Complete Blood Count

WBC: 4,000 – 11,000/cubicmm

WBC DIFFERENTIAL: Neutrophil 40-75% Lymphocytes 15-75% Monocytes 1-10% Eosinophils 1-6% Basophils 0-2%

Normal Ranges

Test examples of causes of

a low countexamples of causes of a high

count

White Blood

Cell Count

Known as leukopeniaor damage

•Autoimmune conditions•Severe infections (sepsis)•lymphoma or other cancer that spread to the bone marrow•Diseases of immune system (e.g., HIV)

Known as leukocytosis

•infections most commonly bacterial or viral•Leukemia, myeloproliferative disorders•inflammation•Allergies , Asthma•Tissue death (trauma, burns, heart attack)•Intense exercise or severe stress

TestFull Nameexamples of causes of a low count

examples of causes of a high count

Neu, PMN, polys

Absolute neutrophil count, % neutrophils

Known as neutropenia

•Severe,over whelming infection (sepsis)

•Autoimmune disorders

•Reaction to drugs, chemotherapy

•Immunodeficiency

•Bone marrow damage (e.g., chemotherapy, radiation therapy)

Known as neutrophilia

•Acute bacterial infections

•Inflammation

•Tissue death (necrosis) caused by trauma, heart

attack, burns

•leukemia

eosAbsolute eosinophil

count, % eosinophils

 not medically significant. Parasitic infections, asthma,allergic reaction.

basoAbsolute basophil count, % basophils

not medically significant bone marrow related conditions such as leukemia

or lymphoma

TESTFull Nameexamples of causes of a low count

examples of causes of a high count

monoAbsolute monocyte 

count, % monocytes

not medically significant. bacterial infection, tuberculosis, malaria, monocytic leukemia

lymphoAbsolute 

Lymphocyte count, % lymphocytes

Known as lymphocytopenia

•Autoimmune disorders (e.g., lupus rheumatoid

arthritis)

•Infections (e.g., HIV, viral hepatitis , typhoid fever, influenza)

•Bone marrow damage (e.g., chemotherapy, radiation

therapy)

•Corticosteroids

Known as lymphocytosis

•Acute viral infections (e.g., chicken

pox,cytomegalovirus (CMV), Epstein-Barr virus

(EBV),herpes)

•Certain bacterial infections (e.g. tuberculosis

•Lymphocytic leukemia, lymphoma

•Stress (acute)

Complete Blood Count :

Hb, RBC, MCV, MCH, MCHC, WBC & Diff, Platelet, Reticulocyte

Anemia

• Anemia: RBC mass• ed level of Hb more than 2SD of mean normal of Hb

according to age

Age Hb level • New born <13 gr/dl• 2-3 months < 9 FT

< 7 premature

• 6m-2y <9.5• 2y – 6 years old <10.5• 6 – 12 y/o <11.5• >12 y/o Male < 14

Female < 12

MCV•Mean corpuscular volume: 100 (fl)

•Age: 2-10 y/o MCV= Age (year) + 70

•Age ≥ 10 y/o MCV < 80: Microcytosis MCH•Mean corpuscular hemoglobin: 100 (Pg)

•More sensitive than MCV

• MCH 25- 27 hypochromia

Rbc

HCT

Calculating the Hematocrit

• More commonly the Hct is calculated directly from the RBC and MCV• Hematocrit % = RBC (cells/liter) x MCV (liter/cell)

• Because the Hct is a derived value, errors in the RBC or MCV determination will lead to false results

Mean Corpuscular Volume

• The MCV is a measure of the average volume, or size, of an RBC

• It is determined by the distribution of the red blood cell histogram• The mean of the red blood cell distribution histogram is the

MCV

Cell Size (fl)

Number Of cells

60 120

MCV

RBC Distribution Histogram

Use of MCV Result

• The MCV is important in classifying anemias

• Normal MCV = normocytic anemia

• Decreased MCV = microcytic anemia

• Increased MCV = macrocytic anemia

Cell Size (fl)

