Adult Onset Vitiligo: Multivariate Analysis Suggests the Need for a Thyroid Screening

The causal relationship between vitiligo and autoimmune thyroid diseases: A bidirectional two-sample Mendelian randomization analysis

BACKGROUND

Vitiligo is an acquired autoimmune depigmented disorder characterized by the presence of white and well-defined patches on the skin, mucous membrane, or both. It is associated with a significant disease burden and has a profoundly impacts patients' quality of life. Autoimmune thyroid diseases (AITDs) result from an autoimmune system dysregulation, leading to an erroneous immune attack on the thyroid gland. Previous observational and epidemiological studies have suggested the association between vitiligo and AITDs. However, the bidirectional cause-effect relationship between vitiligo and AITDs has not been formally assessed.

METHOD

Two-sample bidirectional Mendelian randomization (MR) analysis was conducted to explore potential causal relationships between genetically increased risk of vitiligo and AITDs, using summary statistics from genome-wide association studies in European populations. Causal effects were primarily estimated using the inverse variance weighted method, and additional quality control was performed using the MR-Egger, weighted median, simple mode, and weight mode methods. Sensitivity analysis was conducted to assess the robustness of the results.

RESULTS

The forward MR analysis showed a positive causal relationship between vitiligo and autoimmune thyroiditis (AIT), autoimmune hyperthyroidism (AIH), and Graves' disease (GD). The odds ratio (OR) were 1.17 (95% CI, 1.01-1.35; p = 0.04), 1.12 (95% CI, 1.03-1.22; p = 0.01), and 1.13 (95% CI, 1.06-1.20; p < 0.01), respectively. In the reverse MR analysis, a positive causal relationship was found between AIT and vitiligo, with an OR of 1.10 (95% CI, 1.01-1.35; p = 0.04). However, no causal relationship was observed between AIH (p = 0.10) or GD (p = 0.61) and vitiligo. Sensitivity analysis revealed no evidence of horizontal pleiotropy or heterogeneity.

CONCLUSIONS

The genetic-level investigation provides evidence of a genetic causal association between susceptibility to vitiligo and an increased risk of AITDs. Additionally, the results demonstrate a genetic causal association between susceptibility to AIT and an increased risk of vitiligo, while not indicating a similar association with susceptibility to AIH or GD.

How Does Vitamin D Affect Immune Cells Crosstalk in Autoimmune Diseases?

Vitamin D is a secosteroid hormone that is highly involved in bone health. Mounting evidence revealed that, in addition to the regulation of mineral metabolism, vitamin D is implicated in cell proliferation and differentiation, vascular and muscular functions, and metabolic health. Since the discovery of vitamin D receptors in T cells, local production of active vitamin D was demonstrated in most immune cells, addressing the interest in the clinical implications of vitamin D status in immune surveillance against infections and autoimmune/inflammatory diseases. T cells, together with B cells, are seen as the main immune cells involved in autoimmune diseases; however, growing interest is currently focused on immune cells of the innate compartment, such as monocytes, macrophages, dendritic cells, and natural killer cells in the initiation phases of autoimmunity. Here we reviewed recent advances in the onset and regulation of Graves' and Hashimoto's thyroiditis, vitiligo, and multiple sclerosis in relation to the role of innate immune cells and their crosstalk with vitamin D and acquired immune cells.

Predicting the risk of autoimmune thyroid disease in patients with vitiligo: Development and assessment of a new predictive nomogram

BACKGROUND

This study aimed to develop an autoimmune thyroid disease (AITD) risk prediction model for patients with vitiligo based on readily available characteristics.

METHODS

A retrospective analysis was conducted on the clinical characteristics, demographics, skin lesions, and laboratory test results of patients with vitiligo. To develop a model to predict the risk of AITD, the Least Absolute Shrinkage and Selection Operator (LASSO) method was used to optimize feature selection, and logistic regression analysis was used to select further features. The C-index, Hosmer-Lemeshow test, and decision curve analysis were used to evaluate the calibration, discrimination ability and clinical utility of the model. Internally, the model was verified using bootstrapping; externally, two independent cohorts were used to confirm model accuracy.

