Immunological basis of toxic oil syndrome (TOS).

The toxic oil syndrome (TOS), a multisystemic disease, that occurred in Spain in 1981, was caused by the ingestion of rapeseed oil denatured with 2% aniline. Due to the clinical course of the disease, immunopathological mechanisms have been suspected but a direct connection was never demonstrated. To analyse this possibility, we determined several immunological parameters in the sera of patients with TOS and without the disease, using a case-control design: total immunoglobulins, IgG and IgE antibodies against different toxic agents (oleylanilide, aniline, linoleyl-anilide, and 3-phenylaminopropane-1-2-diol), autoantibodies, cytokines (IL-4, IL-6, TNF, GM-CSF) and soluble receptors (sCD23 and sIL-2R). We detected high levels of sIL-2R in TOS patients compared to controls (P < 0.0001). A higher levels of sCD23 and IgE were also found. In addition, the response to oleyl-anilide of peripheral blood lymphocytes from TOS patients was studied and a significant proliferative response in 30% of TOS patients versus 5% controls was observed. Our data support the implication of the immune system in the acute phase of TOS, with a possible activation of T-cells and release of cytokines, that could explain some of the clinical findings in this phase of the disease.