Measurement of NK cells' cytotoxicity and IFN production as square of the area under the functional curve.

Integral parameters of NK cell cytotoxicity and IFN production measured as square of the area under the cytotoxic and IFN titer curves were correlated with each other. The NK and IFN parameters were also calculated by the standard method using effector : target cell (ET) ratio and correlated with each other again. It was shown that NK cell cytotoxicity and IFN production by normal human PBL reacting against K562 targets correlated positively. At the same time, individual variations of the correlation coefficients obtained by the standard ET technique enabled us to divide all the tested subjects into subgroups with higher and lower positive correlation of the NK and IFN parameters. These subgroups showed differences in standard parameters and their correlation coefficients obtained at ET ratios 100:1 and 6:1; integral parameters of NK cell cytotoxicity and IFN production, as well as their correlation. The data obtained confirm that natural cytotoxic reactions mediated by normal human PBL provide an efficient intimate mechanism for splitting biological signals generated in response to target cells.