Impaired natural killer cytotoxicity during recrudescence of recurrent herpes simplex virus type 1 infection.

We investigated natural killer (NK) cytotoxicity in patients with recurrent herpes infection by using K562 cells infected with Herpes simplex virus type 1 (HSV-1) as target. The NK cytotoxicity was lower than during convalescence and in controls during recrudescence (0 to 3 days postonset of clinical symptoms; P less than 0.001). In the convalescent phase (4 to 14 days postonset of symptoms) the NK cytotoxicity was significantly higher than in controls (P less than 0.05). These results suggest that low NK cytotoxicity is related to the recurrence of herpes.