From the Guidelines
White blood cell counts and individual WBC differentials are reported separately in laboratory results because they serve distinct diagnostic purposes, allowing healthcare providers to accurately diagnose conditions, monitor disease progression, and evaluate treatment effectiveness. The total white cell count provides an overall assessment of immune system activity, while the breakdown of specific cell types, known as a differential count, offers more detailed information about the nature of potential health issues [ 1 ]. For instance, elevated neutrophils often indicate bacterial infections, whereas increased lymphocytes may suggest viral infections. Eosinophil elevation might point to allergic reactions or parasitic infections, and monocytosis can occur with chronic infections or inflammatory conditions.
Key Points to Consider
- The combination of total count and differential is essential for proper clinical interpretation, as normal total counts with abnormal distributions of cell types can still indicate underlying health problems that would be missed by looking at the total count alone [ 1 ].
- Reporting both the proportion and absolute number of lymphocytes is desirable, especially in cases where prolymphocytes are present [ 1 ].
- Automated WBC counts and differentials are preferred, but manual differentials of at least 400 cells can be performed if the specimen is rejected or "flagged" by the instrument [ 1, 1 ].
Clinical Implications
The separate reporting of white blood cell counts and individual WBC differentials is crucial for accurate diagnosis and treatment planning. By considering both the total count and the differential, healthcare providers can identify potential health issues earlier and monitor disease progression more effectively. This comprehensive approach ultimately leads to better patient outcomes and improved quality of life [ 1 ].
From the Research
White Blood Cell Counts and Differentials
- White blood cell (WBC) counts and individual WBC differentials are reported separately in laboratory results to provide a comprehensive understanding of a patient's immune system and potential health conditions 2.
- The separate reporting of WBC counts and differentials allows for the identification of specific cell populations, such as neutrophils, eosinophils, monocytes, and lymphocytes, which can be indicative of various diseases or infections 3.
Clinical Significance of WBC Counts and Differentials
- Elevated WBC counts have been associated with increased mortality and morbidity in patients with acute coronary syndromes, as well as a higher risk of chronic kidney disease progression 4, 5, 6.
- Low WBC counts, on the other hand, have also been linked to adverse outcomes, including chronic kidney disease progression in the elderly 6.
- The reporting of WBC counts and differentials separately enables healthcare providers to assess the severity of a patient's condition and make informed decisions about treatment and management 2, 3.
Diagnostic and Prognostic Value
- WBC counts and differentials have diagnostic and prognostic value in various clinical settings, including the assessment of patients with suspected infections, acute coronary syndromes, and chronic kidney disease 3, 4, 5, 6.
- The use of flow cytometry, such as the Leukoflow assay, can provide additional information on specific cell populations and subsets, which can aid in the diagnosis and monitoring of certain conditions 2.