The Treatment of Refractory Vitiligo With Autologous Cultured Epithelium Grafting: A Real-World Retrospective Cohort Study

BACKGROUND

Surgical intervention is the main therapy for refractory vitiligo. We developed a modified autologous cultured epithelial grafting (ACEG) technique for vitiligo treatment. Between January 2015 and June 2019, a total of 726 patients with vitiligo underwent ACEG in China, with patient characteristics and clinical factors being meticulously documented. Using a generalized linear mixed model, we were able to assess the association between these characteristics and the repigmentation rate.

RESULTS

ACEG demonstrated a total efficacy rate of 82.81% (1754/2118) in treating 726 patients, with a higher repigmentation rate of 64.87% compared to conventional surgery at 52.69%. Notably, ACEG showed a better response in treating segmental vitiligo, lesions on lower limbs, age ≤ 18, and stable period > 3 years. A keratinocyte:melanocyte ratio below 25 was found to be advantageous too. Single-cell RNA sequencing analysis revealed an increase in melanocyte count and 2 subclusters of keratinocytes after ACEG, which remained higher in repigmented sites even after 1 year.

CONCLUSIONS

ACEG is a promising therapy for refractory vitiligo. Patient age, clinical type, lesion site, and stability before surgery influence repigmentation in ACEG. The mechanism of repigmentation after ACEG treatment is likely not confined to the restoration of melanocyte populations. It may also involve an increase in the number of keratinocytes that support melanocyte function within the affected area. These keratinocytes may aid the post-transplant survival and function of melanocytes by secreting cytokines and extracellular matrix components.

TRIAL REGISTRATION

registered with Chictr.org.cn (ChiCTR2100051405).

Autologous cell transplant as a treatment for stable segmental vitiligo: a systematic review

OBJECTIVE

This systematic review provides a comprehensive analysis of the efficacy of autologous cell transplant as a therapeutic approach for stable segmental vitiligo. Vitiligo poses significant challenges for healthcare professionals in terms of treatment selection. Autologous cell transplant has emerged as a promising modality for managing vitiligo, with cultured and noncultured transplants being considered when determining the patient's treatment approach. There is little knowledge and literature on the subject, so we analyze the different studies.

METHOD

Using online medical literature databases and the PRISMA guidelines, six out of 60 articles met the acceptance criteria to be analyzed, emphasizing the lack of current literature on this subject.

RESULTS

Autologous cell transplant achieves excellent pigmentation rates for many body parts. We found that cultivated cells had better results than noncultivated ones. Both types of treatments could pigment 80% or more where needed.

CONCLUSION

This review highlights the importance of autologous cell transplant as a new and reliable tool for the treatment of stable segmental vitiligo, cultured transplants being the most effective. By employing autologous cell transplant, the repigmentation rate is notably high and consistently achievable. Although its cost and logistical complexities hinder the current accessibility to this therapy, efforts are being made to enhance its availability, and its scope is expected to expand further. More studies are needed to understand this therapy method in other kinds of vitiligo.

Lesional CD8+ T-Cell Number Predicts Surgical Outcomes of Melanocyte-Keratinocyte Transplantation Surgery for Vitiligo

The melanocyte-keratinocyte transplantation procedure (MKTP) treats stable and recalcitrant vitiligo. Despite careful selection of candidates based on clinical stability, the success of the procedure is unpredictable. The aim of our study was to define the immunological profile of stable vitiligo lesions undergoing MKTP and correlate them with clinical outcomes. We included 20 MKTP candidates with vitiligo and a patient with piebaldism as a control. Prior to MKTP, T-cell subsets and chemokines in the recipient skin were measured by flow cytometry and ELISA. During MKTP, melanocytes in the donor skin were quantified by flow cytometry. After MKTP, patients were followed for 12 months and repigmentation was assessed clinically and by ImageJ analysis of clinical photographs. Baseline immunologic biomarkers, duration of clinical stability, and transplanted melanocyte number were correlated to postsurgical repigmentation scores. CD8+ T cells were elevated in 43% of the clinically stable vitiligo lesions. CD8+ T-cell number negatively correlated with postsurgical repigmentation scores (r = -0.635, P = 0.002). Duration of clinical stability, skin chemokines, and transplanted melanocyte number did not influence postsurgical repigmentation. This study demonstrates that CD8+ T-cell number correlates negatively with success of postsurgical repigmentation and can be a biomarker to identify ideal surgical candidates.

Safety and Efficacy of Autologous Melanocyte/Keratinocyte Transplantation in Patients with Refractory Stable Vitiligo

BACKGROUND

Vitiligo is a common depigmentation skin disease associated with significant psychosocial morbidity and profound effect on the quality of life. The treatment of vitiligo is still a major challenge in the field of dermatology. Currently, topical steroids, calcineurin inhibitors, ultraviolet phototherapy, surgery, and cultured and non-cultured epidermal melanocyte transplantation are used for the treatment of vitiligo. However, the effectiveness of these treatment modalities is limited by the lack of response, long-term treatment periods, high cost, and inevitable adverse effects.

OBJECTIVES

In this study, we aimed to evaluate the efficacy of intraepidermal injection of autologous non-cultured melanocytes and keratinocytes as an alternative therapy for the refractory and stable (RS) vitiligo.

METHODS

The treatment procedure was performed on thirty-nine RS vitiligo patients. The autologous skin grafts obtained from the buttock area and epidermis were separated from dermis using dispase. Single-cell autologous melanocytes and keratinocytes were prepared from the epidermis by trypsin/ethylene diamine tetra acetic acid and injected at the concentration of 100-400 × 103 cells/cm2, intra-epidermally to the selected vitiligo lesions. Vitiligo re-pigmentation was monitored employing photography. Photographs were taken prior to and 2, 4, and 6 months after the cell transplantation. Improvement of the skin depigmentation was classified as follows: <25% as minimal response, 26-50% as moderate response, 51-75% as good response, and finally 76-100% as excellent response.

RESULTS

Cell infusion appeared to be safe as none of the patients exhibited any adverse effects. At the end of the sixth month follow-up period, of the treated patients, 12.8% demonstrated an excellent response, 36% exhibited a good response, and 51.2% showed a moderate to minimal response to the administered therapy. Obtained significant p value for Wilcoxon test over the checkpoints at 2nd, 4th, and 6th month (p = 0.03, 0.04, and 0.039, respectively) post-cell transplantation confirmed notable growing trend in the re-pigmentation.

CONCLUSION

Our findings provide a strong support for the therapeutic efficacy of autologous non-cultured melanocytes and keratinocytes in patients with RS vitiligo.

