CD45RO Absolute Count Unit Converter

CD45RO Absolute Count measures the number of memory T cells in your blood. These are immune cells that have previously encountered a specific pathogen or antigen and "remember" it, allowing a faster and stronger immune response upon re-exposure.

CD45RO is a form of the CD45 protein found on the surface of T cells that have been activated by an antigen. Naive T cells that have never encountered a pathogen express a different form called CD45RA instead. When a naive T cell meets its target antigen, it switches from CD45RA to CD45RO, marking it as an experienced memory cell.

This marker is typically reported alongside CD45RA (naive T cells) as part of a lymphocyte subset panel, giving a picture of how your adaptive immune system is balanced between experienced and inexperienced T cells.

Memory T cells originate in the thymus as naive T cells, then mature into CD45RO+ memory cells in lymph nodes and tissues after encountering their target antigen. Once formed, they circulate in the blood and persist in tissues throughout the body, including the spleen, bone marrow, and mucosal surfaces.