Background: Vitiligo is a skin depigmentation disorder, for which, repigmentation treatment with combined follicular unit extraction (FUE) graft and narrowband ultraviolet B (NBUVB) is considered superior to micro-punch graft therapy. BMP4 can induce MITF expression in Neural crest stem cells (NCSCs), and α-MSH subsequently promotes the differentiation of MITF-expressing cells along the melanocyte lineage. Objective: To investigate why FUE grafting is superior to epidermal mini grafting in promoting hair follicles (HF) melanocyte cell survival and longevity, we planned the in vitro experiments HF bulge NCSCs differentiate into melanocyte precursors under the co-treatment of BMP4 and α-MSH. Methods: Cells that migrated from the HF bulge of scalp were cultured and assessed using immunofluorescence. Transcriptome analysis was performed on RNA sequencing results. Results: Basic fibroblast growth factor promotes the proliferation and survival of NCSCs, with spontaneous differentiation into SOX10+/SOX2+ glial progenitors, but not into SOX10+/MITF+ precursor melanocytes. Both BMP4 and α-MSH promoted the differentiation into MITF-expressing cells. RNA sequencing revealed a downregulation in neu-regulin-1 (NRG1) and sermaphorin 3C (SEMA3C), and upregulation in WNT10A. Furthermore, FUE grafting had a source of reservoir melanocytes superior to mini-grafting in treatment for vitiligo. Conclusion: We obtained SOX10+/ MITF+ precursor melanocytes through an induction of differentiation along the melanocyte lineage by BMP4 and α-MSH. According to the RNA sequencing results that NRG1 and SEMA3C were downregulated and WNT10A was upregulated, we postulated that HF NCSCs differentiated into melanocyte by co-treatment of BMP4 and α-MSH. Overall, FUE grafting is a more robust and substitutive treatment option for vitiligo. (Ann Dermatol 32(5) 409∼416, 2020

Alopecia areata is a chronic organ-specific autoimmune disease and it could be associated with other autoimmune diseases. We, herein, report a case of alopecia areata in a patient with a thymoma without myasthenia gravis. Multiple hairless patches rapidly developed 6 weeks before the first visit on the patient who had been newly diagnosed with thymoma 2 weeks before the hairless patches occurred, and thymectomy was done 2 weeks before visiting dermatologic department. She had no symptoms associated with myasthenia gravis, and there were no abnormal findings on neurologic exams and acetylcholine receptor autoantibody was not detected in serum. Scalp biopsy showed numerous lymphocytic inflammations around hair follicles and in immunohistochemical staining, the aggregation of CD4+ and CD8+ T cells was observed around hair follicles and FoxP3+ T lymphocytes were rarely observed around hair follicles. The patient refused any treatment and her hairless patches were completely recovered 3 months after thymectomy, without being recurred 3 years after thymectomy. On the basis of both clinical manifestations and histologic findings, we concluded that alopecia areata in the patient had developed in association with thymoma and was recovered rapidly after thymectomy.