Recipient-to-Donor Ratios in the Surgical Treatment of Vitiligo, Leukoderma, and Piebaldism: A Retrospective Review

BACKGROUND

The autologous noncultured melanocyte keratinocyte transplant procedure (MKTP) has emerged as a popular grafting technique with proven efficacy for achieving repigmentation. However, there remains no consensus regarding the optimal recipient-to-donor (RD) ratio required to achieve acceptable repigmentation. In this retrospective cohort study of 120 patients, we sought to examine whether expansion ratios impact the repigmentation success rates following MKTP.

RESULTS

A total of 69 patients (mean [SD] age was 32.4 [14.3] years, mean follow-up was 30.4 [22.5] months, 63.8% were male; 55% were dark-skinned individuals [Fitzpatrick IV-VI]) were included. The mean percent change in the Vitiligo Area Scoring Index (VASI) was 80.2 (±23.7; RD of 7.3) in patients with focal/segmental vitiligo (SV), 58.3 (±33.0; RD of 8.2) in those with non-segmental vitiligo (NSV), and 51.8 (±33.6; RD of 3.7) in those with leukoderma and piebaldism. Focal/SV was positively associated with a higher percent change in VASI (parameter estimate: 22.6, p value <0.005). In the SV/focal group, non-white patients had a higher RD ratio compared to White individuals (8.2 ± 3.4 vs. 6.0 ± 3.1, respectively, p value = 0.035).

DISCUSSION

In our study, we found that patients with SV were significantly more likely to achieve higher repigmentation rates compared to those with NSV. Although repigmentation rates were higher in the low expansion ratio group than in the high expansion ratio group, we did not observe a significant difference between the two groups.

CONCLUSION

MKTP is an effective therapy for restoring repigmentation in patients with stable vitiligo. Therapeutic response of vitiligo to MKTP appears to be influenced by the type of vitiligo, rather than a specific RD ratio.

A pilot multi-centre prospective randomised controlled trial of RECELL for the treatment of venous leg ulcers

Venous leg ulcers (VLUs) have a significant impact on approximately 3% of the adult population worldwide, with a mean NHS wound care cost of £7600 per VLU over 12 months. The standard care for VLUs is compression therapy, with a significant number of ulcers failing to heal with this treatment, especially with wound size being a risk factor for non-healing. This multicentre, prospective, randomised trial evaluated the safety and effectiveness of autologous skin cell suspension (ASCS) combined with compression therapy compared with standard compression alone (Control) for the treatment of VLUs. Incidence of complete wound closure at 14 weeks, donor site closure, pain, Health-Related Quality of Life (HRQoL), satisfaction, and safety were assessed in 52 patients. At Week 14, VLUs treated with ASCS + compression had a statistically greater decrease in ulcer area compared with the Control (8.94 cm2 versus 1.23 cm2 , P = .0143). This finding was largely driven by ulcers >10 to 80 cm2 in size, as these ulcers had a higher mean percentage of reepithelialization at 14 weeks (ASCS + compression: 69.97% and Control: 11.07%, P = .0480). Additionally, subjects treated with ASCS + compression experienced a decrease in pain and an increase in HRQoL compared with the Control. This study indicates that application of ASCS + compression accelerates healing in large venous ulcers.

Disorders of Hypopigmentation

Hypopigmentation and depigmentation of the skin can be due to multiple causes and has a broad differential diagnosis. The most common cause of depigmentation worldwide is vitiligo. This disorder affects 1-2% of the world’s population and is seen in all races. Vitiligo is an autoimmune disorder in which the predominant cause is an attack by CD8+ cytotoxic T cells on melanocytes in the epidermis. This condition can have a significant negative impact on the quality of life of affected individuals. Treatment options currently include psychological counseling, topical therapy, systemic therapy, phototherapy, surgical therapy, and depigmentation. In patients with stable, refractory disease, successful repigmentation has been achieved using mini-punch grafting, blister grafting, and non-cultured epidermal suspension (NCES) grafting. Emerging therapies include the Janus kinase (JAK) inhibitors ruxolitinib and tofacitinib. Further studies exploring the pathogenesis of vitiligo are warranted in order to optimize treatment for affected patients. J Drugs Dermatol. 2019;18(3 Suppl):s115-116.

Bioreactor Microcarrier Cell Culture System (Bio-MCCS) for Large-Scale Production of Autologous Melanocytes

Restoration of cutaneous pigmentation can be achieved in stable vitiligo by autologous cultured melanocyte transplantation. It was the goal of this study to construct a bioreactor microcarrier cell culture system (Bio-MCCS) to produce autologous melanocytes in large scale. In this Bio-MCCS, porcine gelatin microbeads were used as microcarriers, spinning bottle as fermented tank. Autologous melanocytes were able to attach to and proliferate on the gelatin microbeads in serum-free melanocyte medium in the Bio-MCCS, reaching up to 24-fold the cells seeded on day 15 (MTT assay). These autologous melanocytes cultured on gelatin microbeads could leave the microbeads and proliferate on the bottom of tissue culture flasks. Although Pluronic F68 has been widely used to protect animal cells from hydrodynamic stress in animal cell bioreactors, Pluronic F68 at a concentration of 0.25–1.0% showed no significant protective effects on the autologous melanocytes cultured on the microbeads and subjected to mechanical stress in the Bio-MCCS. This Bio-MCCS using porcine gelatin microbeads as microcarriers enabled large-scale production of autologous mela-nocytes, offering a potential treatment for large-area stable vitiligo by direct administration of the melanocytes cultured on the gelatin microbeads to the vitiliginous site.

Management of vitiligo patients with surgical interventions

Vitiligo is an acquired depigmentation disorder of unknown etiology. Medical treatments are usually reasonably effective for nonstable vitiligo patches; however, for vitiligo patches that have been stable for a substantial period of time, surgical intervention should be considered. In this article, surgical interventions for vitiligo are reviewed, including split-thickness skin grafting, suction blister grafting, miniature punch grafting, and cultured melanocyte transplantation.

Vitiligo in adults and children: surgical interventions

INTRODUCTION

Vitiligo is an acquired skin disorder characterised by white (depigmented) patches in the skin, due to the loss of functioning melanocytes. The extent and distribution of vitiligo often changes during the course of a person's lifetime and its progression is unpredictable.

METHODS AND OUTCOMES

We conducted a systematic review and aimed to answer the following clinical question: What are the effects of surgical interventions for vitiligo in adults and in children? We searched: Medline, Embase, The Cochrane Library, and other important databases up to April 2014 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).

RESULTS

We found four studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.

CONCLUSIONS

In this systematic review we present information relating to the effectiveness and safety of the following interventions: blister grafts, cultured cellular transplantation, non-cultured cellular transplantation, punch/mini grafts, and split thickness skin grafts.

