[Immunological studies on chronic active Epstein-Barr virus infection in children--low spontaneous cytotoxicity and lymphokine augmented spontaneous cytotoxicity against Raji cells].

Spontaneous cytotoxicity and lymphokine augmented spontaneous cytotoxicity against Raji cells were tested in 7 patients with chronic active Epstein-Barr virus infection in childhood. The results were as follows: Spontaneous cytotoxicity, tested by 4 hr assay, was 6.6 +/- 5.1% (mean +/- SD) in the patients and 13.9 +/- 9.6% in the controls, and the differences were statistically significant. Spontaneous cytotoxicity, tested by 18 hr assay, in the patients was as high as in controls. Recombinant interferon alpha and OK-432 augmented spontaneous cytotoxicity, tested by 4 hr assay, were 9.4 +/- 6.1% and 9.9 +/- 5.4% in the patients, and 21.0 +/- 10.9% and 24.2 +/- 13.3% in the controls, and the differences were statistically significant. Recombinant interferon alpha and OK-432 augmented spontaneous cytotoxicity, tested by 18 hr assay, were as high in the patients as in controls. Recombinant interleukin 2 (rIL-2) augmented spontaneous cytotoxicity, tested by 4 hr assay, was 14.1 +/- 6.8% in the patients and 28.9 +/- 13.7% in the controls, and the differences were statistically significant. Though differences were not significant, rIL-2 augmented spontaneous cytotoxicity, tested by 18 hr assay, was lower in the patients than in controls. The grade of augmentation of spontaneous cytotoxicity by lymphokines, tested by 4 hr assay, was also low in the patients, but no differences were observed except in the case of rIL-2 when spontaneous cytotoxicity was tested by 18 hr assay. These results suggest that a longer incubation time was required in lytic kinetics of spontaneous cytotoxicity and lymphokine augmented spontaneous cytotoxicity in the patients with chronic active Epstein-Barr virus infection.