CD45


September 24, 2023


CD45, also known as leukocyte common antigen (LCA), is a protein that is expressed on the surface of all hematopoietic cells and their progenitors, except erythrocytes (red blood cells) and platelets. Hematopoietic cells include cells of the immune system, such as B cells, T cells, natural killer (NK) cells, monocytes, and granulocytes. CD45 is a type of protein called a tyrosine phosphatase. It plays a critical role in regulating cell signaling pathways that are important for immune cell activation and differentiation.

How is CD45 used in pathology?

In pathology, CD45 is used as a marker of hematopoietic cells and it helps to identify hematopoietic cells such as T cells and B cells in tissue samples. Common tests performed to look for this protein in a tissue sample include immunohistochemistry and flow cytometry.

What types of tumours are positive for CD45?

Most types of lymphomas (cancers made up of immune cells) are positive for CD45. In contrast, other types of cancer including carcinomas and sarcomas are typically negative for this protein.

About this article

This article was written by doctors to help you read and understand your pathology report. Contact us if you have questions about this article or your pathology report. For a complete introduction to your pathology report, read this article.

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