Approach to Lows of the CBC
Huronia Nurse Practitioner Conference
September 26, 2014
Lauren Gerard, MD, FRCP
Hematologist
Royal Victoria Hospital
gerardl@rvh.on.ca
Objectives




Review the “CBC” and blood films
To develop a differential diagnosis of
anemia
To appreciate blood work requiring
immediate attention
Red flags….when to refer!
Parts of the CBC


RBC = # of RBCs per liter
MCV = mean cell volume






Normal for adult 80 – 100
Normal in pediatrics slightly lower
MCH = avg. amount of Hb in an individual cell
 Decreased in hypochromic anemias
 Total mass of Hb / # RBCs in volume of blood
MCHC = avg. concentration of Hb in a cell
 Increased in HS and Hb SS
RDW = reflection of anisocytosis
 Ddx: IDA, reticulocytosis, blood transfusion etc
 Normal = uniform population of cells
HCT = measures the volume of red blood cells compared to the
total blood volume (red blood cells and plasma)
Parts of the CBC: Hemoglobin




Automated cell counter from a tube of well-mixed EDTA-anticoagulated
blood filled to a predetermined level.
RBCs are lysed, all forms of hemoglobins are converted to the colored
protein cyanomethemoglobin and measured by a colorimeter.
False readings: inadequate sample (due to insufficient volume or
inadequate anticoagulation)
Hemoglobin is quantified based on its absorption characteristics. False
elevations:
 Hyperlipidemias
 Hyperbilirubinemia
 high white blood cell count
 high serum protein can
Indications for Peripheral Blood
Film





Anemia NYD, Jaundice
NYD
Thrombocytopenia or
neutropenia
Features of MPD of LPD
DIC (n.b. acutely
fragments may be
absent)
Suspicion of parasitic
disease
General Approach to the Anemia

Acute vs. Chronic


Anemia alone or multiple cell lines
affected


Look at previous CBCs
Multiple cell lines affected is more
concerning for primary bone marrow
disorder
Detailed PMH/Social/family history

Anemia can result from a number of
other systemic causes
Approach to Anemia





Start with the MCV!
Microcytic
< 80 fL
Normocytic 80-100 fL
Macrocytic > 100 fL
What determines size of red cell?


Hemoglobin is negative regulator of cell
division
Less hemoglobin = extra division =
smaller cells
Anemia
MCV
Normal
High
(Macrocytic)
Reticulocyte Count
Measure B12, (folate)
Low
(Microcytic)
Ferritin
Low (<20)
Fe Def
Establish
Cause
Normal
ACD
or
Hb-opathy
High
Hemolyisis
Or
Blood Loss
Low
ACD
Renal
Disease
BM Failure
Normal
Consider
Bone Marrow
Biopsy
Low
Replace
Establish
Cause
Anemia
MCV
Normal
High
(Macrocytic)
Reticulocyte Count
Measure B12, (folate)
Low
(Microcytic)
Ferritin
Low (<20)
Fe Def
Establish
Cause
Normal
ACD
or
Hb-opathy
High
Hemolyisis
Or
Blood Loss
Low
ACD
Renal
Disease
BM Failure
Normal
Consider
Bone Marrow
Biopsy
Low
Replace
Establish
Cause
Microcytic Anemias
Case # 1


31 female with Hemoglobin 88g/L
Symptoms:


PMH:



None
Family Hx:


IBS
G2P2
Meds:


Fatigue, otherwise well
None
Exam:

Normal
CBC (incl platelet Count)
Hemoglobin
88
WBC Count
10
Platelet Count 488
Neutrophils
7.0
Lymphocytes 3.0
Monocytes
1.2
Eosinophils
0.0
Basophils
0.0
Hematocrit
.294
RBC Count
4.71
MCV
62.4
RDW
18.8
MCH
18.7
MCHC
299
MPV
9.5
130 - 180 g/L
4.0 - 11.0 x10E9/L
150 - 400 x10E9/L
2.0 - 7.5 x10E9/L
1.0 - 4.0 x10E9/L
0 - 1.0 x10E9/L
0 - 0.7 x10E9/L
0 - 0.3 x10E9/L
0.390 - 0.540 L/L
4.00 - 6.00 x10E12/
78 - 96 fL
10.0 - 14.5 %
28.0 - 32.0 pg
310 - 360 g/L
5.0 - 15.0 fL
L
H
H
L
L
CRITICAL
H
CRITICAL
L
What is your Differential of
Microcytic Anemia?


