NK and LAK functions in human chronic Chagas disease

Natural killer (NK) and lymphokine activated killer (LAK) functions were measured in 40 patients with chronic Chagas disease divided into asymptomatic/indeterminate (18) and symptomatic forms (22) and in 24 healthy controls. A chromium release assay was used employing K562 or P815 cell lines as targets. There was no difference in either NK or LAK activity between the three groups. A small number of patients in each group showed results above or below the normal range for controls. However, there was no correlation between NK and LAK values in the same individual. In conclusion, NK and LAK functions do not seem to be involved in the immunosuppression associated with human chronic Chagas disease.