Anti-oxidant defence mechanism in vitiliginous skin increases with skin type

Background Vitiligo skin shows different burning capacity in people with different phototype. In normal skin antioxidant status is correlated to skin phototype, but unexpectedly it appears that there is a gradual decrease in burning susceptibility of depigmented skin of individuals with increasing phototype (II→VI). Objective To assess if the antioxidant response in the lesional vitiligo skin is involved in those protection mechanisms. Moreover, a possible correlation between cutaneous and systemic endogenous antioxidants in vitiligo patients has been investigated. Methods We enrolled in the study 29 patients with active vitiligo, divided into five groups according to skin type (II to VI). We analysed reduced and oxidized glutathione (GSH and GSSG, respectively), ubiquinone (CoQ10), catalase (Cat), superoxide dismutases (Cu/Zn‐SOD and Mn‐SOD), GSH peroxidase (GSH‐Px), as indexes of chemical and enzymatic antioxidants, in suction blister roofs as well as in peripheral blood mononuclear cells (PBMNCs). Results The vitiligo patients showed an imbalance of antioxidant network, both in depigmented skin and PBMNCs. Interestingly, in vitiligo skin a phototype‐related increase of antioxidant enzyme activities (Cat, Mn‐SOD and GPx) and GSH amount have been observed. Similarly in PMBNCs Cat and total SOD activities, as well as GSH content progressively increased from skin type II to skin type VI. Endogenous antioxidants in vitiligo skin are correlated to those in PBMNCs, suggesting that systemic and epidermal antioxidant network functionalities are connected. Conclusions The correlation between antioxidant levels and clinical phototype confirmed the hypothesis that other factors than melanin determine largely the minimal erythema dose values in vitiligo lesional skin.     

Histopathologic features in vitiligo

Nevus depigmentosus is a congenital disorder characterized by a nonprogressive hypopigmented lesion, which may not be apparent at birth. Thus, it is sometimes difficult to differentiate vitiligo from nevus depigmentosus only by clinical features. We postulated that the histologic changes in lesional and perilesional skin might be different in the 2 conditions. We took biopsies from both lesional and perilesional skin of 100 cases of vitiligo to assess the number of melanocytes, the amount of melanin, dermal inflammatory infiltrate, and other changes. We compared them with 30 cases of nevus depigmentosus. Histologically, lesions of vitiligo showed more basal hypopigmentation and dermal inflammation than perilesional normal skin. With Fontana-Masson staining, 16% of cases of vitiligo showed the presence of melanin. The ratio of pigmented area to epidermal area was 0.06% in vitiligo, whereas 17% in perilesional normal skin and 8.9% in nevus depigmentosus. In NKI/beteb staining, 12% of vitiligo showed the presence of melanocytes, and their average number was 7.68 per square millimeter. The number of melanocytes was also decreased in nevus depigmentosus but not as much as in vitiligo. We also confirmed the presence of melanocytes in 1 of 3 cases of vitiligo by electron microscopy. In conclusion, there are a few melanocytes and melanin in some cases of vitiligo. Therefore, the diagnosis of vitiligo should be made considering these points.     

In vivo reflectance confocal microscopy imaging of vitiligo,nevus depigmentosus and nevus anemicus