Thalassemia
Anemic of Chronic Disease (ACD)




Iron Deficiency







Hepcidin prevents eggress of iron from enterocytes
Reduced RBC lifespan
Inflammatory cytokines interfere w/ Epo prodn
Chronic blood loss (GI, hemolysis, menstruation)
Nutritional deficiency
Malabsorption (Celiac, H. Pylori, gastric resection, achlorydia)
Pregnancy, lactation
Hookworm infestation
Lead
Sideroblastic Anemia
Case #1

Ferritin 10

Iron deficiency anemia (ferritin < 30)




Ferritin <18 LR 41
Ferritin 18-45 LR 3.12
Ferritin >100 LR 0.13
But in the setting of inflammation


In inflammation, ferritin may increase 3-fold
Iron studies (TSAT) < 20% may be helpful
Guyatt et al. Am J Medicine 1990;88:205-209
Serum Iron  TIBC = %Transferrin Saturation
(TIBC = total iron binding capacity)
Serum
Iron
Normal
(20-40%)
Iron def:
 serum Fe
 TIBC
 %saturation
ACD:
 serum Fe
N or TIBC
%saturation
Cannot
R/O Fe
def
The Blood Film
Red Blood Cell
Platelet
White Blood Cell
http://meds.queensu.ca/medicine/deptmed/hemonc/macro/slide14.html
Case #1
Hypochromic (1/3),
microcytic
Low Hb
Low MCV
High RDW
Pencil cell
Case #1

Once you have diagnosed iron
deficiency, what is next most
important issue to answer?
A.
B.
C.
D.
Does the patient have malabsorption
of iron or a poor diet?
Does the patient have a source of
blood loss?
Does the patient have chronic vs
acute iron deficiency?
Is there concomitant thalassemia?
Fe deficiency - Causes

Too much OUT



Increased blood loss
Increased iron requirements: use of ESAs,
pregnancy, post-bleeding recovery
Too little IN

Inadequate absorption:
Loss of enterocytes: resection, celiac disease,
IBD
 Antacids, H.pylori, excess dietary bran,
tannins, phytates, starch, competition with
other metals


rare mutations: DMT1, transferrin,
TMPRSS6
Causes of Iron Deficiency
Always think about, look
for, and treat the
underlying cause!
Case #1 – Iron Deficiency Anemia

History:




No GI causes of blood loss
Normal diet (not vegetarian)
2 pregnancies last 4 years
Heavy periods since menarche


Changes pad/tampon q1-2 hours x 6 days
Family History:


Mother & aunt– heavy periods, easing
bruising
Brother – excessive bleeding with dental
extraction
Treatment of Iron Deficiency


Treat underlying cause if possible
Iron replacement








BID to TID dosing
Ferrous gluconate
Ferrous sulfate
Ferrous fumarate
Proferrin
Feramax
30mg/300mg
60mg/300mg
100mg/300mg
11mg po BID
150mg po OD
Take on empty stomach with
vitamin C
At least 3 months…
Poor Response to oral Iron



Lack of response within 4 to 6 weeks of therapy with a minimum of 100 mg po od
elemental dose

Expect reticulocytosis in 7 days
 Increase in Hgb by 10g/L in 14 - 28 days
 SO LONG AS NO BLEEDING: normalize Hgb in 6 to 8 weeks
Review:
 Compliance/Side effects (especially constipation)
 Food inhibitors of iron absorption:
 Oats, bran, rye
 Tea
 Calcium
Rule Out:

