Approach to Lows of the CBC

Lauren Gerard, MD, FRCPHematologist

Royal Victoria Hospitalgerardl@rvh.on.ca

Huronia Nurse Practitioner ConferenceSeptember 26, 2014

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

Look at previous CBCs Anemia alone or multiple cell lines

affected 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

Low

(Microcytic)

High(Macrocytic)

Measure B12, (folate)Ferritin

Low (<20)

Fe Def

Establish Cause

Normal

ACDor

Hb-opathy

LowNormal

ReplaceEstablish

Cause

Consider Bone Marrow

Biopsy

Reticulocyte Count

LowHigh

ACDRenal

DiseaseBM Failure

HemolyisisOr

Blood Loss

Normal

Anemia

MCV

Low

(Microcytic)

High(Macrocytic)

Measure B12, (folate)Ferritin

Low (<20)

Fe Def

Establish Cause

Normal

ACDor

Hb-opathy

LowNormal

ReplaceEstablish

Cause

Consider Bone Marrow

Biopsy

Reticulocyte Count

LowHigh

ACDRenal

DiseaseBM Failure

HemolyisisOr

Blood Loss

Normal

Microcytic Anemias

Case # 1 31 female with Hemoglobin 88g/L Symptoms:

Fatigue, otherwise well PMH:

IBS G2P2

Meds: None

Family Hx: None

Exam: Normal

CBC (incl platelet Count) Hemoglobin 88 130 - 180 g/L L WBC Count 10 4.0 - 11.0 x10E9/L Platelet Count 488 150 - 400 x10E9/L H Neutrophils 7.0 2.0 - 7.5 x10E9/L Lymphocytes 3.0 1.0 - 4.0 x10E9/L Monocytes 1.2 0 - 1.0 x10E9/L H Eosinophils 0.0 0 - 0.7 x10E9/L Basophils 0.0 0 - 0.3 x10E9/L Hematocrit .294 0.390 - 0.540 L/L L RBC Count 4.71 4.00 - 6.00 x10E12/ L MCV 62.4 78 - 96 fL CRITICAL RDW 18.8 10.0 - 14.5 % H MCH 18.7 28.0 - 32.0 pg CRITICAL MCHC 299 310 - 360 g/L L MPV 9.5 5.0 - 15.0 fL

What is your Differential of Microcytic Anemia?

Thalassemia Anemic of Chronic Disease (ACD)

Hepcidin prevents eggress of iron from enterocytes Reduced RBC lifespan Inflammatory cytokines interfere w/ Epo prodn

Iron Deficiency 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 18-45LR 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)

Normal (20-40%)

Iron def: serum Fe TIBC %saturation

ACD: serum Fe N or TIBC %saturation

Serum Iron

Cannot R/O Fe def

TIB

C (

Tra

nsfe

rrin

)

The Blood Film

http://meds.queensu.ca/medicine/deptmed/hemonc/macro/slide14.html

Red Blood Cell

Platelet

White Blood Cell

Hypochromic (1/3), microcyticLow HbLow MCVHigh RDW

Pencil cell

Case #1

Case #1

Once you have diagnosed iron deficiency, what is next most important issue to answer?

A. Does the patient have malabsorption of iron or a poor diet?

B. Does the patient have a source of blood loss?

C. Does the patient have chronic vs acute iron deficiency?

D. 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

30mg/300mg Ferrous sulfate 60mg/300mg Ferrous fumarate 100mg/300mg Proferrin 11mg po BID Feramax 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 92 130 - 180 g/L L WBC Count 10 4.0 - 11.0 x10E9/L Platelet Count 250 150 - 400 x10E9/L Neutrophils 7.0 2.0 - 7.5 x10E9/L Lymphocytes 3.0 1.0 - 4.0 x10E9/L Monocytes 1.2 0 - 1.0 x10E9/L H Eosinophils 0.0 0 - 0.7 x10E9/L Basophils 0.0 0 - 0.3 x10E9/L Hematocrit .294 0.390 - 0.540 L/L L RBC Count 4.71 4.00 - 6.00 x10E12/ L MCV 78 78 - 96 fL L RDW 13 10.0 - 14.5 % MCH 18.7 28.0 - 32.0 pg MCHC 299 310 - 360 g/L L MPV 9.5 5.0 - 15.0 fL

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)

Iron deficiency anemia

Anemia of chronic disease

Thalassemia minor

Blood film Hypochromia, pencil-shaped forms

Variable Uniform size, target cell

Ferritin (12 – 192 g/L)

< 40 g/L High Normal

Serum Iron (10 - 30 mol/L)

< 10 mol/L Low Normal

Transferrin saturation (0.20 - 0.50)

< 15% Normal Normal

Total iron-binding capacity (42 – 72 mol /L)

> 72 mol/L Low Normal to high

Reticulocytes 30 - 90) E9/L

Low Low Normal to high

Red cell distribution (11.0 - 15.0) %

> 14.5% Normal Normal

Mean corpuscular volume (82.0 - 97.0 fL)

< 80 fL 80 – 100 fL Out of proportion low

Red blood cell 4.30 - 5.60 E12/L

Low – normal Normal Normal to high

Mean cell hemoglobin (27.0 - 32.0 pg)

Low Low Low

Hemoglobin (115 - 155 g/L)

< 120 g/L in women < 130 g/L in men

Low Variable

Soluble transferrin receptor (10-30 nmol/L)

