Week 2 - Full Blood Count (FBC) Overview

Overview of Full Blood Count (FBC)

• Definition: A Full Blood Count (FBC) is a comprehensive test that evaluates various components of blood, providing essential information regarding overall health and potential medical conditions.

• Importance: It helps in diagnosing diseases, monitoring health, and guiding treatment decisions. Indicators such as anemia, infection, or malignancy can be detected through FBC results.

Traditional FBC Parameters

1. White Blood Cells (WBC)

   • Includes differential counts: Neutrophils, Lymphocytes, Monocytes, Eosinophils, Basophils.

2. Red Blood Cells (RBC)

   • Hemoglobin (Hb): Concentration of hemoglobin in the blood.

   • Hematocrit (Hct): Proportion of blood volume that is made up of red blood cells (calculated as RBC x MCV/1000).

   • Mean Cell Volume (MCV): Average volume of a red blood cell.

   • Mean Cell Hemoglobin (MCH): Average amount of hemoglobin per red blood cell, expressed in picograms.

   • Mean Corpuscular Hemoglobin Concentration (MCHC): Average concentration of hemoglobin in a given volume of packed red blood cells.

3. Platelets: Essential for blood clotting.

Normal Ranges (for Adults)

• WBC: 4.0 – 10.0 x 10^9/L

• Hemoglobin: 115 – 160 g/L (Female), 125 – 180 g/L (Male)

• Platelets: 150 – 400 x 10^9/L

• RBC: 3.5 – 5.5 x 10^12/L (Female), 4.2 – 6.2 x 10^12/L (Male)

• Hematocrit: 0.350 – 0.460 L/L (Female), 0.390 – 0.520 L/L (Male)

• Mean Cell Volume (MCV): 78 – 98 fL

• Mean Cell Hemoglobin (MCH): 25.0 – 33.0 pg

• Mean Corpuscular Hemoglobin Concentration (MCHC): 315 – 360 g/L

Additional Parameters

• Red Cell Distribution Width (RDW): Variation in red blood cell volume.

• Immature Granulocyte Count: Presence of immature white blood cells.

• Nucleated RBC Count: Indicates the presence of immature red blood cells.

• Reticulocyte Count: Indicates bone marrow function and production of new RBCs.

• Alerts for Abnormalities: Flags for abnormal cells, e.g., blasts and unusual lymphocytes.

History of Blood Cell Observation

• Significant historical advancements in the knowledge of blood cells include:

  • 1678: RBCs described by Jan Swammerdam.

  • 1843: WBCs identified by Gabriel Andral and William Addison.

  • 1865: Platelets discovered by Max Schultz.

  • 1874: Haemocytometer slide invented for cell counting.

  • 1953: First electronic particle counter created by Wallace Coulter.

Manual Cell Counting Methodology

• Haemocytometer Slide: A microscope slide used to count cells manually. Considerations include cell types (RBC, WBC, Platelets) and dimensions for proper calculation.

21st Century Methodology

Benefits of Automation

• Capacity: Increased workload capabilities.

• Time Efficiency: Faster results.

• Accuracy: Reduced human error, improved precision.

• Cost: Potential long-term savings through efficiency.

Principles of Cell Counting Automation

1. Aperture Impedance: Measures changes in electrical impedance across a small aperture when cells pass through, indicating size and number of particles.

2. Optical Methods: Utilizes light scattering to determine cell count and characteristics.

Optical Counting Methodology

• Cells scatter light differently based on size and composition. Light pulses correlate with cell counts and can indicate additional information, such as hemoglobin concentration in RBCs.

FBC Interpretation

• Example patient cases illustrate normal ranges and highlight deviations from normal indicating potential medical issues (e.g., anemia, leukocytosis).

• Sample case interpretations:

  • Patient A: High WBC and low Hb suggesting possible infection.

  • Patient B: Low RBC and Hb indicating anemia.

  • Patient C: Elevated platelets indicating potential clotting issues.

Conclusion: Understanding FBC parameters, methodology, and interpretation is crucial for clinical diagnostics and monitoring health conditions. Automating these processes enhances efficiency and accuracy in laboratories.