Assessing environmental exposure in children: immunotoxicology screening

Abstract

Environmental exposure to a number of xenobiotics, including pesticides, can have serious effects on the immune system of children, thus rendering them susceptible to infections or other disease states. To study this problem, a recycling chromatographic system for assessing cytokine profiles in humans has been developed and used for the measurement of immune system function in children with documented exposure to residential pesticides. The system is capable of measuring 30 different analytes in a single sample thus enabling the same time examination of representative markers of immune differentiation and function. In the present study, a cohort of 25 exposed children were examined and shown to exhibit a number of features; all subjects demonstrated some abnormalities in cytokines associated with hematopoiesis. Additionally, elevations in pro-inflammatory cytokines and neuropeptides indicated a state of generalized and neurogenic inflammation. Further analysis indicated that a depression of the cellular arm of the immune system that correlated with clinical indicators of lowered host resistance to infection could also be detected in a subgroup of the exposed subjects. All exposed children demonstrated evidence of hyperstimulation of the humoral immune system as indicated by elevated IL-5 concentrations and clinical allergy. The degree of immune dysregulation in the exposed children was found to be quite marked when compared to similar studies performed on age-matched controls.