Maximum CD45 Count in Whole Blood (Absolute Lymphocyte Differential Component)

What Does This Test Measure?

CD45 is a glycoprotein present on nearly all white blood cells (leukocytes), including neutrophils, lymphocytes, monocytes, and others. This test specifically looks at the maximum concentration of CD45-positive cells detected during a blood analysis, often part of a complete blood count (CBC) or differential. The result helps doctors evaluate immune function, inflammation, or blood disorders by identifying the presence and proportion of different white blood cell types.

Why Might You Need This Test?

Doctors may order this test if you have symptoms like frequent infections, unexplained fatigue, or signs of a blood disorder. It can also be used to monitor conditions like leukemia, immune deficiencies, or chronic inflammatory diseases. Sometimes, it’s part of a broader evaluation for unexplained anemia or abnormal blood cell counts.

How Is the Test Performed?

A small amount of blood is drawn from a vein, typically in your arm. The sample is then analyzed in a lab to count and identify different white blood cell types, including CD45-positive cells. The test may be performed as part of a routine CBC or specifically requested if additional detail about white blood cell composition is needed.

What Are Common Uses?

This test is often used alongside other blood tests to diagnose or monitor conditions like infections, blood cancers (e.g., leukemia), immune disorders, or chronic diseases. It can also help track responses to treatments, such as chemotherapy or medications for autoimmune conditions.