FREQUENT NATURAL-KILLER-CELL ABNORMALITY IN CHILDREN IN AN AREA HIGHLY CONTAMINATED BY THE CHERNOBYL ACCIDENT

Since January 1991, we have been performing thyroid surveys and hemato logic and immunologic screening on children in Chechersk, Belarus, a c ity situated in one of the areas most seriously contaminated with high levels of radionuclides after the Chernobyl accident. Ten children se lected from 713 children because of goiter did not show a decrease in humoral immunity or in the number and function of T cells. By contrast , natural killer (NK) cell activity against K562 cells was depressed i n 4 of these 10 children. The clinical and laboratory findings indicat ed that previously reported diseases with NK cell dysfunction could be excluded, A comparative analysis of NK cell activity in children from areas with and without high Cs-137 levels revealed a high frequency o f abnormal NK cell activity only in children from the area contaminate d by radioactive fallout. In addition, there was no correlation betwee n NK cell activity and NK cell number as percentage in the children fr om the area with high Cs-137 levels. Neither activity nor number of NK cells was correlated with the body content of Cs-137. Thus, the frequ ent abnormality of NK cell function may not have been due to actual in ternal exposure to the long-lived radionuclide.