Association of IFN-γ : IL-10 Cytokine Ratio with Nonsegmental Vitiligo Pathogenesis

Efficacy and safety of ritlecitinib in vitiligo patients across Fitzpatrick skin types with biomarker analyses

Efficacy and safety of ritlecitinib (an oral JAK3/TEC family kinase inhibitor) were evaluated in patients with nonsegmental vitiligo (NSV) across Fitzpatrick skin types (FSTs). Patients with FST I-III ('light skin'; n = 247) and FST IV-VI ('dark skin'; n = 117) received once-daily ritlecitinib 50 mg (with/without 4-week loading dose), low-dose ritlecitinib or placebo for 24 weeks. At baseline, patients with light skin displayed higher CLM-1 and NCR1 serum levels than patients with dark skin (p < 0.05). At 24 weeks, ritlecitinib 50 mg improved the extent of depigmentation measured by percent change from baseline in facial-vitiligo area scoring index (placebo-adjusted mean difference [90% CI]) in patients with light (-15.2 [-24.7, -5.8]; p = 0.004) and dark (-37.4 [-50.3, -24.4]; p < 0.0001) skin, with continuous re-pigmentation through week 48. Treatment-emergent adverse events were similar across FSTs. At weeks 4 and 24, ritlecitinib 50 mg reduced CXCL11 serum levels (p < 0.001) in patients with light skin, whereas patients with dark skin had increased levels at week 4 (p = 0.05) and no significant change at week 24. Ritlecitinib 50 mg decreased IL-9 and IL-22 expression levels in dark skin compared with light skin (qPCR; p < 0.05). These differences in immune dysregulations may explain why NSV patients with dark skin respond to therapy earlier than patients with light skin.

The role of regulatory T cells in vitiligo and therapeutic advances: a mini-review

BACKGROUND

Regulatory T cells (Tregs) play vital roles in controlling immune reactions and maintaining immune tolerance in the body. The targeted destruction of epidermal melanocytes by activated CD8+T cells is a key event in the development of vitiligo. However, Tregs may exert immunosuppressive effects on CD8+T cells, which could be beneficial in treating vitiligo.

METHODS

A comprehensive search of PubMed and Web of Science was conducted to gather information on Tregs and vitiligo.

RESULTS

In vitiligo, there is a decrease in Treg numbers and impaired Treg functions, along with potential damage to Treg-related signaling pathways. Increasing Treg numbers and enhancing Treg function could lead to immunosuppressive effects on CD8+T cells. Recent research progress on Tregs in vitiligo has been summarized, highlighting various Treg-related therapies being investigated for clinical use. The current status of Treg-related therapeutic strategies and potential future directions for vitiligo treatment are also discussed.

CONCLUSIONS

A deeper understanding of Tregs will be crucial for advancing Treg-related drug discovery and treatment development in vitiligo.

Immunomodulatory properties of chicken cathelicidin-2 investigated on an ileal explant culture

As the threat posed by antimicrobial resistance grows more crucial, the development of compounds that can replace antibiotics becomes increasingly vital. Chicken cathelicidin-2 (Cath-2) belongs to the group of Host Defense Peptides (HDPs), which could provide a feasible solution for the treatment of gastrointestinal infections in poultry. It is a small peptide produced by the heterophil granulocytes of chickens as part of the innate immune response, and its immunomodulatory activity has already been demonstrated in several cell types. In this study, the effects of Cath-2 on the intestinal immune response were examined using ileal explant cultures isolated from chicken. Regarding our results, Cath-2 displayed a potent anti-inflammatory effect as it alleviated the LTA-caused elevation of interleukin (IL)-6 and IL-2 concentrations, and that of the IFN-γ/IL-10 ratio, furthermore, it increased the concentration of IL-10, alleviating the LTA-evoked decreased level of the anti-inflammatory cytokine. Moreover, when applied alone, it elevated the concentrations of IL-6, CXCLi2, and IL-2, providing evidence of its complex immunomodulatory mechanisms. In summary, Cath-2 was able to modulate the immune response of the intestinal wall not only by reducing pro-inflammatory cytokine release, but also through immune stimulation, demonstrating that it has the ability to improve innate immunity via a complex mechanism that may make it a suitable candidate for the control of intestinal infections.

Protective antigen of Bacillus anthracis in combination with TLR4 or TLR5 agonist confers superior protection against lethal challenge in mouse model

The immunogenicity and protective ability of recombinant PA (rPA) with two innate immune system modulators, i.e., monophosphoryl lipid A (MPLA), a TLR4 agonist, and recombinant flagellin C (FliC), a TLR5 agonist, were studied in the mouse model. BALB/c mice were inoculated with three doses of rPA + alum (Alum group), rPA + FliC + alum (FliC group), rPA + MPLA + alum (MPLA group), or only alum adjuvant (Alum alone group). Significant increases in anti-PA IgG titers were observed in the Alum, FliC and MPLA groups when compared to control Alum alone group. Similarly, a significant enhancement of proinflammatory (TNF-α, IL-1β), Th1 (IFN-γ, IL-12(p70), IL-2) and Th2 (IL-10, IL-4) cytokines were also noticed in Alum, FliC and MPLA groups compared to Alum alone group. The rPA-specific IgG and cytokine responses in MPLA and FliC groups were significantly higher than the Alum group, suggesting enhancement of immune response by these TLR agonists. MPLA was also found to skew the IgG1:IgG2a ratio towards IgG2a. At a challenge dose of 25 LD50, complete protection was observed in mice of MPLA group whereas lesser protection was observed in FliC (87%) and Alum (50%) groups. Therefore, we suggest the use of MPLA in further development of rPA based anthrax vaccines.

