Clinical application of a whole blood assay for human natural killer (NK) cell activity.

A whole blood assay for assessment of spontaneous or NK-cell activity has been proposed in order to avoid many of the problems encountered with the conventional methods involving cell separation procedures. Normal subjects and patients with cancer of the kidney or bladder were investigated with the new method. Cancer patients were found to exhibit significantly lower levels of reactivity when compared to normal subjects; furthermore, the results were consistent with the common belief that tumor burden and NK activity were inversely related. The whole blood assay appears useful in monitoring cancer patients, particularly those treated with immune modulators.