Autoantibodies as diagnostic and predictive markers of vitiligo

Study of thyroid disorders in vitiligo

Background and Aims

Vitiligo, an acquired sometimes familial depigmentary disorder of the skin and hair that results from selective destruction of melanocytes or pigment cells. It is the single most important non-neo plastic disease that involves both the immune system and melanocytes which are subsequently destroyed and the affected area turns pale and becomes white. The prevalence of the disease is between 1% and 2% in general population.

Methods

It is a prospective, randomized, and controlled study. Over 90 vitiligo patients attending Dermatology OPD and vitiligo clinic are enrolled in the study. About 35 apparently healthy, age and sex matched individuals are selected to serve as control. A prescribed proforma containing all the demographic data, relevant questionnaire were recorded for each and every case with brief clinical history suggestive of any thyroid disease as well as those referred by the clinicians. P value <0.05 is considered significant. The Quantitative Determination of Thyroglobulin (Tg) Autoantibodies in Human Serum or Plasma by a Microplate Enzyme Immunoassay.

Results

Vitiligo group, thirty four (37.78%) patients have clinical hypothyroidism while 9 (10%) patients have clinical hyperthyroidism. This difference in the distribution is statistically significant (P < 0.05) with a Chi-square value of 10.08. The data are entered, analyzed and computed with SPSS version 15 software and well-known statistical test like Chi-square, students' 't' test have been advocated wherever found applicable. P value <0.05 is considered significant.

Conclusion

There is increased incidence of autoimmune thyroid diseases among vitiligo patients. The reason being vitiligo usually precedes the onset of thyroid dysfunction.

Assessment of thyroid gland hormones and ultrasonographic abnormalities in medical staff occupationally exposed to ionizing radiation

BACKGROUND

Ionizing radiation (IR) is high-energy radiation that has the potential to displace electrons from atoms and break chemical bonds. It has the ability to introduce mutations, DNA strand breakage, and cell death. Being a radiosensitive organ, exposure of the thyroid gland to IR can lead to significant changes in its function.

AIM OF THE WORK

Was to measure the levels of thyroid hormones panel and ultrasonography abnormalities in medical staff occupationally exposed to IR.

SUBJECTS AND METHODS

A total of 120 subjects were divided into three main groups: Group I: radiation-exposed workers occupationally exposed to radioiodine (131I) (n = 40), Group II: radiation-exposed workers occupationally exposed to X-ray (n = 40), and Group III: non-exposed healthy professionals matched in age and sex with the previous groups (n = 40). Thyroid hormones panel including free triiodothyronine (fT3), free thyroxine (fT4), thyroid-stimulating hormone (TSH), anti-thyroperoxidase antibodies (anti-TPO), and thyroglobulin (Tg) were measured. Thyroid ultrasonography was performed. Oxidative stress markers such as malondialdehyde (MDA), hydrogen peroxide (H2O2), and total antioxidant capacity (TAC) were measured.

RESULTS

Group I had significantly higher fT3 levels than the control group. fT3 levels were considerably higher, while TSH was substantially lower in group II participants than in the control group. Tg was markedly lower in radiation-exposed workers. However, anti-TPO levels in radiation-exposed workers were significantly higher than in the control group. MDA and H₂O₂ were substantially higher; TAC was significantly lower in radiation-exposed workers compared to the control group. According to ultrasonographic examination, thyroid volume and the percentage of thyroid nodules in all radiation workers were significantly higher than in the control group.

CONCLUSION

Despite low exposure doses, occupational exposure to IR affects the thyroid hormones and links with a higher likelihood of developing thyroid immune diseases.

Imbalance of peripheral follicular helper T lymphocyte subsets in active vitiligo

Vitiligo is an autoimmune disease characterized by the presence of several autoantibodies, some of which are directed against melanocyte components and have been shown to be associated with the progression of the disease. However, the mechanism involved in the production of autoantibodies remains unclear. Follicular helper CD4⁺ T cells (TFH) are specialized in B-cell activation and antibody production, especially the TFH cell subsets type 2 and type 17. To date, TFH cell subsets have not been studied in human vitiligo. This study in 44 vitiligo patients and 19 healthy controls showed an increase in circulating TFH cells associated with disease clinical progression. A more precise analysis of TFH cell phenotype demonstrated that vitiligo is characterized by populations of peripheral TFH cells responsible for helping B-cell function, such as TFH type 2 and type 17 which produce Th2- and TH17-related cytokines, respectively. These findings suggest a new mechanism involving TFH cell subsets in the pathogenesis of human vitiligo and leading to the production of autoantibodies and disease.