Background/purpose: Hypopigmentary skin disorders such as vitiligo, nevus depigmentosus and nevus anemicus are common diseases in clinic. The lesions of these diseases could be similar to some extent, although each of them has its own characteristic clinical appearance and histological features. Clinically, the atypical lesions are often difficult to be differentiated. In vivo reflectance confocal microscopy (RCM) is a non‐invasive, repetitive imaging tool that provides real‐time images at a nearly cellular histological resolution. Our aim was to investigate the RCM features of vitiligo, nevus depigmentosus and nevus anemicus. Subjects and Methods: A total of 135 patients with a clinical diagnosis of the aforementioned diseases were included in this study. The RCM images from depigmented skin, border of the white macules, adjacent normal‐appearing skin and distant normal skin for all patients at the dermo‐epidermal junction (DEJ) level were investigated. Results: In the active phase of vitiligo (AVP), the RCM demonstrated a complete loss of melanin in lesional skin in eight (53; 15.1%) patients. In 45 patients (53; 84.9%) of the AVP, part of the bright dermal papillary rings normally seen at the DEJ level disappeared or part of the rings lost their integrity and the content of melanin decreased obviously. In 20 patients (53; 37.7%) of the AVP, highly refractile inflammatory cells could be seen within the papillary dermis in the lesional and adjacent normal‐appearing skin, which may indicate the lesion progresses. In addition, part of the dermal papillary rings showed lack of integrity or their brightness decreased in adjacent normal‐appearing skin in all the patients of the AVP. It is important to know that the RCM demonstrated an ill‐defined border. In the stable phase of vitiligo (SPV), the RCM demonstrates a complete loss of melanin in lesional skin and a clear border in 31 (41; 75.6%) patients; the content of melanin and dermal papillary rings in adjacent normal‐appearing skin show no changes. In 10 (41; 24.4%) patients, the dendritic and highly refractile melanocytes arose in the recovery phase of vitiligo, which may indicate the repigmentation of vitiligo. There are three kinds of repigmentation patterns under RCM: marginal, perifollicular and diffuse. Distant normal skin showed no difference from controls in both the active and the SPV. In all the patients with nevus depigmentosus, the content of melanin decreases obviously but the dermal papillary rings are intact. The dermal papillary rings show no differences between lesional skin and adjacent normal‐appearing skin of nevus anemicus. Conclusion: Considering our results, RCM may be useful to non‐invasively discriminate vitiligo, nevus depigmentosus and nevus anemicus in vivo.     

白癜风患者调节性T细胞及单核细胞趋化蛋白-1及可溶性细胞问黏附分子-1的检测

目的 探讨稳定期白癜风患者白斑与非白斑处皮肤单核细胞趋化蛋白-1（MCP-1）及可溶性细胞间黏附分子-1（sICAM-1）的变化以及血液中调节性T细胞的表达变化。方法 稳定期白癜风患者进行负压吸疱移植治疗，收集白斑及正常皮肤的疱液，用ELISA法检测皮肤组织液中MCP-1及sICAM-1的水平；收集稳定期白癜风患者血液与正常人比较，流式细胞仪观察调节性T细胞的变化。结果 稳定期白癜风患者，血液中调节性T细胞的表达与正常人差异无统计学意义：寻常型白癜风患者局部白斑与非白斑处皮肤吸引疱疱液MCP-1及sICAM-1水平比较均显著增高，经统计学分析，差异有统计学意义。节段型白癜风白斑与非白斑处MCP-1及sICAM-1的水平差异无统计学意义。结论 寻常型稳定期白癜风患者局部白斑皮肤微环境仍处于免疫异常状态，移植治疗的失败可能与局部微环境异常有关。     

Gene expression analysis of melanocortin system in vitiligo

BACKGROUND: The melanocortin system in the skin coordinates pigmentation and immune response and could be implicated in the pathogenesis of vitiligo. OBJECTIVES: We aimed to analyze changes in expression of genes involved in skin pigmentation (melanocortin system and enzymes involved in melanin synthesis). METHODS: With quantitative RT-PCR we measured the mRNA expression levels of eight genes from the melanocortin system and two enzymes involved in melanogenesis. RNA was extracted from both lesional and non-lesional skin of vitiligo patients and in non-sun-exposed skin of healthy subjects. RESULTS: POMC (proopiomelanocortin) expression was lower in lesional skin compared to non-lesional skin. Expression of melanocortin receptors was increased in unaffected skin of vitiligo patients compared to healthy subjects and decreased in lesional skin compared to uninvolved skin of vitiligo patients, the differences were statistically significant in the cases of MC1R (melanocortin receptor 1) and MC4R (melanocortin receptor 4). TRP1 and DCT genes were down-regulated in lesional skin compared to non-lesional vitiligo skin or skin of healthy controls and up-regulated in uninvolved vitiligo skin compared to healthy control samples. In non-lesional skin, POMC expression was not elevated, possibly indicating that systemic influences are involved in up-regulation of MC receptor genes. Decreased expression of the analyzed genes in the lesional skin is not surprising, but statistically significant increased expression of studied genes in non-lesional skin from vitiligo patients is not described previously. CONCLUSION: In our mind, up-regulation of melanocortin system in non-lesional skin could be systemic compensation to restore normal pigmentation in lesions.     