RESULTS

Sex, vitiligo type, family history of AITD, family history of other autoimmune disease, thyroid nodules or tumors, negative emotions, skin involvement exceeding 5% of body surface area, and positive immune serology (IgA, IgG, IgM, C3, and C4) were predictors of AITD in the prediction nomogram. The model showed good calibration and discrimination (C-index: 0.746; 95% confidence interval: 0.701-0.792). The accuracy of this predictive model was 74.6%.In both internal validation (a C-index of 1000 times) and external validation, the C-index outperformed (0.732, 0.869, and 0.777). The decision curve showed that the AITD nomogram had a good guiding role in clinical practice.

CONCLUSION

The novel AITD nomogram effectively evaluated the risk of AITD in patients with vitiligo.

Vitiligo-Thyroid Disease Association: When, in Whom, and Why Should It Be Suspected? A Systematic Review

In most dermatological pathologies, the phenomena observed on the skin are a reflection of internal disorders. In patients with associated acral involvement on the dorsal sides of the hands, this "vitiligo phenotype" may lead to the investigation of certain associated pathologies that sometimes have no obvious clinical impact. To assess the link between skin depigmentation and autoimmune pathologies, we conducted a systematic review involving article selection from the PubMed database. Patients with coexisting thyroid pathologies were found to have a predisposition for developing acral vitiligo and depigmentation of the wrists, and autoimmune thyroid pathologies appeared to be the only coexisting autoimmune or inflammatory diseases in vitiligo patients to show a pattern of distribution. The association of concomitant thyroid dysfunction with depigmentation of the hands was found to be so strong that the absence of depigmented macules on the hands may exclude the coexistence of an autoimmune thyroid pathology. Although the frequency of acral involvement in patients with vitiligo and autoimmune pathologies is higher, the mechanism by which thyroid dysfunction influences this distribution pattern remains incompletely elucidated and requires future studies.

Different vitiligo characteristics as predictors of increased risk of metabolic syndrome and insulin resistance: A case-control study

BACKGROUND

Autoimmune and metabolic disturbances have been reported in association with vitiligo, highlighting possible systemic associations that should be considered.

AIMS

To assess the possible association of metabolic syndrome (MetS) as well as insulin resistance (IR) with vitiligo in different age groups.

METHODS

This case-control study included 142 patients with vitiligo aging ≥ 6 years and 142 age- and sex-matched controls. Participants were assessed for MetS using the International Diabetes Federation (IDF) criteria in addition to IR via homeostasis model assessment of IR (HOMA-IR). The study was registered at Clinical Trials.gov, Identifier: NCT03622320, on August 9, 2018.

RESULTS

As per the IDF criteria, patients with vitiligo showed significantly more frequent association with high fasting plasma glucose levels, high blood pressure readings, central obesity, dyslipidemia, and MetS than controls (p = 0.020, p = 0.034, p = 0.014, p < 0.001, and p = 0.002, respectively). Moreover, patients with vitiligo have significantly higher levels of fasting insulin and HOMA-IR (p ≤ 0.001). Results obtained from patients with vitiligo and controls with coexistent MetS/IR demonstrated vitiligo as a risk factor for both MetS and IR. Univariate and multivariate logistic regression highlighted that older age was the significant independent predictor for MetS and IR.

CONCLUSION

Patients with vitiligo showed a significantly higher incidence of MetS than controls. Vitiligo per se can be considered a risk factor for MetS and IR. Therefore, regular follow-up and early metabolic derangement diagnoses are mandatory.

A practical guide to vitiligo differential diagnoses in primary care

ABSTRACT

Primary care providers often encounter different types of pigmentary disorders such as vitiligo. This article arms the provider with the most common vitiligo differential diagnoses, with key findings and tips to identify specific hypopigmentary diseases. Readers will be better-prepared to provide safe and effective care and recommend referrals to appropriate specialties.

[The prevalence of autoimmune endocrine diseases in vitiligo patients]

Vitiligo is a common polygenic autoimmune disease in which the foci of depigmentation are formed on the skin and/or mucous membranes as a result of the death of melanocytes. There are several hypotheses for the pathogenesis of the disease, the leading role among them is played the autoimmune hypothesis. This review summarizes the available literature data on the prevalence and structure of comorbid endocrine autoimmune pathology in vitiligo patients. In most studies conducted in Europe, America and Asia the prevalence of autoimmune thyroid diseases (including autoimmune thyroiditis and Graves disease), diabetes mellitus and autoimmune adrenal insufficiency was higher in vitiligo patients than in the general population. The results of some studies indicate a frequent association of vitiligo with autoimmune polyglandular syndromes. In the structure of comorbid pathology the highest prevalence was in autoimmune thyroid diseases. A number of studies have established a higher prevalence of autoimmune endocrine diseases in women, as well as in nonsegmental vitiligo patients and in cases of family history of vitiligo and/or other autoimmune diseases. In addition, it was shown that the prevalence of endocrine diseases increases with increasing area of depigmentation. The data obtained justify the advisability of conducting a timely examination of vitiligo patients with the aim of early detection of comorbid diseases and the appointment of appropriate treatment. Further studies are needed to investigate the effect of the identified associations on the course of vitiligo and comorbid endocrinopathies, as well as the effectiveness of therapy and the quality of life of patients.