Number Of cells

60 120

MCV

RBC Distribution Histogram

Microcytic Red blood cells

MacrocyticRed blood cells

MCHC

• Mean corpuscular hemoglobin concentration:

100 100

• It is important in diagnosis of congenital Spherocytosis (MCHC > 35)

:Rbc

Hb

Rbc

HCT

PCV or Hematocrit

• 57% Plasma

• 1% Buffy coat – WBC

• 42% Hct (PCV)

Measurement Normal Range

A. RBC count 5 million 4 to 6

B. Hemoglobin 15 g% 12 to 17

C. Hematocrit 45 38 to 50

A x 3 = B x 3 = C - This is the rule of thumb

Check whether this holds good in given results

If not -indicates micro or macrocytosis or hypochro.

RETICULOCYTE COUNT%

NormalLess than

2%

• ‘RBC to be’ or Apprentice RBC

• Fragments of nuclear material

• RNA strands which stain blue

The reticulocyte count

• Increased reticulocytes (greater than 2-3% or 100,000/mm3 total) are seen in blood loss and hemolytic processes, although up to 25% of hemolytic anemias will present with a normal reticulocyte count due to immune destruction of red cell precursors.

• Retic counts are most helpful if extremely low (<0.1%) or greater than 3% (100,000/mm3 total).

• To be useful the reticulocyte count must be adjusted for the patient's hematocrit.

Thus:

• Corrected retic. = Patients retic. x (Patients Hct/45)

• Reticulocyte index (RPI) = corrected retic. count/Maturation time

(Maturation time = 1 for Hct=45%, 1.5 for 35%, 2 for 25%, and 2.5 for 15%.)

• Absolute reticulocyte count = retic x RBC number.

Red Cell Size

Microcytic

MCV

Normocytic Macrocytic

Iron Deficiency IDA

Chronic Infections

Thalassemias

Hemoglobinopathies

Sideroblastic Anemia

Chronic disease

Early IDA

Hemoglobinopathies

Primary marrow disorders

Combined deficiencies

Increased destruction

Megaloblastic anemias

Liver disease/alcohol

Hemoglobinopathies

Metabolic disorders

Marrow disorders

Increased destruction

• Classification by Pathophysiology • Blood Loss

• Decreased Production

• Increased Destruction

• Classification by Morphology• Normocytic

• Microcytic

• Macrocytic

RDW

• Red cell distribution width = anisocytosis

• RDW = 11-14.5%

• IDA: RDW

• -thalassemia minor: RDW

The platelet count is the number of platelets in a person's sample of blood.

Mean platelet volume (MPV) may be reported with a CBC. It is a calculation of the average size of platelets.

Platelet distribution width (PDW) may also be reported with a CBC. It is a measurement of the variation of platelet size.

• Platelet count : 140,000 to 450,000 /cubic mm

• Mean platelet volume: 7.5 – 11.5 fL

• Platelet distribution width: 10% - 17.9%

Testexamples of causes of low result

examples of causes of high result

Platelet Count

Known as thrombocytopenia:•Viral infection (mononucleosis,hepatitis)•Rocky mountain spotted fever•Platelet autoantibody•acetaminophen, quinidine, sulfa •cirrhosis•Autoimmune disorders•Sepsis•Leukemia, lymphoma•Myelodysplasia•Chemo or radiation therapy

Know as thrombocytosis:•Cancer (lung, GI,lymphoma)•Rheumatoid arthritis, IBD, lupus•IDA•Hemolytic anemia•Myeloproliferative disorder (essential thrombocythemia)

TestExamples of causes of

low resultExamples of causes

of high result

Mean Platelet Volume

Indicates average size of platelets is small; older

platelets are generally

smaller than younger ones and a low MPV may mean

that a condition is affecting the production of platelets by the bone marrow.

Indicates a high number of larger, younger platelets in the blood; this may be due to the bone marrow producing and releasing

platelets rapidly into circulation.

Platelet Distributio

n Width

Indicates uniformity in size of platelets

Indicates increased variation in the size of the platelets, which may mean that a condition is present that is affecting platelets