Plasma Cell / Prognostic CLL Marker : CD 38

CD38 is a surface protein measured by flow cytometry on chronic lymphocytic leukemia (CLL) cells. Higher CD38 expression identifies a more aggressive disease subtype linked to faster progression and shorter survival, making it a prognostic—not diagnostic—marker. It is used alongside IGHV mutation and ZAP‑70 status to stratify risk and guide monitoring and treatment decisions, though cutoff values (commonly around 30%) vary by laboratory.

CD38 positive means cells express the CD38 surface protein. It helps identify cell types (notably plasma cells) and indicates immune activation. In blood cancers, CD38 positivity aids diagnosis and classification, can signal more aggressive behavior in conditions like CLL, and is a therapeutic target (for example, in multiple myeloma). Interpretation depends on clinical context.

CD38-positive plasma cells are mature antibody-secreting B lymphocytes that express high levels of the surface glycoprotein CD38. They reside mainly in bone marrow and secondary lymphoid tissues, produce immunoglobulins, and contribute to immune activation, adhesion, and calcium signaling. High CD38 expression helps diagnose plasma cell disorders and serves as a therapeutic target in conditions like multiple myeloma.

Chronic lymphocytic leukemia cells typically co‑express B‑cell markers with CD5: CD19+, CD20 (usually dim)+, CD5+, CD23+. They commonly express CD43+ and CD200+, with surface immunoglobulin (sIg) and CD79b typically weak/low. CD38 can be variably positive. These markers are detected by flow cytometry and used diagnostically and have prognostic relevance in CLL.

CD38 is a surface glycoprotein expressed on plasma cells, activated T and B lymphocytes, natural killer cells and some myeloid cells. It functions in cell adhesion, signal transduction and cyclic ADP‑ribose metabolism. Clinically, CD38 is used as a diagnostic and prognostic marker for plasma cell disorders (eg, multiple myeloma), to characterize leukemias/lymphomas, monitor minimal residual disease, and as a therapeutic target.

CD38 and CD138 are surface markers used to identify plasma cells. CD138 (syndecan‑1) marks mature, bone‑marrow–resident plasma cells and supports adhesion/survival, so it’s relatively specific. CD38 is an ectoenzyme highly expressed on plasma cells and activated B cells but also on other leukocytes, making it less specific. In practice both (CD38high/CD138+) are used together to reliably identify plasma cells.