What is the purpose of ordering a WBC differential?

The purpose of ordering a white blood cell (WBC) differential is to analyze the various types of white blood cells present in the blood, particularly when there is an abnormality noted in the total white blood cell count during a complete blood count (CBC). This differential provides critical insights into a patient's immune status and can help differentiate between various conditions such as infections, inflammatory diseases, allergies, and hematological disorders.

When the total WBC count is abnormal, the differential can indicate which specific type of WBC is elevated or decreased. For example, an increase in neutrophils may suggest a bacterial infection, while a rise in lymphocytes might indicate a viral infection. The information gleaned from the differential helps healthcare providers diagnose and monitor various medical conditions, offering a deeper understanding of the patient's health landscape.

The other choices do not accurately reflect the specific use of a WBC differential:

• Assessing platelet levels pertains to thrombocytes and would require a different test focused on platelet count.

• Determining hemoglobin levels is related to red blood cells and is also assessed through a CBC but is not part of the WBC differential.

• Evaluating liver function involves tests that assess liver enzymes and function, which are unrelated to the WBC differential.

Thus,