lecture 2 recognizing formed elements in blood and reading a differential-winter 2014

8/13/2019 Lecture 2 Recognizing Formed Elements in Blood and Reading a Differential-winter 2014

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LECTURE 2

CLS 3020



COMPLETE BLOOD COUNT (CBC)

and the WBC DIFFERENTIAL (DIFF) Automated Hematology Analyzers run Complete Blood Counts(CBCs) in modern Clinical Hematology Labs: CBC Lab Data

Quantitates all formed elements in whole blood (EDTA, anticoagulated)

RBC Count (in # x 106 /µL or(=) # x 1012 /L)

WBC Count (in # x 103 /µL or(=) # x 109 /L) 5-PART DIFFERENTIAL (Relative (%) and “ABSOLUTE COUNT”(#) of WBCs

NEUTROPHILS (POLYS, PolyMorphoNuclear cells/PMNs) LYMPHOCYTES (LYMPHS)

MONOCYTES (MONOS)

EOSINOPHILS (EOS)

BASOPHILS (BASOS)

PLATELET Count (in # x 103 /µL or(=) # x 109 /L)



CBC from Automated Analyzer



WBC DIFFERENTIAL is REPORTED in 2 WAYS:

% (Relative Count) and ABSOLUTE COUNTRelative Count Percent = # of WBC Sub-types per 100 WBCs Counted

Neutrophils (PMN), Lymphocytes, Monocytes, Eosinophils, Basophils, Bands,etc)

Example: 70 PMN = 70 % PMN

25 LYMPHS = 25% LYMPHS

5 MONOS = 5% MONOS

Note: When you add up all the percents of all the WBC types, THE TOTALMUST be 100%

Note: An Automated Hematology Analyzer counts an Automated Differential and differentiates>1000 WBCs and calculates the percentage of subtypes and reports the relative countsto ONE DECIMAL PLACE

A Medical Technologist/Medical Lab Scientist performs a Manual Differential bydifferentiating 100 WBCs and reports the relative counts in Whole Numbers, withoutdecimals



CALCULATING AN ABSOLUTE WBC COUNT

FROM A RELATIVE (%) WBC COUNT To Calculate the Absolute counts for each WBC sub-

type, you need to know:

Total WBC Count Reported as WBC on an automated CBC printout (hemogram)

Relative counts (%) of each WBC Sub-type

Perform the calculation of the Absolute count of each WBC sub-type as follows:

ABSOLUTE COUNT =

Total WBC Count X Relative Count (written as decimal)




FROM A RELATIVE (%) WBC COUNT ABSOLUTE COUNT =Total WBC Count X Relative Count (written as decimal)Step 1. Convert the Relative Count from a (Whole #)

Percentage (example 70% PMN) to a decimal expressionof percentage. (These are just different ways ofexpressing the same thing.) Example: 70 PMN = 70 % PMN = 0.70

25 LYMPHS = 25% LYMPHS = 0.25

5 MONOS = 5% MONOS = 0.05 To transform a percentage to a decimal, simply divide it

by 100. 70 ÷ 100 = 0.70 25 ÷ 100 = 0.25 5 ÷ 100 = 0.05




FROM A RELATIVE (%) WBC COUNT ABSOLUTE COUNT =Total WBC Count X Relative Count (written as decimal)

Step 2. Locate the Total WBC Count from the CBCReport.

(For our example, we will use a WBC Count of 11.o x 103/µL

Step 3. Multiply the Total WBC Count by the decimal form of theRelative Count Example: Relative Count of PMNs = 70 % PMN = 0.70

Total WBC Count = 11.o x 103/µL

ABSOLUTE PMN Count= 11.0(x 103/µL) x 0.70 = 7.7 x 103/µL which means there are 7.7 x 103 PMNs or 7,700 PMNs per microliterof blood in this blood specimen



QUICK REVIEW OF UNITS and

SCIENTIFIC NOTATION ALWAYS INCLUDE UNITS WHEN REPORTING LAB

VALUES

LEARN THE UNITS FOR EACH BLOOD COMPONENT RBC COUNT (in # x 106/µL or(=) # x 1012/L)

WBC COUNT (in # x 103/µL or(=) # x 109/L)

PLATELET COUNT (in # x 103/µL or(=) # x 109/L)

UNDERSTAND SCIENTIFIC NOTATION 106 MEANS 1 WITH 6 ZEROS OR 1,000,000 (one million)

103 MEANS 1 WITH 3 ZEROS OR 1,000 (one thousand)

µl means 10-6 liters or 0.000001 L or 1÷ 1,000,000 (one

millionth)



Practice Calculating Absolute WBC Sub-Type

Counts from Relative Counts: Self-Check WBC Count 6.8 x 103/µL

RELATIVE COUNTS for 5-Part Differential

PMN 52.6% [÷ 100 =] 0.526

Lymph 36.7% [÷ 100 =] 0.367

MONO 7.8% [÷ 100 =] 0.078

EOS 2.5 % [÷ 100 =] 0.025 BASO 0.4% [÷ 100 =] 0.004

COMPARE YOUR ANSWERS

WBC Count 6.8 x 103/µL

ABSOLUTE COUNTS for

5-Part Differential 0.526 X 6.8 x 103/µL PMN

0.367 X 6.8 x 103/µL Lymph

0.078 X 6.8 x 103/µL Mono

0.025 X 6.8 x 103/µL Eos 0.004 X 6.8 x 103/µL Baso

WITH THE COUNTS ON THE

NEXT SLIDE



HOW DID YOUR ANSWERS

COMPAREFOR ABSOLUTE COUNTS? WBC Count 6.8 x 103/µL ABSOLUTE COUNTS for 5-Part

Differential: REPORT TO ONEDECIMAL PLACE!

