Transcript Getting to know* the CBC

Getting to know
the CBC…
It’s about time!
Ma. Ysabel Lesaca-Medina, MD
Do you know :
How to evaluate anemia using MCV,
MCH, MCHC, RDW and RETIC count
the significance of different RBC shapes
reported in the PBS
How to deal with leukocyte abnormalities
seen on PBS
The causes of thrombocytosis and
thrombocytopenia
Evaluating Anemia
-role of MCV, MCH, MCHC
MCV
(mean corpuscular volume)
Formula
(2-10 yrs old)
– Lower limit: 70 fL + age in years
– Upper limit: 84 fL + ( age in yrs x 0.6 ),
until upper limit of 96 is reached
MEMORIZE !!
Evaluating Anemia
MCH (Mean Corpuscular Hb)
MCHC (Mean Corpuscular Hb conc)
- normo/hyper/hypo chromic
- Used in
- iron deficiency, thalassemia - ↓
- Spherocytosis -
MCH/MCHC
What’s the MCV range?
Give LL and UL
7 year old
answer
LL: 77 fL
UL: 88.2 fL
RETICULOCYTE COUNT
-Expressed as % of
circulating rbc’s
-Take up reticulin
stain (supravital):
bec of inc RNA
-N = 0.5 % to 1.5 %
or = .005 to .015
RETICULOCYTE COUNT
Provide crucial info on RATE of red cell
production
2 broad classes of anemias
1. 2 red cell loss or destruction – inc retic
- e.g. hemolysis, blood loss
2. Dec red cell production – dec retic
e.g. aplastic, iron deficiency
Reticulocyte index
Anemic patient -->
increased retic
so have to correct:
retic observed x
px Hct / 0.45
Example:
Hb 50 Hct 0.15
Retic count=.045= 4.5 %
Corrected retic =
retic x (px Hct / 0.45)
4.5% x .15/.45 = 1.5 %
( N = 0.5-1.5%)
Absolute Retic Count
More accurate
Compute :
RBC (in n x 1012 )
x # retic/1000 rbc
x 1000
 Normal
= 40,000 – 100,000/uL
Absolute Retic count
EXAMPLE
Hb 50
Hct 0.15
RBC = 1.6 x 1012
Retic count
=.045 = 4.5 %
Compute for absolute
retic count
Formula:
RBC (in n x 1012 )
x # retic/1000 rbc
x 1000
= 1.6 x 45 x 1000
= 72 ,000
 Normal = 40,000 – 100,000/uL
Quiz
Compute for absolute
retic count :
Hb 90
RBC 3 x 1012 /L
Retic .015
Answer
45,000 retics / uL
Anemia based on MCV and retic
Increased MCV
– High retic
– Low retic
Decreased MCV
– High retic
– Low retic
Normal MCV
– High retic
– Low retic
Increased MCV
Increased Retic
– Acute blood loss
– Hemolysis
> Increased MCV
- cased by inc # retics
 retics have a large
cellular volume
Anemia based on MCV and retic
Increased MCV
– High retic
– Low retic
Decreased MCV
– High retic
– Low retic
Normal MCV
– High retic
– Low retic
Inc MCV, low retic
1. Bone Marrow Failure
• Retic count greatly dec for degree of anemia
----------------------------------------------------------------E.g. Known case of Aplastic anemia
RBC 1.73 Hb 52 Hct 0.15 Retic = 1 % or 0.010
> Compute for corrected retic count % absolute retic
Answer
You got it!
Corrected retic:
0.33 %
( 0.5 – 1.5 %)
Absolute Retic Count:
17,300 /uL
(40,000-100,000)
Bone Marrow Failure


MCV inc bec of production of stress rbc’s
Examples of bone marrow failure
Aplastic Anemia
o Fanconi’s Anemia
o Diamond-Blackfan anemia
o
(Congenital hypoplastic anemia)
o
Transient Erythroblastopenia of Childhood
(TEC)
TEC vs DBA
Transient
erythroblastopenia
of childhood
–
–
–
–
Acquired
90% cases in > 1 y.o.
Recovery within 2 mos
In recovery phase, inc
MCV bec inc retics
– ADA normal

Diamond Blackfan
Anemia
Congenital
- 90% cases < 6 mos
- Some recover by 7
years old
- ADA increased
-
Inc MCV, Dec Retic
2. Megaloblastic
disorders
 Folate and Vit B 12
deficiency
 Other things seen :
 Hypersegmentation of
PMN’s
 Giant segmenters,
stabs
 Macroovalocytosis
 Megaloblastic changes
in BM
hypersegmentation
Inc MCV, Dec Retic
3. Alcohol

direct toxic effect on BM

Induces folate deficiency
Inc MCV, dec retic
4. Anti-metabolites
a. Methotrexate (folic acid anti-metabolite)
b. Co-trimoxazole
5. Hypothyroidism
a. Causes red cell hypoplasia
b. Usually normocytic/normochromic
c. Macrocytosis may develop
Next …DECREASED MCV
Decreased MCV
Caused by insufficient
Hb synthesis
Mostly caused by:
– Iron deficiency
– Inability to use iron
Chronic disease
Thalassemia
Lead poisoning
Sideroblastic anemia
Decreased MCV
Increased retic
– Thalassemia
major
Normal /decreased
retic
Thalassemia major
Presents : 6 to 24 months old
Symptoms
– Profound anemia
– Hepatosplenomegaly
– Jaundice
– Growth retardation
Decreased MCV
Increased retic
– Thalassemia major
Normal /decreased
retic
– Iron deficiency
– Thalassemia Trait
– Anemia of chronic
disease
– Lead poisoning
– Sideroblastic anemia
hardest differentials !
1. Iron deficiency
Common cause in 1-3 years of age
As iron stores become depleted:
–
↑RDW

