ABSTRACT
Allergic contact dermatitis results from the immunological sensitization of susceptible individuals following topical exposure to chemical allergens. The clonal expansion of allergen-reactive T-lymphocytes in draining lymph nodes is a critical event during the induction phase of skin sensitization, and indeed there is evidence that the extent to which responsive T-lymphocytes expand in number correlates closely with the vigor of sensitization. Development of the local lymph node assay focused on assessment in situ of lymph node cell proliferative responses, thereby obviating the requirement for tissue culture. Since the first description of the local lymph node assay, a number of modifications have been proposed. These vary in nature from minor procedural changes to radical alterations in assay design. The local lymph node assay was developed originally as a novel approach to the identification of skin sensitizing chemicals. Consideration has been given to the possible use of the method for determining relative potency for the purposes of risk assessment.
