Occupational trichloroethylene exposure and antinuclear antibodies: a cross-sectional study in China

There has been concern over the possible risk of autoimmune diseases from exposure to trichloroethylene (TCE), an industrial solvent and common pollutant near hazardous waste sites. Studies of TCE-exposed lupus-prone mouse strains have reported increases in serum antinuclear antibodies (ANA), a marker of autoimmunity, and autoimmune pathologic changes, while epidemiologic studies have provided limited support for an association between TCE exposure and scleroderma. Exposure-related biologic evidence of autoimmunity in humans was investigated by measuring ANA levels in sera from a cross-sectional study of 80 TCE-exposed and 96 TCE-unexposed workers in Guangdong, China. Full-shift personal air exposure measurements for TCE were taken prior to blood collection. Samples from 16 of 176 participants were ANA-positive. Higher levels of TCE exposure (concentrations > 17.27 ppm) were observed to be associated with an elevated odds of ANA positivity compared with unexposed controls. This association remained after excluding two subjects with diagnosed autoimmune disease. An association with ANA at lower exposure levels was not observed. This is a first direct human evidence of an association between TCE exposure and systemic autoimmunity, provide biologic plausibility to epidemiologic evidence relating TCE and autoimmune disease.