CD 19
Part of Lymphocyte Activity Profile, Labcorp

Overview of CD19 CD19 is a protein that serves as a cell surface marker found on B-lymphocytes (B-cells), which are a type of white blood cell crucial to the adaptive immune system. As part of the B-cell receptor complex, CD19 functions as a co-receptor that enhances the sensitivity and response of B-cells to antigens. This protein plays a vital role in B-cell development, activation, proliferation, and differentiation. Key Functions of CD19 - B-cell Development: CD19 is expressed early in B-cell development and remains present throughout the lifespan of B-cells. It is essential for their proper maturation and function. - Signal Transduction: CD19 amplifies the signaling cascade initiated when the B-cell receptor (BCR) binds to an antigen. This amplification is critical for B-cell activation and the subsequent immune response. - Immune Response: By enhancing BCR signaling, CD19 aids B-cells in producing antibodies—proteins that specifically bind to and neutralize pathogens such as bacteria and viruses. Clinical Significance - Immunophenotyping: CD19 is utilized as a marker in flow cytometry and other immunophenotyping techniques to identify and quantify B-cells in blood and tissue samples. - Diagnosis and Monitoring: CD19 levels are important for diagnosing and monitoring certain hematologic malignancies, such as B-cell lymphomas and leukemias. Abnormal levels of CD19+ B-cells can indicate the presence and progression of these diseases. - Therapeutic Target: CD19 is a target for specific immunotherapies, including CAR-T cell therapy. In this treatment, a patient’s T-cells are genetically modified to express chimeric antigen receptors (CARs) that specifically target and kill CD19-expressing cancer cells. Summary CD19 is a critical marker and functional component of B-cells, playing a significant role in the immune response. Its presence on B-cells is leveraged in both diagnostic and therapeutic contexts to manage and treat various immune-related conditions and cancers.

Optimal range 5 – 20 % Learn more
CD 20
Part of Lymphocyte Activity Profile, Labcorp

Overview of CD20 CD20 is a cell surface protein primarily found on B-lymphocytes (B-cells), which are essential white blood cells in the adaptive immune system. CD20 plays a crucial role in regulating B-cell activation, growth, and differentiation, particularly in the immune response to pathogens. Key Functions and Clinical Importance of CD20 B-cell Development and Activation: CD20 is expressed during the early stages of B-cell development and remains present until the cells differentiate into plasma cells, which produce antibodies. It helps regulate calcium influx, which is critical for B-cell activation and function. Target for Immunotherapy: CD20 is a target for specific immunotherapy treatments, particularly for B-cell non-Hodgkin lymphomas and chronic lymphocytic leukemia (CLL). Monoclonal antibodies, such as rituximab, are designed to target CD20 and deplete B-cells, aiding in the treatment of these cancers. It is also utilized in treating certain autoimmune diseases, where reducing B-cell numbers can help control disease activity. Diagnostic Marker: CD20 is used as a marker in flow cytometry and immunohistochemistry to identify and quantify B-cells in various diagnostic tests. This application is useful in diagnosing and monitoring diseases like lymphomas, leukemias, and certain immune disorders. Research Applications: CD20 is widely studied in immunology and cancer research to understand B-cell biology and develop new therapeutic approaches. Monitoring CD20 levels and the presence of CD20+ B-cells can provide valuable insights into immune system functioning and the progression of certain diseases. In clinical settings, assessing CD20 expression helps guide treatment decisions and evaluate the effectiveness of therapies targeting B-cells. In summary, CD20 is a critical protein involved in B-cell development and function, with significant implications for immunotherapy, diagnostics, and research in immunology and cancer.

Optimal range 5 – 20 % Learn more