Letters

S106 Abstracts / Toxicology

P3-07Effect of phenol and hydroquinone associated expo-sure on leukocyte migration into allergic inflamedlung

Alexandre Ferreira, Sandra Manoela Dias Macedo,Suellen Cristine Moreira Vaz, Wothan Tavares Lima,Sandra Helena Poliselli Farsky

University of Sao Paulo, Sao Paulo, Brazil

Benzene is metabolized by the liver generating phe-nol (PHE) and hydroquinone (HQ), which is substrateto myeloperoxidase in the bone marrow resulting in1,4 p-benzoquinone. These metabolites are linked toimmunotoxic effects, however, their effects on leuko-cyte mobilizations during inflammatory processes arenot fully understood. We previously showed that in vivoHQ exposure for an extended period of time (50 mg/kg,i.p., 16 daily doses, with 2-day intervals every 5 doses)impairs the leukocyte migration into lung during an aller-gic response in rats. Now, we investigated the effectof lower doses of HQ, PHE or association of both onleukocyte mobilization into inflamed lungs. Adult, maleWistar rats were sensitized with OA (10 mg; aluminumhydroxide solution, i.p. route) at the 10th day afterbeginning phenolic compounds (5 mg/kg, i.p., 16 dailydoses, with 2-day intervals every 5 doses) or vehicle(ethanol:saline solution 1:20) exposures. Twenty-fourhours after last doses, animals were challenged (1% PBSsolution; 15 min inhalation). Broncheoalveolar lavage(BAL) was collected 24 h after challenge. HQ or PHEexposure induced impairment on number of polymor-phonuclear (PMN, 50%) cells into BAL. The reducedcell migration was not modified by HQ and PHE associ-ated exposure. These data suggest that in vivo lower doseof both phenolic compounds impairs the PMN recruit-ment to inflamed lung and PHE/HQ association does notpromote synergic effect.

Financial support: FAPESP grants 03/04013-8;04/11412-9.

doi:10.1016/j.toxlet.2006.06.222

P3-08The skin allergenic properties of chemicals maydepend on contaminantsEvidence from studies on coumarin

Francois E. Floch

ITEConsult, Lyon, France

Background/aims: Positive patch tests are considered asrepresentative of a contact allergy to the tested chemi-

164S (2006) S1–S324

cal. However, contaminants and derivatives rather thanthe suspected chemical itself could be responsible for theskin allergic reactions. Here, we tested the importance ofcontaminants in the sensitizing and allergenic propertiesof coumarin in mice and humans. Coumarin, an ingre-dient of cosmetics and fragrances, was chosen as thereference chemical since conflicting results have beenobtained regarding its ability to induce contact allergy.This could be explained by the presence, in some chem-ical preparations, of coumarin derivatives endowed withallergenic properties.

Methods: In mice, three different coumarin prepa-rations were tested in the local lymph node assay. Inhumans, we assessed the irritant and allergenic proper-ties of highly pure coumarin in non allergic and fragranceallergic patients.

Results: Pure coumarin did not exhibit irritant or sen-sitizing properties in the LLNA. In contrast, two othercommercially available coumarins and three contami-nants that were detected in these coumarin preparationswere identified as weak and moderate sensitizers, respec-tively. In humans, pure coumarin was extremely welltolerated since only 1 out of 512 patients exhibited pos-itive patch test to the chemical.

Conclusions: These results indicate that coumarincannot be considered as a common contact allergen andfurther emphasize that purity of chemicals is mandatoryfor assessment of their allergenicity.

doi:10.1016/j.toxlet.2006.06.223

P3-09The KLH-assay as alternative to the PFC-assay: Acomparative study with cyclophosphamide

Andre Hendrikus Penninks, Jolanda H.M. van Bilsen,Mary-lene M.H. Brouwer, Karin - Junker, Frieke C.Kuper

TNO Quality of Life, Zeist, Utrecht, The Netherlands

To date the T cell-dependent antibody response (TDAR)is regarded to be the most predictive assay for immuno-toxicity testing. The IgM-plaque forming cell (PFC)assay using sheep red blood cells (SRBC) as antigen isa widely accepted and validated standard test. However,this assay has a number of drawbacks. Therefore, alter-native assays like the KLH-assay using Keyhole LimpetHemocyanin (KLH) as antigen are being developedand validated. In an Immunotoxicity Inter-Laboratory

Project (IILP), a common design for a KLH-assay wasestablished using well known immunosuppressive com-pounds. In this study we assessed for cyclophosphamide(CY) the robustness and sensitivity of the KLH-assay