Interpretation and Reporting of Complete Blood Cell Count (CBC) Results

Quality Assurance and Interpretation

For accurate interpretation, CBC results should be evaluated against established reference ranges, which may vary by laboratory, age, and sex, as recommended by the Centers for Disease Control and Prevention (CDC) 1
Automated differentials should achieve at least 90% lymphocyte purity within the lymphocyte gate (minimally 85%) to ensure accurate results, according to the CDC guidelines 2
The sum of CD3+CD4+ and CD3+CD8+ cells should equal the total CD3+ cells within ±5% (maximum variability ≤10%) for reliable results, as stated by the CDC 3

CBC results should include both percentages and absolute counts when available, as recommended by the CDC 1
Data should be reported with corresponding reference limits of expected normal values, according to the CDC guidelines 5
Absolute lymphocyte subset values should be calculated by multiplying the lymphocyte subset percentage by the absolute number of lymphocytes from the WBC and differential, as stated by the CDC 1

CBC with differential is recommended as baseline monitoring before initiating certain medications, such as biologics for psoriasis treatment, as suggested by the American Academy of Dermatology 4