Interleukin-4 genetic variants correlate with its transcript and protein levels in patients with vitiligo

Implication of regulatory T cells' telomere shortening in pathogenesis of generalized vitiligo

Generalized vitiligo(GV) is a skin depigmenting condition due to loss of melanocytes. Regulatory T cells(Tregs), responsible for peripheral tolerance, show altered numbers and functions in GV patients, likely influenced by the aging process. Therefore, the present study was focused on measuring the relative telomere length of Tregs in 96 GV patients and 90 controls by qPCR, along with correlation of relative telomere length with in vitro Treg suppressive capacity. Interestingly, we found significantly decreased relative telomere length in Tregs of GV patients as compared to controls(p = 0.0001). Additionally, age based-analysis suggested significant decrease in relative telomere length in elderly GV patients(>40 years) in comparison to young GV patients(0-20 years; p = 0.0027). Furthermore, age of onset analysis suggested for reduced relative telomere length in early onset GV patients (0-20 years) in comparison to late onset GV patients(>40 years; p = 0.0036). The correlation analysis suggested positive correlation for relative telomere length with in vitro Tregs suppressive capacity(r = 0.68 & r = 0.45; p < 0.0001). Additionally, the in vitro Tregs suppressive capacity was significantly reduced in elderly GV patients(p = 0.003) and early onset GV patients(p = 0.0074). Overall, our study for the first time demonstrated that, the Tregs ageing due to telomere shortening may be responsible for altered Treg functions and number.

A Mendelian randomization study on the causal effects of circulating cytokines on the risk of vitiligo

Background

Accumulating evidence reveals an association between circulating cytokine levels and vitiligo. However, the causal association between circulating cytokine levels and vitiligo remains unrevealed.

Methods

We performed a two-sample Mendelian randomization (MR) analysis using a genome-wide association study of the 41 cytokines dataset, which was conducted with 3 Finnish cohorts (n = 8,293). Vitiligo data were acquired from strictly defined vitiligo data collected by FinnGenbiobank analysis, which included 207,613 European ancestors (131 vitiligo patients, 207,482 controls). The inverse-variance weighted (IVW) method, weighted median (WME), simple model, weighted model, and MR-Egger were used to determine the changes in vitiligo pathogenic cytokine taxa, followed by sensitivity analysis, including horizontal pleiotropy analysis. The MR Steiger test evaluated the strength of a causal association, and the leave-one-out method was used to assess the reliability of the results. The possibility of reverse causality was also investigated using a reverse MR study.

Results

We observed that rising IL-4 levels generated an enhanced probability of vitiligo in IVW (OR 2.72, 95%CI 1.19-6.22, p = 0.018). According to the results of the MR analysis, there were causal links between IL-4 and vitiligo. Results were steady after sensitivity and heterogeneity analyses.

Conclusion

Our research reveals that a genetically determined increased level of circulating IL-4 may be linked to a higher risk of developing vitiligo. The development of innovative treatment approaches (such as tofacitinib or dupilumab) that focus on blocking IL-4 as a novel way of preventing and treating vitiligo is significantly impacted by our findings.

Animal models unraveling the complexity of vitiligo pathogenesis

Vitiligo is a chronic skin condition marked by the gradual loss of pigmentation, leading to the emergence of white or depigmented patches on the skin. The exact cause of vitiligo remains not entirely understood, although it is thought to involve a blend of genetic, autoimmune, and environmental factors. While there is currently no definitive cure for vitiligo, diverse treatments exist that may assist in managing the condition and fostering repigmentation in specific instances. Animal models play a pivotal role in comprehending the intricate mechanisms that underlie vitiligo, providing valuable insights into the progression and onset of the disease, as well as potential therapeutic interventions. Although induced experimental models lack the nuanced characteristics observed in natural experimental models, relying solely on a single animal model might not fully capture the intricate pathogenesis of vitiligo. Different animal models simulate specific aspects of human vitiligo pathogenesis to varying degrees. This review extensively explores the array of animal models utilized in vitiligo research, shedding light on their respective advantages, disadvantages, and applications.

Exploring the causal relationship between inflammatory cytokines and immunoinflammatory dermatoses: a Mendelian randomization study

Objectives

Previous studies have shown that the onset and progression of several immunoinflammatory dermatoses are closely related to specific immune-inflammatory responses. To further assess the causal relationship between 41 inflammatory cytokines and immunoinflammatory dermatoses, we used a Mendelian randomization method.

