P50 HUMAN HAIR GROWTH PROMOTED BY IMMUNOPHILIN LIGANDS

Krisp A., Niiyama S., Wenzel E., Huth A., Happle R., Hoffmann R.; Department of Dermatology, Philipp University, Marburg, Germany

Immunophilin ligands (Ipl) such as Cyclosporin A (CyA) are not only potent immunosuppressants but also effective modulators of human hair growth. Many CyA-treated patients will experience hypertrichosis whereas FK 506 (FK)-treated patients do not, or only occasionally. The promotion of hair growth by CyA and FK is presented using an ex vivo model of the human hair follicle (HF).

Informed consent was obtained from 18 volunteers and excisional scalp biopsies were taken under local anesthesia. Intact, viable anagen HF were isolated by microdissection as described by Hoffmann et al. The HF were kept in multiwell plates in Williams E medium supplemented with L-glutamine (2 mM), insuline (10mg/ml), transferrin (10mg/ml), sodium selenite (10ng/ml), Fungizone (2.5mg/ml), and penicilline/streptomycin (100U/ml:100mg/ml) up to eight days. HF were incubated with CyA (10nM, 30nM, 100nM) and FK(1nM, 3nM, 10nM) to observe the most growth inducing dose of the Ipl. Thereafter the HF were kept at optimal growth inducing Ipl doses to compare capacities of CyA and FK. Our results show that not only CyA but also FK promote human hair growth in vitro. A clear cut of dose dependent induction was observed with maximal hair growth at doses of 10 nM for CyA and 3 nM for FK. Interestingly the best enhancer of hair growth was FK when the optimal growth inducing doses of the Ipl were compared. We observed increased hair growth even after four days and at a lower dose of CyA compared to the data published by Taylor et al. Though the molecular basis of this pharmalogical side effect remains unknown non immunosuppressant Ipl may be suitable for the treatment of distinct forms of alopecia.