The second IDEA Workshop on pre- and prohaptens took place on June 16th and 17th, 2015 in Genval, Belgium. The workshop was designed to specifically focus on an improved mechanistic understanding of pre- and prohapten formation as well as on progressing the analytical development for following hapten formation from pre-/pro haptens in raw materials and finished products as well as on the skin. Participants therefore included research experts from both Academia and Industry with specific expertise in the areas of skin metabolism, predictive models, analytical chemistry and quality testing of fragrance materials. They all gathered to provide the latest scientific knowledge on pre- and prohaptens in order to better assess their risk.
As reflected in the initial summary by the Rapporteur (Prof. Jim Bridges), the workshop allowed to progress on a number of topics, including:
- Abiotic transformation (activation and detoxification),
- Biotic transformation (activation and detoxification),
- Influence of transporter proteins, local non-specific binding / reservoirs,
- Impact of ingredient modifiers (inducers, inhibitors, etc.),
- Receptor proteins resulting an immune response,
- Cross reactivity.
More information on each of the areas is provided in the presentations provided by the participants:
- Workshop opening - Speaker: Hans Bender (Moderator of IDEA Workshop) and Matthias Vey (IDEA Management Team)
- Cross reactivity when patch testing with oxidized materials - Speaker: Ann-Therese Karlberg (University of Gothenburg)
- IDEA Hydroperoxides Task Force: summary report from the meeting of June 15, 2015 - Speaker: Alain Chaintreau (Firmenich)
- Abiotic transformation developments: pre-hapten activation and consumer products - Speaker: Dave Roberts (Liverpool John Moores University)
- Skin absorption developments. Relevance of current test systems to man - Speaker: Monika Schäfer Korting (Free University of Berlin)
- Prohaptens: one view - Speaker: David Basketter (Consultant)
- Predicting pre- and pro- electrophilic activation of chemicals in skin sensitization assessment - Speaker: Chanita Kuseva (University of Bourgas)
- The skin as a metabolizing organ of pro-haptens. Understanding of the fate of reactive chemicals in the skin - Speaker: Hans Merk (University of Düsseldorf)
- Prohapten activation and subsequent interaction with proteins: mechanistic understanding and quantitative follow up... - Speaker: Jean-Pierre Lepoittevin (University of Strasbourg)
- Minimization of pre-hapten conversion (focus on oxidation) to haptens by improved formulation, storage and packaging - Speaker: Andreas Natsch (Givaudan)
Further in the form of smaller working groups the following questions were discussed:
- What are the main knowledge gaps in the clinical understanding of pre- and prohaptens and how would they be addressed? – Breakout Group Report
- What are the main knowledge gaps in the risk assessment of pre- and prohaptens and how could they be addressed – Breakout Group Report
Following an established procedure, a number of key conclusions were derived at the workshop and agreed by all participants. The Rapporteur's Progress Report is an unbiased summary of the debates held during the event developed by the workshop Rapporteur (Prof. Jim Bridges).
The next IDEA Workshop on pre- and prohaptens is scheduled for October 20 and 21, 2015 in Leuven, Belgium. The intention is to bridge what has been worked out in the June Expert Workshop and progressed over the summer, with the clinical findings.