Vitiligo: Correlation with Cytokine Profiles and its Role in Novel Therapeutic Strategies: A Case-Control Study

Background

The inflammatory and immune factors play a key role in the pathogenesis of vitiligo, and there are very few studies that have investigated the levels of major cytokines produced by T helper (Th) 1, Th2, and Th17 cells. This can enable better understanding of the, pathogenesis, and severity of vitiligo.

Objectives

To evaluate the serum levels of interleukin (IL)-6, tumor necrosis factor (TNF)-α, IL-1β, interferon (IFN)-γ, and IL-10 in patients with vitiligo and to correlate them with the disease severity and activity and to compare them with normal healthy controls.

Materials and Methods

A case-control study was conducted with 100 study participants: 50 cases clinically diagnosed as vitiligo and 50 controls. All patients underwent complete evaluation with detailed demographic parameters, history, and physical examination. The severity of the disease was assessed clinically by Vitiligo Area Scoring Index (VASI) and Vitiligo Disease Activity Score (VIDA). Blood investigations performed were IL-6, TNF-α, IL-1β, IFN-γ, and IL-10.

Results

We observed significantly higher levels of serum IFN-γ levels in the patient group when compared with those of the normal controls (P = 0.002) and showed a positive correlation with the activity and severity of the disease with a significant VASI (P = 0.05) and VIDA score (P = < 0.001). The mean serum IL-10 (p < 0.001) in patients with vitiligo was significantly lower than that in the control group. There was no significant difference in the serum level of TNF-α level (P = 0.347), IL-6 (P = 0.365), and IL-1β (P = 0.362) between vitiligo and healthy controls.

Conclusion

This study proved that high serum level of IFN-γ may be a risk factor for vitiligo progression and significantly low levels of IL-10, which has an anti-inflammatory role, suggesting that they could be used as a marker for assessing vitiligo activity and may open the way for further therapeutic approaches for vitiligo.

The role of cytokines and vitamin D in vitiligo pathogenesis

Vitiligo is a pigment-related disease with a global prevalence of 0.2% to 1.8% associated with considerable burden on quality of life. The treatment is still a challenge because of relapses and/or incomplete re-pigmentation. Although the exact cause is still unclear, its pathogenesis seems to be justifiable with the autoimmune theory, supported by the results of clinical research. In this narrative review, we aimed to summarize the evidence related to cytokines and vitiligo development. This review is consisted of English articles published in PubMed and Google Scholar concerning levels of inflammatory mediators, especially interleukins, in vitiligo patients over the last 20 years. References of relevant articles were also considered for review. Crucial role of dysregulated levels of interleukins and their synergistic function to each other, in the onset or progression of the disease is evident. The theory of autoimmune vitiligo is reinforced by the results of the studies in the literature, due to the association of pathogenesis with increased secretion of pro-inflammatory mediators and reduction of anti-inflammatory mediators. Decreased vitamin D levels may have a considerable role in vitiligo development by affecting Th1- and Th17-related immune responses. Cytokines play an important role in the pathogenesis or progression of the disease. Moreover, we believe that decreased vitamin D level has a considerable role in vitiligo development by affecting Th1- and Th17-related immune responses.

Meta-Analysis of Alterations in Regulatory T Cells’ Frequency and Suppressive Capacity in Patients with Vitiligo

Vitiligo is a noncontagious autoimmune skin depigmenting disease. Regulatory T cells (Tregs) play a key role in maintaining peripheral tolerance; however, Tregs' number, suppressive function, and associated suppressive molecules (FOXP3, IL-10, and TGF-β) are found to be reduced in vitiligo patients. Although, the role of Tregs in vitiligo pathogenesis is well established, there are several contrary findings which suggest a controversial role of Tregs in vitiligo. Therefore, to clarify the role of Tregs in vitiligo pathogenesis, we aimed to study Tregs' frequency, suppressive capacity, and associated suppressive molecules (FOXP3, IL-10, and TGF-β) in vitiligo patients through meta-analysis approach. A total of 30 studies involving 1223 vitiligo patients and 1109 controls were included in the study. Pooled results from our meta-analysis suggested significantly reduced Treg cells' frequency in vitiligo patients (p = 0.002). Interestingly, Tregs' suppressive capacity was also significantly reduced in vitiligo patients (p = 0.0002); specifically, Treg-mediated suppression of CD8⁺T cells was impaired in vitiligo patients (p < 0.00001). Moreover, FOXP3, a key Tregs' transcription factor, was significantly reduced in blood and skin of vitiligo patients (p < 0.00001). Intriguingly, the FOXP3 expression was significantly reduced in the lesional skin as compared to perilesional and nonlesional skin (p = 0.007 and p = 0.04). Furthermore, the expression of key Treg-associated suppressive cytokines IL-10 and TGF-β were significantly reduced in vitiligo patients (p = 0.0005 and p = 0.01). The disease activity-based analysis suggested for reduced Tregs' frequency and FOXP3 expression in active vitiligo patients (p = 0.05 and p = 0.01). We also studied the effect of microRNA-based treatment, narrow band–UVB phototherapy, and Treg-associated treatments on Tregs' frequency, FOXP3, and IL-10 expression. Interestingly, we found increased Tregs' frequency, FOXP3, and IL-10 expression after the treatment (p = 0.007, p < 0.0001, and p = 0.002). Overall, our meta-analysis suggests that the Tregs play a crucial role in pathogenesis and progression of vitiligo, and hence, Treg-based therapeutic interventions could be effective in vitiligo patients.