Adults with a more extensive body involvement, moderate to extremely severe vitiligo and a prolonged clinical course have an early onset in childhood in addition to other prognostic factors as compared to individuals with later-onset vitiligo

BACKGROUND

The extent and disease severity, duration and other associated prognostic cofactors in vitiligo in adults may vary with the age of onset (before or after 10 years of age).

OBJECTIVES

To compare extent and disease severity, duration and other cofactors in adults with early-onset and late-onset vitiligo.

METHODS

The medical records of 408 (M:F 1:1.1) adults aged 20-75 years diagnosed with vitiligo between January 2016 and December 2019 were examined retrospectively. The extent and severity of vitiligo were defined. Characteristics of vitiligo with early onset and late onset were compared statistically and odds ratios calculated for risk assessment.

RESULTS

31 (7.6%, M:F 1:2.4) patients had early-onset vitiligo, and 377 (92.4%, M:F 0.8:1) patients had later-onset vitiligo. Compared to late onset, patients with early-onset vitiligo had a significant number of males (71% vs 45.9%), higher percentages of body surface area involvement and moderate to extremely severe disease (29% vs 10.6%), longer duration of disease (41.9% vs 9%), Koebner's phenomenon (48.4% vs 15.6%) and halo nevus (9.7% vs 1.9%). Differences between the two groups were not significant for types of vitiligo, family history of vitiligo and presence of cutaneous and systemic/autoimmune diseases.

CONCLUSION

The adults, males in particular, with generalised vitiligo (>10% BSA involvement) appear to have an early onset and a prolonged clinical course. The presence of Koebner's phenomenon and halo nevus in patients with early-onset vitiligo was other poor prognostic factors compared to patients with late-onset vitiligo. The retrospective, hospital-based cross-sectional design and small sample size for stratification remain major limitations.

Semi-Automatic Tool for Vitiligo Detection and Analysis

Vitiligo vulgaris is an autoimmune disease which causes a strong reduction of the cells producing melanin, which is the main skin pigment. This results in the growth of white patches on patients’ skin, which are more or less visible, depending on the skin phototype. Precise, objective and fast detection of vitiligo patches would be crucial to produce statistically relevant data on huge populations, thus giving an insight on the disease. However, few methods are available in literature. In the present paper, a semi-automatic tool based on image processing to detect facial vitiligo patches is described. The tool requires pictures to be captured under black light illumination, which enhances patches contrast with respect to healthy skin. The user is only required to roughly define the regions of interest and set a global threshold, thus, no specific image-processing skills are required. An adaptive algorithm then automatically discerns between vitiligo and healthy skin pixels. The tools also allow for a statistical data interpretation by overlapping the detected patches of all patients on a face template through an occurrence map. Preliminary results obtained on a small population of 15 patients allowed us to assess the tool’s performance. Patch detection was checked by an experienced dermatologist, who confirmed the detection for all the studied patients, thus supporting the effectiveness of the proposed tool.

The relationship between stress and vitiligo: Evaluating perceived stress and electronic medical record data

Vitiligo is a T-cell mediated skin disorder characterized by progressive loss of skin color. In individuals genetically predisposed to the disease, various triggers contribute to the initiation of vitiligo. Precipitating factors can stress the skin, leading to T-cell activation and recruitment. Though hereditary factors are implicated in the pathogenesis of vitiligo, it is unknown whether precipitating, stressful events play a role in vitiligo. To understand this, we utilized a validated perceived stress scale (PSS) to measure this parameter in vitiligo patients compared to persons without vitiligo. Additionally, we probed a clinical database, using a knowledge linking software called ROCKET, to gauge stress-related conditions in the vitiligo patient population. From a pool of patients in an existing database, a hundred individuals with vitiligo and twenty-five age- and sex-matched comparison group of individuals without vitiligo completed an online survey to quantify their levels of perceived stress. In parallel, patients described specifics of their disease condition, including the affected body sites, the extent, duration and activity of their vitiligo. Perceived stress was significantly higher among vitiligo individuals compared to those without vitiligo. ROCKET analyses suggested signs of metabolic-related disease (i.e., ‘stress’) preceding vitiligo development. No correlation was found between perceived stress and the stage or the extent of disease, suggesting that elevated stress may not be a consequence of pigment loss alone. The data provide further support for stress as a precipitating factor in vitiligo development.

