Is an absolute lymphocyte count of 0.78 × 10⁹/L (≈ 780 cells/µL), given prior counts of 604 and 669 cells/µL, considered low?

Absolute lymphocyte count interpretation

An absolute lymphocyte count (ALC) of 0.78 × 10⁹/L (≈780/µL) is low for many adult reference cutoffs because adult lymphocytopenia is commonly defined as < 1.0 × 10⁹/L ( < 1000/µL ). [1]

Degree of abnormality

The prior ALC values of 604 cells/µL and 669 cells/µL meet the same commonly used low threshold. [1]

Reference range dependence

Whether the result is “low” can also depend on the laboratory’s own reference interval and the patient’s clinical context. [3]

Clinical significance considerations

Low ALC values are generally considered relevant when persistent or accompanied by clinical risk factors for immunodeficiency or secondary causes. [3]

Action thresholds for follow-up

Clinical follow-up is typically guided by persistence, severity, associated CBC abnormalities, and symptoms or exposures rather than ALC magnitude alone. [3]

Common immediate next steps

Recheck CBC with differential to assess persistence or trend, and correlate with recent infections, medications, and systemic illnesses that can lower lymphocyte counts. [3]