Oxidative activity of ammonium persulfate salt on mast cells and basophils: implication in hairdressers' asthma.

BACKGROUND: Persulfate salts are components of bleaching powders widely used by hairdressers during hair-bleaching procedures. Hairdressers are at high risk for occupational asthma and rhinitis, and ammonium persulfate is the main etiologic agent. OBJECTIVE: To explore the effects of ammonium persulfate on human albumin, mast cells, and basophils in order to evaluate a possible effect of ammonium persulfate oxidizing activity in the mechanism of ammonium persulfate-induced occupational asthma. METHODS: High-performance liquid chromatography/mass spectrometry was performed on ammonium persulfate-incubated human albumin. The activation of LAD2 human mast cell and KU812 human basophil cell lines incubated with ammonium persulfate was evaluated. CD63 expression on persulfate-in-vitro-incubated blood basophils from nonexposed healthy controls (n = 31) and hairdressers with work-related respiratory symptoms (n = 29) was assessed by flow cytometry. RESULTS: No persulfate-albumin conjugate was found. An oxidative process on tryptophan and methionine was detected. Ammonium persulfate induced reactive oxygen species (ROS) generation and the degranulation of LAD2 and KU812 cells. Human basophils from healthy controls, incubated in vitro with ammonium persulfate, showed increased CD63 expression and ROS production. In hairdressers with ammonium persulfate-caused occupational asthma (positive persulfate challenge), basophil-CD63 expression was higher than in those with a negative challenge and in healthy controls. CONCLUSIONS: Ammonium persulfate incubated with human albumin did not generate any adduct but oxidized some amino acids. This oxidizing activity induced human mast cell and basophil activation which might be crucial in the mechanism of persulfate-induced occupational asthma and rhinitis.