白癜风患者调节性T细胞及单核细胞趋化蛋白-1及可溶性细胞间黏附分子-1的检测

目的 探讨稳定期白癜风患者白斑与非白斑处皮肤单核细胞趋化蛋白-1(MCP-1)及可溶性细胞间黏附分子-1(sICAM-1)的变化以及血液中调节性T细胞的表达变化.方法 稳定期白癜风患者进行负压吸疱移植治疗,收集白斑及正常皮肤的疱液,用ELISA法检测皮肤组织液中MCP-1及sICAM-1的水平;收集稳定期白癜风患者血液与正常人比较,流式细胞仪观察调节性T细胞的变化.结果 稳定期白癜风患者,血液中调节性T细胞的表达与正常人差异无统计学意义;寻常型白癜风患者局部白斑与非白斑处皮肤吸引疱疱液MCP-1及sICAM-1水平比较均显著增高,经统计学分析,差异有统计学意义.节段型白癜风白斑与非白斑处MCP-1及sICAM-1的水平差异无统计学意义.结论 寻常型稳定期白癜风患者局部白斑皮肤微环境仍处于免疫异常状态,移植治疗的失败可能与局部微环境异常有关.     

Diminished contact sensitivity response in vitiliginous skin

Thirty patients with vitiligo (ten of the segmental type and 20 of the generalized type) were sensitized with dinitrochlorobenzene (DNCB) in a normal skin site on the upper medial aspect of the arm. Challenge tests with dinitrochlorobenzene were performed in vitiliginous patches and in normal skin sites. In vitiliginous patches diminished contact sensitivity reactions to dinitrochlorobenzene were noted in both patient groups, while in normal skin sites a normal delayed hypersensitivity response to the same antigen developed in the same patients. Tuberculin reactivity was not suppressed in vitiliginous lesions. We suggest that diminished contact reactivity in vitiliginous skin might be due to functional changes in Langerhans' cells, or to an alteration of carrier (skin) proteins in the lesions.     

临床特征和皮肤CT特征判定白癜风分期

目的 采用临床特征和皮肤CT特征来判定白癜风分期。 方法 200例白癜风患者按照临床特征问卷和皮肤CT特征进行分期： ＞ 2分为快速进展期,1 ~ 2分为缓慢进展期, < 1分为稳定期。选择进展期和稳定期白癜风患者各5例,在皮肤CT检测的区域进行HE染色分析。 结果 用临床特征和皮肤CT特征判定200例白癜风患者的分期,差异无统计学意义。临床特征：进展期为白斑边缘隆起或与周围正常皮肤边界不清,三色白癜风,皮损颜色呈灰白色或浅白色;稳定期为白斑区与正常皮肤边界清晰,皮损颜色呈乳白色或瓷白色,可见色素岛。皮肤CT：进展期为表真皮交界处色素环失去完整性,与周边正常皮肤边界不清,在表真皮交界、边缘处可以看到高折光性细胞。稳定期为表真皮交界处色素环完全缺失,与周边正常皮肤边界清,有树突状高折射光的黑素细胞存在。HE染色结果显示,进展期在真皮乳头层内的病灶的边缘可见大量的CD8T淋巴细胞。稳定期在真皮乳头层内的病灶边缘未见CD8T淋巴细胞。 结论 临床特征和皮肤CT特征可以用来判定白癜风的分期,结果与进展期组织病理学基本一致。     

The prevalence of psychological comorbidity in people with vitiligo: a systematic review and meta‐analysis

