Absolute Lymphocyte Count of 3.4 × 10⁹/L Interpretation
An absolute lymphocyte count (ALC) of 3.4 × 10⁹/L (3,400 cells/μL) falls within the normal reference range for adults and does not indicate lymphocytosis or require immediate further investigation in most clinical contexts. 1
Normal Reference Range
- The normal ALC in adults typically ranges from 1.0-4.8 × 10⁹/L (1,000-4,800 cells/μL), making your value of 3.4 well within expected limits 1
- This value represents a physiologically normal lymphocyte count that requires no specific intervention 1
When Further Evaluation Is NOT Indicated
Your ALC of 3.4 does not meet any threshold requiring additional workup:
- For chronic lymphocytic leukemia (CLL) diagnosis, the ALC must exceed 5.0 × 10⁹/L of mature-appearing lymphocytes, which is substantially higher than your value 2, 1
- For patients under 75 years old, flow cytometry screening is not recommended below 4.4 × 10⁹/L 3
- For patients 75 years and older, the threshold for further evaluation is 4.0 × 10⁹/L 3
- Your value of 3.4 falls below all established thresholds for concern 3
Clinical Context Considerations
Avoid over-interpreting this isolated normal laboratory value without clinical symptoms or other abnormalities:
- The American Society of Hematology recommends against reflexive investigation of normal values in asymptomatic patients 1
- Serial measurements may be more informative than a single value if there are specific clinical concerns about disease progression or immune status 1
- Biologic variability in ALC can be substantial, with approximately 10% diurnal variation and 13% week-to-week variation 2
Important Caveats
Laboratory and biologic variability should be considered:
- Automated lymphocyte counts have analytical variability of 1.9-5.3%, while manual counts vary 12.5-27% 2
- The absolute lymphocyte count reflects combined variability from WBC count and differential count 2
- A single normal value does not exclude underlying pathology if clinical suspicion exists based on symptoms, physical examination findings, or other laboratory abnormalities 1