Silicone breast implant-associated pathologies and T cell-mediated responses

Silicone breast implants elicit a foreign body response (FBR) defined by a complex cascade of various immune cells. Studies have shown that the capsule around silicone breast implants that forms as a result of the FBR contains large T cell populations. T cells are implicated in pathologies such as capsular contracture, which is defined by an excessively fibrotic capsule, and breast implant-associated anaplastic large cell lymphoma (BIA-ALCL), a non-Hodgkin's lymphoma. In this article, we provide a synthesis of 17 studies reporting on T cell-mediated responses to silicone breast implants and highlight recent developments on this topic. The lymphocytes present in the breast implant capsule are predominantly Th1 and Th17 cells. Patients with advanced capsular contracture had fewer T-regulatory (Treg) cells present in the capsules that were less able to suppress T effector cells such as Th17 cells, which can promote fibrosis in autoimmune conditions. Textured silicone implants, which are associated with BIA-ALCL, created a more robust T cell response, especially CD30 + T cells in the peri-implant fluid and CD4 + T cells in the capsule. Cultivating a deeper understanding of T cell-mediated responses to silicone breast implants may allow for novel treatments of breast implant-associated complications and malignancies.