complete blood count (CBC)
Introduction
Includes:
- White blood cell count (WBC)
- Hemoglobin (Hgb)
- Hematocrit (Hct)
- Red blood cell count (RBC)
- Red cell indices
- Platelet Count (PLTS)
- White blood cell differential
- Segmented neutrophils (SEGS)
- Bands
- Lymphocytes (LYMPHS)
- Monocytes (MONOS)
- Eosinophils (EOS)
- Basophils (BASO)
Indications
- evaluation of hematologic disease
- evaluation of fever/infection
- evaluation of autoimmune disease
- evaluation of immunodeficiency
- evaluation of inflammatory disease
- evaluation of hemorrhage
- screening for anemia
- family history of hematologic disease
Reference interval
Table
| Component | Reference Interval | |
|---|---|---|
| WBC | 4.4-11.0 x 10E3/uL | |
| Hgb (adult male) | 14.0-17.5 g/dL | |
| Hgb (adult female) | 12.3-15.3 g/dL | |
| Hct (adult male) | 41.5-50.4% | |
| Hct (adult female) | 35.9-44.6% | |
| RBC (adult male) | 4.5-5.9 x 10E6/uL | |
| RBC (adult female) | 4.1-5.1 x 10E6/uL | |
| MCV | 80-96 um3 | |
| MCH | 27.5-33.2 pg | |
| MCHC | 33.4-35.5% | |
| RDW | 11.5-14.5% | |
| PLTS | 150-450 X 10E3/uL | |
| SEGS | 56% (1800-7800/uL) | |
| BANDS | 3% | (0-700/uL) |
| LYMPHS | 34% (1000-4800/uL) | |
| MONOS | 4% | (0-800/uL) |
| EOS | 2.7% (0-700/uL) | |
| BASO | 0.3% (0-200/uL) |
See specific component for pediatric reference intervals
Principle
Coulter counter
Aspirated (anticoagulated) blood is divided into 2 separate volumes. One volume is mixed with diluent & delivered to the cell bath where erythrocyte & platelet counts are performed. The other volume is mixed with diluent & a cytochemical- lytic agent that lyses erythrocytes for leukocyte determination.
The diluted blood specimens are passed through a narrow aperature where the electrical impedance is recorded. The size of the impedance change when a cell passes through the aperature is proportional to the cell size; the number of pulses is related to the cell count.
Particles measuring between 2 & 20 fL are counted as platelets & particles measuring > 36 fL are counted as erythrocytes in the first volume.
In the second volume, the erythrocytes have been lysed. Particles > 35 fL are counted as leukocytes.
Simulataneous measurement of high-frequency electromagnetic energy for nuclear constituents & laser scattering for cell shape & granularity are featured on newer Coulter models.
Specimen
- Whole blood (EDTA). Stable for 24 h at 4 C.
Interferences
- erythrocyte agglutination artifactually raises MCV, MCHC & RDW & lowers RBC count
- platelet aggregation may produce falsely low counts
- enhanced by chelating anticoagulants such as EDTA
- inadequate anticoagulation of blood
- erythrocyte fragments (hemolysis) or leukocyte fragments (leukemia) may provide falsely elevated platelet count
- nucleated RBC, malignant cells, platelet clumps or cryoglobulins may be counted as leukocytes
More general terms
Component of
- deprecated CBC with reticulocyte count
- renal function tests; renal function panel
- HIV panel
- general health panel
- enteral/parenteral nutrition management panel
- DIC panel
- hemolysis panel
- anemia panel
- obstetric panel HIV
- obstetric panel
Components
- basophils in blood
- eosinophils in blood
- monocyte count
- lymphocyte count
- neutrophil count
- white blood cell count (WBC with WBC differential)
- red blood cell count (RBC)
- hemoglobin (Hgb) in blood
- hematocrit (Hct) of blood
- mean corpuscular hemoglobin (MCH)
- mean corpuscular hemoglobin concentration (MCHC)
- red cell distribution width (RDW)
- mean corpuscular volume (MCV)
- platelet count
References
- ↑ Clinical Diagnosis & Management by Laboratory Methods, 19th edition, J.B. Henry (ed), W.B. Saunders Co., Philadelphia, PA. 1996
- ↑ Medical Knowledge Self Assessment Program (MKSAP) 11, American College of Physicians, Philadelphia 1998
- ↑ Tefferi A, Hanson CA, Inwards DJ. How to interpret and pursue an abnormal complete blood cell count in adults. Mayo Clin Proc. 2005 Jul;80(7):923-36. PMID: https://www.ncbi.nlm.nih.gov/pubmed/16007898