ABSTRACT
BACKGROUND: Granzyme B (GrB) is a serine protease secreted, along with pore-forming perforin, by cytotoxic lymphocytes to mediate apoptosis in target cells. GrB has been detected in tumor cells associated with systemic and breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) but its potential use for detection of early BIA-ALCL has not been fully investigated. OBJECTIVES: Prompted by the increased incidence of BIA-ALCL, the aim of this study was to assess GrB as a new biomarker to detect early disease in malignant seromas and to better understand the nature of the neoplastic cell. METHODS: A Human XL Cytokine Discovery Magnetic Luminex 45-plex Fixed Panel Performance Assay was used to compare cytokine levels in cell culture supernatants of BIA-ALCL and other T-cell lymphomas, as well as malignant and benign seromas surrounding breast implants. Immunohistochemistry was employed to localize GrB to cells in seromas and capsular infiltrates. RESULTS: Differences in GrB concentrations between malignant and benign seromas were significant (P < 0.001). GrB was found in and around apoptotic tumor cells, suggesting that the protease may be involved in tumor cell death. CONCLUSIONS: GrB is a useful marker for early detection of malignant seromas and to identify tumor cells in seromas and capsular infiltrates. Because there is an overlap between the lowest concentrations of soluble GrB in malignant seromas and the highest concentrations of GrB in benign seromas, it is recommended that GrB be used only as part of a panel of biomarkers for the screening and early detection of BIA-ALCL.
