025 New developments in alopecia areata using rodent models

K.J. McElwee. Philipp University, Marburg, Germany.

Rodent models of human disease provide an important tool in the investigation of genetic and environmental activation factors, disease pathogenesis, and the development of new and improved treatments. Several inbred rodent models have been identified for alopecia areata (AA), a non-scarring inflammatory hair loss disease with suspected autoimmune elements. Up to 20% of C3H/HeJ mice and 70% of Dundee Experimental Bald Rats (DEBR) develop AA-like, patchy hair loss that may progress to universal alopecia. Hair loss is associated with peri- and intra-follicular lymphocyte and macrophage inflammation, but no significant scarring. These two rodent models have been employed in examining the mechanisms involved in AA. Manipulation of inflammatory cells by selective in vivo cell depletion or transfer between affected and unaffected C3H/HeJ mice indicates AA is primarily a cell mediated disease. Successful induction of AA by skin graft transfer between affected and unaffected mice has been used to examine changes in gene expression within AA-affected skin using flow cytometry and gene array technology. Rodents are now utilized to evaluate a variety of current treatments and for developing new therapies. The ability to follow the full course of AA throughout life including events prior to the onset of actual hair loss makes rodent models a considerable asset in AA research. The ability to induce AA-like disease with visible hair loss several weeks after surgery in the mouse AA model provides a consistent, controllable model for disease investigation and novel drug efficacy studies. Ultimately, animal models will be used to determine the genetic basis of AA, the potential endogenous and/or environmental trigger(s), the mechanism(s) of disease initiation and progression, and allow evaluation of new treatments.