H.Pylori (19% of cases)
 Celiac disease – even in absence of symptoms (5%)
 Atrophic gastritis (26%)
 Achloryhydric gastric atrophy – acid is required to solubilize and reduce dietary
iron
 On going blood loss
IV Iron

If oral iron is not
tolerated, is not
effective or severe
anemia

Intravenous Iron
Iron Sucrose (Venofer)
 Ferumoxytol
(Feraheme)
 Iron Dextran (Infufer,
Dexiron)

Case #1 Summary


Iron deficiency anemia  resolved
completely with oral iron
supplementation
Management of heavy menses:


Mirena IUD placement
VWD Investigations


VWF antigen – 20%, Activity- 20%,
Factor VIII 50%
Consistent with mild VWD type 1
Case #2:


74 year old man with Hb 92 g/L
PMH:


Life long smoker, Type 2 DM, HTN,
Dyslipidemia, Coronary artery disease,
CABG CHF grade III/IV, Rheumatoid
Arthritis, Recurrent UTIs
Medications

ASA, Plavix, Metformin, Ramipril, Lasix,
Metoprolol
CBC (incl platelet Count)
Hemoglobin
92
WBC Count
10
Platelet Count 250
Neutrophils
7.0
Lymphocytes 3.0
Monocytes
1.2
Eosinophils
0.0
Basophils
0.0
Hematocrit
.294
RBC Count
4.71
MCV
78
RDW
13
MCH
18.7
MCHC
299
MPV
9.5
130 - 180 g/L
4.0 - 11.0 x10E9/L
150 - 400 x10E9/L
2.0 - 7.5 x10E9/L
1.0 - 4.0 x10E9/L
0 - 1.0 x10E9/L
0 - 0.7 x10E9/L
0 - 0.3 x10E9/L
0.390 - 0.540 L/L
4.00 - 6.00 x10E12/
78 - 96 fL
10.0 - 14.5 %
28.0 - 32.0 pg
310 - 360 g/L
5.0 - 15.0 fL
L
H
L
L
L
L
Case #2

Iron Studies




Ferritin 120
TIBC – 0.40
Iron Saturation 0.22
Blood Film

Microcytic hypochromic
Table 1: Laboratory values to distinguish causes of microcytic anemia
Laboratory marker
(ref range)
Blood film
Ferritin
(12 – 192 g/L)
Serum Iron
(10 - 30 mol/L)
Transferrin saturation
Iron deficiency
anemia
Hypochromia,
pencil-shaped forms
< 40 g/L
Anemia of
chronic disease
Variable
High
Thalassemia
minor
Uniform size,
target cell
Normal
< 10 mol/L
Low
Normal
< 15%
Normal
Normal
> 72 mol/L
Low
Normal to high
Low
Low
Normal to high
> 14.5%
Normal
Normal
< 80 fL
80 – 100 fL
Low – normal
Normal
Out of
proportion low
Normal to high
Low
Low
Low
< 120 g/L in women
< 130 g/L in men
> 30 nmol/L
Low
Variable
< 30 nmol/L
10-30 nmol/L
Normal
Normal
Variable†
(0.20 - 0.50)
Total iron-binding
capacity
(42 – 72 mol /L)
Reticulocytes
30 - 90) E9/L
Red cell distribution
(11.0 - 15.0) %
Mean corpuscular volume
(82.0 - 97.0 fL)
Red blood cell
4.30 - 5.60 E12/L
Mean cell hemoglobin
(27.0 - 32.0 pg)
Hemoglobin
(115 - 155 g/L)
Soluble transferrin
receptor
(10-30 nmol/L)
Serum hemoglobin
electrophoresis
Clues to Microcytic Anemia
MCV < 80 fl
Serum Iron
TIBC /
Serum
Iron
BM Perls stain
Iron Def. Anemia
↓↓
↑↑ /
LOW
0
Chronic Infection
↓↓
↓↓/
Low or
Normal
++
Thalassemia
↑↑
N
++++
Hemoglobinopathy
N
N
++
Lead poisoning
N
N
++
Sideroblastic
↑↑
N
++++
Anemia of Chronic Disease
1) Iron restricted erythropoiesis
2) Blunted erythropoietin response
IL-6
Lipopolysaccharides
Inflammation
↓Oral absorption
Iron trapping
within RES
Andrews. Blood 2008;112:219
Anemia of Chronic Disease