Analysis of blood and lymph vascularization patterns in tissue-engineered human dermo-epidermal skin analogs of different pigmentation

PURPOSE

Bioengineered dermo-epidermal skin analogs containing melanocytes represent a promising approach to cover large skin defects including restoration of the patient's own skin color. So far, little is known about the development of blood and lymphatic vessels in pigmented skin analogs after transplantation. In this experimental study, we analyzed the advancement and differences of host blood and lymphatic vessel ingrowth into light- and dark-pigmented human tissue-engineered skin analogs in a rat model.

METHODS

Keratinocytes, melanocytes, and fibroblasts from light- and dark-pigmented skin biopsies were isolated, cultured, and expanded. For each donor, melanocytes and keratinocytes were seeded in ratios of 1:1, 1:5, and 1:10 onto fibroblast-containing collagen gels. The skin analogs were subsequently transplanted onto full-thickness wounds of immuno-incompetent rats and quantitatively analyzed for vascular and lymphatic vessel density after 8 and 15 weeks.

RESULTS

The skin analogs revealed a significant difference in vascularization patterns between light- and dark-pigmented constructs after 8 weeks, with a higher amount of blood vessels in light compared to dark skin. In contrast, no obvious difference could be detected within the light- and dark-pigmented group when varying melanocyte/keratinocyte ratios were used. However, after 15 weeks, the aforementioned difference in blood vessel density between light and dark constructs could no longer be detected. Regarding lymphatic vessels, light and dark analogs showed similar vessel density after 8 and 15 weeks, while there were generally less lymphatic than blood vessels.

CONCLUSION

These data suggest that, at least during early skin maturation, keratinocytes, melanocytes, and fibroblasts from different skin color types used to construct pigmented dermo-epidermal skin analogs have distinct influences on the host tissue after transplantation. We speculate that different VEGF expression patterns might be involved in this disparate revascularization pattern observed.

Transplantation of melanocytes obtained from the skin ameliorates apomorphine-induced abnormal behavior in rodent hemi-parkinsonian models

Tyrosinase, which catalyzes both the hydroxylation of tyrosine and consequent oxidation of L-DOPA to form melanin in melanocytes, is also expressed in the brain, and oxidizes L-DOPA and dopamine. Replacement of dopamine synthesis by tyrosinase was reported in tyrosine hydroxylase null mice. To examine the potential benefits of autograft cell transplantation for patients with Parkinson’s disease, tyrosinase-producing cells including melanocytes, were transplanted into the striatum of hemi-parkinsonian model rats or mice lesioned with 6-hydroxydopamine. Marked improvement in apomorphine-induced rotation was noted at day 40 after intrastriatal melanoma cell transplantation. Transplantation of tyrosinase cDNA-transfected hepatoma cells, which constitutively produce L-DOPA, resulted in marked amelioration of the asymmetric apomorphine-induced rotation in hemi-parkinsonian mice and the effect was present up to 2 months. Moreover, parkinsonian mice transplanted with melanocytes from the back skin of black newborn mice, but not from albino mice, showed marked improvement in the apomorphine-induced rotation behavior up to 3 months after the transplantation. Dopamine-positive signals were seen around the surviving transplants in these experiments. Taken together with previous studies showing dopamine synthesis and metabolism by tyrosinase, these results highlight therapeutic potential of intrastriatal autograft cell transplantation of melanocytes in patients with Parkinson’s disease.

Vitiligo surgical, laser, and alternative therapies: a review and case series

INTRODUCTION

Vitiligo is a condition caused by the destruction of melanocytes, resulting in areas of skin without pigmentation. While many topical therapies exist for its treatment, not all patients respond to such treatments. Various surgical, laser and other alternative therapies are available for use as well.

OBJECTIVE

The objective of this review was to describe the various surgical, laser, and alternative therapies available for vitiligo. A literature review was conducted through Pubmed and Ovid using the search terms "Vitiligo treatment", "Vitiligo surgery", "Vitiligo laser". Since no articles were available about needling on both Pubmed and Ovid using the search criteria, individual articles were sought out through Google.

RESULTS

The literature review yielded many possible surgical interventions including autologous mini-punch grafting, suction epidermal blister grafting, split-thickness grafting, and cultured and noncultured melanocyte keratinocyte transfer. Laser options included the helium-neon and xenon-chloride lasers, with tattooing and needling serving as other options. While all the above techniques can provide improvement to pigmentation in vitiliginous patches, physician comfort and experience are important factors with regards to outcome. Our case series of four patients treated with the needling method yielded favorable results, with repigmentation rates ranging from 25-50%, with one patient having 90% repigmentation.

CONCLUSION

There are many surgical, laser, and alternative treatment options available for vitiligo when conventional medical therapy fails or for use in conjunction with medical therapies. Autologous mini punch grafting and needling both have minimal equipment requirements and are easy to learn. Physician experience and comfort play a large role in outcome and availability of services.

Improved method of differentiation, selection and amplification of human melanocytes from the hair follicle cell pool

Hair root harbours a complex cell pool with an immense developmental potential. Several lineages, including skin, can be differentiated from the multipotent to pluripotent cells of outer root sheath (ORS) of hair follicle. Outer root sheath presents the most opulent non-invasively gained adult stem cell source known. For the purposes of cultivating melanocytes designated for graft-based treatments of depigmentation disorders, we have established an ex vivo/in vitro cultivation method by introducing several methodological improvements to the ORS explant method of Dieckmann. As a result, we gained a higher, purer yield of differentiated melanocytes in half the time (at least 10(6) of 95% pure cells in 4 weeks). This reliable cultivation procedure begins with the epilation of 60 hairs and yields high numbers of ORS melanocytes that could be used for grafting applications. The procedure not only utilises the developmental potential of hair root cell pool and favors differentiation into melanocytes, but also contributes to the general trend of minimal-to-non-invasive strategies for regenerative medicine.

Melanocytes transplantation in patients with vitiligo using needling micrografting technique

BACKGROUND

Some cases of vitiligo require melanocyte transplantation, but these surgical techniques have varying degrees of success.

OBJECTIVES

To perform melanocytes transplantion in patients with vitiligo using a new needling micrografting technique.

PATIENTS AND METHODS

This interventional case study took place at the Department of Dermatology and Venereology at Baghdad Teaching Hospital from December 2010 to September 2011. Twelve patients with vitiligo were included. A split-thickness skin graft was taken from the normal area and cut into micropieces ranging from 0.1 mm to 0.3 mm in diameter. The recipient area was anesthetized, and the micrografts were then implanted into the dermis using the needling technique. The number of implanted micrografts depended on the size of the recipient area. Follow-up was conducted every 2 weeks for the first month and then every 4 weeks for a further 16 weeks.

