LLNA (Murine Local Lymph Node Assay)

1. Biological Effect: Sensitization
2. Turnaround time: 8 weeks
3. Sample Requirements:

ISO

50 cm² (test item < 0.5 mm thick);
25 cm² (test item ≥ 0.5 mm thick);
2 grams;
at least 6 test items;

4. Animal Quantity: 25 mice or more

ISO 10993-10

The purpose of the study is to determine the allergenic potential or sensitizing capacity of the medical device in the lymph nodes of mice. This reaction is measured by an increase in proliferation of lymphocytes in the lymph nodes draining the site of administration. The assay procedure is used for screening contact allergens in mice and extrapolating the results to humans but does not establish the actual risk of sensitization. The study involves 3 consecutive days of topical dosing to both ears followed by 2 days without treatment. The draining lymph nodes are subsequently harvested and a single cell suspension made. The Stimulation Index (SI) is obtained by comparing the proliferation of lymph node cells in assay animals versus that of the control animals. The medical device is considered:

• non-sensitizing when SI of test item ≤ 1.6 and SI of positive control (PC) > 1.6

or

• sensitizing when SI of test item > 1.6 and SI of positive control (PC) > 1.6