Research in vitiligo has continued for over 50 years, taking many interesting twists and turns along the way. The basic defect in vitiligo is the loss of melanocytes, the pigment-producing cells, resulting in visible white spots on the skin. However, the exact cause of this melanocyte disappearance has been the focus of a long-term debate. The truth has come on the shoulders of many scientists, each contributing important pieces to our understanding. Many are members of the VWG who provide their own research summaries below.
As a brief introduction to the field, early clinical observations in patients and their families revealed that vitiligo was closely associated with other autoimmune diseases, including type 1 diabetes, thyroiditis, pernicious anemia, Addison’s disease, suggesting that it was caused by autoimmunity. This was supported by the fact that melanocyte-specific antibodies were elevated in patient serum compared to healthy controls. However, clear evidence for their role in pathogenesis is lacking. Next, several groups reported that melanocytes from vitiligo patients are intrinsically fragile, having signs of elevated stress levels compared to those from healthy controls. This suggests that melanocytes were not merely targets of the immune system in vitiligo, but also contribute to the disease. Close histological examination revealed T cell infiltration into affected skin, and functional studies later implicated cytotoxic T cells as necessary and sufficient for killing of melanocytes in vitliginous skin. Recent genetic studies reveal a strong immune contribution toward disease susceptibility as well.
Many current basic and translational studies now focus on understanding the connection between melanocyte stress and autoimmune responses, novel pathways involved in pathogenesis, as well as targeting these pathways for the development of new treatments. Clinical research aims to measure the effect of vitiligo on patient quality of life, to improve diagnosis of disease, to better understand how often it occurs in the population, to measure the efficacy of current treatments, and to test new treatments in clinical trials.