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Detection of hexamethylene diisocyanate-hemoglobin adducts using an ELISA antigen-capture assay.

Lukinskiene L; Lemus R; Wisnewski AV; Redlich CA; Karol MH
Toxicologist 2001 Mar; 60(1):83
Isocyanates including 1,6-hexamethylene diisocyanate (HDI), are a prominent cause of occupational asthma. HDI is used as a polymerizing agent in paint formulations employed in the automobile industry. There is a need to monitor occupational exposure in workers to prevent the onset of disease. HDI has been reported to form stable adducts with N-terminal valine of globin. Since the lifetime of such adducts is 3 or more months, these adducts can be a useful biomarker of exposure over a period of time. The aim of this study was to develop and apply an assay for HDI exposure of auto paint sprayers in local garages. A sensitive and specific rabbit anti-HDI antiserum was used, and an HDI-Hb conjugate was synthesized as a positive control for the immunoassay. A sham-exposed Hb was used as a negative control. To develop the assay, the immunoglobulin G (IgG) fraction from the antiserum was purified by a caprylic acid/ammonium sulfate precipitation. Hemoglobin was purified from human blood samples by gel filtration. Microtiter plates were coated with the rabbit IgG antibodies and detection of the Hb adducts was accomplished using stepwise: Hb samples from workers, goat anti-human Hb, peroxidase labeled anti-goat IgG, followed by substrate. The assay was found to be capable of detecting as few as 6 pmoles of HDI when adducted to protein. This is the first report of a sensitive immunoasay for biomonitoring of workplace HDI exposure. Erythrocytes were obtained from workers who had tested positive for HDI specific IgG antibodies, as well as workers with recent exposure to HDI. The immunoassay indicated that none of the workers (n=26) had detectable HDI adducted to Hb. Further studies are needed to investigate possible HDI adducts with other proteins (serum albumin) and with sputum specimens, to indicate their potential role as biomarkers in detecting occupational exposure to isocyanates.
Hexanes; Isocyanates; Occupational-health; Bronchial-asthma; Automotive-industry; Occupational-exposure; Monitoring-systems; Workers; Worker-health; Diseases; Biomarkers; Paint-spraying; Paints; Laboratory-animals; Animals; Animal-studies; Blood-samples
110-82-7; 822-06-0
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Disease and Injury: Asthma and Chronic Obstructive Pulmonary Disease
Source Name
The Toxicologist. Society of Toxicology 40th Annual Meeting, March 25-29, 2001, San Francisco, California
Performing Organization
Yale University, New Haven, Connecticut
Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division