Elevated Liver Enzymes in Asymptomatic Patients

To the Editor: In their useful review of liver-enzyme elevations in asymptomatic patients, Pratt and Kaplan (April 27 issue) 1 do not mention liver-enzyme elevations due to occupationally associated hepatic injury, although toluene in glues and trichloroethylene and chloroform are listed as substances of abuse in Table 3 of their article. Chlorinated hydrocarbon solvents are workplace toxins that have been important historically because of carbon tetrachloride and related compounds. However, a wide variety of chemical agents have led to outbreaks of disease in more recent years, including dimethylformamide 2 (used in textile coatings), hydrazine and derivatives 3 (used in jet and rocket fuels), . . .