RESULTS

The intake rate of grafting at week 2 ranged from 90% to 100%. The micrografts started producing noticeable pigmentation at week 2, and pigmentation was obvious at week 4. At week 8, the rate of pigmentation ranged from 10% to 90% (25.24%), and at week 16 it ranged from 10% to 100% (61.36%).

CONCLUSION

This new approach to the treatment of vitiligo delivers rapid and satisfactory pigmentation.

Dermal mesenchymal stem cells (DMSCs) inhibit skin-homing CD8+ T cell activity, a determining factor of vitiligo patients' autologous melanocytes transplantation efficiency

We here investigated the efficiency of autologous melanocyte transplantation of 23 vitiligo patients by focusing on perilesional skin homing CD8+ T lymphocytes, and studied the potential effect of dermal mesenchymal stem cells (DMSCs) on CD8+ T cell activities in vitro. Out of 23 patients with the autologous melanocyte transplantation, 12 patients (52.17%) had an excellent re-pigmentation, 6 patients (26.09%) had a good re-pigmentation, 5 patients (21.74%) had a fair or poor re-pigmentation. CD8+ T cells infiltrating was observed in the perilesional vitiligo area of all patients. Importantly, the efficiency of the transplantation was closely associated with skin-homing CD8+ T cell activities. The patients with high number of perilesional CD8+ T cells or high level of cytokines/chemokines were associated with poor re-pigmentation efficiency. For in-vitro experiments, we successfully isolated and characterized human DMSCs and skin-homing CD8+ T cells. We established DMSCs and CD8+ T cell co-culture system, where DMSCs possessed significant inhibitory effects against skin homing CD8+ T lymphocytes. DMSCs inhibited CD8+ T cells proliferation, induced them apoptosis and regulated their cytokines/chemokines production. Our results suggest that vitiligo patients’ autologous melanocytes transplantation efficiency might be predicted by perilesional skin-homing CD8+ T cell activities, and DMSCs might be used as auxiliary agent to improve transplantation efficacy.

Co-culture of melanocytes with adipose-derived stem cells as a potential substitute for co-culture with keratinocytes

Cell-to-cell interactions between melanocytes and keratinocytes increase the proliferation and migration of melanocytes. In fact, mixed keratinocyte and melanocyte cultures have been used for autologous cell transplantation for treatment of vitiligo. However, this may require taking an amount of skin tissue large enough to leave scars. In this study, the in vitro effect of adipose-derived stem cells (ADSCs) on proliferation, differentiation and migration of melanocytes was compared with that of keratinocytes using immunohistochemistry and a Boyden chamber migration assay. The proliferation and migration of melanocytes was significantly stimulated by co-culture with ADSCs compared with melanocyte monocultures, al-though the effect of ADSCs was less powerful than that of keratinocytes. This may be related to increases in stem cell factor and basic fibroblast growth factor, growth factors for melanocytes, produced by the ADSCs. The ratios of melanocytes stained with antibodies against Trp-2, E-cadherin and N-cadherin were significantly increased by co-culturing with ADSCs compared with co-culturing with keratinocytes as well as melanocyte monocultures. The proportion of less-pigmented melanocytes was also increased and sustained for a longer duration in the presence of ADSCs. Our data show that co-culturing with ADSCs results in increased melanocyte proliferation and migration while reducing differentiation, and could provide a means to treat disorders such as vitiligo.

Treatment of vitiligo with a melanocyte-keratinocyte cell suspension versus dermabrasion only: a pilot study with a 12-month follow up

BACKGROUND

Dermabrasion is a surgical procedure that has been used for repigmentation; however, autologous transplantation of uncultured melanocytes in a suspension combined with the use of adjunct treatment provides better results.

PURPOSE

To evaluate the clinical effectiveness of dermoabrasion (DA) and melanocyte-keratinocyte cell suspension transplantation (DA+MKT) vs. dermabrasion with no adjunct treatment.

MATERIALS AND METHODS

We selected 11 patients (six women and five men) with stable vitiligo. From these, two achromic maculae of similar size were selected. One macule was treated with DA+MKT and the other with DA only. The main parameter of treatment efficacy was the percentage of repigmentation in the area treated, three and 12 months after implantation.

RESULTS

In seven of the 11 patients, slightly better pigmentation occurred with DA+MKT. Two of these patients had a repigmentation greater than 50 percent and in two other patients, the result was similar for both techniques, although slightly better with MKT. Two more patients showed less than 20 percent repigmentation, but only in the area treated with DA+MKT. One patient showed pigmentation initially after DA+MKT only, and subsequent depigmentation.

CONCLUSION

DA+MKT produced slightly better repigmentation than DA only when given without adjunct treatment in a 12-month follow-up period.

Vitiligo: current medical and scientific understanding

Vitiligo is a relatively common acquired skin depigmentary disease with a complex presentation, therapy, and etiology. Both the prognosis and therapeutic response for patients with vitiligo is unpredictable. Multiple current therapies exist however the efficacy of these are not optimal. The cause of vitiligo appears to be a combination of genetic effects in both the immune system and the melanocyte itself with a precipitating factor instigating their interaction and resulting in the melanocyte destruction. Headway is being made in understanding the etiology of vitiligo that should culminate in new and improved therapies.

[Perspectives of surgical treatment of vitiligo]

The absence of causal and poor results of conservative treatment of vitiligo in many cases leads to the search for different treatment possibilities such as surgical treatment. All techniques of surgical treatment of vitiligo are based on autologous melanocytes grafting into the achromatic skin lesions. Individual surgical methods for such treatment differ in the preparation of recipient skin site, in harvesting and processing of autologous melanocytes before their grafting. The surgical treatment is useful for patients with stabile achromatic skin lesions up to 30% of total body surface area in cases in which medical treatment has failed. This article is a review of different surgical techniques in surgical treatment of vitiligo.

Treatment of vitiligo on difficult-to-treat sites using autologous noncultured cellular grafting

BACKGROUND

Because of the limitations of medical treatment, various surgical therapies have been developed and are being accepted to treat vitiligo. However, certain areas such as the fingers and toes, palms and soles, lips, eyelids, nipples and areolas, elbows and knees, and genitals are considered difficult-to-treat areas.

OBJECTIVE

To evaluate data pertaining to individual sites considered to be difficult to treat and highlight that noncultured melanocyte-keratinocyte transplantation (MKT) does not require any special precautions to treat these anatomical sites.