↓serum Fe 
↓ MCV  ↓ Hb
Remember!
First manifestation :
RDW
1. Iron deficiency
Reasonable
approach: Oral iron
replacement
(+) response:
Hb by 15-20 in 1 month
PRESUMPTIVE DX MADE !
2. Thalassemia trait
Microcytosis +/- mild anemia
– 1 of 2 B-globin genes are intact
– or 2 of 4 alpha-globin genes are intact
Often confused with iron deficiency
Thal trait vs Iron deficiency
Thal trait
Iron deficiency
< 12
>13
(MCV/RBC count)
Smaller cells,
More rbc number
Bigger cells, less rbc
number
Poikilocytosis;
Basophilic stippling
More
RDW
Normal
Mentzer index
increased
RED CELL DISTRIBUTION WIDTH
Quantitative measure of anisocytosis
The greater the # of sizes of rbc’s, the
higher the RDW
Normal = 11.5-14.5
No subnormal values have been reported
RDW
HIGH ( HIGH-F )
– Iron deficiency
– Hb H disease
– Fragmentation
– G-6PD
– Chronic disease
3. Anemia of Chronic Disease
Mild to moderate anemia (Hb 100 – 110)
Slight inc RDW; dec Fe, inc Ferritin
Px has chronic INFLAMMATION
Disturbs iron recycling  iron left trapped
in RES
– Cytokines IL-1, IL-6  inc ferritin syn 
empty ferritin shells provide excess iron
storage capacity  iron sequestered in RES
Decreased MCV
4. Lead poisoning
Inhibits enzymes
involved in heme
synthesis
Reduction of
intracellular iron
5. Sideroblastic
Anemia
Rare in childhood
Failure to incorporate
iron into heme
Causes:
– Inherited (XL)
– MDS
– Drugs ( INH, ethanol)
NEXT. ..
NORMAL MCV
MCV NORMAL
MCV NORMAL
INC RETIC
1. HEMOLYSIS
2. BLOOD LOSS
DEC RETIC
N OR DEC RETIC
MCV NORMAL
MCV NORMAL
DEC RETIC
INC RETIC
1.
2.
3.
4.
5.
BALANCED
PRCA/TEC
APLASTIC
HYPOTHYROIDISM
REPLACEMENT OF MARROW
N OR DEC RETIC
MCV NORMAL
Normal or decreased retic
Renal disease
Hyperparathyroidism
Liver disease
Chronic Inflammation
Renal Disease
Cause:
– erythropoeitin
insufficiency
– Serum inhibitors of
erythropoeisis
accumulate in uremic
patients  shortened
rbc lifespan
– Acanthocytosis
When BUN > 150
mg/dL
Hyperparathyroidism
Fibrosis in marrow
cavity
Decreased erythropoeisis
Liver disease
Anemia is due to
– Hypersplenism
– Vitamin-nutritional
deficiencies (lipid
soluble)
– Blood loss
PLATELETS
Cytoplasmic fragments ; no nucleus
Life span = 7-10 days
1/3 in spleen, 2/3 in circulation
Size= 1 – 4 um
– Large
Young
2 peripheral destruction
– Small or normal
Production defect
THROMBOCYTOSIS
Platelet count > 600,000
Rarely causes complications !
– Therefore, antiplatelet tx is rarely indicated
– Kawasaki is an exception
THROMBOCYTOSIS
Hemolytic anemia
Hemorrhage
Infection
Iron def anemia
Vit E deficiency
Vascular Collagen
disorders
HIV is the PITS !
Post-splenectomy
Post-op
Inflammatory Bowel Dis
Trauma
Tumors
Syndrome, kawasaki
Syndrome, nephrotic
Syndrome, myeloprolif
THROMBOCYTOPENIA
Immune Platelet Destruction
Infections
Platelet clumping
- falsely low
- 2 inadequate coagulation
RBC abnormalities
Anisocytosis
– Microcytes
– Macrocytes
– Normocytes
Poikilocytosis
– Different shapes
Spherocytes
– Hereditary
spherocytosis
– ABO incompatibility
– Hemolytic anemia
– Hypersplenism
– Malaria
– Hemoglobinopathies
– Post-transfusion !
– Liver disease
Acanthocytes
–
–
–
–
–
–
–
–
Abetalipoproteinemia
Hemolytic anemias
Thalassemia
Liver disease
Severe burns
Post splenectomy
Renal disease
Enzyme deficiencies
Schistocytes
- Hemolytic anemia
– Hypersplenism
– Megaloblastic
anemia
– Thalassemia
– Acute Leukemia
– Post severe burns
Ovalocyte
Normochrom ovalocyte
