Sensitive Detection of the Natural Killer Cell-Mediated Cytotoxicity of Anti-CD20 Antibodies and Its Impairment by B-Cell Receptor Pathway Inhibitors

Figure 5

Comparison of the impairment of ADCC against primary CLL cells by different irreversible BTK inhibitors. The antibody-dependent increase in the percentages of minimal calcein retention was determined with 3-fold excess of 1708-LC3E11 effector cells over CLL target cells in seven independent experiments. (a) Asterisks above the boxes and whiskers denote the significance of enhanced cytotoxicity compared to the control without addition of antibodies and inhibitors as determined by paired t-tests. Furthermore combination treatment was compared to that with anti-CD20 antibodies as single agents. (b) The mean differences ± SEM in the cytotoxicity against CLL cells in the presence and absence of rituximab and obinutuzumab were calculated from the data shown in (a). The ADCC of rituximab and obinutuzumab was compared by paired two-tailed t-test. ; ; .

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