CD

Cluster of Differentiation
Other names	CD markers
Specialty	Immunology, Molecular biology

Cluster of Differentiation (CD) refers to a protocol used for the identification and investigation of cell surface molecules providing targets for immunophenotyping of cells. In the context of healthcare, CD markers are used extensively to classify the multiple facets of cell types in immunology. The CD system is commonly used in research and diagnostic contexts, particularly in the study of immune system disorders and cancer.

History

The CD system was first established in the early 1980s during a series of international workshops aimed at standardizing the classification of monoclonal antibodies generated against surface molecules of leukocytes. It was recognized that a unified nomenclature was necessary to categorize these antibodies.

Function

CD markers are used to identify different types of cells based on their specific surface molecules. Each CD marker (e.g., CD4, CD8) corresponds to a specific molecule that plays a role in immune function. These markers are crucial for the functioning of the immune system, including the activation and suppression of immune responses.

Clinical Significance

1. 1. 1. Immunodeficiency

CD markers are essential in diagnosing various types of immunodeficiency, such as HIV/AIDS, where CD4+ T-cell counts are crucial.

1. 1. 1. Autoimmune Diseases

In autoimmune diseases, abnormal expressions of CD markers may occur, and their study helps in understanding the disease mechanism.

1. 1. 1. Cancer

CD markers also play a role in the diagnosis and treatment of cancers, particularly in cases like leukemia and lymphoma, where cells express specific CD markers that can be targeted by therapies.

Research

In research, CD markers help in the identification and classification of the different cell types involved in immune responses and other biological processes. They are also vital in the development of new therapeutic strategies, including the creation of monoclonal antibodies that target specific CD molecules.

See Also

• Immunophenotyping
• Monoclonal antibodies
• Leukocytes