Comorbid diseases of vitiligo: A 10-year cross-sectional retrospective study of an urban US population

BACKGROUND

Vitiligo is associated with medical conditions, primarily autoimmune disorders; however, only a few studies in the United States have investigated these associations.

OBJECTIVE

Our purpose was to investigate the diseases associated with vitiligo in the New York, New York, population and evaluate if these associations differ by race/ethnicity and sex.

METHODS

In this retrospective study, we analyzed data collected from the medical records of 1487 vitiligo patients seen at New York University during a 10-year period.

RESULTS

Vitiligo patients had a statistically significant higher prevalence of hypothyroidism, multiple sclerosis, rheumatoid arthritis, idiopathic thrombocytopenic purpura, seronegative arthritis, pernicious anemia, myasthenia gravis, inflammatory bowel disease, lymphoma, and systemic lupus erythematosus. Rates of comorbid autoimmune diseases varied by race and sex.

LIMITATIONS

Medical charts did not consistently report race/ethnicity, type of vitiligo, and total body surface area affected. Information from nondermatology medical visits was also included.

CONCLUSION

This study revealed multiple new disease associations for vitiligo, including multiple sclerosis, idiopathic thrombocytopenic purpura, and lymphoma, as well as confirmed previously reported associations with other autoimmune diseases, the most common being hypothyroidism followed by rheumatoid arthritis. Associations did vary by race/ethnicity and sex.

Thyroid diseases and skin autoimmunity

The skin is the largest organ of the body, at the boundary with the outside environment. Primarily, it provides a physical and chemical barrier against external insults, but it can act also as immune organ because it contains a whole host of immune-competent cells of both the innate and the adaptive immune systems, which cooperate in eliminating invading pathogens following tissue injury. On the other hand, improper skin immune responses lead to autoimmune skin diseases (AISD), such as pemphigus, bullous pemphigoid, vitiligo, and alopecia. Although the interplay among genetic, epigenetic, and environmental factors has been shown to play a major role in AISD etiology and progression, the molecular mechanisms underlying disease development are far from being fully elucidated. In this context, epidemiological studies aimed at defining the association of different AISD with other autoimmune pathologies revealed possible shared molecular mechanism(s) responsible for disease progression. In particular, over the last decades, a number of reports have highlighted a significant association between thyroid diseases (TD), mainly autoimmune ones (AITD), and AISD. Here, we will recapitulate the epidemiology, clinical manifestations, and pathogenesis of the main AISD, and we will summarize the epidemiological evidence showing the associations with TD as well as possible molecular mechanism(s) underlying TD and AISD pathological manifestations.

Decreased SUMOylation of the retinoblastoma protein in keratinocytes during the pathogenesis of vitiligo