The Efficacy and Psychoneuroimmunology Mechanism of Camouflage Combined With Psychotherapy in Vitiligo Treatment

Background and Objectives

The efficacy of camouflage combined with psychotherapy and the underlying mechanisms are poorly understood in vitiligo management. This study aimed to investigate the joint efficacy and further explore psycho-neuro-endocrine-immune-skin interactions.

Patients and Methods

In a prospective, non-randomized and concurrent controlled trial, patients were divided into two groups. Quality of life (QOL) was evaluated using the Chinese version of the Vitiligo Life Quality Index (VLQI-C). Serum levels of neuropeptides and cytokines were detected by enzyme-linked immunosorbent assay.

Results

A total of 149 patients were included for final evaluation. After treatment for 4 weeks, total and subcategory quality of life scores in the intervention group were much lower than in the control group. Serum levels of neuropeptide-Y (NPY) and melanin-concentrating hormone (MCH) significantly decreased, and serum level of adrenocorticotropic hormone (ACTH) increased in both active and stable patients of the intervention group, but not in the control group. In addition, the serum levels of interferon-γ (IFN-γ), CXC chemokine ligand 10 (CXCL10), and interleukin-1β (IL-1β) decreased in both the active and stable patients of the intervention group and only in the active patients of the control group.

Conclusions

The combination of camouflage and psychotherapy provided a clinically meaningful improvement in quality of life and ameliorated the outcome by likely modulating the psycho-neuro-endocrine-immuno-skin system during vitiligo management.

Clinical Trial Registration

www.clinicaltrials.gov/ct2/show/NCT03540966, identifier: NCT03540966.

The Immunogenetics of Vitiligo: An Approach Toward Revealing the Secret of Depigmentation

Vitiligo is a hypomelanotic skin disease and considered to be of autoimmune origin due to breaching of immunological self-tolerance, resulting in inappropriate immune responses against melanocytes. The development of vitiligo includes a strong heritable component. Different strategies ranging from linkage studies to genome-wide association studies are used to explore the genetic factors responsible for the disease. Several vitiligo loci containing the respective genes have been identified which contribute to vitiligo and genetic variants for some of the genes are still unknown. These genes include mainly the proteins that play a role in immune regulation and a few other genes important for apoptosis and regulation of melanocyte functions. Despite the available data on genetic variants and risk alleles which influence the biological processes, only few immunological pathways have been found responsible for all ranges of severity and clinical manifestations of vitiligo. However, studies have concluded that vitiligo is of autoimmune origin and manifests due to complex interactions in immune components and their inappropriate response toward melanocytes. The genes involved in the immune regulation and processing the melanocytes antigen and its presentation can serve as effective immune-therapeutics that can target specific immunological pathways involved in vitiligo. This chapter highlights those immune-regulatory genes involved in vitiligo susceptibility and loci identified to date and their implications in vitiligo pathogenesis.

Polymeric nanoparticles containing rapamycin and autoantigen induce antigen-specific immunological tolerance for preventing vitiligo in mice

Vitiligo is an autoimmune disease in which pigment is lost in patches of the skin. CD4⁺ T cells are implicated in vitiligo while regulatory T cells (Tregs) could ameliorate vitiligo. Rapamycin together with autoantigen have been shown to induce immunological tolerance and promote Tregs in multiple autoimmune diseases. In the current study, we synthesized nanoparticles containing rapamycin and autoantigen HEL_46-61 (NP_{HEL46-61/Rapa}) and investigated their effects on vitiligo. We treated bone marrow-derived dendritic cells (BMDCs) from TrpHEL mice with NP_{HEL46-61/Rapa} and monitored the phenotype of BMDCs. We investigated the effects of NP_{HEL46-61/Rapa}-treated BMDCs on CD4⁺ T cell proliferation and differentiation. We administrated NP_{HEL46-61/Rapa} to TCR-TrpHEL mice and investigated the effects on vitiligo. We found that BMDCs can uptake the NP_{HEL46-61/Rapa}, which resulted in decreased expression of costimulation molecules CD80 and CD86 in BMDCs. BMDCs treated with NP_{HEL46-61/Rapa} suppressed antigen-specific CD4⁺ T cell proliferation while promoted the differentiation of these CD4⁺ T cell to Tregs in vitro. Administration of NP_{HEL46-61/Rapa} to TCR-TrpHEL mice ameliorated vitiligo, promoted Treg production, and suppressed IFN-γ and IL-6 production, while induced IL-10 production. Therefore, our study provides experimental evidence that nanoparticles containing rapamycin and autoantigen could induce antigen-specific immunological tolerance and prevent vitiligo.

