Hematology

Complete Blood Count (CBC)

The complete blood count (CBC) is probably one of the most frequently performed
lab tests. This test gives the physician a great deal of information about the
general health of the patient.

The complete blood count can help the physician
diagnose a large number of conditions, and aid in the ultimate diagnosis of
many other problems:

1. LEUKEMIA (white blood cell disorder)Complete Blood Count (CBC)
2. LYMPHOMA (white blood cell disorder)
3. ANEMIA (low hemoglobin and red cell count)
4. THROMBOCYTOPENIA (a low platelet count secondary to drug side effect,
vitamin deficiency, or bone marrow disease)
5. INFECTION (shows increase in white blood cells)
6. GENERAL INFLAMMATION (shows increase in white blood cells)
7. NEUTROPENIA (low white blood cell count)

This test is performed from a standard venipuncture specimen.

APPROXIMATE NORMAL VALUES (Adult)

Hemoglobin (grams/deciliter): 12-16 (Women) and 14-18 (Men)
Hematocrit (expressed as a percent of the blood volume that is occupied by red
blood cells):
Men 40% to 54%
Women 37% to 47%
Children 31% to 41%
Newborns 44% to 64%

White Blood Cell Count: 4,500 – 11,000 (per cubic millimeter). Slightly higher
counts are normal in children.

Causes of Low White Blood Cell Counts (Neutropenia):

1. Aplastic anemia
2. Leukemia
3. Myelodysplastic syndromes
4. Drug induced (chemotherapeutic agents, chloramphenicol, penicillins, sulfa
drugs, phenothiazines, and anti-inflammatory agents)
5. Nutritional deficiency (vitamin B12 and folate)
6. Infection (TB, measles, mononucleosis, viral hepatitis, malaria,
histoplasmosis, and HIV)
7. Autoimmune disease (lupus and rheumatoid arthritis)
8. Hemodialysis
9. Cardiopulmonary bypass
10. Overwhelming sepsis (bacterial infection in the bloodstream)
11. Myelofibrosis

Red Blood Cell Count: 4.6-6.2 million per cubic millimeter in Men and 4.2-5.4
million per cubic millimeter in Women.

RED BLOOD CELL INDICES

The following red blood cell indices are determined to help diagnose the cause
of anemia.

MCV = Mean Corpuscular Volume – This is a measurement of the size of an average
red cell. It is useful in the evaluation of anemia. Normal values should be
in the range of 80 – 96 cubic microns (cu u).
MCH = Mean Corpuscular Hemoglobin – This index describes the weight of
hemoglobin in an average red cell. Normal values should be in the range of 27 –
31 picograms (pg).
MCHC = Mean Corpuscular Hemoglobin Concentration – This index describes the
amount of hemoglobin in an average red cell. Normal values should be in the
range of 32% – 36%.

EXAMPLES

Iron Deficient Anemia Pernicious Anemia
MCV 60 – 80 cu u 95 – 150 cu u
MCH 5 – 25 pg 33 – 53 pg
MCHC 20% – 30% 33% – 38%

Platelet Count: 150,000-400,000 per cubic millimeter are considered a normal
range.

White Blood Cell Differential (percentages of the different types of white
blood cells that comprise the total white blood cell count):

Neutrophils 47% to 77% (elevated in infection, inflammation, and
stress)
Bands 0% to 3% (elevated in some cases of bacterial
infection)
Lymphocytes 16% to 43% (elevated in some cases of viral infection
and some leukemias)
Monocytes 0.5% to 10% (elevated in some viral and fungal
infections, lupus, cancer, and tuberculosis)
Eosinophils 0.3% to 7% (elevated in allergic conditions, some
cancers, some leukemias, and autoimmune disease)
Basophils 0.3% to 2% (elevated in some leukemias, some cancers,
and hypothyroidism)