0.526 X 6.8 x 103/µL PMN=3.57 = 3.6 x 103/µL

0.367 X 6.8 x 103/µl LYMPH=2.49=2.5 x 103/µL

0.078 X 6.8 x 103/µL Mono=

0.53= 0.5 x 103

/µL 0.025 X 6.8 x 103/µL Eos=

0.17=0.2 x 103/µL

0.004 X 6.8 x 103/µL Baso=

0.02 = 0.0 x 103/µL



LEARN REFERENCE VALUES FOR WBC COUNTS

( For Both Reference % Counts and Absolute Counts)

See Back of First Page in Textbook for Reference Values for WBC Parameters. Learn Adult Reference Ranges

Note: Textbook uses units of x 109/L for WBC units

whereas most labs use x 103

/µL (These are equal)

Total WBC Count 4.5-11.0 x 103/µL Neutrophils (PMN) 40-80% 1.8-7.0 x 103/µL

Bands 0-5 % 0-0.7 x 10

3

/µL Lymphocytes 25-35% 1.0-4.8 x 103/µL Monocytes 2-10% 0.1-0.8 x 103/µL Eosinophils 0-5 % 0-0.4 x 103/µL Basophils 0-1% 0-0.2 x 103/µL



Another Set of Reference Ranges:

Notice the Relative Frequencies of WBCs in a Diff A normal differential leukocyte count would typically

produce the following cell frequencies (numbers inparentheses are the range of normal frequenciesreported in different texts):

~ 60% Neutrophils (50% - 70%)

~ 30% Lymphocytes (20% - 40%)

~ 5% Monocytes (1% - 9%) ~ 3% Eosinophils (>0% - 5%)

~ 0.5% Basophils (>0% - 2%)



Excellent Reference http://www.lab.anhb.uwa.edu.au/mb140/corepages/bl

ood/blood.htm#Basophilic

Describes the blood cells, what they look like, theirfunctions, and life spans

It is a histology program’s description, so ignore theunique staining that is histo-related (Leishman’s stain)

http://www.lab.anhb.uwa.edu.au/mb140/corepages/blood/blood.htm







LEARNING TO RECOGNIZE WBCs



Hematopoiesis of the

Neutrophil Lineage Pluripotential Hematopoietic Stem Cell

Myeloid Stem Cell (multipotential)

Myeloblast (multipotential)

(Neutrophilic)Promyelocyte(PROMYELO)(unipotential) (Neutrophilic) Myelocyte (MYELO)

(Neutrophilic) Metamyelocyte (META)

(Neutrophilic) Band (BAND)(“Stab”)

Neutrophil (PMN, SEG, POLY)



Look at Slides in Bernarda’s

Morphology Powerpoint Look at other WBC lines

Other Granulocyte lines

EOSINOPHILS Slide 10

BASOPHILS Slide 11

Agranulocyte lines

LYMPHOCYTES Slide 19

MONOCYTES Slide 21

Look at PLATELETS (THROMBOCYTES)

(See next slide)



PLATELETS (THROMBOCYTES) ~ 3 µ in size

Fragments of thecytoplasm ofmegakaryocytes

No nucleus

Role in Hemostasis

Arresting Bleeding



Granulocytes: PMNs, EOS, BASOs



Agranulocytes: Lymphs and Monos



READING A PERIPHERAL SMEAR Prepare Peripheral Smear

Stain with Wright-Giemsa Stain

10X Objective (low power) Assess quality of Smear; Focus; Scan for Abnormal Cells

or Abnormal # of Cells

40X Objective (high-dry; NO OIL!) Find area of smear where RBCs evenly distributed,

barely touching each other (2-3 cells may overlap) WBC Count Estimate can be done in this field

Average # of WBCs in 10 fields x 2.0 = WBC Estimate as WBC X 103/ ul



READING A PERIPHERAL SMEAR 100X Objective Oil Immersion (Use Oil)

Perform WBC Differential

In field area of 200-250 RBCs

Use Battlement Pattern when reading slide

Count 100 WBCs

Note WBC Morphology Abnormalities

Note RBC Morphology Abnormalities

Note Platelet Clumps or Large Platelets if seen



Moment of Clarity & Muddy MomentLecture 2: RECOGNIZING FORMED ELEMENTS IN BLOOD:

READING A DIFFERENTIAL

Crystal Clear Point Muddy/Unclear

lecture 2 recognizing formed elements in blood and reading a differential-winter 2014

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