Immune-modulatory effects of lenalidomide inhibited the progression of lesions in a vitiligo mouse model

Vitiligo, an autoimmune disorder, is associated with altered cytokine levels and T lymphocytes. Lenalidomide modulates immune system components by altering cytokine production and regulating T-cell stimulation. In this study, effect of lenalidomide was checked on the development of vitiligo lesions, level of various cytokines, and T lymphocytes in the mouse model. The vitiligo mouse model was developed by immunizing C57BL/6 mouse with anti-mouse tyrosine-related protein 2. Lenalidomide was orally given to mice daily, and the effect was observed on the development of vitiligo lesions. The level of T lymphocytes in blood was checked by flow cytometry. Serum cytokine levels were checked by enzyme-linked immunosorbent assay. Vitiligo lesions were found significantly smaller in lenalidomide-treated mice models. It significantly decreased the serum levels of IFN-γ, TNF-α, IL-1β, and IL-6 but elevated the levels of IL-4 and IL-10. It non-significantly elevated CD4⁺ /CD8⁺ T-cell ratio. Lenalidomide had an inhibitory effect on the development of vitiligo lesions in mice models by suppressing the serum level of pro-inflammatory cytokines and increasing anti-inflammatory cytokine levels. It modulated the immune response in vitiligo mice models toward an anti-inflammatory profile suggesting its use in the management of vitiligo.

Immune modulatory effects of lenalidomide on the cultured peripheral blood mononuclear cells from vitiligo patients

Vitiligo is a depigmentary disease in which epidermal melanocytes are lost. It is considered to be an autoimmune disease. Lenalidomide, an immunomodulatory drug is being employed in the treatment of various autoimmune and inflammatory disorders. In the present manuscript, the effect of lenalidomide on T cells and major cytokines in the cultured peripheral blood mononuclear cells (PBMCs) derived from vitiligo patients was checked. Eight patients with a clinical diagnosis of active vitiligo volunteered for the study. Blood was collected from them and PBMCs were isolated, cultured, and treated with lenalidomide. After 72 hours, PBMCs were harvested and checked for CD8⁺ and CD4⁺ T cells by flow cytometry. Further supernatant was collected and the levels of cytokines namely tumor necrosis factor-alpha (TNF-α), interferon-gamma (IFN-γ), interleukin-10 (IL-10), and interleukin-4 (IL-4) were checked using ELISA kits. Lenalidomide nonsignificantly decreased the level of CD8⁺ T cells but increased CD4⁺ T cells leading to increased CD4⁺ /CD8⁺ T cell ratio. It declined the level of pro-inflammatory cytokines, that is, TNF-α and IFN-γ whereas elevated anti-inflammatory cytokines, that is, IL-10 and IL-4, thus ultimately decreasing the ratio of pro-inflammatory to anti-inflammatory cytokines. Lenalidomide suppressed the proliferation of T lymphocytes and modulated the cytokines secretion toward an anti-inflammatory profile.

Urinary metabolomic investigations in vitiligo patients

Urinary metabolomics is a useful non-invasive tool for large-scale screening of disease-related metabolites. However, no comprehensive urinary metabolomic analysis of vitiligo is presently available. To investigate the urine metabolic pattern of vitiligo patients, we conducted a combined cross-sectional and prospective self-control cohort study and an untargeted urinary metabolomic analysis. In the cross-sectional study, 295 vitiligo patients and 192 age‐ and sex‐matched controls were enrolled, and 71 differential metabolites between two groups were identified. Pathway enrichment analysis revealed that drug metabolism-cytochrome P450, biopterin metabolism, vitamin B9 (folate) metabolism, selenoamino acid metabolism, and methionine and cysteine metabolism showed significant enrichment in vitiligo patients compared with the status in healthy controls. In the self-control cohort, 46 active vitiligo patients were recruited to analyse the urinary metabolic signatures after treatment. All of these patients were asked to undertake follow-up visits every 2 months three times after first consulting and the disease stage was evaluated compared with that at the last visit. Folate metabolism, linoleate metabolism, leukotriene metabolism, alkaloid biosynthesis, and tyrosine metabolism were predicted to be involved in vitiligo activity. Our study is the first attempt to reveal urinary metabolic signatures of vitiligo patients and provides new insights into the metabolic mechanisms of vitiligo.

Expression analysis of PD-1 and Tim-3 immune checkpoint receptors in patients with vitiligo; positive association with disease activity