Methods

Mendelian two-sample randomization utilized inflammatory cytokines from a GWAS abstract containing 8,293 healthy participants as well as psoriasis (4,510 cases and 212,242 controls), atopic dermatitis (7,024 cases and 198,740 controls), and vitiligo (131 cases and 207,482 controls). The causal relationship between exposure and outcome was explored primarily using inverse variance weighting. In addition, multiple sensitivity analyses, including MR-Egger, weighted median, simple model, weighted model, and MR-PRESSO, were simultaneously applied to enhance the final results.

Results

The results showed that in clinical practice, IL-4 and IL-1RA were suggestive indicators of atopic dermatitis risk (OR = 0.878, 95% CI = 0.78-0.99, p = 0.036; OR = 0.902, 95% CI = 0.82-1.00, p = 0.045). SCGF-b was a suggestive indicator of psoriasis risk (OR = 1.095, 95% CI = 1.01-1.18, p = 0.023). IL-4 is a suggestive indicator of vitiligo risk (OR = 2.948, 95% CI = 1.28-6.79, p = 0.011).

Conclusion

Our findings suggest that circulating inflammatory cytokines may play a crucial role in the pathogenesis of chronic skin inflammation. IL-4 and IL-1RA may have inhibitory roles in the risk of developing atopic dermatitis, while SCGF-b may have a promoting role in the risk of developing psoriasis. Furthermore, IL-4 may contribute to the risk of developing vitiligo. These results provide insights into further understanding the mechanisms of chronic skin inflammation and offer new targets and strategies for the prevention and treatment of related diseases.

Altered regulatory T cell-mediated Natural Killer cells suppression may lead to generalized vitiligo

Generalized vitiligo (GV) is characterized by white patches due to autoimmune loss of melanocytes. Regulatory T cells (Tregs) maintain immune homeostasis, while NK cells eliminate pathogens and tumors. Increased NK cell frequency and reduced Treg frequency and suppressive capacity are observed in vitiligo patients. However, studies assessing Treg-mediated suppression of NK cell functions in GV are lacking. Therefore, our study aimed to assess in vitro Treg-mediated suppression of NK cells function over K562 and SK-Mel-28 cells in 31 GV patients and 30 controls using the BrdU-cell proliferation assay. We found decreased Treg-mediated suppression of NK cell function in GV patients (p = 0.0289). Moreover, increased NK cell-mediated K562 and SK-Mel-28 cells' suppression was observed in GV patients (p = 0.0207,p = 0.0419). Disease activity-based analysis, suggested reduced Treg-mediated suppression of NK cell function and increased NK cell function in active vitiligo patients (p = 0.03,p = 0.0436). Interestingly, age-based analysis suggested decreased Treg-mediated suppression of NK cell function in 1-20 and 21-40 years age groups compared to 41-60 years age group of GV patients (p = 0.005,p = 0.0380). Overall, our study, for the first time, suggests that decreased Treg-mediated suppression of NK cells may lead to increased destruction of melanocytes in GV, and this knowledge may help in developing effective therapeutics based on Tregs and NK cells for GV.

Genetic association of Nuclear factor of activated T cells' 3'UTR and structural polymorphisms with susceptibility to generalized vitiligo in Gujarat population

Generalized vitiligo(GV) is an autoimmune skin depigmenting disease characterized by loss of functional melanocytes. Nuclear factor of activated T cells(NFATs) play a key role in regulatory T cells' (Tregs) activation and function. Our previous studies have highlighted the role of reduced NFATs expression and activity in impaired Tregs suppressive capacity, leading to GV pathogenesis. 3'UTR region and structural single nucleotide polymorphisms(SNPs) could lead to reduced NFAT expression and activity. Therefore, we studied the association of NFATs 3'UTR [NFATC2 rs4811198(T>G) &NFATC4 rs11848279(A>G)] and structural [NFATC1 rs754093(T>G) &NFATC2 rs12479626(T>C)] SNPs in 427 GV patients and 415 controls from Gujarat population by Polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP). Additionally, we carried out genotype-phenotype correlation and in silico analysis to assess the effect of NFATs SNPs on NFATs expression and structure. NFATC2 rs4811198(T>G) 3' UTR &NFATC2 rs12479626(T>C) structural SNPs were significantly associated with GV(p<0.0001). Interestingly, for NFATC2 rs4811198(T>G) SNP, there was a significant difference in the TT vs GG genotypes' frequencies (p=0.0034; Table 2), and for NFATC2 rs12479626(T>C) SNP there was a significant difference between TT vs TC and CC genotypes' frequencies(p<0.0001 & p=0.0002) between GV patients and controls. Furthermore, Odds ratio suggested that the susceptible alleles for NFATC2 rs4811198(T>G) &NFATC2 rs12479626(T>C) SNPs increased the risk of GV by 1.38 & 3.043 fold. However, the NFAT 3' UTR [NFATC2 rs4811198 (T>G)] and structural [NFATC1 rs754093(T>G)] SNPs were not significantly associated with GV. Interestingly, the genotype-phenotype correlation suggested that the susceptible 'G' allele of NFATC2 rs4811198(T>G) &NFATC4 rs11848279(A>G) 3' UTR SNPs lead to reduced NFATC2 and NFATC4 expression(p<0.0001). Furthermore, in silico analysis suggested that hsa-miR-3183 & hsa-miR-6720-3p miRNAs specifically bound to 'G' allele of NFATC2 rs4811198 SNP and has-miR-4652-3p miRNA specifically bound to 'G' allele of NFATC4 rs11848279 SNP. Overall, our study suggests that NFATC2 rs4811198(T>G) 3' UTR &NFATC2 rs12479626(T>C) structural SNPs may be associated with GV susceptibility in Gujarat population. Moreover, the susceptible alleles for the 3' UTR SNPs could lead to reduced NFATs levels, which may further possibly, affect the Treg suppressive function leading to GV.

