What is a plasma cell?

Plasma cells are terminally differentiated cells that play a crucial role in immune responses. Their primary function is to synthesize and secrete antibodies, thereby participating in immune regulation and inflammatory responses.

Plasma cells originate from B lymphocytes. Upon antigen stimulation, B lymphocytes become activated and proliferate under the assistance of helper T (Th) cells, subsequently differentiating into plasma cells. Most activated B lymphocytes differentiate into plasma cells, while a minority develop into memory B cells. Plasma cells are typically small, round or oval in shape. The nucleus is round and eccentrically located; chromatin is coarse and arranged radially along the nuclear membrane—resembling a “cartwheel” pattern. Finer granular or delicate reticular chromatin is evenly dispersed throughout the nucleus, which exhibits basophilia and stains blue with standard histological dyes.

Upon antigen stimulation, mature B cells become activated—with assistance from antigen-presenting cells and Th cells—and further differentiate into plasma cells. These plasma cells synthesize and secrete various immunoglobulins and express plasma cell-specific markers such as plasma cell antigen-1 (PC-1). In healthy individuals, plasma cells reside in specific anatomical regions of the spleen and lymph nodes. Plasma cells possess the capacity to synthesize, store, and secrete antibodies and immunoglobulins, playing a central role in humoral immunity. Immunoglobulins are primarily synthesized within the cisternae of the rough endoplasmic reticulum. Immunofluorescence studies have confirmed that following antigen injection, the corresponding antibodies first appear in the cytoplasm of plasma cells—highlighting their critical role in defending the body against bacterial and viral infections.

It is recommended to maintain a light, bland diet and avoid spicy or irritating foods—such as garlic, spicy hotpot, and mustard. Additionally, adequate rest should be ensured, and excessive physical exertion should be avoided to safeguard overall health.