Induction of immunologic tolerance: Desensitization to occupational allergens

Abstract

Contact sensitivity is a major cause of skin disease and industrial morbidity. The incidence of industrial dermatitis in a number of industries is listed in Table I. The purpose of this investigation was to develop a means of specifically suppressing the development of contact sensitivity to simple chemicals with a common exposure in industry. A simple epicutaneous route of administration was used. Work from this laboratory and others has indicated that when an individual is sensitized to a simple chemical sensitizer such as DNFB, there is a parallel development of a control or regulating mechanism that limits the extent of the damage produced. Regulation is by suppressor lymphocytes, either T or B, or by macrophages.‘.* One of the ways in which an effective and acceptable tolerance might be produced in humans would be to boost the suppressor arm of the immune response selectively and specifically by the epicutaneous application of a cross-reacting, weakly sensitizing chemical. Such a possibility has been demonstrated for DNFB by the use of DNTB in the guine pig.’ We have also shown that DNTB, when applied directly to guinea pig skin, would markedly reduce the state of sensitivity induced by DNFB , This effect could be abrogated by prior treatment with cyclophosphamide that selectively depleted the suppressor cells that normally regulated the immune response. Moreover, suppression could be transferred passively by cells from epicutaneously tolerized animals. ” To search for compounds of a wider use in industry, it was important to discover why the epicutaneous application of DNTB should preferentially induce tolerance while that of DNCB induces sensitization. Therefore, the ability of dinitrobenzenes to sensitize or tolerize was compared with their ability to bind to the amino and sulphydryl groups of proteins. In the second part of this article, a similar investigation is reported that involved a group of acrylates known to produce contact dermatitis in humans. Acrylates are used in industry as adhesives (with which the sensitizers are mainly the monoacrylates) and in printing, where the use of ultraviolet curing inks include triacrylates that are also strong sensitizers.