Vitiligo is a long‐term condition where pale white patches develop on the skin. It's caused by a lack of melanin, a pigment (colour) in the skin. People of any age, skin type and gender can develop vitiligo and it can affect any area of skin. It is estimated that about 1 in 100 people around the world has vitiligo. The researchers who conducted this study are based in Nigeria and the UK. Our study aimed to find out how commonly psychological symptoms such as depression and anxiety occur in people in vitiligo, by looking at all relevant published studies from around the world. After extracting data from 29 studies published in this area we found that people living with vitiligo experience a range of psychological symptoms or disorders. Approximately one in four people with vitiligo appear to have depression and at least one in seven have anxiety. However, they were significantly less likely to show symptoms of depression than people with psoriasis. We also found that there were many tools to measure psychological outcomes (the emotional impact) in skin diseases, and more work needs to be done to develop tools which can be used in people with vitiligo. Our conclusion is that assessment of psychological state during clinical evaluation of vitiligo patients, as suggested by the British Association of Dermatologists’ guidelines, is essential. The same can be said for clinical evaluation of people with other skin conditions.     

无色素痣的临床、组织学和超微结构观察

目的 探讨无色素痣的临床和组织学特征。方法 分析85例无色素痣患者的发病年龄、类型和皮损特点,并对部分患者行皮肤色素测定和反射式共聚焦显微镜（RCM）观察。对其中17例患者的皮损区和正常区皮肤组织进行组织病理检查,透射电镜观察皮损区超微结构。免疫组化法检测皮损区和正常皮肤处酪氨酸酶（TYR）、HMB45、酪氨酸酶相关蛋白1（TRP-1）、TRP-2和CD117表达。结果 85例无色素痣患者中,23例（27.1%）出生时发现皮损,21例（24.7%）出现于3岁以后,最大发病年龄为29岁。皮损分布于躯干部25例（29.4%）,颈部13例（15.3%）;72例（84.7%）皮损边缘不规则,54例（63.5 %）仅有1处皮损。19例无色素痣患者患处的黑素指数（186.56 ± 52.86）和相对黑素指数（80 ± 11）低于正常人皮肤（分别为223.88 ± 63.19和100）,高于12例白癜风患者皮损处（分别为128.57 ± 64.31和60 ± 20）,差异均具有统计学意义（P < 0.01）。反射式共聚焦显微镜示,无色素痣皮损中含黑素细胞数量减少,亮度减低,黑素分布均匀,皮损区与正常皮肤分界区常不清晰。皮损区Fontana-Masson染色示皮损区黑素强度为1810.12 ± 327.96,较正常区（2064.24 ± 260.41）明显减弱。电镜下发现黑素细胞数量减少,黑素小体减少,黑素细胞胞质和树突以及角质形成细胞中可见Ⅱ、Ⅲ期未成熟的黑素小体,角质形成细胞中可见聚集成团的黑素小体。17例患者正常区TYR表达水平为1827.35 ± 307.09,TRP-1为6102.54 ± 1642.64,而皮损区TYR（1477.35 ± 224.05）和TRP-1（5322.33 ± 1565.26）表达下降,正常区与皮损区比较,P均 < 0.01;HMB45、TRP-2、CD117表达两处比较差异均无统计学意义。 结论 无色素痣是一种早期发病、非家族聚集性、稳定的不规则色素减退性疾病,其皮损中黑素细胞和黑素小体数量均减少,可见未成熟黑素小体。相对黑素指数和反射式共聚焦显微镜检查可作为诊断无色素痣的无创性检测方法。     

