Adjuvant effect of quaternary ammonium compounds in a murine model

It has been suggested that occupational exposure to quaternary ammonium compounds (QACs) may promote the development of allergic airway diseases. In this study, hazard identifications of the adjuvant effect of cetylpyridinium chloride (CPC), dimethyldioctadecylammonium bromide (DDA), hexadecyltrimethylammonium bromide (HTA), and tetraethylammonium chloride (TEA) were performed in a screening bioassay. Female BALB/c mice were injected subcutaneously with the model allergen ovalbumin (OVA) alone or together with different quantities of one of the QAC test compounds. After one or two boosters, levels of OVA-specific IgE, IgG1 and IgG2a antibodies were measured in sera. CPC and DDA increased IgE and IgG1 antibody production, respectively, compared to the OVA control group, whereas HTA and TEA showed no adjuvant effect. Nevertheless, when TEA was given in combination with DDA, the adjuvant effect was up to six-fold higher than the adjuvant effect of DDA alone. Only DDA had a statistically significant adjuvant effect on IgG2a antibody levels.