Complement activation in tear fluid during occupational mold challenge

Indoor air quality is important in occupational healthcare when evaluating the health risks of a work environment. Components of the classical and alternative complement pathways are present in ocular tissues and fluids. The authors determined the levels of complement components C1INH, C3, and C4 in sera and C3a in tear fluids of normal persons and of those who were exposed to molds.

Nine patients environmentally exposed to molds and 6 controls were selected from the Indoor Air Clinic of the Skin and Allergy Hospital. Tear fluid samples were collected from patients during the exposure to molds and after 2 weeks without mold exposure. At the same time, conjunctival cytology samples were obtained from each patient. Tear fluid was taken from 6 control subjects. All had negative skin prick tests to common environmental allergens.

In 4 patients subjective eye symptoms and tear fluid C3a levels decreased during 2 weeks of sick leave as did conjunctival eosinophils but other inflammatory cells were unchanged.

Elevated complement C3a levels in tear fluids may be influenced by environmental exposure to molds. According to the authors' clinical experience, eosinophilia is not a consistent finding in patients exposed to molds. However, molds may cause eosinophilic inflammation in the eye.