NASAL CHALLENGE SHOWS PATHOGENETIC RELEVANCE OF SPECIFIC IGE SERUM ANTIBODIES FOR NASAL SYMPTOMS CAUSED BY HEXAHYDROPHTHALIC ANHYDRIDE

Hexahydrophthalic anhydride (HHPA) is a component of some epoxy resin systems. A high fraction of HHPA-exposed workers display nasal symptom s, and some of them have specific serum antibodies. To test the pathog enetic relevance of the antibodies, nasal challenge tests were perform ed with a conjugate of HHPA and human serum albumin (HSA) at three inc reasing concentrations. Eleven subjects, who were IgE-sensitized again st HHPA (positive in RAST and in skin-prick test against the HHPA-HSA conjugate), and who reported work-related nasal symptoms, had a signif icant increase of nasal symptoms and a decrease of nasal inspiratory p eak flow after the challenges. The symptoms were associated with speci fic serum IgE, but with IgG. Further, significant increases were found in eosinophil and neutrophil counts, and in levels of tryptase, and a lbumin, whereas no clear rise was recorded for eosinophil cationic pro tein in nasal lavage fluid. Nine subjects, who were not sensitized, bu t who complained of work-related nasal symptoms, and 11 subjects, who were not sensitized and had no symptoms, displayed no significant chan ge in any of these parameters. It is concluded that the symptoms in so me of the workers were caused by an IgE-mediated mast cell degranulati on, followed by an inflammatory reaction, engaging eosinophil and neut rophil cells.