Presents as normocytic or
microcytic anemia
Usually does not cause “severe”
anemia
Can be challenging to differentiate
from iron deficiency
Treatment


Treat underlying cause (if possible)
Treatment of Anemia (if symptomatic)

Consider IV iron + Erythropoeitin
Macrocytic Anemias
Case #3


45F with Hb 108 MCV 112
PMH



Meds:


Hyperthyroism - treated with
radioactive iodine
Ulcerative colitis (mild)
Synthoid
Social Hx:

Non-smoker, minimal ETOH
What is the DDx of Macrocytic anemia?

Round






Liver disease
Hypothyroid
Alcohol
Reticulocytosis
Drugs
Oval

Myelodysplastic
syndrome

Megaloblastic



B12 Deficiency
Folate Deficiency
Drugs
 Folate: Methotrexate
 DNA: Hydroxyurea,
azathioprine, AZT
Investigations of Macrocytosis







Liver disease
Hypothyroid
Alcohol
Drugs
Reticulocytosis
Myelodysplastic
syndrome
Megaloblastic (B12,
folate, other drugs)
•
•
•
•
•
•
•
•
Blood film
Liver enzymes, INR, albumin
TSH
Alcohol and Drug history
Retic count
CBC  look at other cell lines
Serum B12
(RBC folate)
Case #3

CBC







Only anemia with macrocytis
Liver enzymes - normal
Unconjugated bilirubin 41
LDH: 450 (elevated)
TSH 3 (normal)
Vitamin B12 < 40 pmol/L
RBC folate – not performed
Case #3
Seen with
Megaloblastic
Anemias
Low Hb
MCV 120
Hypersegmented
neutrophil (>5 lobes)
B12 Deficiency









Needed for DNA and RNA production in nucleus
Deficiency results in asynchronous maturation of cytoplasm with nuclear
arrest in G2 phase – thus megaloblasts form
Diagnosis
 Serum Cobalamin level < 150 pmol/L on 2 occasions
 Or Serum cobalamin level < 150 pmol/L + MMA > 0.4 umol/l and
homocysteine > 13 umol/L
Etiology
 Pernicious Anemia - Immune destruction of parietal cells that make
IF
 Anti-parietal Abs
 Anti-IF Abs
 (Schilling test)
Dietary deficiency
Achlorydia
Exocrine failure
Ileal resection
Crohn’sdisease
B12 Deficiency - Treatment




Identify etiology
 Refer for OGD – rule out celiac disease
Pernicious Anemia
 Refer for OGD - Increased risk of gastric cancer (3%)
B12 replacement
 B12 1000 mcg IM (if severe)
 Oral supplementation – high dose may be just as effective even if
pernicious anemia
 Watch for rebound hypokalemia
 Hyperseg PMNs – 14 days
 Reticulocytosis 3-4 days
 Normalization of Hgb by 8 weeks
Food: eggs, milk, cheese, milk products, meat, fish, shellfish and poultry
Case #4


72 year old woman
PMH
 Breast cancer

Awaiting CABG for CAD
Hb 95 MCV 105
Surgeon notes that she was started on
iron p.o. for a Hgb of 109 g/ L.



