6. Reticulocytes Flashcards by Trisha Anne

These are blue-stained, granulomatous materials that are made of residual RNA present in immature non-nucleated RBCs

Reticulum

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Immature non-nucleated RBCs which contain >2 reticulum after staining with supravital stain

Reticulocytes

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Last stage in RBC development that still produces hemoglobin

Reticulocyte

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If Wright stain is used to stain reticulocytes, no reticulum are seen and therefore reticulocytes are called (2)

diffusely basophilic erythrocyte
polychromatophilic erythrocyte

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Normal maturation time for reticulocytes in blood

1 day

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usual number of reticulocytes produced per day

50 x 10^9/L per day

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This is a measure of effective erythropoiesis because it permits effective assessment of RBC production by the bone marrow

Reticulocyte count

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Normal reference range for Reticulocyte count in adults

0.5-1.5%

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Normal reference range for Reticulocyte count in newborns

1.5-5.8%

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The reference age for reticulocyte count in newborns (1-2 weeks of age) are

the same as adults

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Terms for increased reticulocyte count

reticulocytosis
polychromasia
polychromatophilia

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This is considered as the first sign of accelerated erythropoiesis

Reticulocytosis/Polychromasia/Polychromatophilia

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Accelerated RBC production results to polychromasia and is observed in (5)

hemolytic anemia
IDA receiving Fe therapy
sideroblastic anemia
thalassemia
chronic and acute blood loss

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A term for decreased reticulocyte count

Reticulocytopenia

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This is observed in aplastic anemia and in conditions in which the bone marrow is not producing RBCs

reticulocytopenia

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T/F

New Methylene blue is chemically different from Methylene blue.

True

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Supravital stains used in staining reticulocytes

New Methylene Blue
Brilliant Cresyl Blue

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2 components of New methylene blue and functions

sodium oxalate: prevents coagulation
sodium chloride: provides isotonicity

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components of BCB and functions

sodium citrate: anticoagulant
sodium chloride: provides isotonicity

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The supravital stain that is more preferred in staining reticulocytes

new methylene blue

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T/F

Medical technologists can still count reticulocytes even without using Miller disk

True

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What anticoagulant is used in the collecting tube for reticulocyte count spx

EDTA

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A calibrated disk placed in the ocular of the microscope

Miller disk

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Large square/Square A is used for

counting reticulocytes

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Small square/Square B is used for

counting RBCs

Square B's size is _____ of Square A

1/9

Minimum number of RBCs that should be counted in Small square (B)

112

Square B's size is 1/9th of Square A and the minimum number of RBCs that should be counted in SB is 112. Therefore, 112 is multiplied by

112 multiplied by 9 is

1008

Methods of counting reticulocytes (3)

Routine light microscope method calibrated miller disk method flow cytometry

Procedure of routine light microscope method in reticulocyte counting

1. Equal parts blood + supravital stain (2-3 drops/50 uL) in a tube. 2. Incubate for 3-10 mins at room temp 3. Remix 4. Prepare 2 blood smears 5. Have another MT check the other smear. 6. Count 1000 RBCs in the field where RBCs are near each other without overlapping. Also count reticulocytes as RBCs (included in the 1000).

In routine light microscope method for reticulocyte count, 2 blood smears are prepared and examined by 2 MTs. The Retic counts should agree within

20%

Formula for routine light microscope method for reticulocyte count

RC = (# of retics counted/1000) x 100

Formula for routine light microscope method for reticulocyte count

RC = (retics counted/1000) x 100

RC formula for calibrated miller disk method

RC= (total retics SA / total RBCs in SB x 9) x 100

Most rapid, accurate, and precise method for reticulocyte count

flow cytometry

In flow cytometry, reticulocytes are counted on the basis of _______ after treatment with fluorescent dyes or nucleic acid stains

optical scatter or flourescence

In flow cytometry, the test values are reported in

absolute and relative terms

Example of a machine that uses flow cytometry to count reticulocytes

Sysmex-3500

Sysmex-3500 uses what supravital fluorescent dye

auramine O

In flow cytometry, reticulocytes fall into --- regions

low-, middle-, high-fluorescence

In optical scatter, less mature reticulocytes fall into

high-fluorescence regions

IRF means

Immature reticulocyte fraction

the sum of the middle-fluorescence and high-fluorescence ratios

IRF

T/F IRF is the most sensitive index of bone marrow erythropoietic activity. However, it does not demonstrate an early indication of erythropoiesis.