The role of SUMOylation in the pathogenesis of vitiligo has not been reported previously. The present study aimed to reveal abnormalities in small ubiquitin‑like modifier (SUMO) conjugation in keratinocytes from depigmented lesions of patients with vitiligo and confirm the role of SUMOylation in keratinocytes from patients with vitiligo. Skin samples used for immunohistochemistry were obtained by punch biopsy from the depigmented lesions of 6 patients. Blisters were produced by vacuum and the roofs were collected for keratinocyte culture. HaCaT cells were transduced with SUMO1 knockdown vectors. The protein expression of SUMO1, SUMO‑specific peptidase 1 (SENP1), ubiquitin‑conjugating enzyme E2 I (Ubc9), SUMO‑activating enzyme subunit 1 (SAE1), cyclin‑dependent kinase (CDK)2, CDK6, proliferating cell nuclear antigen (PCNA), retinoblastoma protein (Rb), phosphorylated Rb (pRb) and β‑actin was assessed by western blotting. The SUMOylation status of proteins was assessed by immunoprecipitation. Cell cycle analysis was performed by flow cytometry and cell proliferation rate was investigated using a Cell Counting Kit‑8. The results demonstrated that the levels of SUMO1‑conjugated proteins were decreased in vitiligo lesions and vitiligo keratinocytes compared with normal controls. The protein expression of Ubc9 was decreased and SENP1 was increased in vitiligo keratinocytes compared with normal keratinocytes, with no alterations in SAE1 expression. Following knockdown of SUMO1 in HaCaT cells, the proliferation of HaCaT cells was reduced and the cell cycle was arrested in G1 phase. Furthermore, the protein expression levels of PCNA, CDK2, CDK6 and pRb were reduced in SUMO1‑knockdown HaCaT cells, and SUMOylated Rb was also decreased markedly in keratinocytes from lesions of patients with vitiligo compared with normal keratinocytes. In conclusion, vitiligo lesions in the present study exhibited dysregulated SUMOylation and deSUMOylation balance and dysregulation of cell cycle progression may be present in SUMO1 knockdown HaCaT cells. These results indicate that deSUMOylation of Rb of keratinocytes may serve an important role in vitiligo, providing a novel direction for the study into the mechanism of vitiligo.

Comorbidities in vitiligo: comprehensive review

Vitiligo is a common skin disorder characterized by idiopathic, progressive cutaneous hypomelanosis. Vitiligo is associated with several comorbid autoimmune, systemic, and dermatological diseases, primarily thyroid disease, alopecia areata, diabetes mellitus, pernicious anemia, systemic lupus erythematosus, rheumatoid arthritis, Addison's disease, inflammatory bowel disease, Sjögren's syndrome, dermatomyositis, scleroderma, ocular and audiological abnormalities, psoriasis, and atopic dermatitis. It is essential to increase awareness of these comorbidities in order to improve the disease burden and quality of life of patients with vitiligo. Herein, we review the association with the most frequent comorbidities associated with vitiligo.

The effect of topical piperine combined with narrowband UVB on vitiligo treatment: A clinical trial study

Vitiligo is the most common acquired hypopigmentary disease in the community. Piperine as an herbal extract derived from black pepper has strong impact on the melanocyte proliferation and adverse side effects less than synthetic drugs such as corticosteroids. For the first time, this study was aimed to evaluate the effect of topical piperine combined with narrowband ultraviolet B (NB-UVB) on vitiligo treatment. In this double-blind clinical trial, 63 patients with facial vitiligo were randomly divided into 2 groups: treated with piperine (case) and placebo (control). Also, both groups received NB-UVB phototherapy every other day for 3 months. In the case group, 10 patients have burning sensation on their skin areas (p value = .002). Also, redness of the treated areas was observed in 6 patients (p value = .028). Both side effects were temporary. Regarding repigmentation at time intervals of 1, 2, and 3 months after treatment, its level in the case group was significantly higher than the control group (p value < .001). Based on our findings, the combination therapy with NB-UVB/topical piperine has more influence on facial vitiligo than that of NB-UVB alone. It could be concluded that the simultaneous use of NB-UVB and topical piperine has a remarkable effect on treatment of vitiligo.

Vitiligo and Autoimmune Thyroid Disorders

Vitiligo represents the most common cause of acquired skin, hair, and oral depigmentation, affecting 0.5-1% of the population worldwide. It is clinically characterized by the appearance of disfiguring circumscribed skin macules following melanocyte destruction by autoreactive cytotoxic T lymphocytes. Patients affected by vitiligo usually show a poorer quality of life and are more likely to suffer from depressive symptoms, particularly evident in dark-skinned individuals. Although vitiligo is a non-fatal disease, exposure of affected skin to UV light increases the chance of skin irritation and predisposes to skin cancer. In addition, vitiligo has been associated with other rare systemic disorders due to the presence of melanocytes in other body districts, such as in eyes, auditory, nervous, and cardiac tissues, where melanocytes are thought to have roles different from that played in the skin. Several pathogenetic models have been proposed to explain vitiligo onset and progression, but clinical and experimental findings point mainly to the autoimmune hypothesis as the most qualified one. In this context, it is of relevance the strong association of vitiligo with other autoimmune diseases, in particular with autoimmune thyroid disorders, such as Hashimoto thyroiditis and Graves' disease. In this review, after a brief overview of vitiligo and its pathogenesis, we will describe the clinical association between vitiligo and autoimmune thyroid disorders and discuss the possible underlying molecular mechanism(s).