METHODS AND MATERIALS

Forty patients (13 male and 27 female) with bilateral vitiligo and nine (4 male and 5 female) with unilateral vitiligo were treated using noncultured MKT, for "difficult-to-treat" sites at the National Center for Vitiligo and Psoriasis, Riyadh, Saudi Arabia, and were analyzed for response according to region. Repigmentation was graded as excellent with 95% to 100% pigmentation, good with 65% to 94%, fair with 25% to 64%, and poor with 0% to 24% of the treated area.

RESULTS

For bilateral vitiligo, more than 50% of patients treated for difficult sites showed more than 65% repigmentation of the treated areas. For unilateral vitiligo, all of the patients except for two treated for the eyelids showed more than 65% repigmentation of the treated area.

CONCLUSIONS

The concept of a "difficult-to-treat site" is a relative term and depends upon the technique used. The noncultured MKT does not require any special precautions to treat these anatomical sites. This review may help physicians to change the concept of "difficult-to-treat site."

Isolation and culture of different epidermal and dermal cell types from human scalp suitable for the development of a therapeutical cell spray

BACKGROUND

Previous studies demonstrated, that cultured epithelial autografts (CEA) can be isolated and skin cell sprays can be produced for application on different types of wounds. The purpose of the present study was to determine which cell types can be isolated from the human scalp and whether these cells can be used for spray transplantation.

METHODS

Outer root sheath cells (ORS), keratinocytes, melanocytes, dermal papilla cells (DP), and dermal sheath cells (DSC) were isolated from human scalp tissue. Isolated cells were characterized, expanded and sprayed in an in vitro model. Growth behaviour, morphology and cell counts were compared with non-sprayed cells.

RESULTS

With acceptable time, equipment and laboratory personnel a sufficient amount of keratinocytes, ORS, melanocytes, DP cells and DSC cells could be achieved. The cells are sufficient for application as a cell spray. Cells, positive for Integrin alpha6, Cytokeratin 19, CD73 and CD105 were identified within the cultures.

CONCLUSIONS

Human scalp is suitable to gain epidermal and dermal cells for the development of therapeutic cell spray transplantation. Further studies have to determine, whether these cells can be combined to produce wound specific skin substitutes.

Autologous cultured melanocytes in vitiligo treatment

BACKGROUND

Surgical treatment of vitiligo is indicated when lesions are localized in poorly responding areas.

OBJECTIVES

The objectives were: (1) to establish the melanocyte culture obtained from the epidermis of vitiligo patients for future treatment; (2) to estimate the influence of selected factors on the formation of suction blisters and the results of culture; and (3) to compare the results of treatment of vitiliginous macules localized in the dorsum of the hands and lower limbs by transplantation of cultured autologous melanocytes plus psoralen and ultraviolet A (PUVA) therapy (CMP), suction blister transplantation plus PUVA therapy (SBP), cryotherapy plus PUVA-therapy (CP), and only PUVA therapy (OP).

METHODS

Forty patients were qualified for the study. The roofs of the suction blisters were used as a melanocyte source for culture establishment or were directly transplanted.

RESULTS

The CMP procedure was successfully performed on only 10 of 20 patients because of the difficulties in cell culture establishment. The SBP method was carried out on all 20 patients. A total lack of effectiveness was found in CP and OP methods.

CONCLUSIONS

The effectiveness of culture depends on time of suction blister forming, phototype, and previous PUVA therapy. This study demonstrated the advantage of the SBP over the CMP method.

New and Experimental Treatments of Vitiligo and Other Hypomelanoses

This article deals with new and experimental treatments that can be used to treat various forms of depigmenting disorders. Ultraviolet B-focused therapies and new surgical approaches are analyzed in this article. These therapies were mainly or only developed to treat vitiligo, which is the most studied and probably the most challenging of all the hypomelanoses, but the results obtained in trials and clinical experiences about vitiligo sometimes can be referred to other depigmenting disorders.

Reversible transfection of human melanocytes mediated by Cre/loxP site-specific recombination system and SV40 large T antigen

OBJECTIVE

To study the reversible transfection of human melanocytes mediated by simian virus 40 large T antigen (SV40LTAg) and Cre/loxP site-specific recombination system.

METHODS

The reconstructed SV40LTAg-EGFP-neo-loxP vector was transfected into primary cultured human melanocytes with Sofast(TM) transfection reagent and the positive cells were selected using G418. After expanding culture of these positive cell clones, the expression of SV40LTAg was detected by polymerase chain reaction (PCR), reverse transcription-polymerase chain reaction (RT-PCR) and immunofluorescent method. After that, these positive cells were infected by virus supernatant of Cre-ER(T2) retrovirus vector and Cre recombinase was induced to act by tamoxifen. On the 6th and 10th day after Cre recombinase acting, the expression of SV40LTAg was detected using the same methods as above, and cell tumorigenicity was studied using soft agar assay, athymic mouse study and karyotype analysis. On 10th day after tamoxifen treatment, cell biological characters were identified with immunofluorescent staining and transmission electron microscopy. Then these cells were transplanted into vitiligo animal model to observe their melanogenesis ability in vivo.

RESULTS

The genome DNA and total RNA were isolated from the positive cells transfected by SV40LTAg (designated as MCT) and specific 288 bp fragment was amplificated using PCR and RT-PCR methods. The results of immunofluorescence confirmed the expression of SV40LTAg in cell nucleus. On the 6th day after tamoxifen treatment in infected cells by Cre-ER(T2) retrovirus vector (designated as MCT-Cre), there could be detected SV40LTAg expression, but on 10th day, there could not be detected SV40LTAg expression in cells. These results showed that the excised efficiency of Cre recombinase increased along with time prolongation, and would obtain complete recombination efficiency. The identification of MCT-Cre cell biological characters showed that these cells had normal parent-cell-like cell phenotype and no tumorigenicity in vitro. The pigmentation started in 4 weeks and formed black macula in 3 months after grafting. The pathological results showed that there had been significant melanocytes and melanin accumulation in epidermis and some hair follicle in transplanted area, which confirmed that MCT-Cre had melanogenesis function in vivo.

CONCLUSION

Human melanocytes could be mediated by reversible transfection by SV40LTAg and Cre/loxP site-specific recombination system, which had stable parent-cell-like phenotypic characters and no tumorigenicity in vitro; moreover, these cells still had melanogenesis function in vivo.

Autologous melanocyte transfer via epidermal grafts for lip vitiligo

BACKGROUND

Vitiligo of the lips is a common concern of great psychologic consequence. Medical therapies are often ineffective due mainly to the absence of hair follicles. The transfer of melanocytes or melanocyte-bearing skin by a surgical procedure may repigment this condition. Only a few surgical modalities have been successful in this "difficult to treat" site.

