Erythrogram (CBC and graphs) - AKG Flashcards
ADVIA, perox vs basophil channels, scattergrams, sysmex, HCT, MCV, MCHC, CHCM, reticulocytes, platelets etc.
Spectral interferences causing falsely increased blood hemoglobin measurements? Would these affect CHCM?
- Lipid droplets from grossly lipemic samples
- Pigments in icteric samples
- Nuclei or intact WBCs in samples with extreme leukocytosis
- Heinz zbodies (due to incomplete erythrocyte lysing)
- Precipitates from immunoglobulins (e.g., immunoglobulin A)
Only heinz bodies will falsely increase CHCM due to altering light-scattering properties
List the pathologic conditions that cause true increases in MHCH/CHCM:
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
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?
- Sodium dodecyl sulfate (SDS)
- Glutaraldehyde
When RBCs and platelets are isovolumetrically sphered, shape is eliminated as a variability factor
In the ADVIA 120 RBC method, low angle scatter measures ____ and high angle scatter measures ____.
low angle - volume
high angle - HGB concentration
Please identify 1-4 on the graph.
- Low angle scatter (volume)
- High angle scatter (hemoglobin)
- Mie map containing RBCs
- Platelets detected in RBC method
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.
x axis - hemoglobin concentration (CHCM)
y axis - volume (MCV)
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.
coefficient of variation
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?
standard deviation
dependent on cell volume -
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.
independent
standard deviation
Caculate HCT
(RBC x MCV) ÷ 10
Caculate MCH and MCHC
MCH = (HGB ÷ RBC) x 10
MCHC = (HGB ÷ [RBC x MCV]) x 1000
Please label 1-5.
X axis vs y axis?
- Platelets
- Large platelets
- RBCs
- RBC fragments
- RBC ghosts
X-axis: refractive index (high scatter) = platelet content
Y-axis: volume (low scatter) = size
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.
zwitterionic detergent
Oxazine 750
Please label A-F on the RETIC Scatter ABS cytogram, along with the x-axis and y-axis
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)
CHr vs CHCMr
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
ADVIA 120 PEROX 1 reagent contains surfactants _____ and ____ that are used in combination with ____ to lyse the RBCs.
sodium dodecyland Brij-35
Thermal stress
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.
4-chloro-1-naphthol
H2O2 + 4-chloro-1-naphthol –cellular peroxidase–> dark precipitate within the cells
Blasts have the highest number of peroxidase + neurophil granules and mature polymorphonuclear cells have the least amount of these granules. T/F
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)
Label 1-8 on the perox cytogram.
- Noise
- Nucleated RBCs
- Platelet clumps
- Lymphocytes and Basophils
- Large untsained cells
- Monocytes
- Neutrophils
- Eosinophils
The ADVIA 120 BASO reagent contains _____ and a surfactant which lyses the RBCs, platelets, and cytoplasm of all white cells (except basophils in humans).
Phthalic acid
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.
cyan-met-Hgb
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?
Interferences:
Intravascular hemolysis
In vitro hemolysis
On a RBC scattergram, how can I tell the difference between sample storage artifact/hypernatremia/hyperglycemia from regenerative anemia?
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
Which drug would cause RBCs on the RBC scattergram to shift directly upwards? (only macrocytic)
hydroxyurea
What would cause a squigly worm shape on the basophil channel?
Lipemia
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 ____.
Flourescence and complexity
fluorescent polymethine agent
lymphocytes and monocytes
Fluouresence
complexity
side scatter (SSC)
What is the population of cells that the arrow is pointing to? Sysmex graph at the bottom is normal.
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
