Plasma cells are a type of white blood cell that are responsible for producing immunoglobulins or antibodies. They are an important part of our acquired immune system.
The B lymphocyte is then stimulated into converting into a plasma cell. In turn, this plasma cell then begins to devote all of its energy toward producing proteins called immunoglobulins or antibodies that are targeted toward that specific antigen. These immunoglobulins have the ability to destroy the invaders directly.
When our body is exposed to the same antigen again in the future, the plasma cells will remember the invader and be able to quickly produce more antibodies against it.
In myeloma, the cancerous cell is the plasma cell. An abnormal amount of a single clone of plasma cell is produced, leading to uncontrolled release of a particular immunoglobulin protein.
Otto, S. Protective Mechanisms. in Otto, S. ed (2001) Oncology Nursing 4th ed. Mosby:St. Louis. (pp. 917-948).
Williams, L. “Comprehensive Review of Hematopoiesis and Immunology: Implications for Hematopoietic Stem Cell Transplant Recipients” in Ezzone,S. (2004) Hematopoietic Stem Cell Transplantation: A Manual for Nursing Practice. Oncology Nursing Society. Pittsburg, PA (pp.1-13).