– Ovalocytosis
– Thalassemia
Hypochrom ovalocyte
– Iron deficiency
Macrocytic ovalocyte
– Megaloblastic anemia
Elliptocytes
– Elliptocytosis
– Megaloblastic
anemia
– Myelofibrosis
– Thalassemia
TARGET CELLS
– Liver disease
– Thalassemia
– Iron deficiency
– Postsplenectomy
Abn RBC shapes
Blister cell
– Microangiopathic
hemolytic anemia
Tailed RBC
– Megaloblastic anemias
– Iron deficiency
Tear drop
– Hypersplenism
– Thalassemia
– Hemolytic Anemia
BURR CELLS
– Hemolytic
anemias
– Iron deficiency
– Megaloblastic
anemia
– Thalassemia
– Hypersplenism
STOMATOCYTES
– Hereditary
stomatocytosis
– Artefact
– Acute leukemia,
treated
– Alcoholics with
liver disease
The following scale is used by many laboratories in the delta region of the U. S.
morphology
normal
1+
2+
3+
4+
characteristics
limits
Macrocytes (>9 μ dia.)
0-5
5 - 10 10 - 20 20 - 50
>50
Microcytes (<6 μ dia.)
0-5
5 - 10 10 - 20
0 - 50
>50
Hypochromia
0-2
3 - 10 10 - 50
50 - 75
>75
Poikilocytosis
0 -2
3 - 10 10 - 20
20 - 50
>50
Anisocytosis
0-2
3 - 10
10 - 20 20 - 50
>50
Acanthocyte
none
1-5
5 - 10 10 - 20
>20
Burr Cell
0-2
3 - 10
10 - 20 20 - 50
>50
Target cell (codocyte)
0-2
3 - 10
10 - 20 20 - 50
>50
Tear drop cell (dacryocyte) 0 - 2
2-5
5 - 10
10 - 50
>50
Sickle Cell (depranocyte)
none (If present in any number, report as positive.)
Elliptocyte/Ovalocyte
0-2
2 - 10
10 - 20 20 - 50
>50
Helmet cell / Bite cell
none
1-5
5 - 10
10 - 20
>20
Schistocytes
none
1-5
5 - 10
10 - 20 >20
Spherocytes
0-2
2 - 10 10 - 20
20 - 50
>50
Stomatocytes
0-2
2 - 10 10 - 20
20 - 50 >50
Basophilic stippling
0-1
1-5
5 - 10
10 - 20 >20
Polychromatophilia, adult
0-1
2-5
5 - 10
10 - 20 >20
Polychromatophilia, infant
1-6
7 - 15 15 - 20
20 - 50 >50
Howell-Jolly (HoJo) body
none 1 - 2
3-5
5 - 10 >10
Pappenheimer body (siderocyte) none 1 - 2
3-5
5 - 10
>10
RBC abnormalities
Severe hemolysis
– Nucleated rbc’s
– Schistocytes: helmet cells, triangle cells, bite
cells
– Spherocytes (immune mediated)
– acanthocytes
RBC Inclusions
Howell-Jolly bodies
– Nuclear remnants not
extruded from mature
erythrocytes
– Indicate splenic
hypofunction
– Seen in
Post-splenectomy
Leukemia
Hemolytic
thalassemia
RBC Inclusions
Basophilic stippling
– Caused by aggregated
ribosomes in rbc
– Seen in
Thalassemia
Lead intoxication
/heavy metal
WBC abnormalities
Toxic changes
– Toxic granules
– Dohle bodies
Dark blue cytoplasmic
inclusions
Seen in neutrophils
Seen in : infection,
burns, MDS, pregnancy
– Vacuolations
Toxic granules
DOHLE BODIES
remnants of free
ribosomes of RER
Single or multiple,
blue, grayish-blue,
or greenish
inclusions.
Vacuolization
QUIZ SHOW
10 year old with Hb 80, WBC 9 plt 350.
On co-tri for repeated UTI. MCV 102
MCH 340 Retic ct 0.002
What is most likely diagnosis ?
a.
b.
c.
d.
Fe deficiency
Megaloblastic anemia
Diamond Blackfan Anemia
Hemolytic anemia
Answer
B
MEGALOBLASTIC
ANEMIA
(Prob 2 folate def)
The ff is a cause of thrombocytosis
A. Immune thrombocytopenic purpura
B. Pregnancy
C. Iron deficiency anemia
D. Renal failure
ANSWER
C
Iron deficiency
anemia
Compute absolute retic count
Hb 45
RBC 1.5 x 1012 / L
Retic count: 0.016
ANSWER
24,000 / uL
4/4 Quiz show
Which presents as a microcytic anemia
A.
B.
C.
D.
B-thalassemia
Hemolytic Anemia
Aplastic Anemia
Anemia 2 blood loss
ANSWER
A
B- Thalassemia
Which is the pbs of px with vit B12
deficiency?
Answer
7
Which is pbs of px with iron
deficiency?
1
2
Answer
1