Natural killer cell activity in herpes zoster in children without underlying disease

We determined natural killer cell (NKC) activity in 10 otherwise normal children with herpes zoster. NKC activity values in children with vs. without varicella-zoster virus specific IgM antibodies and in controls were 28.3 +/- 8.6%, 11.9 +/- 3.6% and 20.2 +/- 3.8% (mean +/- SD), respectively. There were significant differences between the children with and without IgM antibodies during the acute phase (p < 0.005) and between children without IgM antibodies and controls (p = 0.005). NKC values in children with mild vs. moderate morbidity were 11.7 +/- 4.1% and 25.7 +/- 9.9%, respectively (p < 0.05). The morbidity was moderate in all children with IgM antibodies, but in only 2 of the 5 children without IgM antibodies. Children who contracted varicella when a few months old had the highest IgM antibody titers and the highest value of NKC activity. NKC activity was related both to the presence of IgM antibodies and to the morbidity of herpes zoster.