白癜风表皮黑素细胞超微结构及小眼畸形相关转录因子转录调控研究

目的 研究白癜风黑素细胞超微结构和小眼畸形相关转录因子 （MITF）及其转录调控的酪氨酸酶相关蛋白（TRP）与白癜风临床类型与病程的相关性。方法 选择不同病程的寻常型白癜风（VV）12例和节段型白癜风（SV）8例,分别取白斑区、白斑边缘正常肤色区和远离白斑正常肤色区的表皮片,经组织学确定其表皮的完整性。透射电镜观察10例患者（VV 6例,SV 4例）不同区表皮黑素细胞的超微结构特点。对所有20例远离白斑正常肤色区的表皮片黑素细胞进行培养,应用免疫印迹方法检测 MITF及其转录调控的酪氨酸酶（TYR）、酪氨酸酶相关蛋白1（TYRP1）和酪氨酸酶相关蛋白2（TYRP2）的表达水平。结果 白癜风表皮黑素细胞超微结构病理改变：10例中7例白斑区表皮内未见黑素细胞,1例短病程和2例长病程VV分别可见少量黑素体显著减少或缺失的黑素细胞;白斑边缘正常肤色区,6例VV中,3例病程小于15个月者可见黑素细胞超微结构异常,而4例SV中仅1例异常;远离白斑正常肤色区,10例黑素细胞超微结构均正常。白癜风表皮黑素细胞MITF及其转录调控TRP的表达：VV的MITF表达下调与TYR、TYRP1、TYRP2的表达下调一致;SV存在MITF显著表达下调,而TYR、TYRP1、TYRP2几均正常表达。结论 VV和SV可能存在不同的表皮黑素细胞超微结构病理改变和MITF转录调控机制。     

Topical 0.05% clobetasol propionate versus 1% pimecrolimus ointment in vitiligo

Vitiligo is a common skin condition resulting from loss of normal melanin pigments in the skin which produces white patches. Topical corticosteroids are indicated for the treatment of limited areas of vitiligo. Pimecrolimus, which inhibits calcineurin, has recently been shown to be effective for the treatment of vitiligo. We performed a prospective study to evaluate the efficacy of the 0.05% clobetasol propionate and 1% pimecrolimus in the treatment of vitiligo. Ten patients with virtually bilateral symmetrical lesions of vitiligo were included. 0.05% clobetasol propionate was applied twice daily over the lesion on right side of the body, and topical 1% pimecrolimus was applied twice daily over the lesion on left side of the body. It was determined that both treatment modalities resulted in a comparable rate of repigmentation. Response to treatment was varied according to the anatomical location of the lesions where better results were seen on the trunk and extremities. Results from this pilot study indicate that topical 1% pimecrolimus is as effective as clobetasol propionate in restoring skin disfiguring due to vitiligo. For a better conclusive statement further studies involving larger groups of patients should be performed.     

Vitiligo skin types in Koreans

There is uncertainty and controversy about the relationship between skin type and development of vitiligo. The present study was undertaken to study whether vitiligo patients have a different skin type than the control group. We investigated the skin types of 201 Korean vitiligo patients and 70 healthy Korean volunteers. Skin type was determined by the skin phototyping method proposed by Fitzpatrick. Compared to normal controls, skin type II was significantly less frequent and skin type V was quite common in the vitiligo group. These results suggest that people with dark skin have a higher probability of developing vitiligo than people with light skin.     

Eumelanin and phaeomelanin contents of depigmented and repigmented skin in vitiligo patients

BACKGROUND: There are two chemically distinct types of melanin: the red-yellow phaeomelanin and the brown-black eumelanin. Both types of melanin have been detected in human hair, epidermis and cultured melanocytes. OBJECTIVES: In a preliminary study, to quantify levels of both eumelanin and phaeomelanin in depigmented as well as repigmented patches of vitiligo following psoralen plus ultraviolet A (PUVA) therapy. METHODS: We enrolled five patients with vitiligo for this study. We took biopsies from depigmented as well as repigmented lesions after PUVA therapy. The eumelanin and phaeomelanin contents of the skin biopsies were quantified by high-performance liquid chromatography. RESULTS: The mean concentrations in depigmented lesions were 229.4 ng per piece for phaeomelanin and 572 ng per piece for eumelanin (mean phaeomelanin/eumelanin ratio 0.36). In repigmented lesions, the mean concentration of phaeomelanin was 74.8 ng per piece and that of eumelanin was 1657.6 ng per piece (mean phaeomelanin/eumelanin ratio 0.049). CONCLUSIONS: Depigmented lesions showed both types of melanin, and contained a substantial amount of phaeomelanin, whereas repigmented lesions after PUVA showed predominantly eumelanin. We detected melanin in depigmented lesions of vitiligo of 5 years duration, suggesting that some residual melanocytes are still active in depigmented lesions.     

