IgG antibodies against polyisocyanates in car painters

Area of Science:

• Occupational Health
• Immunology
• Toxicology

Background:

• Hexamethylene diisocyanate (HDI) is a common chemical in paints.
• Exposure to HDI can occur in occupational settings like car painting.
• Understanding the immunological response to HDI is crucial for worker safety.

Purpose of the Study:

• To investigate the immunological response to hexamethylene diisocyanate (HDI) in car painters.
• To analyze specific IgE and IgG antibody levels against HDI monomer and prepolymer.
• To explore the association between HDI exposure, antibody levels, and reported symptoms.

Main Methods:

• Studied thirty car painters exposed to HDI-containing paint aerosols and vapors.
• Measured specific IgE antibodies using RAST assay and IgG antibodies using ELISA.
• Conjugated haptens with human serum albumin for antibody analysis.
• Compared antibody levels in exposed painters to non-exposed referents.

Main Results:

• No significant increase in serum IgG antibodies against HDI monomer or specific IgE antibodies against HDI monomer/prepolymer was observed.
• Significantly increased specific IgG antibodies against prepolymerized HDI were found in exposed painters compared to controls (median absorbance 0.11 vs 0.03).
• Six painters had specific IgG4 antibodies against HDI prepolymer, and four against HDI monomer, indicating an association between exposure and IgG antibodies.

Conclusions:

• Occupational exposure to HDI in car painters is associated with an increase in specific IgG antibodies against HDI prepolymer.
• No significant association was found between reported symptoms (rhinitis, conjunctivitis, bronchitis) and specific antibody levels.
• Most symptoms reported were mild and unspecific, suggesting potential irritant effects of HDI exposure rather than a strong allergic response.