Erythrocytes Flashcards
Manual RBC count is rarely done because of its
inaccuracy and questionable necessity
other more accurate manual rbc tests when automation is unavailable
microhematocrit
hemoglobin concentration
T/F
Manual WBC count and PLT count are now unreliable.
False
People living in higher altitude have higher
RBC count, hematocrit, hemoglobin
At 2 km altitude, hgb is elevated at around
1 g Hb/dL
At 3 km altitude, Hgb will be elevated at around
2 g Hb/dL
RBC count reference range for children (8-13 yo) and adult women
conventional: 4.00-5.40 x 10^6/uL
SI: 4.00-5.40 x 10^12/uL
RBC count reference range for adult male
conventional: 4.60-6.00 x 10^6/uL
SI: 4.60 - 6.00 x 10^12/uL
Major glycolytic pathway
Embden-Meyerhof Pathway
Glycolysis diversion pathways or alternate pathways that branch from the glycolytic pathway
Hexose monophosphate shunt
Methemoglobin reductase shunt
Rapaport-Luebering shunt
Glucose penetrates the rbc with no energy expenditure via this transmembrane protein
Glut-1
EMP handles what percent of glycolization in the RBCs
90%
EMP handles what percent of glycolization in the RBCs
90%
T/F
EMP is a non-oxidative, anaerobic pathway
True
How many molecules of ATP is produced by EMP
2 molecules of ATP
ATP is used by the RBC in 3 ways:
maintenance of shape and deformability
gives energy for active transport of cations
helps modulate the amount 2,3-BPG
EMP modulates the amount of 2,3-BPG, while _______ actually creates 2,3-DPG
Rapaport-Luebering Shunt
2,3-BPG meaning
2,3-Bisphosphoglycerate
2,3-BPG was previously known as
2,3-Diphosphoglycerate (2,3-DPG)
To what particular pathway is the Pyruvate kinase deficiency related to?
Embden-Meyerhof Pathway
HNSHA stands for
Hereditary nonspherocytic hemolytic anemia
most common enzyme deficiency of the EMP and is the most common form of HNSHA
PK deficiency
Possible PBS findings in PK deficiency
acanthocytes
burr cells
recommended screening test for PK deficiency
PK fluorescent spot test
Screening tests for PK deficiency
PK fluorescent spot test
Autohemolysis test
confirmatory test for PK deficiency
Quantitative PK assay
In PK deficiency Type II, autohemolysis is greatly increased and glucose has no effect. What molecule corrects the hemolysis?
ATP
Hexose monophosphate shunt is also known as
Pentose Phosphate Pathway
Phosphogluconate Pathway
This shunt aerobically converts glucose to pentose and produces reduced nicotinamide adenine dinucleotide phosphate
PPP/HMP/PGP
NADPH reduces
glutathione
Reduced glutathione reduces peroxides and guards proteins, lipids, and heme iron from
oxidation
HMP is functionally dependent on
G6PD
What patway is G6PD related to?
HMP
Most common enzyme deficiency in the PPP and is the most common RBC enzyme defect
G6PD deficiency
prevalence of G6PD deficiency
5% of the world population
about 400 million people worldwide
Possible PBS findings in G6PD deficiency include
heinz bodies
bite cells
Possible PBS findings in G6PD deficiency include
heinz bodies
bite cells
screening tests for G6PD deficiency
G6PD fluorescent spot test
autohemolysis test
recommended screening test for G6PD deficiency
G6PD fluorescent spot test
confirmatory test for G6PD deficiency
Quantitative G6PD assay
Pattern of hemolysis in G6PD deficiency
autohemolysis is slightly/moderately increased but is partially corrected by glucose
Inclusion bodies brought about by the precipitation of the globin portion of the hemoglobin due to the absence of G6PD.
Heinz bodies
Heinz bodies undergo _______ in the spleen
pitting
The process of removing a part of the rbc
Pitting
After heinz bodies are removed by splenic macrophages during pitting, the rbc becomes
bite cells
Bite cells undergo _______ in the spleen
culling
The process of removing a whole rbc in the circulation
culling
Repeated culling will lead to
hemolytic anemia
G6PD deficiency is classified by the WHO into
5 classes
G6PD-Madrid and G6PD-Serres belong in what class
Class I
G6PD-Madrid and G6PD-Serres belong in what class
Class I
Class I G6PD-deficiency have severely deficient enzyme activity. State the %
<1% enzymatic activity or not detectable
clinical manifestations of class I G6PD-deficiency
chronic HNSHA, variable severity, rare
examples of Class II G6PD-deficiency
G6PD-Chatham
G6PD-Mediterranean
G6PD enzyme activity in class II G6PD-deficiency
severely deficient, <10% activity
class II G6PD-deficiency has severe episodic acute hemolytic anemia associated with infections, certain drugs, and ______
fava beans
T/F
Class II G6PD-deficiency is self-limited and does not require blood transfusions during hemolytic episodes
False
Only a small group of G6PD-deficient px demonstrate unusual sensitivity to fava beans and most of these people have what variant of G6PD-deficiency?
G6PD-Mediterannean variant
unusual sensitivity to fava beans
favism
Class III G6PD-deficiency is mild to moderately deficient with _____ enzyme activity
10-60%
T/F
Class III G6PD-deficiency is not self-limited and may require blood transfusions during hemolytic episodes that are associated with infections and certain drugs,
False
Variants of Class III G6PD-deficiency
G6PD-A^-
G6PD-Canton
what classes of G6PD-deficiency have no clinical manifestations
Class IV and V
Class IV G6PD-deficiency has mildly deficient to normal enzymatic activity, with _____ % activity
60-150%
variants of class IV G6PD-deficiency
G6PD-B (wildtype)
G6PD-A^+
G6PD-A^+ may also manifest as
Class III G6PD-deficiency
Class V G6PD-deficiency has increased enzymatic activity:
> 150% activity
Some foods/chemicals to avoid if px has G6PD-deficiency
legumes
mothballs
red wine
fava beans
blueberry
bitter gourd
menthol
soya food
Methemoglobin reductase is also known as
cytochrome b5 reductase
methemoglobin reductase pathway maintains iron in its
reduced form (ferrous)
methemoglobin reductase pathway maintains iron in its
reduced form (ferrous)
The pathway that protects the globin portion of the hemoglobin
HMS
Pathway that protects the heme portion of hemoglobin effectively
MRP
Pathway that protects the heme portion of hemoglobin effectively
MRP
T/F
HMS can also protect the heme from being oxidized. However, it is less effective than MRP in doing so.
True
Rapoport-Luebering Shunt produces
2,3-BPG
Binds to Hgb and decreases the affinity of O2 to Hgb
2,3-BPG
two variables that affect the degree of association/dissociation between oxygen and hemoglobin
pO2
affinity of Hgb for O2
the affinity of hemoglobin for oxygen is dependent on 5 factors
pH
pCO2
2,3-BPG
Temperature
presence of other Hgb species that are non-functional
what happens to the affinity of oxygen to hgb if pH is increased
increased affinity
what happens to the affinity of oxygen to hgb if pH is decreased
affinity is decreased
the curve produced when po2 and the affinity of hgb for O2 are plotted on a graph
oxygen dissociation curve
increased pH
decreased pCO2, 2,3-BPG, and temp
shift to the left
decreased pH
increased pCO2, 2,3-BPG, and temp
shift to the right
a shift in the curve due to an alteration in pH or the effect of H ions and CO2 on the affinity of hemoglobin for O2
Bohr effect
Depicts the occurrence by which the binding of O2 to the hemoglobin promotes the release of CO2
Haldane effect
