CD5positive

CD5 is a protein found on the surface of certain types of cells in the immune system, primarily T lymphocytes and B lymphocytes. When a cell expresses CD5 on its surface, it is referred to as CD5 positive. This marker plays a role in cell signaling and immune cell development and function.

In the context of blood cancers, CD5 positivity is a significant characteristic. Chronic lymphocytic leukemia (CLL) is a type of cancer where the malignant cells are almost always CD5 positive. This marker is routinely used in laboratory diagnosis to help identify and classify CLL cells, distinguishing them from other types of leukemia or lymphoma.

While CLL is the most common CD5 positive leukemia, other B-cell malignancies can also express CD5. These include mantle cell lymphoma and some cases of T-cell prolymphocytic leukemia. The presence or absence of CD5, along with other surface markers, is crucial for accurate diagnosis and treatment planning for these conditions. Research continues to explore the precise role of CD5 in normal immune responses and its contribution to the pathogenesis of CD5 positive malignancies. Understanding CD5 expression is a fundamental aspect of hematologic oncology.