Molecular Dynamic Simulations Unravel the Underlying Impact of Missense Mutation in Autoimmunity Gene PTPN22 on Predisposition to Rheumatoid Arthritis

Genetic mutations in various proteins have been implicated with increased risk or severity of rheumatoid arthritis (RA) in different population groups. In the present case-control study, we have investigated the risk association of single nucleotide mutations present in some of the highly reported anti-inflammatory proteins and/or cytokines, with RA susceptibility in the Pakistani subjects. The study involves 310 ethnically and demographically similar participants from whom blood samples were taken and processed for DNA extraction. Through extensive data mining, 5 hotspot mutations reported in 4 genes, that is, interleukin (IL)-4 (-590; rs2243250), IL-10 (-592; rs1800872), IL-10 (-1082; rs1800896), PTPN22 (C1858T; rs2476601), and TNFAIP3 (T380G; rs2230926), were selected for RA susceptibility analyses using genotyping assays. The results demonstrated the association of only 2 DNA variants [rs2243250 (odds ratio, OR = 2.025, 95% confidence interval, CI = 1.357-3.002, P = 0.0005 Allelic) and rs2476601 (OR = 4.25, 95% CI = 1.569-11.55, P = 0.004 Allelic)] with RA susceptibility in the local population. The former single nucleotide mutation was nonfunctional, whereas the latter, residing in the exonic region of a linkage-proven autoimmunity gene PTPN22, was involved in R620→W620 substitution. Comparative molecular dynamic simulations and free-energy calculations revealed a radical impact on the geometry/confirmation of key functional moieties in the mutant protein leading to a rather weak binding of W620 variant with the interacting receptor (SRC kinase). The interaction imbalance and binding instabilities provide convincing clues about the insufficient inhibition of T cell activation and/or ineffective clearance of autoimmune clones-a hallmark of several autoimmune disorders. In conclusion, the present research describes the association of 2 hotspot mutations in IL-4 promoter and PTPN22 gene with RA susceptibility in the Pakistani study cohort. It also details how a functional mutation in PTPN22 impacts the overall protein geometry, charge, and/or receptor interactions to contribute to RA susceptibility.

Age and Cytokine Gene Variants Modulate the Immunogenicity and Protective Effect of SARS-CoV-2 mRNA-Based Vaccination

The introduction of anti-SARS-CoV-2 vaccines in late 2020 substantially changed the pandemic picture, inducing effective protection in the population. However, individual variability was observed with different levels of cellular response and neutralizing antibodies. We report data on the impact of age, gender, and 16 single nucleotide polymorphisms (SNPs) of cytokine genes on the anti-SARS-CoV-2 IgG titers measured 31 and 105 days after administration of the second dose of BNT162b2 vaccine to 122 healthy subjects from the health care staff of the Palermo University Hospital, Italy. The higher titers at 31 days were measured in the younger subjects and in subjects bearing T-positive genotypes of IL-1R1 rs2234650 or the GG homozygous genotype of IL-6 rs1800795 SNP. T-positive genotypes are also significantly more common in subjects with higher titers at day 105. In addition, in this group of subjects, the frequency of the CT genotype of IL-4 rs2243250 is higher among those vaccinated with higher titers. Moreover, these SNPs and TNFA rs1800629 are differently distributed in a group of subjects that were found infected by SARS-CoV-2 at day 105 of evaluation. Finally, subjects that were found to be infected by SARS-CoV-2 at day 105 were significantly older than the uninfected subjects. Taken together, these data seem to suggest that age and polymorphisms of key cytokines, which regulate inflammation and humoral immune response, might influence the magnitude of the antibody response to vaccination with BNT162B2, prompting speculation about the possible benefit of a genetic background-based assessment of a personalized approach to the anti-COVID vaccination schedule.

