CD45RA Absolute Unit Converter

CD45RA Absolute measures the number of naive lymphocytes in your blood that express the CD45RA surface marker. These are immune cells, primarily T cells, that have matured in the thymus but have not yet encountered a foreign antigen.

CD45RA is one of two major isoforms of CD45, a protein tyrosine phosphatase found on virtually all white blood cells. The other isoform, CD45RO, marks memory T cells that have already responded to an infection or vaccine. Together, the ratio of CD45RA to CD45RO reflects the balance between your immune system's capacity to respond to new threats and its memory of past ones.

The result is reported as the absolute number of CD45RA-expressing cells per microliter of blood (cells/µL), giving a direct count rather than a percentage.

Naive CD45RA-positive T cells originate from precursor cells in the bone marrow that migrate to the thymus, where they mature and are selected for the ability to recognise foreign antigens. Once released into the bloodstream, they circulate as part of the adaptive immune system until they encounter their specific antigen.