Research

Scientific description of Vitiligo program at Kaohsiung Medical University

Our work on vitiligo focused on two major topics: elucidating the pathogenesis of vitiligo vulgaris and clarifying the mechanisms involved in vitiligo treatment. For our work regarding the pathogenesis of vitiligo, we have elucidated that (1) Langerhans cell is one of major cells involved in MC destruction (Kao and Yu, 1990), (2) IgG antibodies purified from patients with vitiligo (anti-MC Abs) destroy MC through antibody–dependent cellular cytotoxicity pathway (Yu et al, 1993), (3) presence of non-cytotoxic anti-keratinocyte (KC) IgG in vitiligo patients (Yu et al, 1993), and (4) IgG anti-MC Abs induce abnormal expressions of HLA-DR and ICAM-1 on MCs that would facilitate the attack of antigen-specific immune effector cells leading to melanocytotoxicity (Li et al, 2000). For our studies regarding the mechanisms involved in vitiligo treatments, we have shown that (1) psoralen plus UVA (PUVA) therapy depletes vitiligo-associated MC antigens, therefore preventing residual functional MC from further damages (Kao and Yu, 1992), (2) narrow-band UVB treatment stimulates proliferation and migration of MCs, promoting repigmentation of vitiligo lesions (Wu et al, 2004), (3) helium-neon laser irradiation is an effective treatment for vitiligo. It stimulates pigment cells at various maturation stages in different ways to promote efficient repigmentation (Yu et al, 2003, Lan et al, 2006, Lan et al, 2009), (4) FK506 effectively treats vitiligo by inducing stem cell factor release from KCs, therefore creating a favorable environment for pigment cells to grow (Lan et al, 2005), and (5) PUVA and narrow-band UVB induce repigmentation in vitiligo through different pathways (Wu et al, 2007).  Using the vitiligo repigmentation platforms which we have already established, we are now exploring the possibility of using visible lights at different wavelengths at cellular and tissue levels for vitiligo repigmentation.  We are looking forward to embark on relevant clinical trials in a timely manner.   Taking advantage of the recent technical developments in medical research, we are also establishing a new classification scheme for vitiligo at genomic level.  It is our hope that in the near future, we will able to treat vitiligo patients according to this new classification scheme.

Reference:

Kao CH, Yu HS. Depletion and repopulation of Langerhans cells in nonsegmental type vitiligo. J Dermatol 17:287-296, 1990.

Kao CH, Yu HS. Comparison of the effect of 8-methoxypsoralen (8-MOP) plus UVA (PUVA) on human melanocytes in vitiligo vulgaris and in vitro. J Invest Dermatol 98:734-740, 1992.

Lan CC, Chen GS, Chiou MH, Wu CS, Chang CH, Yu HS. FK506 promotes melanocyte and melanoblast growth and creates a favourable milieu for cell migration via keratinocytes: possible mechanisms of how tacrolimus ointment induces repigmentation in patients with vitiligo. Br J Dermatol 153: 498-505, 2005.

Lan CC, Wu CS, Chiou MH, Hsieh PC, Yu HS. Low-energy helium-neon laser induces locomotion of the immature melanoblasts and promotes melanogenesis of the more differentiated melanoblasts: recapitulation of vitiligo repigmentation in vitro. J Invest Dermatol 126:2119-2126, 2006.

Lan CC, Wu CS, Chiou MH, Chiang TY, Yu HS. Low-energy helium-neon laser induces melanocyte proliferation via interaction with type IV collagen: visible light as a therapeutic option for vitiligo. Br J Dermatol 2009, in press.

Li YL, Yu CL, Yu HS. IgG anti-melanocyte antibodies purified from patients with active vitiligo induce HLA-DR and intercellular adhesion molecule-1 expression and an increase in interleukin-8 release by melanocytes. J Invest Dermatol 115: 969-973, 2000.

Wu CS, Yu CL, Wu CS, Lan CC, Yu HS. Narrow-band ultraviolet-B stimulates proliferation and migration of cultured melanocytes. Exp Dermatol 13:755-763, 2004.

Wu CS, Lan CC, Wang LF, Chen GS, Wu CS, Yu HS. Effects of psoralen plus ultraviolet A irradiation on cultured epidermal cells in vitro and patients with vitiligo in vivo. Br J Dermatol 156:122-129, 2007.

Yu HS, Kao CH, Yu CL. Coexistence and relationship of antikeratinocyte and antimelanocyte antibodies in patients with non-segmental-type vitiligo. J Invest Dermatol 100: 823-828, 1993.

Yu HS, Wu CS, Yu CL, Kao YH, Chiou MH. Helium-neon laser irradiation stimulates migration and proliferation in melanocytes and induces repigmentation in segmental-type vitiligo. J Invest Dermatol 120:56-64, 2003.