ALTERATION OF T-CELLS AND NATURAL-KILLER-CELLS DURING CHICKENPOX IN INFANCY

To determine the reasons for the low immune response and the mild morb idity of chickenpox in infancy, we investigated alteration of T cells and natural killer (NK) cells during chickenpox in children <1 year an d greater than or equal to 2 years old using flow cytometry. The CD4/C D8 ratio decreased only in the <1-year-old group from the acute to the convalescent phase (P < 0.05). The CD3-CD16+CD56+ and CD57-CD16+ coun ts increased in the <1-year-old group, but those in the greater than o r equal to 2-year-old group did not increase from the acute to the con valescent phase. The CD3-CD16+CD56+ counts and the CD57-CD16+ counts a nd percentage were larger in the <1-year-old group than those in the g reater than or equal to 2-year-old group (P = 0.001, P = 0.002, and P < 0.05) in the convalescent phase. These results seem to indicate that the low immune response in infancy after chickenpox are related to th e small number of CD8 in contrast with CD4 and that increased subsets of NK cells during chickenpox may correlate to the mild morbidity of c hickenpox in infancy.