • Hematopoiesis in facial nones
  • Hepatosplenomegaly

92

Causes of microangiopathic hemolytic anemia

  • Microthombi
    • TTP-HUS
    • DIC
    • HELLP
  • prostetic heart valves
  • Aortic stenosis

*When prsent, microthrombi produce shistocytes on blood smear

93

Laboratory findings:

  • Increased ferritin
  • Decreased TIBC
  • Decreased serum iron
  • Decreased %saturation
  • Increased free erythrocyte protoporphyrin

Anemia of chronic disease

94

Causes of macrocytic anemia with megaloblastic change

Folate and B12 deficiency

95

Methylmalonic builds up in ______ in spinal cord.

Myelin

96

What conditions lead to an increased risk of sickling?

Hypoxemia

Dehydration

Acidosis

97

Biopsy of aplastic anemia

Emplty, fatty marrow

98

Cause of immune hemolytic anemia

Antibody-mediated destruction of RBCs

99

B-thalassemia presents with a risk of aplastic crisis with __________ infection of erythroid precursors.

Parvovirus B19

100

What are the consequences of autosplenectomy seen with extensive sickling?

  • Increased risk of infection with encapsulated organisms such as S. pneumonia and H. influenza
  • Increased risk of Salmonella paratyphi osteomyelitits
  • Howell-Jolly bodies on blood smear

101

Which vitamin is deficient in sideoblastic anemia?

B6

102

  • Increased RDW
  • Increased mean corpuscular hemoglobin concentration (MCHC)
  • Splenomegaly, jaudice with unconjugated bilirubin
  • Spherocytes with loss of central pallor

Hereditary spherocytosis

103

What is the confirmatory test for paraoxysmal nocturnal hemoglobinuria?

Acidified serum test or glow cytometry to detect lack of CD55 (DAF) on blood cells

104

Organs of reticuloendothelial system

Macrophages of spleen

Liver 

Lymph nodes

105

MCV <80

Microcytic

106

Hb Barts

Gamma chains form a tetramer

107

Causes of folate deficiency

  • Poor diet
  • Increased demand (pregnancy, cancer, and hemolytic anemia)
  • Folate antagonists (methotrexate)

108

Oxidative stress precipitates Hb as ___________.

heinz bodies

*heinz bodies are removed from RBCs by splenic macrophages, resulting in bite cells

109

________ on the surface of blood cells protects against complement-mediated damge by inhibiting C3 convertase.

Decay accelerating factor (DAF)

*DAF is secured to the membrane by GPI

110

Common cause of iron deficiency in the elderly?

Colon polyps/ carcinoma in the western world

Hookworm (Anyclostoma duodenale and  Nectar americanus) in the developing world

111

parvovirus B19 infects __________.

Progenitor red cells

*Temporary halts erythropoiesis

112

Folate is absorbed in the ___________.

Jejunum

113

______ is used to diagnose immune hemolytic anemia

  • Coombs test (direct or indirect)

114

Causes of oxidative stress

infections

drugs (primaquine, sulfa drugs, and dapsone)

Fava beans

115

Laboratory findings:

  • Microcytic, hypochromic RBCs with increase in RDW
  • Decreased ferritin
  • Increase TIBC
  • Decreased serum iron
  • Decreased % saturation
  • Increased free erythrocyte protoporphyrin

iron-deficiency anemia

116

What are the results of consumption of RBCs by macrophages?

This is extravascular hemolysis

  • Hemoglobin is broken down
  • Globin broken down into amino acids
  • Heme is broken down to iron and protoporphyrin, 
    • Iron is recycled
    • Protoporphyrin is broken down in unconjugated bilirubin, which is bound to serum albumin and delivered to the liver for conjugation and excretion into bile

117

Larger cells with bluish cytoplasm

Reticulocytes

*Due to residual RNA

118

Clinical feautres of iron deficiency

Anemia, koilonychia, and pica

119

___ (IgG/IgM)- mediated disease usually involves extravascular hemolysis. ____ (IgG/IgM) can lead to intravascular hemolysis.

IgG, IgM

120

intravascular hemolysis and sickle cell anemia

  • RBCs with damaged memnranes dehydrate, leading to hemolysis with decreased haptoglobin and target cells on blood smear

*Target cells are due to dehydration

121

__________ is a inherited defect of RBC cytoskleton-membrane tethering proteins. 

Hereditary spherocytosis

122

Plasmodium affects ______ and the ______.

RBCs ; liver

*RBCs rupture as a part of the Plasmodium life cycle

123

_________ is used to screen for paroxysmal nocturnal hemoglobinuria.

Sucrose test

*Sucrose activates complement

124

Role of hepcidin

Acute phase reactant that sequesters iron in storage sites by:

  • Limiting iron transfer from macrophages to eythroid precursors
  • Suppressing erythropoietin production

*Aims to prevent bacteria from accessing iron, which is necessary ofr their survival

125

What attributes to the production of spherocytes in IgM mediated immune hemolytic anemia?

  • IgM binds to RBCs and fixes complement
  • RBCs inactivate complement but residual C3b serves as an opsonin for splenic macrophages resulting in spherocytes

*Extreme activation of complement can lead to intravascular hemolysis

126

Cause and symptoms of acute chest syndrome

Cause: vaso-occlusion in pulmonary microcirculation

Symptoms

  • Chest pain, shortness of breath, and lung infiltrates
  • Precipitated by pneumonia
  • Most common cause of death in adult patients

127

HbH

B chains forming a tetramer

*Damage RBCs

128

Types of microcytic anemias

  • iron deficiency anemia
  • Anemia of chronic disease
  • Sideorblastic anemia
  • Thalassemia

129

Treatment with _________ increases levels of HbF.

Hydroxyurea

130

What happens to iron is protoporphyrin is deficient?

Iron is trapped in the mitochondria

*iron-laden mitochondria form a ring around the nucleus of erythroid precursors called ringed sideroblasts

131

Frequent pigment gall stones

Hereditary spherocytosis

132

Against protein based antigens

IgG

133

Against carbohydrate based antigens

IgM

134

Indications for packed red blood cells

  • (Restoration of red cell oxygen carrying capacity)
  • Improve Tissue Oxygen Delivery
  • Alleviation of signs & symptoms of anemia

135

Guidelines for packed red cells

General Guidelines:

  • Maintain Hgb > 7mg/dl
    • Increased mortality when Hgb drops to < 5 mg/dl
  • Need to keep higher HCT in CAD, pulmonary disease (Hgb > 8mg/dl)
  • Important to maintain normovolemia even with acute blood loss

136

Contraindications for Platelet Transfusion

  • Thrombotic thrombocytopenic purpura (TTP)
  • Heparin induced thrombocytopenia (HIT)
  • Immune mediated thrombocytopenic purpura (ITP)

137

Cryoprecipitated AHF components

contains fibrinogen, Factors VIII and XIII,

  von Willebrand factor

138

Cryoprecipitated AHF indications

  • Hypofibrinogenemia/Dysfibrinogenemia
  • Uremic bleeding
  • Second-line treatment of Hemophilia A, Factor XIII deficiency and von Willebrand disease

139

Treatment for allergic transfusion reactions

diphenylhydramine

140

RBC receptors for Malaria

Glycophorin A for P. falciparum and Duffy antigen for P. vivax

141

Mode of transmission for leishmania

Sandlfy

142

Treatment for leishmania

Sodium stibogluconate