Ammonium persulfate can initiate an asthmatic response in mice

Background Persulfate salts are the main cause of occupational asthma (OA) in hairdressers. The aim of this study was to verify whether ammonium persulfate ((NH4)(2)S2O8, AP) is capable of triggering an asthma-like response in mice. Methods BALB/c mice were dermally treated on days 1 and 8, with dimethylsulfoxide (DMSO), 1% AP or 5% AP (20 mu l/ear). On day 15, the auricular lymph nodes were removed and an in vitro lymphocyte proliferation test (LPT) was performed. AP was tested for its ability to elicit an asthmatic response using a locally developed mouse model of chemical-induced asthma. On days 1 and 8, BALB/c mice received 20 mu l AP (5%) or DMSO on each ear. On day 15, they received an intranasal instillation of AP (1%) or saline. Afterwards, ventilatory, inflammatory and immunological parameters were assessed. Results The LPT showed that in vitro stimulation of lymphocytes with AP leads to specific proliferation of lymphocytes from AP-sensitised mice. In vivo, AP induced, in AP-sensitised mice only, an 'early' ventilatory response (increased Penh (enhanced pause)) immediately after challenge, and airway hyper-reactivity to methacholine 22 h later. Pulmonary inflammation was mainly characterised by neutrophils (10-15%). AP-sensitised mice showed an increase in total number of T helper (Th) and B lymphocytes together with an increased in vitro secretion of interleukin-4 (IL-4), IL-10 and IL-13 and an increase in total serum immunoglobulin E. Conclusions In a mouse model, it was confirmed that dermal sensitisation to AP can lead to asthma-like responses after a single administration via the airway.