EXPERIMENTAL ASSESSMENT OF THE SENSITIZING PROPERTIES OF FORMALDEHYDE

Formaldehyde causes upper respiratory tract irritation and has been re ported in some investigations to be a cause of occupational allergic a sthma. The data are equivocal, however, and it has proved difficult to confirm that exposure to formaldehyde induces respiratory sensitizati on or provokes the production of specific immunoglobulin E (IgE) antib ody. In this study the sensitizing properties of formaldehyde were exa mined experimentally. This chemical elicited strong positive responses in three independent methods for the prospective identification of co ntact sensitizing chemicals-the guinea pig maximization test, the occl uded patch test of Buehler and the murine local lymph node assay. In c ontrast, in a novel predictive test method for assessment of respirato ry sensitization potential-the mouse IgE test-formaldehyde at the same test concentrations was negative. Furthermore, formaldehyde induced i n mice a pattern of cytokine secretion by draining lymph node cells in consistent with the stimulation of IgE antibody responses or respirato ry sensitization. These data indicate that, although formaldehyde is a potent contact allergen, it lacks a significant potential to cause se nsitization of the respiratory tract. Copyright (C) 1996 Elsevier Scie nce Ltd