Thyroid Autoimmunity in Patients with Chronic Urticaria

INTRODUCTION

chronic urticaria (CU) is a skin disorder characterized by transient, pruritic wheals persisting for longer than 6 weeks. The etiopathogenesis of the disease is still unclear, but there is evidence that autoimmunity and endocrine dysfunction may be involved.

AIM

the aim of this study was to determine whether chronic urticaria is statistically associated with thyroid autoimmunity.

PATIENTS AND METHODS

in a prospective case-control study, we compared the frequency of thyroid auto-antibodies (thyroglobulin antibody, anti-Tg and thyroid peroxidase antibody, anti-TPO) in 70 patients with chronic urticaria and in 70 healthy volunteers. Thyroid auto-antibodies and thyroid hormones (thyroxine (T4), triiodthyronine (T3) and thyroid stimulating hormone (TSH) were measured in all subjects.

RESULTS

thyroid functional abnormalities were found in 8 (11.43%) patients. Anti-Tg and anti-TPO were positive in 16 (23%) and 21 (30%) patients, respectively. In control group, only one subject (1.42%) had abnormalities in thyroid hormonal status, and two subjects (2.86%) had positive thyroid auto-antibodies. Compared with the control group, the frequency of both anti-Tg and anti-TPO was significantly higher in those with chronic urticaria (P < 0.05).

CONCLUSION

this study shows a significant association between chronic urticaria and thyroid autoimmunity, and that tests to detect thyroid auto-antibodies are relevant in patients with chronic urticaria.

Thyroid abnormalities in paediatric patients with vitiligo: retrospective study

INTRODUCTION

The association between vitiligo and thyroid disease is not fully investigated especially in paediatric patients.

AIM

To determine the incidence of vitiligo and thyroid disorders in children. This is the first report from middle Anatolia and the second report from Turkey.

MATERIAL AND METHODS

A retrospective chart review was performed to examine the presence of thyroid abnormalities in paediatric patients who had been admitted to the dermatology department with vitiligo.

RESULTS

A total of 155 paediatric patients, including 80 (52%) male and 75 (48%) female patients were included. The mean age was 8.6 years. Non segmental vitiligo was the most common type of the disease in 140 (90%) reviewed patients, while segmental vitiligo appeared only in 15 (10%) patients. The mean onset of vitiligo was 5.6 ±0.9 years. A family history of vitiligo was found in 14 (9%) children. Thirty-four (22%) patients had thyroid function tests and/or thyroid autoantibody abnormality. All of these patients had non segmental vitiligo. It was statistically significant (p < 0.05) in types of vitiligo and thyroid disease parameters.

CONCLUSIONS

Our results show that it may be useful to screen thyroid in children with non segmental vitiligo.

Anti-thyroid peroxidase antibody in vitiligo: a prevalence study

Aim. The aim of the study was to study the relation of vitiligo with demographic data like age, sex, and duration and determine the prevalence of thyroid autoimmunity in vitiligo patients. Materials and Methods. This study was a cross sectional study consisting of 100 patients clinically diagnosed (old and new) as having vitiligo irrespective of age or sex. Patients with known thyroid disease on supplementation therapy, or who had undergone thyroid surgery, those on antithyroid medication, patients with other causes of leukoderma, and cases who do not provide informed consent were excluded from the study. Serum TSH and anti-TPO antibodies were measured in all the patients. Results. The prevalence of anti-TPO antibody positivity was found to be 28%. Conclusion. According to our study, none of our vitiligo patients had symptoms or signs of thyroid disease at the time of presentation but, on biochemical evaluation, anti-TPO antibodies were found in a considerable number of patients. Hence, we recommend screening of these patients with thyroid antibodies.

