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Use of cause-and-effect analysis to optimize the reliability of in vitro inhalation toxicity measurements using an air-liquid interface



Elijah Petersen, Monita Sharma, Amy Clippinger, John Gordon, Aaron Katz, Peter Laux, Lars Leibrock, Andreas Luch, Joanna Matheson, Andreas Stucki, Jutta Tentschert, Frank Bierkandt


In vitro inhalation toxicology methods are increasingly being used for research and regulatory purposes. While the opportunity for increased human relevance of in vitro inhalation methods compared to in vivo tests has been established and discussed, how to systematically account for variability and maximize the reliability of these in vitro methods, especially for assays that use cells cultured at an air liquid interface (ALI), has received less attention. One tool that has been used to evaluate the robustness of in vitro test methods is cause-and-effect (C&E) analysis, a conceptual approach to analyze key sources of potential variability in a test method. These sources of variability can then be evaluated using robustness testing or they can be incorporated into process control measurements in the assay protocol. There are many differences among in vitro inhalation test methods—including the use of different types of biological test systems, exposure platforms/conditions, substances tested, and endpoints—all of which should be considered when evaluating these methods. In this manuscript, we describe how C&E analysis can be applied using a modular approach based on the idea that shared components of different test methods (e.g., the same exposure system is used) have similar sources of variability even though other components may differ. C&E analyses of different in vitro inhalation methods revealed a common set of recommended exposure system and biological in-process control measurements. The approach described in this paper, when applied in conjunction with Good Laboratory Practices (GLP) criteria, should help improve the inter- and intralaboratory agreement of in vitro inhalation test results, leading to increased confidence in these methods for regulatory and non-regulatory purposes.
Chemical Research in Toxicology


Petersen, E. , Sharma, M. , Clippinger, A. , Gordon, J. , Katz, A. , Laux, P. , Leibrock, L. , Luch, A. , Matheson, J. , Stucki, A. , Tentschert, J. and Bierkandt, F. (2021), Use of cause-and-effect analysis to optimize the reliability of in vitro inhalation toxicity measurements using an air-liquid interface, Chemical Research in Toxicology, [online], (Accessed March 4, 2024)
Created September 29, 2021, Updated November 29, 2022