Role of In Vivo Reflectance Confocal Microscopy in Determining Stability in Vitiligo: A Preliminary Study

Background:

Vitiligo is an acquired pigmentary disorder. In vivo reflectance confocal microscopy (RCM) reproducible imaging technique has already been reported to be useful in the diagnosis of other skin diseases.

Objective:

To define RCM features of vitiligo on different clinical stages.

Materials and Methods:

A total of 125 patients with a clinical diagnosis of vitiligo were included in this study. After informed consent, lesional skins of those vitiligo patients were characterized by using RCM. Five patients with inflammatory cell infiltration observed at the edge of skin lesions and another 5 patients without inflammatory cell infiltration were selected. Biopsies were performed at same sites of the RCM examination areas for histological and immune-histological analysis.

Results:

In the active stage of vitiligo, the RCM examination revealed that the bright dermal papillary rings presented at the dermoepidermal junction level in normal skin lost their integrity or totally disappeared, border between vitiligo lesion and normal skin became unclear, and highly refractile cells that referred to infiltrated inflammatory cells could be seen within the papillary dermis at the edge of the lesions. In the stable stage of vitiligo, the RCM showed a complete loss of melanin in lesional skin and a clear border between lesional and normal skin.

Conclusion:

A simple clinical examination with RCM may reliably and efficiently allow evaluation of the stability status of vitiligo lesions.     

Ultrastructural findings in progressive macular hypomelanosis indicate decreased melanin production

Background The pathogenesis of progressive macular hypomelanosis (PMH) is unknown. Recently, Westerhof et al. (Arch Dermatol 2004; 140: 210–214) hypothesized that Propionibacterium acnes produces a depigmenting factor that interferes with melanogenesis in the skin, resulting in hypopigmented spots. The purpose of the study is to gain an insight into the pathogenesis of PMH. Materials and methods We took a biopsy of 2‐mm diameter from normal and lesional skin in eight PMH patients. Using electron microscopy, we compared melanization of melanosomes, melanosome transfer and amount of epidermal melanin in normal and lesional skin. Result Compared to non‐lesional skin, we observed a decrease of epidermal melanin and less melanized melanosomes in lesional skin of all patients. When comparing normal and lesional skin of patients with skin type V and VI, we observed a difference in melanosome size and maturation and a switch of transferred melanosomes from single stage IV transferred melanosomes to aggregated stage I, II and III transferred melanosomes, as seen in healthy skin of skin type I to IV. Conclusion Hypopigmentation in PMH seems to be the result of an altered melanogenesis based on a decrease in melanin formation and a change in the distribution of melanosomes. In lesional skin of PMH patients with skin type V and VI less melanized, aggregated melanosomes in stead of single, mature melanosomes are transferred from melanocytes to keratinocytes. This results in a decrease of epidermal melanin. Further investigations are needed to determine the precise role of Propionibacterium acnes in this alteration of melanogenesis.     

Epidermal photoprotection: comparative study of narrowband ultraviolet B minimal erythema doses with and without stratum corneum stripping in normal and vitiligo skin