Circulating autoantibodies and autoimmune comorbidities in vitiligo patients: a multicenter Italian study

BACKGROUND

Autoimmune comorbidities and circulating autoantibodies have been observed in vitiligo patients, but differences in rate are present according to countries in which the studies were performed, perhaps owing to ethnic diversities or different trigger factors.

OBJECTIVE

To estimate the prevalence of circulating autoantibodies and overt autoimmune diseases in a fairly large sample of Italian vitiligo patients.

METHODS

175 outpatients affected by vitiligo and referred to nine dermatological centers were included in the study. Patients were offered routine blood test, serological testing for thyroid function and search for autoantibodies.

RESULTS

At least one circulating autoantibody was detected in 61 (41.8%) of 146 subjects who underwent laboratory tests. Anti-thyroperoxidase (25.6%), anti-thyroglobulin (23.4%), antinuclear antibodies (16.8%) and anti-gastric parietal cell antibodies (7.8%) were the most noticed autoantibodies. 74 (41.5%) autoimmune comorbidities, mainly autoimmune thyroiditis (37%), were reported.

CONCLUSION

The prevalence of autoimmune comorbidities and circulating autoantibodies in this study was in agreement with other surveys conducted on Caucasian patients.

Autoimmune thyroid disease in vitiligo: multivariate analysis indicates intricate pathomechanisms

BACKGROUND

Vitiligo/nonsegmental vitiligo (NSV) is often associated with thyroid dysimmunity although very few reports have studied this association using multivariate logistic regression.

OBJECTIVE

To identify weighted factors associated with the presence of autoimmune thyroid disease (AITD) in a large cohort of patients with vitiligo/NSV.

METHODS

This was a prospective observational study in 626 patients with a confirmed diagnosis of vitiligo/NSV attending the vitiligo clinic of the University Hospital Department of Dermatology, Bordeaux, France, from 1 January 2006 to 1 May 2012. The Vitiligo European Task Force (VETF) questionnaire was completed for each consecutive patient. AITD was defined as the presence of significant levels of serum antithyroperoxidase antibodies or evidence of autoimmune thyroiditis. Univariate and multivariate logistic regression procedures were conducted to identify factors associated with AITD in this cohort of patients with vitiligo/NSV.

RESULTS

A total of 626 patients with vitiligo/NSV were included, of whom 131 had AITD (AITD-vitiligo). Stress as an onset factor, familial history of AITD, body surface involvement and duration of the disease were positively associated with AITD-vitiligo using univariate analysis, whereas female sex, age at onset of vitiligo, personal history of autoimmune disease and localization on the trunk were found to be independently associated with AITD-vitiligo.

CONCLUSION

Vitiligo associated with AITD has clinical features distinct from vitiligo without AITD. In particular, female patients, and patients with longer duration of disease and greater body surface involvement are more likely to present with AITD and should thus be monitored for thyroid function and antithyroid antibodies on a regular basis.

The prevalence of thyroid disease in patients with vitiligo: a systematic review

BACKGROUND

Thyroid disease has been suggested to be associated with vitiligo. However, the outcomes of prevalence studies on thyroid disease in vitiligo vary widely.

OBJECTIVES

To summarize and critically appraise current evidence of the prevalence of thyroid diseases in vitiligo.

METHODS

A systematic review was performed searching the electronic databases OVID MEDLINE, OVID EMBASE and PubMed. Guidelines for the critical appraisal of studies on prevalence of a health problem were adapted to evaluate the methodological quality of the included studies. Results were analysed in a meta-analysis with a risk ratio (RR).

RESULTS

Forty-eight studies published between 1968 and 2012 met the inclusion criteria. Most of the studies (50%) were of fair methodological quality, whereas 18 studies (38%) were of poor quality and six studies (12%) were of good quality. Thyroid disease, autoimmune thyroid disease and presence of thyroid-specific autoantibodies showed a mean prevalence of, respectively, 15·1%, 14·3% and 20·8% in patients with vitiligo and an RR of, respectively, 1·9, 2·5 and 5·2 (all statistically significant). This review shows an increased prevalence and an increased risk of (autoimmune) thyroid disease in patients with vitiligo compared with nonvitiligo. This risk seems to increase with age.

