plasma cell
Meaning of plasma cell: A plasma cell is a mature immune cell derived from an activated B cell that manufactures large quantities of a specific antibody.
Definition of plasma cell
A plasma cell is a specialized immune cell that develops from a B cell, a type of white blood cell, after that B cell has been activated by encountering a specific foreign substance. Once fully developed, a plasma cell functions primarily as an antibody factory, producing large quantities of a single, specific antibody targeted against whatever triggered its activation.
Plasma cells are found mainly within lymphoid tissue and the bone marrow, and the antibodies they release circulate through the blood and other body fluids, where they help mark foreign invaders such as bacteria and viruses for destruction by other parts of the immune system. Unlike the B cells they arose from, mature plasma cells generally no longer display the same surface markers.
Because plasma cells are the source of circulating antibody, abnormal proliferation of plasma cells themselves, as occurs in multiple myeloma, can result in production of large amounts of a single, functionally abnormal antibody rather than the varied antibody response of a healthy immune system.
Also known as
Used in a sentence
Bone marrow biopsy revealed an abnormal increase in plasma cells consistent with multiple myeloma.
Good to know
Plasma cells are the mature, antibody-producing form of activated B cells, so a disorder involving plasma cells, such as multiple myeloma, reflects abnormal antibody production rather than a defect in the initial immune recognition step.
Word origin
Where “plasma cell” comes from
Plasma derives from Greek plasma, meaning something molded or formed.