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正

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Peripheral blood mononuclear cells（PBMNC）isolated from patients with acuteleukemia（AL）and from normal controls were cultured in a medium containing1000units/ml of recombinant interleukin-2（IL-2）.Marked LAK activity was induced onthe third culture day in the normal controls

with the highest cytotoxicity appearing be-tween day 3 and 5

whereas induction of LAK activity in the AL patients began on the5th day of culture

with a peak level appearing at day 15

showing that the peak ofLAK activity was significantly delayed in AL.LAK cells surface phenotyping tests showedthat CD

8

and CD

16

positive cells began to increase significantly from day 5 and reachedthe highest level at week 3

whereas CD

4

-

subclass began to decrease at day 5 anddropped to the nadir at week 3

indicating that LAK activity was positively correlatedwith the proportion of CD

8

+

and CD

16

+

cells

but negatively with that of CD

4

+

cells.