The contribution of immune checkpoint receptors in the immunopathogenesis of various autoimmune diseases has been addressed in previous reports. In this study,  the expression profile of T-cell immunoglobulin and mucin-domain containing-3 (Tim-3) and programmed cell death-1 (PD-1) checkpoint molecules was investigated in CD8⁺ T cells of Vitiligo patients. The association of Tim-3 and PD-1 expression with disease activity was also explored. The frequency of Tim-3⁺ /PD-1⁺ /CD8⁺ T cells in 30 patients with vitiligo and 30 sex- and age-matched controls was determined by flow cytometry. CD8⁺ T cells were then positively isolated by magnetic beads, and the mRNA expression of PD-1 and Tim-3 was determined by TaqMan-based real-time PCR. To measure the cytokines production, PBMCs were stimulated with PMA/ionomycin and concentrations of IL-4, IFN-γ and TNF-α were measured in culture supernatants by ELISA. Disease activity of patients with vitiligo was determined using the Vitiligo Area Severity Index. Patients with vitiligo have significantly shown more expression of Tim-3 and PD-1 on their CD8⁺ T cells compared with controls. Expression analysis of Tim-3 mRNA, but not PD-1, confirmed the results obtained from flow cytometry. While the production levels of TNF-α and IFN-γ were found higher by patients with vitiligo, IL-4 production was lower in patients compared with controls. A direct association was observed between the Tim-3 and PD-1 expression and also the production of pro-inflammatory cytokines with disease activity of patients with vitiligo. Our results indicate that Tim-3 and PD-1 are involved in immune dysregulation mechanisms of CD8⁺ T cells in vitiligo and may introduce as potential biomarkers for disease progression and targeted immunotherapy.

Can monocyte to HDL cholesterol ratio and monocyte to lymphocyte ratio be markers for inflammation and oxidative stress in patients with vitiligo? A preliminary study

Both systemic inflammation and oxidative stress play crucial roles in the pathogenesis of vitiligo. In recent studies, monocyte to high-density lipoprotein cholesterol ratio (MHR), monocyte to lymphocyte ratio (MLR), neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), mean platelet volume (MPV) and plateletcrit (PCT) have been shown to reflect inflammation and oxidative stress in chronic inflammatory and autoimmune diseases. In this study, we aimed to investigate the hematological and inflammatory parameters in patients with vitiligo and to evaluate their possible relationship with disease severity. The parameters including MHR, MLR, NLR, PLR, MPV, and PCT were retrospectively investigated in patients with vitiligo and healthy controls. Disease severity was evaluated using the vitiligo extent tensity index (VETI) score. A total of 180 patients with vitiligo, and age-gender-matched 180 healthy controls were enrolled in the study. MHR, MLR, PLR, PCT values were found to be significantly higher in patients with vitiligo (p < 0.05). MPV and NLR values showed no statistically significant difference between the two groups. A positive correlation was also detected between MHR and MLR values, disease duration, and VETI score (p < 0.05). We suggest that MHR and MLR can be used as markers of inflammation and oxidative stress in patients with vitiligo. Both markers may also reflect disease severity.

Decreased suppression of CD8+ and CD4+ T cells by peripheral regulatory T cells in generalized vitiligo due to reduced NFATC1 and FOXP3 proteins

Regulatory T cells (Tregs) are involved in the suppression of activated T cells in generalized vitiligo (GV). The study was aimed to investigate Tregs functional defects in Treg:CD8⁺ and Treg:CD4⁺ T cells' co-culture systems of 55 GV patients and 45 controls. CD8⁺ and CD4⁺ T-cell proliferation was assessed by BrdU assay; production of IL-10, TGF-β and IFN-γ cytokines was assessed by ELISA; and FOXP3, CD25, NFATC1 and CD44 proteins were measured by flow cytometry. Generalized vitiligo patients showed reduced suppression of CD8⁺ and CD4⁺ T cells (P = .0384, P = .0084), increased IFN-γ (P < .0001, P = .0019), decreased IL-10 and TGF-β (P < .0001) and decreased FOXP3, CD25 and NFATC1 proteins (P < .0001). Active vitiligo (AV) patients showed reduced suppression of CD8⁺ & CD4⁺ T cells (P = .006, P = .015), increased IFN-γ (P = .036, P = .045), decreased IL-10 (P = .009, P = .021), FOXP3 (P = .0244) and NFATC1 (P = .019). Severe GV (50%-75% VASI) patients showed reduced suppression of CD8⁺ and CD4⁺ T cells (P = .0003, P = .001), increased IFN-γ (P = .0029, P < .0001), decreased IL-10 (P = .0057, P = .0017), FOXP3 (P = .002) and NFATC1 (P = .0347). VASI score was positively correlated with the suppression of CD8⁺ and CD4⁺ T cells (P = .0006, P < .0001), IL-10 (P = .0096, P = .029), FOXP3 (P = .0008) and NFATC1 (P = .043), whereas it was negatively correlated with IFN-γ (P = .0029, P = .0017). Early age of onset patients' Tregs demonstrated decreased suppression of CD8⁺ and CD4⁺ T cells (P = .0156, P = .0074), decreased TGF-β (P = .0212, P = .0083) and NFATC1 (P = .0103). NFATC1 was positively correlated with FOXP3 in Tregs (P < .0001). Our results suggest impaired Tregs suppressive function in GV patients due to decreased NFATC1, FOXP3, CD25, IL-10 and TGF-β resulting into increased CD8⁺ and CD4⁺ T-cell proliferation and IFN-γ production. For the first time, decreased NFATC1 levels were correlated with decreased FOXP3, thereby altering Treg cell function in GV patients. Additionally, decreased Treg cell function also affected onset, activity and severity of GV.

