P49 USE OF CRUDE HAIR FOLLICLE EXTRACTS TO INDUCE, OR TO INCREASE RESISTANCE TO ALOPECIA AREATA IN C3H/HeJ MICE.

¹McElwee KJ., ¹Wenzel E., ¹Freyschmidt-Paul P., ²Sundberg JP., ¹Hoffmann R. ¹Dept. Dermatology, Philipp University, Marburg, Germany; ²The Jackson Laboratory, Bar Harbor, ME, USA.

AA can be induced in normal haired recipient mice by transfer of draining lymph node cells. Here, we investigated the potential of hair follicle antigen extracts to promote, or increase resistance to, AA.

Crude hair follicle extracts from AA affected and normal haired mouse skin were emulsified with an equal volume of complete Freund’s adjuvant (CFA) and 0.2 mls were injected subcutaneously in normal haired C3H/HeJ mice. Four groups of 6 mice received either 400mg or 50mg of AA affected hair follicle extract, 400mg normal hair follicle extract, or a PBS – CFA emulsion. In addition, all mice received 400ng pertussis toxin intraperitoneally. Two weeks later, mice received a booster injection of the same antigen type and concentration emulsified in incomplete Freund’s adjuvant. One mouse that received 400mg and one that received 50mg AA hair follicle antigen extract developed temporary hair loss adjacent to the site of injection and granuloma formation that persisted for 7 and 3 weeks respectively. Two control mice and 3 mice receiving AA affected hair follicle antigen extracts died as a result of the adjuvant and pertussis toxin challenge. Remaining mice showed no hair loss.

In a separate study, 4 mice each were injected intraperitoneally with 750mg antigen extract from AA affected mouse hair follicles, normal follicles, or bovine albumin and grafted with AA affected skin three weeks later. None of eight mice receiving hair follicle antigen extracts developed AA whereas 3 of 4 mice receiving bovine albumin developed AA 6 to 10 weeks after grafting.

Preliminary study results must be confirmed with larger trials. However, initial observations suggest appropriately presented hair follicle antigens may promote tolerance to AA onset. Induction of AA with hair follicle antigens may be possible with purified antigen extracts.