Erythrogram (CBC and graphs) - AKG

Question 1

Spectral interferences causing falsely increased blood hemoglobin measurements? Would these affect CHCM?

Answer 1

1. Lipid droplets from grossly lipemic samples
2. Pigments in icteric samples
3. Nuclei or intact WBCs in samples with extreme leukocytosis
4. Heinz zbodies (due to incomplete erythrocyte lysing)
5. Precipitates from immunoglobulins (e.g., immunoglobulin A)

Only heinz bodies will falsely increase CHCM due to altering light-scattering properties

Question 2

List the pathologic conditions that cause true increases in MHCH/CHCM:

Answer 2

Marked eccentrocytosis and pyknocytosis - oxidative condensation of Hgb and fusion of cell membranes cause a loss of cell volume without proportionate loss of hemoglobin

Pyknocytes = RBCs that appear distorted, irregular, and small with abnormal projections

Question 3

What two specific solutions in the ADVIA 120 RBC/PLT reagent cause sphering of the RBCs and platelets? Why do we want this to occur?

Answer 3

1. Sodium dodecyl sulfate (SDS)
2. Glutaraldehyde

When RBCs and platelets are isovolumetrically sphered, shape is eliminated as a variability factor

Question 4

In the ADVIA 120 RBC method, low angle scatter measures ____ and high angle scatter measures ____.

Answer 4

low angle - volume

high angle - HGB concentration

Question 5

Please identify 1-4 on the graph.

Answer 5

1. Low angle scatter (volume)
2. High angle scatter (hemoglobin)
3. Mie map containing RBCs
4. Platelets detected in RBC method

Question 6

The volume/hemoglobin concentration (V/HC) cytogram is a linear version of the RBC map that appears on the RBC cytogram. On this cytogram, ______ is plotted on the x axis and ______ is plotted on the y axis.

Answer 6

x axis - hemoglobin concentration (CHCM)

y axis - volume (MCV)

Question 7

The RBC volume histogram represents the distribution of RBCs by cell volume. The MCV is the mean of the RBC volume histogram, and the RDW is the _____ of the population.

Answer 7

coefficient of variation

Question 8

The RBC hemoglobin concentration (RBC HC) histogram represents the distribution of RBCs by cellular hemoglobin concentration. CHCM is the mean of the RBC HC histogram. HDW is the _____ of the RBC HC histogram.

This method is dependent or independent of cell volume?

Answer 8

standard deviation

dependent on cell volume -

Question 9

The RBC CH (cellular hemoglobin) histogram represents the distribution of RBCs by the amount of hemoglobin present in each cell ______ of cell volume.

CH is the mean of RBC CH histogram.

CHDW is is the _____ of the RBC CH histogram.

Answer 9

independent

standard deviation

Question 10

Caculate HCT

Answer 10

(RBC x MCV) ÷ 10

Question 11

Caculate MCH and MCHC

Answer 11

MCH = (HGB ÷ RBC) x 10

MCHC = (HGB ÷ [RBC x MCV]) x 1000

Question 12

Please label 1-5.

X axis vs y axis?

Answer 12

1. Platelets
2. Large platelets
3. RBCs
4. RBC fragments
5. RBC ghosts

X-axis: refractive index (high scatter) = platelet content

Y-axis: volume (low scatter) = size

Question 13

The ADVIA 120 autoRETIC reagent contains a ________ detergent that serves as a surfactant and isovolumetrically spheres the RBCs. It also contains a cationic dye ______, that stains cells according to RNA content.

Answer 13

zwitterionic detergent

Oxazine 750

Question 14

Please label A-F on the RETIC Scatter ABS cytogram, along with the x-axis and y-axis

Answer 14

A. Mature RBCs

B. Low absorption retics

C. Medium absorption retics

D. High absorption retics

E. Platelets

F. Coincident events

X-axis: absorption (cell maturation)

Y-axis: light scatter (cell size)

Question 15

CHr vs CHCMr

Answer 15

CHr = cellular hemoglobin content reticulocytes –> mean of the RETIC CH histogram for the reticulocyte population

CHCMr = cell hemoglobin concentration mean reticulocytes –> mean of the Retic HC histogram for the reticulocyte population

Question 16

ADVIA 120 PEROX 1 reagent contains surfactants _____ and ____ that are used in combination with ____ to lyse the RBCs.

Answer 16

sodium dodecyland Brij-35

Thermal stress

Question 17

The ______ in ADVIA 120 PEROX 2 serves as a substrate that enables the hydrogen peroxide in ADVIA PEROX 3 to form a dark precipitate at sites of peroxidase activity in the granules of WBCs.

Answer 17

4-chloro-1-naphthol

H2O2 + 4-chloro-1-naphthol –cellular peroxidase–> dark precipitate within the cells

Question 18

Blasts have the highest number of peroxidase + neurophil granules and mature polymorphonuclear cells have the least amount of these granules. T/F

Answer 18

False - blasts have NO granules. Promyelocytes have the most. Mature PMN have the least.

Eosinophils have the highest perox activity (except cats - where oxazine 750 is used to detect eosinophil)

Question 19

Label 1-8 on the perox cytogram.

Answer 19

1. Noise
2. Nucleated RBCs
3. Platelet clumps
4. Lymphocytes and Basophils
5. Large untsained cells
6. Monocytes
7. Neutrophils
8. Eosinophils

Question 20

The ADVIA 120 BASO reagent contains _____ and a surfactant which lyses the RBCs, platelets, and cytoplasm of all white cells (except basophils in humans).

Answer 20

Phthalic acid

Question 21

The hemoglobin channel has a cyanmethemoglobin method that contains potassium cyanide and dimethyllaurylamine After cell lysis, free ______ is measured spectrophotometrically. The have developed cyanide-free modications.

Answer 21

cyan-met-Hgb

Question 22

Cellular HGB is detected from light scatter (CHCM, MCV, and RBC count). The hemoglobin delta is the difference between HGB channel and the cellular HGB. What would cause it to be > 1?

Answer 22

Interferences:

Intravascular hemolysis

In vitro hemolysis

Question 23

On a RBC scattergram, how can I tell the difference between sample storage artifact/hypernatremia/hyperglycemia from regenerative anemia?

Answer 23

Sample stroage - the whole population of RBCs will shift up and to the left

Regenerative anemia: small amount of RBCs that extend out to the upper left corner

Question 24

Which drug would cause RBCs on the RBC scattergram to shift directly upwards? (only macrocytic)

Answer 24

hydroxyurea

Question 25

What would cause a squigly worm shape on the basophil channel?

Answer 25

Lipemia

Question 26

The Sysmex XT-2000iV performs WBC count in 2 different channels. Cells on the WBC/DIFF cytogram are differentiated based on ____ and _____. The cells are stained with ____ agent after being permeabilized with a surfactant. Polymethine dye binds to nucleic acids and cytoplasmic organelles. Leukocytes with high amount of nucleic acids (____ and ____) are placed higher on the scattergram y-axis which corresponds to ______. Neutrophils and eosionphils becuase of their cytoplasmic ____, are found toward the right side of the x-axis, which corresponds to ____.

Answer 26

Flourescence and complexity

fluorescent polymethine agent

lymphocytes and monocytes

Fluouresence

complexity

side scatter (SSC)

Question 27

What is the population of cells that the arrow is pointing to? Sysmex graph at the bottom is normal.

Answer 27

Basophils - this is a cat sysmex scattergram. The population is still being counted under neutrophils, but you can visually see a distinct population.

Veterinary clinical pathology45.2 (2016): 225-228