Full or Complete Blood Count (FBC CBC)

Related Subjects: | Ferritin | CEA | ESR | CRP | ALP | LDH | HbA1c | Alpha Fetoprotein | Anti-Hu ab | Biochemical Lab values

About

• These are performed on automated equipment and provide haemoglobin concentration, red cell indices, white cell count (with a differential count) and platelet count. The presence of abnormal white cell and red cell morphology is flagged by the analysers.
• Blood films may be inspected to confirm and interpret abnormalities identified by the cell counter, or to look for certain specific haematological abnormalities.
• There is no need to request a blood film to obtain a differential white count. It is, however, important that clinical details are provided to allow the laboratory to decide whether a blood film, in addition to the automated analysis, is required.
• The normal range describes the range where 95% of the normal healthy population will lie. This also means that there is 5% of the normal healthy population will fall outside the "normal range", however they too are normal. Normal ranges are a guide. There are many instances where the FBC will fall outside the "normal range" and yet these could be described as totally normal for the given clinical situation
• Ethnicity can affect the WBC and platelet normal ranges. If the patient is Black Afro-Caribbean or Black African, the WBC and neutrophils count normal ranges are much lower. In these instances, the normal adult range must be interpreted depending on the patient's ethnic background.

Sample Requirements

• 2ml or 4ml EDTA sample Purple or Red tubes.
• Do not store, send to laboratory within 4 hours
• EDTA samples are retained for a minimum of 48 hours at 2-10 C

The FBC comprises the following tests

• Haemoglobin (Hb)
  • High: Polycythaemia
  • Low: Anaemia
• White Blood Count (WBC)
  • High: Leucocytosis
  • Low: Leucopenia
• Platelet Count (Plt)
  • High: Thrombocythaemia
  • Low: Thrombocytopenia
• Red Cell Count (RBC)
• Haematocrit (HCT)
• Mean Cell Volume - Red cell (MCV)
• Mean Cell Haemoglobin (MCH)

Differential White Cell Count (where applicable)

• Neutrophils : Bacterial and acute viral infections
• Lymphocytes : Viral infections, TB
• Monocytes : Bacterial, Viral, Autoimmune
• Eosinophils : Parasitic infections
• Basophils : Marrow related conditions