> 30 nmol/L < 30 nmol/L 10-30 nmol/L

Serum hemoglobin electrophoresis

Normal Normal Variable†

Clues to Microcytic Anemia

MCV < 80 fl Serum IronTIBC /Serum

IronBM Perls stain

Iron Def. Anemia ↓↓↑↑ /LOW

0

Chronic Infection ↓↓

↓↓/Low or Norma

l

+ +

Thalassemia ↑↑ N + + + +

Hemoglobinopathy

N N + +

Lead poisoning N N + +

Sideroblastic ↑↑ N + + + +

Anemia of Chronic Disease 1) Iron restricted erythropoiesis2) Blunted erythropoietin response

Andrews. Blood 2008;112:219

IL-6Lipopolysaccharide

sInflammation

↓Oral absorption

Iron trapping within RES

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

Hyperthyroism - treated with radioactive iodine

Ulcerative colitis (mild) Meds:

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

Low HbMCV 120

Hypersegmentedneutrophil (>5 lobes)

Seen with Megaloblastic Anemias

Case #3

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 Treated with mastectomy and chemotherapy

8 years agoAwaiting CABG for CAD

Hb 95 MCV 105 Surgeon notes that she was started on

iron p.o. for a Hgb of 109 g/ L.

CBC (incl platelet Count) Hemoglobin 95 130 - 180 g/L L WBC Count 2.5 4.0 - 11.0 x10E9/L Platelet Count 72 150 - 400 x10E9/L L Neutrophils 0.8 2.0 - 7.5 x10E9/L CRITICAL Lymphocytes 1.0 1.0 - 4.0 x10E9/L L Monocytes 0.7 0 - 1.0 x10E9/L Eosinophils 0.0 0 - 0.7 x10E9/L Basophils 0.0 0 - 0.3 x10E9/L Hematocrit .294 0.390 - 0.540 L/L L RBC Count 4.71 4.00 - 6.00 x10E12/ L MCV 105 78 - 96 fL H RDW 12 10.0 - 14.5 % MCH 18.7 28.0 - 32.0 pg CRITICAL MCHC 299 310 - 360 g/L L MPV 9.5 5.0 - 15.0 fL

Case #4

How would you manage this patient?A. Start i.v. iron as she has not had response to

oral ironB. Check her RBC folate and vitamin B12

stores; then replaceC. Refer to a hematologist for further

evaluationD. 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 HbMCV 105

Pelger-Huet anomaly(dumb-bell nucleus)

Seen with MDS

Case #4

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 Elevated

Generalized DisordersAnemia of Chronic DiseaseRenal dysfunctionEarly/combined nutritional deficiencies

Primary bone marrow disordersMarrow infiltration/infectionAplastic anemiaMDS

Evidence of Hemolysis?

(LDH, bilirubin, haptoglobin)

No Hemolysis Hemolytic Anemia

Intrinsic & Extrinsic causesBlood Loss

Hemolytic Anemia(LDH, bilirubin,

haptoglobin)

Intrinsic Causes

MemebranopathiesHereditary SpherocytosisHereditary eliptocytosis

EnzymopathiesG6PD DeficiencyPK Deficiency

HemoglobinopathiesSickle cell

Extrinsic Causes

Immune MediatedAutoimmune Hemolytic Transfusion reaction

Microangiopathic Hemolytic Anemia (MAHA)TTP/HUSDICMechanical heart valve

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 HbNormal MCV

HemoglobinopathySickle 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

Spherocytes – round RBC lacking central pallor

Spherocytes DDx:Immune mediatedHereditary spherocytosis

Case #5

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

What is her most likely diagnosis?

A. Warm Autoimmune Hemolytic anemia

B. Oxidative hemolysisC. Acute blood lossD. Disseminated Intravascular

CoagulationE. 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 AlgorithmAnemia

MCV

Microcytic: Normocytic: Macrocytic:Iron Deficiency (next page) MegaloblasticThalassemia - Folate, B12Anemia of chronic disease DrugsSideroblastic anemia Myelodysplasia

AlcoholLiver DiseaseReticulocytosisThyroid disease

Anemia AlgorithmAnemia

MCV

Microcytic: Normocytic: Macrocytic:Iron Deficiency (next page) MegaloblasticThalassemia - Folate, B12Anemia of chronic disease DrugsSideroblastic anemia Myelodysplasia

AlcoholLiver DiseaseReticulocytosisThyroid disease

Blood film Blood film examSerum ferritin, iron studies (Serum B12)Hgb electrophoresis RBC folate

Liver enz, TSHRetic count

NormocyticRetic Count

Low: High:

Generalized Disorders- Anemia of chronic disease Hemorrhage- Chronic renal failure Hemolysis- Nutritional deficiencies (Hematinic)- Toxins, drugsPrimary Bone marrow- Hematologic- Infiltration/Infection

NormocyticRetic Count

Low: High:

Generalized Disorders- Anemia of chronic disease Hemorrhage- Chronic renal failure Hemolysis- Nutritional deficiencies (Hematinic)- Toxins, drugsPrimary Bone marrow- Hematologic- Infiltration/Infection

Blood film Bili, LDHFerritin, Iron studies HaptoglobinCreatinineTSH, B12Exam/Abdom. ultrasound

NormocyticRetic Count

Low: High:

Generalized Disorders- Anemia of chronic disease Hemorrhage- Chronic renal failure Hemolysis- Nutritional deficiencies (Hematinic)- Toxins, drugsPrimary Bone marrow- Hematologic- Infiltration/Infection

Blood film Bili, LDHFerritin, Iron studies HaptoglobinCreatinineTSH, B12Exam/Abdom. ultrasound Direct Antiglobulin Test

When to refer to Hematology?

Anemia with Thrombocytopenia Leukopenia Macrocytic Anemia Evidence of hemolysis Red cell fragmentation

Anemia with Hb < 100

Conclusions

Many types of anemia have a “non-hematologic 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