Treated with mastectomy and chemotherapy
8 years ago
CBC (incl platelet Count)
Hemoglobin 95
WBC Count
2.5
Platelet Count 72
Neutrophils
0.8
Lymphocytes 1.0
Monocytes
0.7
Eosinophils
0.0
Basophils
0.0
Hematocrit
.294
RBC Count
4.71
MCV
105
RDW
12
MCH
18.7
MCHC
299
MPV
9.5
130 - 180 g/L
4.0 - 11.0 x10E9/L
150 - 400 x10E9/L
2.0 - 7.5 x10E9/L
1.0 - 4.0 x10E9/L
0 - 1.0 x10E9/L
0 - 0.7 x10E9/L
0 - 0.3 x10E9/L
0.390 - 0.540 L/L
4.00 - 6.00 x10E12/
78 - 96 fL
10.0 - 14.5 %
28.0 - 32.0 pg
310 - 360 g/L
5.0 - 15.0 fL
L
L
CRITICAL
L
L
L
H
CRITICAL
L
Case #4
How would you manage this patient?
A. Start i.v. iron as she has not had response
to oral iron
B. Check her RBC folate and vitamin B12
stores; then replace
C. Refer to a hematologist for further
evaluation
D. Liase with anesthesia to ensure usage of
cell saver etc.
Case #4

Investigations:




Liver enzymes – normal
INR – 1.0, PTT – 29
B12 – 800, RBC folate – 1000
Reticulocyte Count - 15
Low Hb
MCV 105
Case #4
Seen with
MDS
Pelger-Huet anomaly
(dumb-bell nucleus)
Case #4: Summary



Macrocytic anemia with other
cytopenias (pancytopenia)
Previous chemotherapy
Low reticulocyte count


Suggests primary bone marrow failure
Likely mylodysplastic syndrome
(MDS)
Normocytic Anemia
Normocytic Anemia
Reticulocyte Count
Low
Generalized Disorders
Anemia of Chronic Disease
Renal dysfunction
Early/combined nutritional
deficiencies
Primary bone marrow
disorders
Marrow infiltration/infection
Aplastic anemia
MDS
Elevated
Evidence of Hemolysis?
(LDH, bilirubin,
haptoglobin)
No Hemolysis
Hemolytic Anemia
Blood Loss
Intrinsic & Extrinsic
causes
Hemolytic Anemia
(LDH, bilirubin,
haptoglobin)
Intrinsic Causes
Extrinsic Causes
Memebranopathies
Hereditary Spherocytosis
Hereditary eliptocytosis
Immune Mediated
Autoimmune Hemolytic
Transfusion reaction
Enzymopathies
G6PD Deficiency
PK Deficiency
Microangiopathic Hemolytic
Anemia (MAHA)
TTP/HUS
DIC
Mechanical heart valve
Hemoglobinopathies
Sickle cell
Normocytic Anemia Investigations





Reticulocyte count
 If elevated RBC loss or destruction
Hemolytic Markers
 LDH, Haptoglobin, Bilirubin
Nutritional Markers
 Iron indices and B12 (RBC folate)
 May have combined deficiency
Direct Antiglobulin Test (DAT)
 If positive suggests immune hemolysis
Peripheral blood film
Low Hb
Normal MCV
Hemoglobinopathy
Sickle Cell
G6pd slide
Bite Cell
G6PD Deficiency
Case #5




45 year old woman
 Hb 105, MCV 92 fl, WBC 4, Plt 300
Otherwise well
Family Hx:
 Brother had splenectomy as child
Investigations:
 Reticulocyte count – 300 (elevated)
 Unconjugated bili – 42, LDH 550, Haptoglobin
undetectable
 Abdo U/S – mild splenomegaly (16 cm)
What Additional Investigations Should We Order?
Direct Antiglobulin Test (DAT) and Blood Film
Case #5
Spherocytes DDx:
Immune mediated
Hereditary spherocytosis
Spherocytes – round RBC
lacking central pallor
Case #6




57 year old woman, previously well
Brought to ED feeling “generally
unwell”, headache and husband
noted mild confusion
Physical exam – normal
Investigations:


Hb 98 g/L, MCV 94fL, WBC – normal, Plts 34 x 10
9/L
CT head - normal
Case #6

What is your next step in this
patients management?




