INTEGRATION OF T‐CELL CLONALITY SCREENING USING TRBC‐1 IN LYMPHOMA SUSPECT SAMPLES BY FLOW CYTOMETRY

Background: The diagnosis of T-cell non-Hodgkin lymphomas (NHL) is challenging. Many cases T-NHL have normal immunophenotypes, and currently available clonality assays limitations, including suboptimal sensitivity. development a monoclonal antibody (mAb) specific for receptor β constant region 1 (TRBC1) provides an alternative to discriminate clonal T cells. aim this study was evaluate the diagnostic potential anti-TRBC1 mAb identification T-NHL. Materials Methods: We performed cross-sectional analytic samples tested lymphoma. All sent lymphoma screening were first evaluated using standard Euroflow Lymphoma Screening Tube (LST), which second additional custom-designed assessment tube added. LST included CD45/CD3/CD4/CD5/CD8/CD19/ CD20/CD38/TRCγδ/CD56 CD45/TRBC1/CD2/CD7/CD4/TRCγδ/CD3. results TRBC1 expression in patient compared 10 peripheral blood (PB). Flow cytometry reports with morphological molecular tests. Clinical data obtained from electronic database. This approved by institutional IRB Ethics Committee. Results: 69 evaluated. healthy controls, 59 samples. Overall, individuals had median 52 years (interquartile range [IRQ], 35–70 years) 53.6% female. Normal assessed PB Within population (CD45+/CD3+), CD4+ cells expressed (±SD) 42% (4.2), while CD8+ 38% (4.7). resulted TRBC1+/- ratio 0.72 ± 0.13 0.61 Cut-off percentages 29.4% 54.6%, 23.9 52.1% T-cells. ratios 0.33 1.1, between 0.22 1.0. Using predefined cut-off values, 18 (30.5%) showed restricted (monotypic) TRBC1. 6/18 monotypic positive (33.3%) 12/18 negative (66.6%). A final confirmed IHC 15 (83.3%). TCR gene rearrangement assay 3/15 cases, clonality. 3 discordant 2 EBV+ primary effusion (PEL) lung adenocarcinoma. There no morphology / expression. Non-neoplastic behaved values. Conclusions: Expression robust method T- cell assessment, very high sensitivity good correlation complementary methods. can be integrated into routine strategies via flow improve capacities. research funded by: Fondecyt 11200805 Clínica Alemana de Santiago ID1025 Keyword: prognostic biomarkers No conflicts interests pertinent abstract.