HEMOGLOBIN ADDUCTS AND SPECIFIC IMMUNOGLOBULIN-G IN HUMANS AS BIOMARKERS OF EXPOSURE TO HEXAHYDROPHTHALIC ANHYDRIDE

The aim of this study was to determine whether haemoglobin adducts (Hb ) of hexahydrophthalic anhydride (HHPA) and HHPA-specific immunoglobul in G (IgG) can be used as biomarkers of exposure to HHPA. The exposure s of HHPA in 10 workers were determined from the mean urinary hexahydr ophthalic acid (HHP acid) levels (range 76-3300 nmol HHP acid mmol(-1) creatinine) during a period of 4 weeks. Blood was collected at the en d of the period and Hb-HHPA adducts were analysed by gas chromatograph y mass spectrometry. The Hb-HHPA adduct levels ranged from 0.45 to 24. 7 pmol g-l Hb. There was a close correlation between the urinary HHP a cid levels and the amount of Hb-HHPA adducts (r = 0.87). One-day expos ures to HHPA and methylhexahydrophthalic anhydride (MHHPA) in 142 work ers were determined from analysis of urinary HHP acid (range 0-3300 nm ol HHP acid mmol(-1) creatinine) and methylhexahydrophthalic acid (MHH P acid; range 0-1700 nmol MHHP acid mmol(-1) creatinine). HHPA-specifi c IgG were analysed in the 142 workers with an ELISA method. The optic al density for HHPA-specific IgG varied between 0 and 1.25. There was no statistically significant correlation between the sum of the urinar y HHP acid and MHHP acid and the HHPA-specific IgG (r = 0.12; p = 0.14 ). Thus, Hb-HHPA adducts seem to be applicable as biomarkers of exposu re to HHPA while the possible role of HHPA-specific IgG as an indicato r of exposure has to be further evaluated.