We conducted a genome-wide association study of generalized vitiligo in the Chinese Han population by genotyping 1,117 cases and 1,429 controls. The 34 most promising SNPs were carried forward for replication in samples from individuals of the Chinese Han (5,910 cases and 9,916 controls) and Chinese Uygur (713 cases and 824 controls) populations. We identified two independent association signals within the major histocompatibility complex (MHC) region (rs11966200, Pcombined=1.48x10(-48), OR=1.90; rs9468925, Pcombined=2.21x10(-33), OR=0.74). Further analyses suggested that the strong association at rs11966200 might reflect the reported association of the HLA-A*3001, HLA-B*1302, HLA-C*0602 and HLA-DRB1*0701 alleles and that the association at rs9468925 might represent a previously unknown HLA susceptibility allele. We also identified one previously undescribed risk locus at 6q27 (rs2236313, Pcombined=9.72x10(-17), OR=1.20), which contains three genes: RNASET2, FGFR1OP and CCR6. Our study provides new insights into the genetic basis of vitiligo.

Various surgical procedures for the treatment of vitiligo which involve melanocyte transplantation or skin grafts have different inherent DR ratios. Transplantation of cultured pure melanocytes is an expensive and complicated procedure; however, it provides the highest DR ratio (> 1 : 10 and up to 1 : 60). Surgeons can select one of these methods for the treatment of vitiligo based on their experience and skill, on the size of lesions, and the availability of laboratory support.

BackgroundInterferon-γ (IFN-γ) plays an important role in the proceedings of vitiligo through recruiting lymphocytes to the lesional skin. However, the potential effects of IFN-γ on skin melanocytes and the subsequent contribution to the vitiligo pathogenesis are still unclear.ObjectiveTo investigate the effects of IFN-γ on viability and cellular functions of melanocytes.MethodsPrimary human melanocytes were treated with IFN-γ. Cell viability, apoptosis, cell cycle melanin content and intracellular reactive oxygen species (ROS) level were measured. mRNA expression was examined by real-time PCR. The release of interleukin 6 (IL-6) and heat shock protein 70 (HSP-70) was monitored by ELISA. β-galactosidase staining was utilized to evaluate melanocyte senescence.ResultsPersistent IFN-γ treatment induced viability loss, apoptosis, cell cycle arrest and senescence in melanocytes. Melanocyte senescence was characterized as the changes in pigmentation and morphology, as well as the increase of β-galactosidase activity. Increase of p21Cip1/Waf1 protein was evident in melanocytes after IFN-γ treatment. IFN-γ induction of senescence was attenuated by siRNAs against p21, Janus kinase 2 (JAK2) or signal transducer and activator of transcription 1 (STAT1), but not by JAK1 siRNA nor by p53 inhibitor pifithrin-α. IFN-γ treatment increased the accumulation of intracellular ROS in melanocytes, while ROS scavenger N-acetyl cysteine (NAC) effectively inhibited IFN-γ induced p21 expression and melanocyte senescence. IL-6 and HSP-70 release was significantly induced by IFN-γ treatment, which was largely inhibited by NAC. The increase of IL-6 and HSP-70 release could also be observed in senescent melanocytes.ConclusionIFN-γ can induce senescence in melanocytes and consequently enhance their immuno-competency, leading to a vitiligo-prone milieu.

All the three methods are safe and effective to treat vitiligo. Future studies with larger groups are warranted to confirm our results.