Background. Recent accumulating data in the literature have indicated a complex photoprotective role of the epidermis, and the role of melanin as the major epidermal photoprotective mechanism has become debatable. Aim. Comparative assessment of the photoprotective roles played by different epidermal structures and compounds. Methods. In total, 64 participants, comprising patients with vitiligo (n = 32) and healthy volunteers (n = 32), with skin phototypes (SPTs) II to V, were enrolled in the study. Areas of skin were delineated; for both lesional and nonlesional skin, the stratum corneum (the SC) was stripped, followed 24 h later by exposure to narrowband ultraviolet B (NB‐UVB) irradiation, to measure the minimal erythema dose (MED) in normal, stripped normal, vitiliginous and stripped vitiliginous skin models. These MED values were used to assess the photoprotective role of epidermal structures: melanin, viable epidermis (VE) and the SC. Results. In the vitiligo group, the MED values were significantly (P < 0.05) different between the skin models, being highest in normal skin, followed by stripped normal, vitiliginous and stripped vitiliginous skin. A similar significance level was found within each SPT for almost all comparisons. There was also a significant (P < 0.001) positive correlation between MED and SPTs. There were also significant (P < 0.05) differences in MED values calculated for epidermal structures, being highest for VE, followed by melanin and then the SC, and there was a significant (P < 0.05) positive correlation between MED and SPTs. Conclusion. Epidermal photoprotection may extend beyond melanin production, involving several factors such as epidermal layer thickness, optical properties and chromophores. Such a role was perceived to be reactive to UV irradiation, and more efficient in those with higher SPTs.     

Emerging role of dermal compartment in skin pigmentation: comprehensive review

The variations in human skin colour mainly occur due to differences in the distribution of melanin pigment throughout the body, synthesized by epidermal melanocytes which are further taken up by keratinocytes present in epidermis. Recently, it has been discovered that besides these cells, dermis derived fibroblast factors also play a prominent role in regulating skin pigmentation. There exists a signal crosstalk between epidermal melanocytes, keratinocytes and dermal fibroblasts and any impairment in these signalling pathways may give rise to pigmentary disorders. Vitiligo is a hypopigmentary disorder and alteration in the expression level of several fibroblast-specific factors has been reported in the lesional skin of vitiligo patients. In such patients, there is decrease in the expression levels of factors such as basic fibroblast growth factor, stem cell factor (SCF) and keratinocyte growth factor (KGF) along with a steep increase in the expression levels of Dickkopf 1. Patients affected with hyperpigmentary disorder like melasma exhibit a marked increase in SCF and KGF expression levels leading to increase in melanin production and those affected with solar lentigo experience upregulation in the expression levels of SCF, KGF and HGF (hepatocyte growth factor). Hence, we conclude that new therapeutic strategies can be adopted to cure these pigmentary disorders by targeting factors involved in crosstalk signalling between epidermal melanocytes, keratinocytes and dermal fibroblasts.     

Involvement of non‐melanocytic skin cells in vitiligo

Despite melanocytes are the key players in vitiligo, a continuous cross‐talk between epidermal and dermal cells may strictly affect their functionality, in both lesional skin and non‐lesional skin. Focusing on this interplay, we have reviewed existing literature supporting evidence on cellular and functional alterations of surrounding epidermal keratinocytes, extracellular matrix (ECM) proteins and fibroblasts in the underlying dermal compartment that may contribute to melanocyte disappearance in vitiligo. We have also examined some clinical and therapeutic aspects of the disease to sustain the non‐exclusive involvement of melanocytes within vitiligo. As a result, a different and more complex scenario has appeared that may enable to provide better understanding about origins and progress of vitiligo and that should be considered in the evaluation of new treatment approaches.     

白癜风患者表皮内郎格罕细胞观察

用改良的Ｊｕｈｌｉｎ－ＳｈｅｌｌｅｙＡＴＰ酶细胞化学染色法检查了１３例白癜风（进展期）患者的白斑、白斑边缘区及对侧相应正常皮肤中郎格罕细胞情况，结果白斑部位表皮郎格罕细胞数目较对应正常皮肤表皮变化不大，而白斑边缘部皮肤郎格罕细胞数目较正常皮肤显著增多（Ｐ＜０．００５）。在白斑及白斑边缘区还可见到印格罕细胞的形态学变化：胞体变大、深染、胞突消失以及细胞积聚现象，在白斑边缘部尤其明显。本研究显示郎格罕细胞数目和形态学的变化与病情活动有关。提示郎格罕细胞在白癜风发病机制中起一定的作用。