OBJECTIVE

To assess the effectiveness of autologous melanocyte transfer by epidermal grafts for lip vitiligo and to review the literature on the surgical correction of lip vitiligo.

METHODS

Twenty-six vitiligo patients (20 women and six men; age range, 13-43 years; mean, 26.8 years) having 31 affected lips with stable disease were included in the study. The suction blisters were raised using our own modified device on the lateral aspect of the thigh. The roofs of the blisters were transferred to the dermabraded recipient area. The dressing, together with the grafts, was removed on day 8. Patients were given photochemotherapy for 6 weeks. In addition, meta-analysis of the published literature on the surgical management of lip vitiligo was also performed.

RESULTS

Complete repigmentation was observed in 27 of the 31 lip areas (87%) in 23 of 25 patients (92%) in whom a follow-up for 6 months or more was available. Complications observed were persistent hyperpigmentation in 12 lips and reactivation of herpes in one patient. Minimal hyperpigmentation was seen in most of the remaining lips. The results of the meta-analysis revealed that the success rate varies from 32.5% to 100% with various surgical procedures.

CONCLUSION

Autologous melanocyte transfer is an effective and safe therapeutic option for stable vitiligo of the lips. It is cosmetically more acceptable, as there is no abnormal keratinization, which is a problem associated with dermo-epidermal grafts.

Increased expression of integrins and decreased apoptosis correlate with increased melanocyte retention in cultured skin substitutes

Losses of human melanocytes (HM) in transplantation of cultured skin substitutes (CSS) may result from poor cellular attachments. To test this hypothesis, HM integrin expression was measured in four culture media: (a) melanocyte growth medium (MGM), an HM proliferation medium; (b) UCMC 160, a CSS maturation medium; (c) mMGM, modified MGM with 1.8 mM calcium; and (d) modified UCMC 160 with HM supplements (mUCMC 160). HM grew well in all media except UCMC 160. Increased expression of beta1, beta4, alpha3beta1 and alpha5 integrins on HM cultured in MGM and mMGM versus UCMC 160 was found by flow cytometry. Annexin V-allophycocyanin (APC) labeled HM in apoptosis and increased significantly in UCMC 160 (31.1%) compared with MGM (11.9%) or mMGM (13.9%). CSS were incubated in UCMC 160, mMGM or mUCMC 160 media, and grafted to athymic mice. In the mMGM group, grafts were darker as measured with a chromameter through 6 weeks and the average number of basal HM per field was greater at 12 weeks post-grafting. Increased graft loss was observed in the mMGM group which corresponded with the poor epidermal morphology in vitro. Although HM retention improved in vivo using mMGM to culture the CSS, the stability of the epidermis decreased. These results indicate that expression of integrins on HM in vitro correlates with HM retention in CSS and short-term survival after transplantation, but that long-term survival depends also on stable epithelium.

In vivo and in vitro evidence of dermal fibroblasts influence on human epidermal pigmentation

Using chimeric human epidermal reconstructs, we previously demonstrated that epidermal pigmentation is dependent upon the phototype of melanocytes. We report here several lines of experimental evidence for dermal modulation of human epidermal pigmentation. First, phototype II-III epidermal reconstructs grafted on the back of immunotolerant Swiss nu/nu mice developed a patchy pigmentation dependent on the presence of colonizing human or mouse fibroblasts. Similarly, human white Caucasoid split-thickness skin xenografted on the same mouse strain became black within 3 months and histochemistry revealed a phototype VI pattern of melanin distribution. In vitro, human fibroblasts colonizing human dead de-epidermized dermis (DDD) induced a decrease in epidermal pigmentation whereas mouse (Swiss nu/nu) fibroblasts increased epidermal pigmentation. Conditioned medium from mice (Swiss nu/nu) fibroblasts also increased pigmentation whereas conditioned medium from human fibroblasts had no significant effect. Lastly, epidermal reconstructs made with normal or vitiligo keratinocytes and/or normal or vitiligo melanocytes from the same donor grown on DDD originating from several donors of the same clinical phototype did not pigment similarly and no specific dermal influence was noted for vitiligo. Thus, fibroblast secretion and acellular dermal connective tissue itself significantly influence melanocyte proliferation and melanin distribution/degradation. Our study suggests that murine fibroblasts are more potent than human fibroblasts in secreting soluble factors which can act directly on pigmentation, such as SCF, or activate keratinocytes to produce basement membrane proteins or melanogenic factors.

Melanocyte transformation associated with substrate adhesion impediment

Exclude experimental models of malignant transformation employ chemical and physical carcinogens or genetic manipulations to study tumor progression. In this work, different melanoma cell lines were established after submitting a nontumorigenic melanocyte lineage (melan-a) to sequential cycles of forced anchorage impediment. The great majority of these cells underwent anoikis when maintained in suspension. After one deadhesion cycle, phenotypic alterations were noticeable in the few surviving cells, which became more numerous and showed progressive alterations after each adhesion impediment step. No significant differences in cell surface expression of integrins were detected, but a clear electrophoretic migration shift, compatible with an altered glycosylation pattern, was observed for beta1 chain in transformed cell lines. In parallel, a progressive enrichment of tri- and tetra-antennary N-glycans was apparent, suggesting increased N-acetylglucosaminyltransferase V activity. Alterations both in proteoglycan glycosylation pattern and core protein expression were detected during the transformation process. In conclusion, this model corroborates the role of adhesion state as a promoting agent in transformation process and demonstrates that cell adhesion disturbances may act as carcinogenic stimuli, at least for a nontumorigenic immortalized melanocyte lineage. These findings have intriguing implications for in vivo carcinogenesis, suggesting that anchorage independence may precede, and contribute to, neoplastic conversion.

Subjective and Objective Evaluation of Noncultured Epidermal Cellular Grafting for Repigmenting Vitiligo

BACKGROUND

Noncultured epidermal cell transplantation in vitiligo permits the coverage of relatively large areas without culturing cells.

OBJECTIVE

To investigate the effectiveness of noncultured epidermal cell transplantation in treating stabilized vitiligo using objective and subjective evaluation methods.

METHODS

Noncultured autologous melanocytes and keratinocytes were grafted in a hyaluronic-acid-enriched suspension on superficially laser-abraded vitiligo lesions in 40 patients with refractory stable vitiligo (30 with generalized and 10 with localized vitiligo). The repigmentation was evaluated 3-12 months after grafting using a digital image analysis system. Furthermore the treatment was evaluated from the patients' point of view with the DLQI (Dermatology Life Quality Index) and a 'global assessment'.

