Biomedical Testing of the Kidney for Persons Exposed to Hazardous Substances in the Environment

To identify kidney injury and dysfunction among persons exposed to hazardous substances in the environment, a battery of biomarker tests has been identified for systematic public health use. The standardized use of tests for conducting field epidemiology studies was reviewed in a 1995 joint American-European workshop, and recommended tests were selected by the Agency for Toxic Substances and Disease Registry (A TSDR) and the Centers for Disease Control and Prevention (CDC). These tests would be useful in conducting public health activities but are not recommended in a manner that would suggest changes in routine clinical practice. The tests selected include serum creatinine, urine analysis, urinary albumin, retinol-binding protein, N-acetyl-β-D-glucosaminidase (NAG), alanine aminopeptidase (AAP), and osmolality. Urinary creatinine was also included to adjust for urine concentration. The tests were chosen for use not only in epidemiologic field studies but also clinically oriented population screening and case studies of persons exposed to hazardous substances at waste sites. Studies using the battery may address the relationship between kidney damage and dysfunction and exposures to hazardous substances, especially in susceptible populations including chidren. Also, longitudinal studies should be conducted to evaluate the long-term health implications of abnormal tests and to measure the tests' predictive value for renal injury. These studies could evaluate the continuum of renal dysfunction as expressed by persistent decrements in glomerular filtration to the development of end-stage renal disease.