RBC Disorders Flashcards
(142 cards)
1
Q
Results of renal papillary necrosis
A
Results in gross hematuria and proteinuria
2
Q
Main cause of death in paroxysmal nocturnal hemoglobinuria
A
Thrombosis of the hepatic, portal or cerebral veins
*Destroyed platelts release cytoplasmic contents into circulation, inducing thrombosis
3
Q
_____ inhibits dihydrofolate reductase.
A
Methotrexate
4
Q
Why do cells sickle in sickle cell anemia?
A
HbS polymerizes when deoxygenated; polymers aggregate into needle-like structures, resulting in sickle cells
5
Q
Blood smear in Hemoglobin C
A
HbC crystals in RBCs
6
Q
What type of mutation is seen in B-thalassemia?
A
Point mutations in promotor or splicing sites
*Seen in individuals of African and Mediterranean descent
7
Q
- Microcytic, hypochromic RBCs with target cells and nucleated red blood cells
- HbA2
- HbF
A
B-thalassemia major
8
Q
- Macrocytic RBCs with hypersegmented neutrophils
- Glossitis
- Subacute combined degeneration of the spinal cord
A
B12 deficiency
9
Q
What strain of malaria causes daily fever?
A
P. falciparum
10
Q
- Severe anemia
- B chains form tetramers (HbH)
- HbH seen on electrophoresis
A
Three gene delection in a-thalassemia
11
Q
Most common type of anemia in hospitilized patients
A
Anemia of chronic disease
12
Q
Enterocytes transport iron across the cell membrane into blood via _______. _____ transports iron in the blood. Stored intracellular iron is bound to _________.
A
Ferroportin; Transferrin; Ferretin
13
Q
Under what conditions does IgG bind to RBCs?
A
- In relatively warm temps of the central body
*Membrane of antibody-coated RBC is consumed by splenic macrophages, resulting spherocytes
14
Q
Cause of paroxysmal nocturnal hemoglobinuria
A
- Acquired defect in myeloid stem cells resulting in absent glycosylphosphatidylinositol
- Cells are rendered desctructible by complement
15
Q
Stored iron bound to ferritin prevents iron from forming free radicals via the _______ reaction.
A
Fenton
16
Q
Presentation of a two gene deletion in a-thalassemia
A
- Mild anemia with increase in RBC count
- Cis: Asians; worse
- Trans: Africans
17
Q
- Microcytic, hypochromic RBCs and target cells seen on blood smear
- Slightly decreased HbA
- Increased HbA2
- HbF
A
B-thalassemia minor
*The mildest form of disease and is usually asymptomatic with an increased RBC count
18
Q
Laboratory findings:
- Increased ferritin
- Decreased TIBC
- Increased serum iron
- Increased % saturation
A
Sideroblastic anemia
19
Q
What is the most common congenital defect in sideroblastic anemia?
A
Defect in aminolevunilic acid synthetase (ALAS)
20
Q
What is the relationship between ferritin and TIBC?
A
Inverse
21
Q
What causes sickling in the medulla of people with sickle cell trait?
A
- Extreme hypoxia and hypertonicity of the medulla
- Results in microinfarctions leading to microscopic hematuria and, eventually decreased ability to concentrate urine
22
Q
Complications of paroxysmal noctunal hemoglobinuria
A
- Iron deficiency anemia
- Aute myeloid leukemia (develops in 10% of patients)
23
Q
- Hemoglobinemia
- Hemoglobinuria
- Hemosiderinuria
- Decreased serum haptoglobin
A
Intravascular hemolysis
24
Q
________ screen causes cells with any amount of HbS to sickle.
A
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
