Phenotypic And Functional Long-Term Dynamics Of Peripheral Blood Natural Killer Cell Compartment In Diffuse-Large-B-Cell Lymphoma Patients Before And After R-Chop-Based Immunochemotherapy

Methods: PBMC from 32 DLBCL patients and 27 healthy, age- and sex-matched controls were analyzed for: 1) the percentage (over PBMC) of CD56dim, CD56bright, and CD16+ NK cell subsets, measured by multi-parameter flow cytometric (FACS) analysis; 2) the functional capability of NK cell subsets: i.e. the frequency of IFN-gamma-expressing cells and cytotoxic granule-containing (granzyme B+, GrzB+) cells, evaluated by intracellular staining and FACS analysis; and 3) “natural” and CD16-dependent NK cytotoxic functions, quantified by 51Cr release assay. Patients’ PBMC were analyzed at diagnosis, at mid-therapy, and at different timepoints up to 12 months after the end of R-CHOP therapy. All subjects gave informed consent; the study was approved by the institutional Ethical Committee.

Phenotypic and functional long-term dynamics of peripheral blood Natural Killer (NK) cell compartment in Diffuse-Large-B Cell-Lymphoma patients before and after R-CHOP-based chemoimmunotherapy M.C. Cox1,6 , S. Battella2,6, S. Pelliccia1, R. La Scaleia2, A. Di Napoli3,4, E. Alma, A. Porzia2, F. Mainiero2, L. Ruco3,4, A. Tafuri1,4, A. Santoni5, G. Palmieri2 1Haematology Unit, Sant'Andrea Hospital; 2Department of Experimental Medicine; 3Pathology Unit, Sant'Andrea Hospital; 4Department of Clinical and Molecular Medicine; 5Department of Molecular Medicine; Sapienza University of Rome, Italy. 6equal contribution Background: Natural Killer (NK) cells represent an important component of tumor immune surveillance, and play a key role in rituximab-dependent killing of lymphoma cells through antibody-dependent cellular cytotoxicity (ADCC) mechanism. Since NK functions might significantly contribute to the success of rituximab-based treatment, we focused our work on monitoring changes of NK subsets and functional activities during the treatment of Diffuse-large-B-cell-lymphoma (DLBCL) patients. Aims: To assess the phenotypic and functional asset of peripheral blood NK cell subsets in newly diagnosed DLBCL patients, and to evaluate its acute and long-term modifications upon R-CHOP regimen. Methods: PBMC from 32 DLBCL patients and 27 healthy, age- and sex-matched controls were analyzed for: 1) the percentage (over PBMC) of CD56dim, CD56bright, and CD16+ NK cell subsets, measured by multi-parameter flow cytometric (FACS) analysis; 2) the functional capability of NK cell subsets: i.e. the frequency of IFN-gamma-expressing cells and cytotoxic granule-containing (granzyme B+, GrzB+) cells, evaluated by intracellular staining and FACS analysis; and 3) “natural” and CD16-dependent NK cytotoxic functions, quantified by 51Cr release assay. Patients’ PBMC were analyzed at diagnosis, at mid-therapy, and at different timepoints up to 12 months after the end of R-CHOP therapy. All subjects gave informed consent; the study was approved by the institutional Ethical Committee.