DETECTION OF SNOW-CRAB ANTIGENS BY AIR SAMPLING OF A SNOW-CRAB PRODUCTION PLANT

Background and objective We previously assessed the prevalence of occu pational asthma (OA) to snow-crab in production plant workers. We also showed that this type of OA is related to immediate immunological rea ctivity as demonstrated by skin reactivity and increased specific IgE antibodies. However, we did not show that snow-crab antigens causing i mmunological reactivity and OA could be found in the air sampling in t he plants atmosphere. This was the purpose of the current work. Materi al and methods Area air samples worn by workers at four different work sites of a snow-crab producing plant were obtained on PVC filters with an SKC pump run at 1.5 L/min for 2 h. Snow-crab was being boiled and processed during the air sampling periods. Filters were analysed by PA ST inhibition in a blind manner (i.e. without knowledge of the worksit e where the filter originated). Results Eluate from one of the four si tes (#2) had the highest protein concentration and yielded the highest per cent inhibition of RAST - 13% inhibition with the snow-crab meat, 23% and 28% inhibition with the snow crab water RAST in two separate assays. An eluate taken from a filter at another site (#1) showed bord erline reactivity (1% and 10% inhibition in two assays) whereas the tw o other ones and a control filter were negative. The two filters that contained snow-crab proteins were the ones nearest the boiling process , site #2 being the nearest followed by site #1. It was estimated that a 28% inhibition corresponded to similar to 8.6 mu g of proteins and to similar to 1.5 mu g of allergens on the filter. Conclusion This stu dy suggests that airborne snow-crab-derived proteins, released during the boiling process, are the cause of immunological reactivity and of OA to snow-crab.