CD38 is a 46 kDa type II transmembrane glycoprotein with a short N-terminal cytoplasmic tail (20 amino acids) and a long extracellular domain (256 amino acids). CD38 is expressed by a variety of leukocytes, including plasma cells (which show the highest levels of expression), immature and mature B and T cells, NK cells, monocytes, macrophages, and myeloid progenitors. It has enzymatic activity as a cyclic ADP ribose hydrolase, which contributes to the regulation of intracellular calcium. The ligand of CD38 is CD31. In mature B cells, CD38 expression is induced once naive B lymphocytes are activated, reaches a first peak when B cells enter the germinal center, decreases during centrocyte/centroblast differentiation, is completely absent in memory B cells, and reaches its maximum levels as B cells terminally differentiate to plasma cells. In HIV, increased T-cell CD38 expression is associated with disease progression. CD38 expression has been described in some non-hematopoietic tissues.
Subcellular Localization: Membranous
Disease State: Acute Myeloid Leukemia (AML) / Myeloid Sarcoma, B Cell NHL with Plasmacytoid Differentiation, Burkitt's Lymphoma, Chronic Lymphocytic Leukemia / Small Lymphocytic Lymphoma (CLL/SLL), HIV-Associated Lymphoma, Lymphoplasmacytic Lymphoma, Plasma Cell Myeloma/Neoplasm, Precursor B-Lymphoblastic Lymphoma/Leukemia (B-ALL)
CPT Code(s): 88342 or 88341
Turnaround Time: Within 1-2 business days of receipt
Schedule: Monday - Friday
• Formalin-fixed, paraffin-embedded (FFPE) tissue block or cell block - OR -
• 1 unstained slide for each test requested plus 3-4 additional unstained slides cut at 4µm