Altered expression of nuclear factor of activated T cells, forkhead box P3, and immune-suppressive genes in regulatory T cells of generalized vitiligo patients

The study was aimed to analyze expression of nuclear factor of activated T cells (NFATs), forkhead box P3 (FOXP3), and their associated genes (sCTLA4, flCTLA4, IL10, TGFB, IL2, IL4, CD25) in regulatory T cells (Tregs) of 48 generalized vitiligo (GV) patients and 45 unaffected controls. The transcripts of NFATC1 to NFATC4, FOXP3, IL10, flCTLA4 (p < .0001), NFAT5 (p = .0003), sCTLA4 (p = .001), and FOXP3 protein in Tregs and plasma IL-10 levels were reduced significantly (p < .0001) in GV Tregs compared to controls. The FOXP3 promoter polymorphisms [rs3761548(C > A), rs3761547(A > G), and rs2232365(A > G)] revealed significantly decreased FOXP3 protein levels in patients' Tregs with susceptible AA, GG, and GG genotypes (p < .0001, p = .028, p = .022, respectively). The active vitiligo Tregs showed reduced levels of NFATC3, NFATC4, NFAT5, FOXP3, TGFB, and flCTLA4 transcripts (p = .0005, p = .0003, p = .0002, p = .020, p < .0001, p = .006, respectively) and FOXP3 and TGF-β proteins (p = .0394 and p = .0013) compared to stable vitiligo. Early-onset patients (1-20 years) demonstrated decreased IL-10, sCTLA-4, flCTLA-4, TGFB, and FOXP3 transcripts and FOXP3 protein as compared to late-onset patients (41-60 years) (p = .001, p = .003, p = .009, p = .005, p = .038, p = .0226, respectively). Overall, our results for the first time suggest a likely role of NFATs and FOXP3 together with Treg immune-suppressive genes in GV pathogenesis and disease progression, warranting additional investigations.

Lack of association of IL-10 (rs1800896) and IL-13 (rs1800925) with non-segmental vitiligo susceptibility in South Indian population

Background

Vitiligo is an autoimmune depigmentation disorder caused by multiple etiologies. Genetic polymorphisms in cytokine genes influence their expression and augment disease development. Analyzing the influence of genetic polymorphisms will help in better understanding of the complex etiopathogenesis of vitiligo.

Aim

To study the influence of interleukin IL-10 (rs1800896) and IL-13 (rs1800925) polymorphisms on vitiligo risk in South Indian population.

Methods

Two hundred and sixty-four vitiligo patients and 264 controls were recruited in this study. Genotyping was done by quantitative PCR and plasma cytokine levels were measured by ELISA.

Results

Allele frequencies of IL-10 (rs1800896) and IL-13 (rs1800925) SNPs were observed to be equal in the groups. Mutant allele G of IL-10 (rs1800896) enhanced the familial inheritance of vitiligo (P < 0.0001, OR-25.1, 95% CI-7.64-82.7) and influenced the development of vulgaris type of vitiligo (P = 0.034, OR-1.83, 95% CI-1.07-3.13). Ancestral allele A of IL-10 (rs1800896) conferred protection against development of acrofacial vitiligo (P = 0.04, OR-0.56, 95% CI-0.33-0.95). Circulatory IL-10 levels in vitiligo patients were higher than controls (P < 0.0001). Individuals with genotype GG of IL-10 (rs1800896) had the highest circulatory levels of IL-10 (P < 0.0001). Among the genotypes of IL-13 (rs1800925) variant, none influenced the phenotype of nonsegmental vitiligo such as gender, family history, age of onset and types of vitiligo (P > 0.05). In addition, no difference was noted in the circulatory levels of IL-13 between patients and controls (P = 0.48). Within patients, CC genotype of IL-13 (rs1800925) was observed to enhance the circulatory IL-13 levels (P < 0.0001).

Limitation

Replication group analysis in a larger multicentric cohort in future would validate further understanding of vitiligo susceptibility in South Indian ethnics.

Conclusion

IL-10 (rs1800896) and IL-13 (rs1800925) polymorphisms did not confer risk to develop vitiligo in South Indian population.

Safety Assessment of Bacteroides Uniformis CECT 7771, a Symbiont of the Gut Microbiota in Infants

The formulation of next-generation probiotics requires competent preclinical studies to show their efficacy and safety status. This study aims to confirm the safety of the prolonged oral use of Bacteroides uniformis CECT 7771, a strain that protected against metabolic disorders and obesity in preclinical trials, in a sub-chronic 90 day trial in animals. The safety assessment was conducted in male and female Wistar rats (n = 50) administered increasing doses (108 CFU/day, 109 CFU/day, or 1010 CFU/day) of B. uniformis CECT 7771, 1010 CFU/day of B. longum ATCC 15707T, which complies with the qualifying presumption of safety (QPS) status of the EU, or vehicle (placebo), as the control. Pancreatic, liver, and kidney functions and cytokine concentrations were analyzed. Bacterial translocation to peripheral tissues was evaluated, and colon integrity was investigated histologically. No adverse metabolic or tissue integrity alterations were associated with treatments; however, alanine aminotransferase levels and the ratio of anti-inflammatory to pro-inflammatory cytokines in serum indicated a potentially beneficial role of B. uniformis CECT 7771 at specific doses. Additionally, the microbial community structure was modified by the interventions, and potentially beneficial gut bacteria were increased. The results indicated that the oral consumption of B. uniformis CECT 7771 during a sub-chronic 90 day study in rats did not raise safety concerns.