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 for Association of Interleukin 4 VNTR Polymorphism with Rheumatoid Arthritis Risk and Severity

Rheumatoid Arthritis (RA) is a chronic autoimmune disease characterized by severe joint pain. There are conflicting results for the association of Interleukin 4 (IL4) variable number tandem repeats (VNTR; rs8179190) polymorphism with RA. Therefore, we performed a meta-analysis of the available studies to investigate the association of IL4 VNTR polymorphism with RA risk and severity in the overall populations and Asian, Egyptian, European, and Turkish ethnicities by sub-group analyses. Eight studies involving 1993 RA patients and 1732 controls were included in this meta-analysis. We found increased RA risk for the susceptible "R2R2" genotype and "R2" allele under heterozygous, recessive, and allelic models in the Asian populations (p < 0.00001, p < 0.0001, p = 0.001). We observed a significant association between "R2R2" genotype and "R2" allele for RA protection in the Turkish population under heterozygous, recessive, and allelic models (p = 0.01, p = 0.004, p = 0.002). Disease severity-based analysis revealed significant association for "R2R2" genotype and "R2" allele with RA severity under homozygous, heterozygous, recessive, dominant, and allelic models(p = 0.0004, p = 0.03, p = 0.02, p = 0.003, p = 0.01), specifically in Asian populations (p = 0.009, p = 0.02, p = 0.003, p = 0.03, p = 0.01) and under heterozygous, dominant, and allelic genetic models in Egyptian (p = 0.0001, p < 0.0001, p < 0.0001) and European (p = 0.002, p = 0.0007, p = 0.0006) populations. In silico analysis suggested that the susceptible "R2" allele changes the RNA secondary structure to a stable form by changing minimum free energy(ΔG) from - 115.20 to - 136.40 kcal/mol, which might lead to increased stability of IL-4 in RA patients. Overall, the meta-analysis suggests for the involvement of susceptible "R2" allele with RA risk in the Asian populations, RA severity in the overall populations (specifically in Asian, Egyptian, & European populations), and RA protection in the Turkish population.

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.

Increased susceptibility to pneumonia due to tumour necrosis factor inhibition and prospective immune system rescue via immunotherapy

Immunomodulators such as tumour necrosis factor (TNF) inhibitors are used to treat autoimmune conditions by reducing the magnitude of the innate immune response. Dampened innate responses pose an increased risk of new infections by opportunistic pathogens and reactivation of pre-existing latent infections. The alteration in immune response predisposes to increased severity of infections. TNF inhibitors are used to treat autoimmune conditions such as rheumatoid arthritis, juvenile arthritis, psoriatic arthritis, transplant recipients, and inflammatory bowel disease. The efficacies of immunomodulators are shown to be varied, even among those that target the same pathways. Monoclonal antibody-based TNF inhibitors have been shown to induce stronger immunosuppression when compared to their receptor-based counterparts. The variability in activity also translates to differences in risk for infection, moreover, parallel, or sequential use of immunosuppressive drugs and corticosteroids makes it difficult to accurately attribute the risk of infection to a single immunomodulatory drug. Among recipients of TNF inhibitors, Mycobacterium tuberculosis has been shown to be responsible for 12.5-59% of all infections; Pneumocystis jirovecii has been responsible for 20% of all non-viral infections; and Legionella pneumophila infections occur at 13-21 times the rate of the general population. This review will outline the mechanism of immune modulation caused by TNF inhibitors and how they predispose to infection with a focus on Mycobacterium tuberculosis, Legionella pneumophila, and Pneumocystis jirovecii. This review will then explore and evaluate how other immunomodulators and host-directed treatments influence these infections and the severity of the resulting infection to mitigate or treat TNF inhibitor-associated infections alongside antibiotics.

