SAN FRANCISCO—A small study suggests an abnormal immune response characterized by the production of interleukin-13 (IL-13) underlies the pathogenesis of breast implant-associated anaplastic large-cell lymphoma (BIA-ALCL).
The immune response appears to be directed toward bacterial antigens on the surface of the breast implants.
Marshall E. Kadin, MD, of Roger Williams Medical Center in Providence, Rhode Island, presented these findings at the 9th Annual T-cell Lymphoma Forum.
Dr Kadin noted that BIA-ALCL is a rare type of CD30+ T-cell ALCL that has been reported in more than 200 women worldwide.
Although a cause-and-effect relationship between breast implants and BIA-ALCL has been suggested, the underlying pathogenesis of this malignancy is unclear.
A bacterial biofilm containing gram-negative bacilli has been detected in breast implants from patients with BIA-ALCL.
Therefore, Dr Kadin and his colleagues hypothesized that an immune response toward the bacterial antigens may mediate the pathogenesis of BIA-ALCL.
The researchers studied 13 clinical samples of breast implant capsules and regional lymph nodes from 4 patients with BIA-ALCL, 7 patients with systemic ALCL, and 1 patient with peripheral T-cell lymphoma-not otherwise specified (PTCL-NOS).
Immunohistochemistry was used to determine the presence of IL-13, IL-4, GATA3, and immunoglobulin E (IgE) in these samples.
All clinical samples of anaplastic cells from breast implant capsules tested positive for the presence of IL-13 (13/13). GATA3 was expressed in most anaplastic cell samples (12/13), and IL-4 expression was found in some anaplastic cell samples (6/13). IL-13 and GATA3 expression were observed in some intra-capsular small lymphocytes.
While IL-13 was also detected in BIA-ALCL cell lines, it was not found in 4 of the 7 systemic ALCL cases or the PTCL-NOS case.
Dr Kadin said the lack of IL-13 receptor expression in BIA-ALCL cell lines suggests that IL-13 is not an autocrine growth factor for BIA-ALCL, and its expression is most likely associated with an allergic immune response.
IL-13 is known to induce immunoglobulin class switching in plasma cells to produce IgE. H&E and Giemsa staining of the BIA-ALCL tumor tissue and involved regional lymph nodes revealed IgE and eosinophils on the surface of mast cells and follicular dendritic cells.
Taken together, these data point to an allergic reaction in breast implant capsules of BIA-ALCL.
Dr Kadin was hopeful that these findings could be extrapolated to prevent BIA-ALCL by identifying individuals at higher risk for developing the disease.
The next step for this research is to decipher the role of bacterial antigens in mediating the immune response and whether women who develop BIA-ALCL have a significant increase in other atopic conditions.