Predominant role of innate pro-inflammatory cytokines in vitiligo disease

Vitiligo is a skin disorder with melanocyte destruction and an autoimmune basis. Given the importance of cytokines in autoimmunity, we aimed to find the cytokine profile of innate and adaptive immunity in vitiligo patients, and correlate them with clinical parameters. The serum levels of innate immunity [interleukin(IL)-1α, IL-1β, IL-6, IL-8, IL-12, IL-15 and tumor necrosis factor (TNF)-α] and T helper(Th)1 [IL-2, interferon (IFN)-γ, TNF-β], Th2 (IL-4, IL-5, IL-10, IL-13) and Th17 (IL-17, IL-23) cytokines in 44 vitiligo patients were measured by multiplex cytokine assay and compared with 44 healthy subjects. All innate immunity (p < 0.04), Th1 (p < 0.01), Th2 (p < 0.05) and Th17 (p < 0.001) cytokines were higher in patients than controls. Total summation levels of innate immunity and adaptive immunity cytokines showed a remarkable up-regulation in the patients (p < 0.0001). The ratio of innate immunity to Th1 (p = 0.03), Th2 (p = 0.01) and Th17 (p = 0.03) cytokines was significantly higher in patients vs. controls. We found significant higher ratio of Th1 to Th2 cytokines and TNF-β elevated levels in patients with a family history of autoimmunity (p < 0.05). IL-4 and IL-13 (p < 0.04) levels were lower in patients with amelanotic hair. Increased IL-10 level was observed in patients with stable disease (p = 0.02).In conclusion, the profile of cytokines in patients showed a dominant role of innate immunity pro-inflammatory cytokines in vitiligo, which suggests the potential of targeting these cytokines for vitiligo treatment. While a higher ratio of Th1/Th2 cytokines was observed in the patients, association of decreased Th2 cytokines with disease complications suggests a protective role for Th2 pathway.

Immunophenotype of circulatory T-helper cells in patients with non-segmental vitiligo

Introduction

Non-segmental vitiligo (NSV) is an immune-mediated skin depigmentation disease. Cytokine-mediated interaction between T lymphocytes and melanocytes leads to death of melanocytes, causing a defect in melanin synthesis and thereby depigmentation. There is an increased population of T-helper cells in the skin lesions as well as in the peripheral circulation in NSV. However, the relative percentage of each T-cell phenotype in the disease pathogenesis is rarely studied.

Aim

To study the immunophenotype of the different T-helper/Treg cell subsets in patients with NSV, in comparison to healthy controls.

Material and methods

A total of 80 patients with NSV and eighty age- and gender-matched healthy controls were recruited in this cross-sectional study. Disease activity was determined by vitiligo index of disease activity (VIDA) scoring. Peripheral blood mononuclear cells were separated by Ficoll-Paque density centrifugation, and T-cell immunophenotyping was done by flow cytometric analysis.

Results

In patients with NSV, we observed an imbalance in T-cell immunophenotype, characterized by an increase in Th1 (p < 0.0001) and Th17 cells (p = 0.01). There is no difference in relative percentage of Th2/Treg cells, as compared to the healthy controls (p > 0.05).

Conclusions

There is a significant immune-dysregulation with a preponderance of circulatory Th1/Th17 phenotype in NSV patients.

Therapeutic effects of iNOS inhibition against vitiligo in an animal model

Nitric oxide (NO) is involved in several biological processes, but its role in human melanogenesis and vitiligo need further studies. Previous studies revealed that exposure to UVA and UVB were capable of the inducing nitric oxide production in keratinocytes and melanocytes through the activation of constitutive nitric oxide synthase, whereas inducible nitric oxide synthase overexpression has been reported to play an important role in hyperpigmentary disorders. The aim of this study was to evaluate iNOS inhibitor aminoguanidine (AG) as a therapeutic agent in our mouse model of vitiligo. In this study, male C57BL/6J Ler-vit/vit mice were purchased to evaluate the effect of iNOS inhibitor (aminoguanidine) (50 and 100 mg/kg) and L-arginine (100 mg/kg) in a mouse model of vitiligo induced by monobenzone 40%. Moreover, we used phototherapy device to treat the mice with NBUVB as a gold standard.The findings revealed that monobenzone was capable of inducing depigmentation after 6 weeks. However, aminoguanidine in combination with monobenzone was decrease the effect of monobenzone, while L-arginine play a key role in promoting the effect of monobenzone (P<0.001). Based on the phototherapy, the efficacy of phototherapy significantly increased by adding L-arginine (P<0.05). Taken together, we suggest that iNOS inhibitor can be a novel treatment for the prevention and treatment of vitiligo by combination of NBUVB therapy, furthermore; NO agents like L-arginine could also increase the effectiveness of phototherapy. Taken together, this pilot study showed significant repigmentation of vitiligous lesions treated with iNOS inhibitor plus NBUVB therapy, where other aspect including expression of an inducible iNOS, NO and TNF levels remained to be evaluated in mice model.

Neutrophil to lymphocyte ratio in patients with vitiligo

Introduction

There are a few studies showing an increased risk of insulin resistance, metabolic syndrome, and oxidative stress in patients with vitiligo.

Aim

To investigate whether systemic inflammation is increased in vitiligo patients in a case-control study design.

