The LLNA (Local Limp Node Assay) is the only validated for predicting the sensitisation potential with the lowest possible animal use and virtually no animal suffering (ECVAM, ICCVAM)
The LLNA (Local Lymph Node Assay) is highly predictive of the sensitization potential of chemicals.
The LLNA is the only approved test for this use both in Europe (ECVAM) and the US (ICCVAM). This test is quantitative (i.e., it establishes the sensitizing potential of the tested substances). Moreover, it s performed in mice, with limited animal number and suffering, as compared to previously available, “classical” tests on guinea pigs (e.g., GMPT, Buheler test) and it can not be performed for the evaluation of cosmetics. It is useful for biomedical devices, biocides, drugs, household detergents, chemicals. The LLNA is recommended by the EC Directive ReACH
Recently, a reduced variant of this test has been approved by ECVAM (see abstract) which allows only a preliminary evaluation (i.e., a “yes or no” type of answer) and is suitable for systematic analysis of several substances. The reduced LLNA can also be used for single substances, which are predicted to be non-sensitizers, but have never been specifically tested.
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LLNA has been designed and approved with the explicit intent to prevent and limit animal sufferings and the number of test animals. It is the only assay accepted for the prediction of skin sensitization both in Europe and in the US. All reproducibility and sensitivity evaluations allowed conclude, over a 15-years trial period, that inter- and intra-laboratory variability can be limited to acceptable levels, when the approved protocol is carefully respected. Moreover, this test allows quantification of the sensitization potential of the test substance.