Sensitization of repeat plasmapheresis donors to ethylene oxide gas

Repeat plasma donors were studied to determine whether there was a relationship between allergic-type reactions during plasmapheresis and IgE-dependent sensitization to ethylene oxide gas used for sterilization of disposable fluid administration sets. Serums from 32 donors with allergic-type reactions and 84 donors who had no reactions but were exposed to the same materials and served as controls were tested for IgE-antibodies to ethylene oxide. The results, expressed as an IgE ethylene oxide index, were greater than 2 in 78 percent of serums from donors with allergic reactions and 12 percent of serums from controls. This association was significant (p less than 0.0001). Reactivity of the antibodies was directed against an ethylene oxide-human serum albumin conjugate and not against human serum albumin carrier protein. IgG antibodies with ethylene oxide specificity also were present in the serums of repeat plasmapheresis donors. Each of seven rabbits immunized with an ethylene oxide-protein conjugate responded with a high serum level of antibody with ethylene oxide specificity. It was concluded that the residual ethylene oxide in fluid administration sets is immunogenic and may cause allergic reactions in plasma donors.