Material and methods

Nonsegmental vitiligo patients who had been followed at the outpatient dermatology clinic of a university-affiliated teaching hospital, and healthy controls were enrolled in the study. Patients who were receiving systemic treatments and having a systemic disease such as diabetes mellitus and thyroiditis were excluded. Demographic features were recorded and peripheral blood samples were taken from all participants to study serum whole blood count, creatinine, and C-reactive protein (CRP).

Results

Fifty patients with localized vitiligo, 43 patients with generalized vitiligo, and 50 healthy volunteers were enrolled in the study. Neutrophil to lymphocyte ratio and serum CRP levels were significantly higher in patients who have generalized vitiligo than those with localized vitiligo and healthy controls. However, there was no significant difference regarding neutrophil to lymphocyte ratio (NLR) and CRP between localized vitiligo and control groups.

Conclusions

Patients with generalized vitiligo seem to have increased systemic inflammation compared with localized vitiligo and control subjects in our cohort. To the best of our knowledge, this is the first study in the literature showing increased NLR values in generalized vitiligo patients. Further studies with cardiovascular disease markers are required to elicit this association better.

Vitiligo blood transcriptomics provides new insights into disease mechanisms and identifies potential novel therapeutic targets

BACKGROUND

Significant gaps remain regarding the pathomechanisms underlying the autoimmune response in vitiligo (VL), where the loss of self-tolerance leads to the targeted killing of melanocytes. Specifically, there is incomplete information regarding alterations in the systemic environment that are relevant to the disease state.

METHODS

We undertook a genome-wide profiling approach to examine gene expression in the peripheral blood of VL patients and healthy controls in the context of our previously published VL-skin gene expression profile. We used several in silico bioinformatics-based analyses to provide new insights into disease mechanisms and suggest novel targets for future therapy.

RESULTS

Unsupervised clustering methods of the VL-blood dataset demonstrate a "disease-state"-specific set of co-expressed genes. Ontology enrichment analysis of 99 differentially expressed genes (DEGs) uncovers a down-regulated immune/inflammatory response, B-Cell antigen receptor (BCR) pathways, apoptosis and catabolic processes in VL-blood. There is evidence for both type I and II interferon (IFN) playing a role in VL pathogenesis. We used interactome analysis to identify several key blood associated transcriptional factors (TFs) from within (STAT1, STAT6 and NF-kB), as well as "hidden" (CREB1, MYC, IRF4, IRF1, and TP53) from the dataset that potentially affect disease pathogenesis. The TFs overlap with our reported lesional-skin transcriptional circuitry, underscoring their potential importance to the disease. We also identify a shared VL-blood and -skin transcriptional "hot spot" that maps to chromosome 6, and includes three VL-blood dysregulated genes (PSMB8, PSMB9 and TAP1) described as potential VL-associated genetic susceptibility loci. Finally, we provide bioinformatics-based support for prioritizing dysregulated genes in VL-blood or skin as potential therapeutic targets.

CONCLUSIONS

We examined the VL-blood transcriptome in context with our (previously published) VL-skin transcriptional profile to address a major gap in knowledge regarding the systemic changes underlying skin-specific manifestation of vitiligo. Several transcriptional "hot spots" observed in both environments offer prioritized targets for identifying disease risk genes. Finally, within the transcriptional framework of VL, we identify five novel molecules (STAT1, PRKCD, PTPN6, MYC and FGFR2) that lend themselves to being targeted by drugs for future potential VL-therapy.

Agrobacterium sp.-derived β-1,3-glucan enhances natural killer cell activity in healthy adults: a randomized, double-blind, placebo-controlled, parallel-group study

BACKGROUND/OBJECTIVES

The present study investigated the hypothesis that a highly pure linear β-1,3-glucan produced by Agrobacterium sp. R259 enhances human natural killer (NK) cell activity and suppresses pro-inflammatory cytokines.

SUBJECTS/METHODS

In an eight-week, double-blind, randomized, placebo-controlled clinical trial, 83 healthy adults with white blood cell counts of 4,000-8,000 cells/µL were participated and randomly assigned to take two capsules per day containing either 350 mg β-1,3-glucan or placebo. Six participants withdrew their study consent or were excluded due to NK cell activity levels outside the normal range. NK cell activity and serum levels of immunoglobulin G (IgG) and cytokines, such as interferon (IFN)-γ, interleukin (IL)-2, IL-4, IL-6, IL-10, IL-12 and tumor necrosis factor (TNF)-α were measured.

RESULTS

NK cell activity and the serum levels of IL-10 were significantly higher from baseline to week 8 in the β-glucan group compared with the placebo group (P = 0.048, P = 0.029). Consumption of β-1,3-glucan also significantly increased NK cell activity compared with placebo after adjusting for smoking and stress status (P = 0.009). In particular, the effect of β-1,3-glucan on NK cell activity was greater in participants with severe stress than in those experiencing mild stress. However, the administration β-1,3-glucan did not significantly modulate the levels of IFN-γ, IL-2, IL-4, IL-6, IL-12, TNF-α and IgG compared with the placebo.

CONCLUSION

The results showed that supplementation with bacterial β-1,3-glucan significantly increased NK cell activity without causing any adverse effects. Additionally, the beneficial effect of β-1,3-glucan on NK cell activity was greater in participants experiencing severe stress.