CD138

CD138 is a protein found on the surface of certain cells in the body. It plays a role in cell communication and adhesion, which means it helps cells stick together and send signals to each other. This protein is also known as syndecan-1.

What types of cells and tissues normally express CD138?

CD138 is normally found on the surface of:

• Plasma cells: These are a type of white blood cell that produces antibodies to help fight infections.
• Epithelial cells: These cells line the surfaces and cavities of many organs, including the skin, intestines, and respiratory tract.

How do pathologists test for CD138?

Pathologists use a technique called immunohistochemistry (IHC) to test for CD138. Here’s a simple explanation of how it works:

• Sample preparation: A small tissue sample is taken from the body and placed on a glass slide.
• Antibody application: A special solution containing antibodies that specifically bind to CD138 is applied to the tissue sample.
• Detection: If CD138 is present, the antibodies will stick to it, and a chemical reaction will cause a color change in those areas. This makes it easy to see where this protein is located in the tissue.
• Results reporting: The pathologist examines the stained tissue under a microscope and reports whether CD138 is present and, if so, how much of it there is. Cells that express CD138 will be described are typically described as positive, while those that do not are described as negative.

What types of malignant (cancerous) tumours express CD138?

Several types of malignant (cancerous) tumours express CD138, including:

• Plasma cell neoplasm and multiple myeloma: These are cancers made up of plasma cells that commonly show high levels of CD138.
• Certain carcinomas: These are cancers that arise from epithelial cells, such as those found in the breast, prostate, colon, skin, and liver. Some of these cancers can express CD138.