What is the Origin of Foreign Body Reaction?

The term is derived from surgical pathology and immunology, where it describes the universal tissue response to materials that cannot be degraded or fully integrated by the body. In the context of endocrinology, it is particularly relevant to the use of subcutaneous hormone pellets or long-term glucose sensors.

What is the Mechanism of Foreign Body Reaction?

Following implantation, proteins from the tissue adsorb onto the foreign material surface, initiating a cascade that attracts monocytes, which differentiate into macrophages. These macrophages fuse to form multinucleated foreign body giant cells, which attempt to phagocytose the material. The sustained inflammatory process results in the formation of a collagenous fibrous capsule, often termed fibrosis, around the implant. This encapsulation can impede the diffusion of hormones from a therapeutic pellet or obstruct the sensor readings, affecting the clinical efficacy of the treatment.

Foreign Body Reaction ∞ Area

Foreign Body Reaction

Meaning

A foreign body reaction is a chronic inflammatory response initiated by the host immune system upon contact with an implanted non-biological material or medical device. This physiological defense mechanism is characterized by the persistent presence of immune cells, including macrophages and foreign body giant cells, at the material-tissue interface. The reaction attempts to isolate the implant by encapsulating it in a dense fibrous layer, which can significantly compromise the device’s function. In endocrinology, this is relevant to the efficacy of hormone pellets or glucose sensors.