Natural killer (NK) activity in normal donors undergoing leukapheresis.

: The effect of leukapheresis performed with intermittent flow blood separator on normal donors NK activity is presented. There was statistically significant decrease of NK activity immediately after leukapheresis (p less than 0.001) which did not return to predonation values 1 day after leukapheresis (p less than 0.05), however, none of the donors values fell outside the normal range. It seems that NK cells are not as quickly replaced as T lymphocytes.