CD23positive

CD23 positive refers to cells that express CD23 on their surface. CD23, also known as Fc epsilon receptor II (FcεRII) or the product of the FCER2 gene, is a transmembrane glycoprotein detected by antibodies used in flow cytometry and immunohistochemistry. Cells described as CD23-positive show a detectable level of this antigen, which helps define their immunophenotype in laboratory testing.

CD23 expression is most prominent on mature B lymphocytes and on certain dendritic cell populations. It can be upregulated on other leukocyte subsets, including activated T cells and monocytes, under specific stimuli. CD23 functions as a receptor for immunoglobulin E (IgE) and participates in the regulation of IgE synthesis and B cell growth. It also participates in immune regulation through its soluble form, soluble CD23 (sCD23), which is generated by proteolytic shedding and can influence allergic responses and antibody production.

In clinical immunology and hematopathology, CD23 positivity is used as part of immunophenotyping panels to classify B-cell neoplasms. It is commonly expressed in chronic lymphocytic leukemia (CLL) and in some cases of small lymphocytic lymphoma (SLL), where it supports a CLL/SLL phenotype. By contrast, mantle cell lymphoma is typically CD23 negative, which helps distinguish it from CLL/SLL in diagnostic workups. CD23 is often evaluated alongside other markers such as CD5, CD19, and CD20 to refine diagnosis and guide treatment decisions.

Measurement of CD23 can aid in prognosis and disease monitoring in certain contexts, and serum levels of sCD23 have been explored as biomarkers in allergy and some hematologic conditions.