CONCLUSIONS

Clinicians should be aware of this increased risk in patients with vitiligo and should be attentive for symptoms of thyroid disease. To make recommendations on screening for thyroid disease in patients with vitiligo future research of good methodological quality, including differentiation of vitiligo types and the use of standardized outcome measures, is needed.

Association between Vitiligo and Thyroid Autoimmunity

Background. Vitiligo is a common skin disorder characterized by macular depigmentation of the skin. The etiopathogenesis of the disease is still unclear, but there is evidence that autoimmunity and endocrine disfunction may be involved. Objective. The aim of this study was to determine whether vitiligo is statistically associated with thyroid autoimmunity. Method. In a prospective case-control study, we compared the frequency of thyroid autoantibodies (thyroglobulin antibody, anti-Tg and thyroid peroxidase antibody, and anti-TPO) in 33 patients with vitiligo and in 33 healthy volunteers. Thyroid autoantibodies and thyroid hormones (thyroxine (T4), triiodothyronine (T3), and thyroid stimulating hormone (TSH) were measured in all subjects. Results. Thyroid functional abnormalities were found in 6 (18.18%) patients. Anti-Tg and anti-TPO were positive in 9 (27.27%) and 8 (24.24%) patients, respectively. In control group, only one subject (3.03%) had abnormalities in thyroid hormonal status, and two subjects had positive thyroid autoantibodies. Compared with the control group, the frequency of both anti-Tg and anti-TPO was significantly higher in those with vitiligo (P < .05). Conclusion. This study shows a significant association between vitiligo and thyroid autoimmunity, and that tests to detect thyroid autoantibodies are relevant in patients with vitiligo.

Anti-thyroid peroxidase antibody and vitiligo: a controlled study

Background

Vitiligo is an acquired depigmenting disorder due to destruction of melanocytes. Although many theories have been suggested for its pathogenesis, the role of autoimmunity is the most popular one. The association of vitiligo with autoimmune thyroid diseases and the increased prevalence of autoantibodies including thyroid autoantibodies in vitiligo favor this role. Our objective was to compare the frequency of thyroid peroxidase antibody (anti-TPO) in vitiligo patients with healthy subjects in Iran.

Methods

Ninety-four cases of vitiligo (46 female and 48 male) and 96 control subjects (49 female and 47 male) were enrolled in this controlled study. Patients with known thyroid disease, history of thyroid surgery and those receiving thyroid medications were not included. The two groups were matched regarding gender and age. The demographic data, symptoms related to thyroid diseases and results of skin and thyroid examinations were recorded in a questionnaire for each subject. Thyroid function tests including free T3, free T4 and TSH-IRMA were performed. Anti-TPO levels were assessed as well. The collected data were analyzed by SPSS version-11 in vitiligo patients and subgroups according to gender, age, extent, and duration of the disease compared with the control group.

Results

Anti-TPO was detected in 17 (18.1%) of patients affected by vitiligo, while this figure was 7 (7.3%) in the control group; the difference was significant with p-value < 0.025 (Phi & Cramer's V = 0.162). When analyzing subgroups, the difference in the frequency of anti-TPO remained significant only in females (p-value < 0.044) (Phi & Cramer's V = 0.207) and in patients in the age ranges of 18–25 (p-value < 0.05) (Phi & Cramer's V = 0.28) and 26–35 year-old (p-value < 0.042) (Phi & Cramer's V = 0.304).

The difference of the frequency of anti-TPO was not significant regarding the duration and extent of vitiligo. In addition, there was no significant difference in the levels of free T3, free T4, and TSH in vitiligo patients compared with the control group.

Conclusion

According to our study, anti-TPO was shown to be significantly more common in vitiligo patients especially in young women, compared with control group. As this antibody is a relatively sensitive and specific marker of autoimmune thyroid disorders including Hashimoto thyroiditis and Graves' disease, and considering the fact that vitiligo usually precedes the onset of thyroid dysfunction, periodic follow-up of vitiligo patients for detecting thyroid diseases is further emphasized especially in young women with increased level of anti-TPO.