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759691 
Journal Article 
Abstract 
Antibodies against CYP2E1 after exposure To 1, 1, 1-trifluoroethane and 1, 1, 1, 2- tetrafluoroethane 
Gunnare, S; Vidali, M; Albano, E; Johanson, G 
2005 
1 
Toxicologist
ISSN: 0731-9193 
TOX/5001040 
84 
1-S 
185 
English 
Hydrofluorocarbons (HFC) are used as substitutes for the ozone depleting chlorofluorocarbons, e.g. for refrigeration. Associations between high exposure to refrigerants and pain in joints and influenza-like symptoms have been shown for refrigeration mechanics. These symptoms may be signs of autoimmune reactions. Exposure to similar substances (e.g. trichloroethylene, vinyl chloride and the anaesthetic halothane) has previously been associated with autoimmune diseases. The HFCs are metabolised by Cytochrome P450 2E1 (CYP2E1). Our hypothesis is that trifluoroacetaldehyde formed during metabolism binds to CYP2E1. If trifluoroacetyl- CYP2E1 is seen as non-self, antibodies against the adduct and/or against CYP2E1 may be produced. Antibodies against CYP2E1 have been found in humans accidentally exposed to hydrochlorofluorocarbons, a group of substances similar to the HFCs. The aim of this pilot study was to determine if experimental and/or occupational exposure to HFCs generates measurable increases in antiCYP2E1 titres. Healthy, male refrigeration mechanics were exposed to 500 ppm 1, 1, 1-trifluoroethane (n=9) and 1, 1, 1, 2-tetrafluoroethane (n=10) at two different occasions in an exposure chamber. Plasma sampled 22 hours post exposure was screened for antibodies against CYP2E1 with enzyme-linked immunosorbent assay. The titres were compared to titres from an unexposed group of controls (n=10). The study was approved by the Regional Ethical Committee at Karolinska Institutet. There was no difference in antibody level between the exposed subjects and the unexposed controls. However, since only healthy subjects were allowed to participate, sensitive individuals may have been excluded from the study. Also, the experimental and occupational exposure levels may have been too low to generate measurable autoimmune reactions. In conclusion, antibodies against CYP2E1 could not be detected in healthy refrigeration mechanics experimentally and occupationally exposed to HFCs. 
Society of Toxicology Annual Meeting