Complete Blood Count

From Anvita Health Wiki

Contents 1 Introduction 2 Reference-interval 3 Principle 4 Specimen 5 Interferences 6 More General Terms 7 References

Introduction

• Includes:

• White blood cell count (WBC)
• Hemoglobin (Hgb)
• Hematocrit ( Hct)
• Red blood cell count ( RBC)
• Red cell indices

• Mean corpuscular volume ( MCV)
• Mean corpuscular hemoglobin ( MCH)
• Mean corpuscular hemoglobin concentration ( MCHC)
• Red cell distribution width ( RDW)

• Platelet Count ( PLTS)
• White blood cell differential

• Segmented neutrophils ( SEGS)
• Bands
• Lymphocytes ( LYMPHS)
• Monocytes ( MONOS)
• Eosinophils (EOS)
• Basophils (BASO)

Reference-interval

* Component                 Reference Interval 
* WBC                       4.4-11.0 x 10E3/uL 
* Hgb (adult male)          14.0-17.5 g/dL 
*     (adult female)        12.3-15.3 g/dL 
* Hct (adult male)          41.5-50.4% 
*     (adult female)        35.9-44.6% 
* RBC (adult male)          4.5-5.9 x 10E6/uL 
*     (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

• clinical hematology test

References

1. Clinical Diagnosis & Management by Laboratory Methods, 19th edition, J.B. Henry (ed), W.B. Saunders Co., Philadelphia, PA. 1996
2. Medical Knowledge Self Assessment Program (MKSAP) 11, American College of Physicians, Philadelphia 1998
3. 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: [1]

complete blood count (CBC)