| کلیدواژههای انگلیسی مقاله |
vitamin D, folic acid, homocysteine, vitiligo, children, INTRODUCTIONVitiligo is an acquired autoimmune dermatologic disorder that presents with depigmented lesions. The disease pathogenesis is not completely known, but several factors such as genetic background, autoimmunity, oxidative stress, neurohormonal etiology, and cytotoxicity of melanocytes may be involved 1,- 3, . Recently, the effect of hyperhomocysteinemia on impaired melanogenesis has been elucidated 4,- 6, . Decreased activity of the catalase enzyme can lead to hyperhomocysteinemia in vitiligo patients. Hyperhomocysteinemia results in an increased level of oxidative stress, cytokine activation (interleukin 6), nuclear factor &,kappa &,beta activation, and tyrosinase inhibition, destroying melanocytes and impairing melanogenesis 5,- 8, . On the other hand, low levels of B12 and folic acid in serum, as co-factors for homocysteine methylenetetrahydrofolatereductase (MTHFR) in homocysteine to methionine conversion, have been demonstrated in hyperhomocysteinemic patients 8,, 9,, 10, .Vitamin D protects melanocytes from apoptosis by its antioxidant effect, activation of T regulatory cells, and immunomodulatory effects via shifting the immune response from T-helper (Th) 1 to Th 2 and inhibiting the maturation of dendritic cells. It also augments tyrosinase activity and melanogenesis, affecting the vitamin D receptor (VDR) of melanocytes 11,- 15, .To date, few have evaluated the serum levels of vitamin D, homocysteine, vitamin B12, and folate in vitiligo patients, with paradoxical results due to confounding factors such as genetic polymorphism on MTHFR, diet habits, age, and sun exposure. Some authors recommend regular measurements of these factors in patients suffering from vitiligo 16,- 20, .Regarding the relatively high cost of laboratory tests and confounding results, we decided to check these factors in Iranian children with vitiligo in comparison with healthy children.MATERIAL AND METHODSThe current study was performed on a case-control basis, where 30 vitiligo-affected children and 30 sex- and age-matched healthy children referred to the Pediatric Dermatology Clinic of Afzalipour Hospital in Kerman, Iran, from April 2018 to August 2020 were enrolled. Inclusion criteria were children less than 18 years old diagnosed with new cases of vitiligo that received no treatment. The control group included healthy age- and sex-matched children with negative history of autoimmune diseases, recruited from children who came to our clinic complaining of minor skin problems such as impetigo, herpes simplex, or nevus. Exclusion criteria consisted of patients with other systemic or cutaneous diseases, smoking, taking folic acid, vitamin D, vitamin B12, and vitamin B6 since six months ago, and unwillingness to participate in the study. The current research was approved by the Ethics Committee of Kerman University of Medical Sciences (IR-KMU.REC.1395.763). According to Atas et al. 1, , serum levels of homocysteine in the case and control groups were 16.9 &,plusmn 8.4 and 9.10 &,plusmn 3.4 &,micro mol/l, respectively therefore, a minimum sample size of 15 participants in each group was calculated (power=80%, &,alpha =0.05). However, to increase the study&apos,s power, the sample was expanded to 30 in each group.Parents provided written informed consent if their child was less than 12 years old, while it was obtained from both children and parents if children were older than 12. Vitiligo diagnosis was confirmed based on clinical examination and Wood&,rsquo s lamp assessment. Demographic features of the participants, including age, gender, and family history of vitiligo or other autoimmune disorders, were acquired by face-to-face interviews and questionnaires. Also, clinical features of vitiligo, including the site of the lesions, duration of the disease, and type of vitiligo, were recorded by history taking and physical examination. Based on the vitiligo disease activity (VIDA) score, the disease activity was classified using six points from -1 to +4. Furthermore, the area of involved skin was calculated using the vitiligo area scoring index (VASI) score (within the range of 10&,ndash 100%) in five regions of the body according to the following equation (range, 0&,ndash 100),VASI = &,sum all body sites (hand units) &,times depigmentation 20, .After 12 hours of fasting, the serum level of vitamin D was assessed by a laboratory technician that was not aware of the two groups via the enzyme-linked fluorescence assay (ELFA) using Vidas kits (France), and homocysteine, vitamin B12, and folic acid levels were assessed by chemiluminescence method using Siemens kits (Germany). The blood samples were obtained from all participants during the same season of the year to eliminate the confounding effect of weather on vitamin D serum levels. The analytical sensitivity for serum levels of vitamin D, homocysteine, vitamin B12, and folic acid were 8.1 ng/ml, 0.5 &,micro mol/l, 125 pg/ml, and 0.8 ng/ml, respectively. The normal ranges for vitamin D, homocysteine, vitamin B12, and folic acid serum levels in pediatrics were 30-100 ng/ml, 0-15 &,micro mol/l, 180-914 pg/ml, and 4.6-34.8 ng/ml, respectively. Statistical analysisSPSS 16 (software IBM, Armonk, NY, USA) was utilized for data analysis. Frequency and percentage were used to describe qualitative data, and mean &,plusmn standard deviation (SD) was used to describe quantitative data. Comparison of the two groups and association between clinical and demographic features of the case group with levels of vitamin B12, homocysteine, folate, and vitamin D were evaluated using the independent T-test, Fisher&,rsquo s exact test, and chi-squared test.RESULTSThirty children with vitiligo and 30 healthy age- and sex-matched children were enrolled in this study (Figure 1,). Table 1, demonstrates the clinical features of children with vitiligo. The serum vitamin D in patients and controls were 19.34 &,plusmn 8.41 and 32.28 &,plusmn 15.41 ng/ml, respectively (95% CI -19.87 to -2.96, P=0.001). The level of folic acid in the case and control groups was 12.62 &,plusmn 3.28 ng/ml and 14.60 &,plusmn 4.17 ng/ml, respectively (95% CI -4.15 to -4.18, P=0.046).Figure 1. Flowchart of the studyVariableNumberPercentageSite of the lesionsHead &,amp neck2353.4Extremity1240Trunk96.7Type of the lesionSegmental310Generalized723.3Localized2066.7VIDA scoreActive in past 1 year723.3Active in past 6 months1343.3Active in past 3 months930Active in past 6 weeks13.3VASI score&,lt 302480&,gt 30620VIDA, Vitiligo Disease Activity Score VASI, Vitiligo Area Scoring Index |