Erythrocytes Flashcards by Trisha Anne

Manual RBC count is rarely done because of its

inaccuracy and questionable necessity

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other more accurate manual rbc tests when automation is unavailable

microhematocrit
hemoglobin concentration

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T/F

Manual WBC count and PLT count are now unreliable.

False

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People living in higher altitude have higher

RBC count, hematocrit, hemoglobin

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At 2 km altitude, hgb is elevated at around

1 g Hb/dL

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At 3 km altitude, Hgb will be elevated at around

2 g Hb/dL

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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

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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

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Major glycolytic pathway

Embden-Meyerhof Pathway

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Glycolysis diversion pathways or alternate pathways that branch from the glycolytic pathway

Hexose monophosphate shunt
Methemoglobin reductase shunt
Rapaport-Luebering shunt

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Glucose penetrates the rbc with no energy expenditure via this transmembrane protein

Glut-1

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EMP handles what percent of glycolization in the RBCs

90%

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EMP handles what percent of glycolization in the RBCs

90%

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T/F

EMP is a non-oxidative, anaerobic pathway

True

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How many molecules of ATP is produced by EMP

2 molecules of ATP

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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

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EMP modulates the amount of 2,3-BPG, while _______ actually creates 2,3-DPG

Rapaport-Luebering Shunt

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2,3-BPG meaning

2,3-Bisphosphoglycerate

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2,3-BPG was previously known as

2,3-Diphosphoglycerate (2,3-DPG)

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To what particular pathway is the Pyruvate kinase deficiency related to?

Embden-Meyerhof Pathway

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HNSHA stands for

Hereditary nonspherocytic hemolytic anemia

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most common enzyme deficiency of the EMP and is the most common form of HNSHA

PK deficiency

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Possible PBS findings in PK deficiency

acanthocytes
burr cells

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recommended screening test for PK deficiency

PK fluorescent spot test

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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