RESULTS

The mean percentage of repigmentation, evaluated at the last follow-up visit, was 72% (median 84%), and a repigmentation of >or=70% was observed in 62% of patients. The best results were achieved in the neck and the presternal region. A subjective evaluation was performed in half of the subjects. The mean DLQI score at inclusion (6.95, SD = 6.68, n = 20) was significantly decreased after treatment (p = 0.013, mean 3.85, SD = 4.13, n = 20). The patients were satisfied with the achieved result, found it worthwhile to undergo the treatment and would choose it again.

CONCLUSION

According to both subjective and objective evaluation methods, noncultured epidermal cell transplantation is promising in patients with stable vitiligo.

Stable Vitiligo Treated by a Combination of Low-Dose Oral Pulse Betamethasone and Autologous, Noncultured Melanocyte-Keratinocyte Cell Transplantation

BACKGROUND

Various surgical procedures are in use to treat stable vitiligo. The possibility of Koebner phenomenon always exists with surgical treatment. Partial or complete failure to repigment is observed in spite of clinical stability.

AIM

To evaluate the usefulness of a combination treatment of low-dose oral betamethasone and melanocyte-keratinocyte transplantation.

METHODS

Oral betamethasone was given to patients who failed to respond either completely or partially to melanocyte-keratinocyte cell transplantation, and the procedure was repeated for previously treated and nontreated area. A simpler and modified method described by Mulekar was performed.

RESULTS

Seventeen patients with vitiligo vulgaris and eight patients with segmental vitiligo were retransplanted after giving oral betamethasone for 2 to 10 months after the initial procedure. Two patients of vitiligo vulgaris and one of segmental vitiligo failed to respond completely even after repeat transplantation. Fifteen vulgaris and seven segmental patients showed excellent to good repigmentation after repeat transplantation.

CONCLUSION

Combined treatment of oral betamethasone and melanocyte cell transplantation has a potential to produce complete repigmentation in patients with large vitiliginous areas.

Dermatosurgical techniques for repigmentation of vitiligo

There are a number of dermatosurgery techniques available to achieve repigmentation of vitiligo, such as suction blister grafting, split-thickness skin grafting, punch grafting, follicular grafting, cultured-melanocytes transplantation, and noncultured-melanocytes transplantation. Each method has advantages and disadvantages. As there are no specific data available from the prospective studies in this field it is uneasy to recommend which surgical approach to vitiligo offers the best result. According to a systematic review by Njoo et al.,(17) suction blister and split-thickness skin grafting have the highest rates of success (87%), while the average success rates for other methods varied from 13% to 53%. Punch grafting has the highest rate of adverse effects, including cobblestoning appearance (27%) and scar formation (40%) in the donor site. Accordingly, it is also mandatory to appropriately select vitiligo patients in order to achieve a complete and permanent repigmentation.

A study of autologous melanocyte transfer in treatment of stable vitiligo

BACKGROUND

Replenishing melanocytes selectively in vitiliginous macules by autologous melanocytes is a promising treatment. With expertise in culturing melanocytes, it has now become possible to treat larger recipient areas with smaller skin samples.

AIM

To study the extent of repigmentation after autologous melanocyte transplantation in patients with stable vitiligo.

METHODS

The melanocytes were harvested as an autologous melanocyte rich cell suspension from a donor split thickness graft. Melanocyte culture was performed in selected cases where the melanocyte cell count was insufficient to meet the requirement of the recipient area. These cells were then transplanted to the recipient area that had been superficially dermabraded.

RESULTS

An excellent response was seen in 52.17% cases with the autologous melanocyte rich cell suspension (AMRCS) technique and in 50% with the melanocyte culture (MC) technique.

CONCLUSION

Autologous melanocyte transplantation can be an effective form of surgical treatment in stable but recalcitrant lesions of vitiligo.

Enhanced cell survival of melanocyte spheroids in serum starvation condition

Autologous melanocyte transplantation for vitiligo treatment by use of melanocyte suspension has drawbacks including cell damage in cell preparation and transportation, difficult manipulation and low engraftment rate in acral vitiligious lesions. We have proposed the concept of cellular patch as an alternative solution. In the development of melanocyte patches, we have shown that chitosan membrane supports the growth and phenotype expression of melanocytes. Surprisingly, melanocytes spontaneously grow into three-dimensional spheroids on chitosan-coated surface. In this work, we demonstrate that, compared with monolayered melanocytes, melanocyte spheroids show a better survival in growth factor and serum-deprived condition. Survival of melanocytes is further ameliorated when a greater portion of melanocytes is precultured into spheroidal morphology. Melanocyte spheroids disintegrate and the cells return to a physiological dendritic morphology after they are reinoculated on collagen I-coated surface. Our results show that melanocytes are morphologically transformable depending on the substratum used and spheroidal melanocytes have a superior survival to that of monolayered dendritic melanocytes in stringent conditions. Preculturing melanocytes into spheroids can provide melanocytes a survival advantage. Chitosan-based melanocyte patch can be a promising method to enhance the engraftment rate and facilitate the cell preparation and transplantation procedures in melanocyte transplantation for vitiligo treatment.

Genital vitiligo treated by autologous, noncultured melanocyte-keratinocyte cell transplantation

BACKGROUND

Genital vitiligo is common and has a deleterious effect on the psychosexual function of patients. It is well known that glabrous skin (non-hair-bearing skin such as below the ankles, genitalia, lips, distal ends of fingers) rarely responds to the therapy unless it has some residual pigment.

OBJECTIVE

The objective was to report genital vitiligo treated successfully by autologous, noncultured, melanocyte-keratinocyte cell transplantation.

METHODS

Three cases of clinically stable genital vitiligo were treated by autologous, noncultured melanocyte-keratinocyte cell transplantation.

RESULTS

All lesions treated repigmented almost completely. All patients were very satisfied with the excellent cosmetic results.

CONCLUSION

Autologous, noncultured melanocyte-keratinocyte cell transplantation may be an effective surgical treatment for management of genital vitiligo.

Efficacy of autologous transplantation of noncultured epidermal suspension in two different dilutions in the treatment of vitiligo

BACKGROUND

Previous reports have shown the effectiveness of a basal layer cell suspension in the treatment of stable vitiligo; however, there has been no mention in the literature until now of the optimal number of melanocytes required in an autologous noncultured epidermal suspension for transplantation to obtain early and acceptable results.

METHODS

In this randomized prospective study, we compared the efficacy of two different dilutions to determine the optimum density of melanocytes required for transplantation to achieve early and cosmetically acceptable results. We enrolled 20 patients with stable vitiligo with a body surface area involvement of< 10%.