A) Discharge patient and reassure that
likely related to a viral illness
B) Discharge to be seen in hematology
clinic within 2 – 4 weeks
C) Urgent peripheral blood film
D) Start on B12 supplement
Case #6



What would you like to know on
history?
What investigations would you
order?
Investigations:
 Reticulocyte count 408
 LDH 568
 Haptoglobin < 0.06
 Indirect bilirubin 55
 Direct Antibody test:
negative
 PT 11.0 sec, PTT 31.0 sec
 Creatinine 120 umol/L
 Urinalysis: + blood

A.
B.
C.
D.
E.
What is her most likely
diagnosis?
Warm Autoimmune Hemolytic
anemia
Oxidative hemolysis
Acute blood loss
Disseminated Intravascular
Coagulation
Thrombotic Thromocytopenia
Purpura
Fragments
Case #6
Microangiopathic Hemolytic
Anemia










DIC
HUS/ TTP
Gestation-related
 HELPP
 AFLP
Malignant HTN
Catastrophic Antiphospholipid Syndrome
Medication induced Endotheliopathies
 Ticlopidine, Clopidogrel
 Mitomycin C
 Calcineurin Inhibitors
Valvulopathies
Kidney rejection
Scleroderma crisis, lupus, APLA crisis
March hemoglobinuria
Anemia Algorithm
Anemia
MCV
Microcytic:
Normocytic:
Macrocytic:
Iron Deficiency
Thalassemia
Anemia of chronic disease
Sideroblastic anemia
(next page)
Megaloblastic
- Folate, B12
Drugs
Myelodysplasia
Alcohol
Liver Disease
Reticulocytosis
Thyroid disease
Anemia Algorithm
Anemia
MCV
Microcytic:
Normocytic:
Macrocytic:
Iron Deficiency
Thalassemia
Anemia of chronic disease
Sideroblastic anemia
(next page)
Megaloblastic
- Folate, B12
Drugs
Myelodysplasia
Alcohol
Liver Disease
Reticulocytosis
Thyroid disease
Blood film
Serum ferritin, iron studies
Hgb electrophoresis
Blood film exam
(Serum B12)
RBC folate
Liver enz, TSH
Retic count
Normocytic
Retic Count
Low:
Generalized Disorders
- Anemia of chronic disease
- Chronic renal failure
- Nutritional deficiencies
- Toxins, drugs
Primary Bone marrow
- Hematologic
- Infiltration/Infection
High:
Hemorrhage
Hemolysis
(Hematinic)
Normocytic
Retic Count
Low:
Generalized Disorders
- Anemia of chronic disease
- Chronic renal failure
- Nutritional deficiencies
- Toxins, drugs
Primary Bone marrow
- Hematologic
- Infiltration/Infection
Blood film
Ferritin, Iron studies
Creatinine
TSH, B12
Exam/Abdom. ultrasound
High:
Hemorrhage
Hemolysis
(Hematinic)
Bili, LDH
Haptoglobin
Normocytic
Retic Count
Low:
Generalized Disorders
- Anemia of chronic disease
- Chronic renal failure
- Nutritional deficiencies
- Toxins, drugs
Primary Bone marrow
- Hematologic
- Infiltration/Infection
Blood film
Ferritin, Iron studies
Creatinine
TSH, B12
Exam/Abdom. ultrasound
High:
Hemorrhage
Hemolysis
(Hematinic)
Bili, LDH
Haptoglobin
Direct Antiglobulin Test
When to refer to Hematology?
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Anemia with
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Thrombocytopenia
Leukopenia
Macrocytic Anemia
Evidence of hemolysis
Red cell fragmentation
Anemia with Hb < 100
Conclusions
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Many types of anemia have a “nonhematologic cause”…look for it and
treat it whenever possible
The most important investigation of
normocytic anemia is the
reticulocyte count.
Peripheral blood film can provide
important diagnostic clues.
Questions?
Email: gerardl@rvh.on.ca