IRC is used together with ____ to distinguish types of anemias

absolute reticulocyte count

IRF indicates the ratio of immature reticulocytes to ---- in a blood sample

total reticulocytes

BCB also stains reticulocytes. State the disadvantage of BCB in staining retics

Shows too much unpredictability in staining for routine use

If a px is very anemic or polycythemic, the proportion of dye to blood should be adjusted. How?

anemic/low Hct: larger portion of blood to dye polycythemic/high Hct: smaller amount of blood to dye

T/F The time allowed for staining of the reticulocyte is critical. It should not be more than 10 minutes.

First statement is false. Second statement is true.

2 factors that can cause the reticulocytes to appear pale

use of heparin as anticoagulant increased blood glucose

2 factors that can cause the reticulocytes to appear pale

use of heparin as anticoagulant increased blood glucose

The blood and the stain should be mixed well prior to smearing. Why?

reticulocytes have lower SG compared to RBCs, therefore they settle on top of RBCs in the mixture

Color of Howell-Jolly bodies when using NMB

deep purple

color of heinz bodies when using NMB

light blue green

color of pappenheimer bodies when using NMB

purple

color of hemoglobin H bodies when using NMB

greenish-blue

Other RBC inclusions stained by NMB (4)

howell-jolly bodies heinz bodies pappenheimer bodies hemoglobin h bodies

This RBC inclusion still has nuclear fragments (DNA) present

howell-jolly bodies

rbc inclusion that is usually present at the peripheral edge of the red cell, and contains denatured and precipitated hemoglobin

heinz bodies

Generally appear as several granules in a small cluster. Hemosiderin in mitochondria.

Pappenheimer bodies

Stains used to confirm the presence of pappenheimer bodies

wright stain prussian blue

multiple dots in rbc

hemoglobin h

hemoglobin h is seen in what condition

alpha thalassemia

3 methods of reporting reticulocyte count

absolute reticulocyte count corrected reticulocyte count reticulocyte production index

This is the actual number of reticulocytes in 1 liter of whole blood

ARC

ARC formula

ARC= [retic (%) x rbc count (x10^12) / 100] x 1000

Reference range for ARC

25-75x10^9/L

ARC and IRF of px with hemolytic anemia

both increased

ARC and IRF of px with hemorrhage

both increased

ARC and IRF of px with chronic renal disease

both decreased

ARC and IRF of px with chronic renal disease are both decreased. why?

damaged kidneys cannot produce EPO to stimulate erythropoiesis in the BM

ARC of px's early response to tx in nutritional anemias. why?

normal to low; ARC is not a sensitive index

IRF of px's early response to tx in nutritional anemias

increased

3 other terms for CRC

Reticulocyte Index Hematocrit Correction Poor Man's Bone Marrow Aspirate

There is a need for CRC since the percentage of retics may falsely increase due to (2)

early release of reticulocytes into the bloodstream the number of mature rbcs in the circulation is decreased

The CRC corrects the observed retic count to a normal Hct of _____ to allow correction for the degree of the px's anemia

0.45 L/L

the average normal Hct for both male and female

0.45 L/L or 45%

CRC formula

CRC= Retic (%) x (px Hct / 0.45 L/L)

Reticulocyte production index is also known as

shift correction

Provides a further refinement of the CRC

RPI

A general indicator of the rate of rbc production increase above normal in anemias

shift correction

RPI formula

RPI= CRC/maturation time in peripheral blood

maturation time for px with Hct of 40-45%

1.0 day

Hct (%); Maturation time (days) 40-45 ; 1.0 35-39; ----- --------; 2.0 15-24: ----- -------; 3.0

1.5 25-34 2.5 <15

If RPI is >3,

adequate BM response

If RPI <2,

inadequate BM response

Case: 29/M px Hct: 28% RC: 5.0% Calculate CRC and RPI

CRC: 3.11% RPI: 1.6 --> inadequate BM response