RESULTS

Fifty per cent of patients in Group A (where the recipient area transplanted was approximately three times the size of the donor area, and the density of melanocytes transplanted per square millimeter was approximately 231.60+/- 27.03) showed marked (> 75%), 20% moderate, 10% mild, and 20% minimal repigmentation (or no response). In Group B (where the recipient area was increased to five-fold the donor area), none of the patients showed marked, 10% showed moderate, 20% showed mild, and 70% showed either minimal or no repigmentation. The density of melanocytes transplanted in this group was 154.90+/- 27.65/mm(2). The extent of repigmentation was significantly greater (P< 0.05) in Group A than in Group B, and the density of melanocytes in the suspension was also significantly greater (P< 0.01) in Group A than in Group B.

CONCLUSION

We contend that the minimum number of melanocytes required to produce satisfactory repigmentation is probably in the range of 210-250/mm(2).

Establishing melanocyte cultures in a serum-free system for transplantation in vitiligo patients

BACKGROUND

The aim of the study was to establish melanocyte cultures obtained from the epidermis of vitiligo patients for future treatment and to estimate the influence of selected factors on the formation of suction blisters and the results of culture.

MATERIAL/METHODS

Twenty patients with generalized vitiligo were qualified to the study. The melanocyte donor site was the arm or forearm where, using an electric vacuum suction machine and a plastic plate, suction blisters were formed. The removed roofs of the blisters were used as a melanocyte source for culture establishment. After an enzymatic bath, the cell suspension was transferred to culture flasks containing melanocyte growth medium (MGM M2). The melanocytes in culture were identified by immunocytochemistry.

RESULTS

Suction blisters were formed in all patients. No melanocyte cultures were established from patients whose blisters appeared over a period 58 minutes. In addition, a suitable quantity of melanocytes was not obtained for eight other patients (with skin phototype II and/or without previous PUVA therapy).

CONCLUSIONS

The epidermis of the arm and forearm is a good donor site for the establishment of melanocyte cultures. The effectiveness of culture depends mainly on the time of the formation of suction blisters, the phototype of the skin, and previous PUVA therapy.

The effect of the flavonoid diosmin, grape seed extract and red wine on the pulmonary metastatic B16F10 melanoma

OBJECTIVE

To study the effect of different phenolic compounds and red wine on pulmonary metastatic melanoma.

METHODS

Swiss mice were inoculated with 500000 melanocytes B16F10 and given oral doses of diosmin, grape seed extract (GSE) and red wine. A macroscopic count was made of the metastatic nodules on the lung surface and a microscopic study by image analysis of five sections, calculating the implantation percentage and tumoral growth and invasion indices.

RESULTS

Macroscopically, the group treated with diosmin showed the greatest reduction (52%) in the number of metastatic nodules compared with the control group, which was treated with ethanol, while GSE and red wine caused decreases of 26.07 and 28.81%, respectively. Microscopically, there was a decrease in the implantation percentage after the administration of diosmin (79.4%) and red wine (20.19%), and an increase of 2.12% after the administration of GSE, all relative to the ethanol-treated control. As regards the growth index, diosmin produced a reduction of 67.44% and red wine a reduction of 20.62%, while GSE again produced an increase (25.33%). The reductions in the invasion index were 45.23, 31.65 and 17.57% with diosmin, GSE and red wine, respectively.

CONCLUSIONS

Diosmin originated the greatest reduction in pulmonary metastases, both at the macroscopic and microscopic levels.

Autografts and cultured epidermis in the treatment of vitiligo

Skin transplants can be a useful and efficacious method to treat vitiligo. The aim is to repopulate areas lacking melanocytes with functional cells taken from normally pigmented areas. Several procedures have been devised and tested: some consist in the simple transfer of epidermis sampled and implanted as is, whereas others are based on the transplantation of disaggregated and manipulated cells. The therapeutic success of the former methods is partly determined by the ability and experience of the surgeon performing the operation, whereas the results of the latter methods mainly depend on the laboratory facilities and abilities of the personnel who manipulate the cells to be transplanted. The transplantation of cultured cells is the most fascinating and promising procedure but requires the observance of still not completely predictable procedures. The use of biological material of animal origin and the use of factors to stimulate cell proliferation, such as growth factors and promoting agents, are other points that require attention.

Surgical approaches for stable vitiligo

BACKGROUND

Vitiligo therapy is difficult. Depending on its clinical presentation, unilateral or bilateral vitiligo lesions respond well with different repigmentation rates, according to age, affected anatomic area, extension of lesions, time at onset, timing of depigmentation spread, and other associated factors. When stable and refractory to medical treatment, vitiligo lesions may be treated by implanting pigment cells on depigmented areas.

OBJECTIVE

To describe the main events of depigmentation and the fundamentals of surgical techniques for repigmenting vitiligo by implanting noncultured cellular or tissue grafts, in vitro cultured epidermis-bearing pigment cells, or melanocyte suspensions.

METHODS

A description of the available techniques for repigmentation of vitiligo is done, emphasizing the most important details of each procedure to obtain the best repigmentation and minimize side effects.

RESULTS

With most of these techniques, adequate repigmentation is obtained, although there are limitations when applying some methods to clinical practice.

CONCLUSIONS

Restoration of pigmentation may be accomplished with all available surgical procedures in most anatomic locations, but they are of little value for acral areas. Unilateral vitiligo responds well in a high proportion of patients, and bilateral disease may also respond when stable. Appropriate patient selection is important to achieve the best results.

The fate of human malignant melanoma cells transplanted into zebrafish embryos: assessment of migration and cell division in the absence of tumor formation

Certain aggressive melanoma cell lines exhibit a dedifferentiated phenotype, expressing genes that are characteristic of various cell types including endothelial, neural, and stem cells. Moreover, we have shown that aggressive melanoma cells can participate in neovascularization in vivo and vasculogenic mimicry in vitro, demonstrating that these cells respond to microenvironmental cues and manifest developmental plasticity. To explore this plasticity further, we transplanted human metastatic melanoma cells into zebrafish blastula-stage embryos and monitored their behavior post-transplantation. The data show that human metastatic melanoma cells placed in the zebrafish embryo survive, exhibit motility, and divide. The melanoma cells do not form tumors nor integrate into host organs, but instead become scattered throughout the embryo in interstitial spaces, reflecting the dedifferentiated state of the cancer cells. In contrast to the fate of melanoma cells, human melanocytes transplanted into zebrafish embryos most frequently become distributed to their normal microenvironment of the skin, revealing that the zebrafish embryo contains possible homing cues that can be interpreted by normal human cells. Finally, we show that within the zebrafish embryo, metastatic melanoma cells retain their dedifferentiated phenotype. These results demonstrate the utility of the zebrafish embryonic model for the study of tumor cell plasticity and suggest that this experimental paradigm can be a powerful one in which to investigate tumor-microenvironment interactions.