V-set domain containing T-cell activation inhibitor-1 (VTCN1): A potential target for the treatment of autoimmune diseases

Autoimmunity eventuates when the immune system attacks self-molecules as a result of the breakdown in immune tolerance. Targeting autoimmune diseases via immunomodulation has become an essential strategy in today's era. A B7 superfamily member immune checkpoint, the V-set domain containing T-cell activation inhibitor-1 (VTCN1), also known as B7-H4, B7S1, and B7x, is involved in negatively regulating T-cell activation. VTCN1 transcript has been reported in various lymphoid and non-lymphoid tissues, but its protein expression is restricted, indicating its translational regulation. Dysregulation of VTCN1 has resulted in the exacerbation of various autoimmune diseases. Moreover, increased soluble form of VTCN1 in the patient's sera positively correlates with the disease progression and severity. The current review summarizes all the reports till date, unfolding the role of VTCN1 in various autoimmune diseases and its therapeutic potential.

Altered Levels of Negative Costimulatory Molecule V-Set Domain-Containing T-Cell Activation Inhibitor-1 (VTCN1) and Metalloprotease Nardilysin (NRD1) are Associated with Generalized Active Vitiligo

BACKGROUND

Vitiligo is characterized by depigmented macules on the skin caused due to autoimmune destruction of melanocytes. V-set domain-containing T-cell activation inhibitor-1 (VTCN1) is a negative costimulatory molecule that plays a vital role in suppressing autoimmunity and tuning immune response. Nardilysin (NRD1), a metalloproteinase, cleaves membrane-tethered VTCN1 resulting in the shedding of soluble-VTCN1 (sVTCN1). However, the role of VTCN1 and NRD1 in vitiligo pathogenesis is unexplored.

OBJECTIVES AND METHODS

This study was aimed to (i) Investigate the association of VTCN1 intronic polymorphisms (rs10923223 T/C and rs12046117 C/T) with vitiligo susceptibility in Gujarat population by using Polymerase Chain Reaction- Restriction Fragment Length Polymorphism (PCR-RFLP) (ii) Estimate VTCN1 & NRD1 transcript levels from peripheral blood mononuclear cells (PBMCs) and skin samples of vitiligo patients by real-time PCR, (iii) Estimate sVTCN1 and NRD1 protein levels from plasma by ELISA and (iv) Estimate VTCN1 protein levels in the skin samples of vitiligo patients by immunofluorescence.

RESULTS

The analysis revealed increased VTCN1 and NRD1 transcript levels in the skin (p = .039, p = .021 respectively), increased sVTCN1 and NRD1 levels (p  = .026, p = .015 respectively) in the plasma, and decreased VTCN1 protein levels (p = .0002) in the skin of vitiligo patients as compared to healthy controls. The genetic analysis revealed no significant association of VTCN1 intronic polymorphisms rs10923223 T/C and rs12046117 C/T with vitiligo susceptibility in Gujarat population (p = .359, p = .937, respectively).

CONCLUSIONS

The present study revealed altered VTCN1 and NRD1 expressions in the blood and skin of vitiligo patients, suggesting their potential role in the development and progression of Vitiligo.

Frequency distribution of cytokine and associated transcription factor single nucleotide polymorphisms in Zimbabweans: Impact on schistosome infection and cytokine levels

Cytokines mediate T-helper (TH) responses that are crucial for determining the course of infection and disease. The expression of cytokines is regulated by transcription factors (TFs). Here we present the frequencies of single nucleotide polymorphisms (SNPs) in cytokine and TF genes in a Zimbabwean population, and further relate SNPs to susceptibility to schistosomiasis and cytokine levels. Individuals (N = 850) were genotyped for SNPs across the cytokines IL4, IL10, IL13, IL33, and IFNG, and their TFs STAT4, STAT5A/B, STAT6, GATA3, FOXP3, and TBX21 to determine allele frequencies. Circulatory levels of systemic and parasite-specific IL-4, IL-5, IL-10, IL-13, and IFNγ were quantified via enzyme-linked immunosorbent assay. Schistosoma haematobium infection was determined by enumerating parasite eggs excreted in urine by microscopy. SNP allele frequencies were related to infection status by case-control analysis and logistic regression, and egg burdens and systemic and parasite-specific cytokine levels by analysis of variance and linear regression. Novel findings were i) IL4 rs2070874*T’s association with protection from schistosomiasis, as carriage of ≥1 allele gave an odds ratio of infection of 0.597 (95% CIs, 0.421–0.848, p = 0.0021) and IFNG rs2069727*G’s association with susceptibility to schistosomiasis as carriage of ≥1 allele gave an odds ratio of infection of 1.692 (1.229–2.33, p = 0.0013). Neither IL4 rs2070874*T nor IFNG rs2069727*G were significantly associated with cytokine levels. This study found TH2-upregulating SNPs were more frequent among the Zimbabwean sample compared to African and European populations, highlighting the value of immunogenetic studies of African populations in the context of infectious diseases and other conditions, including allergic and atopic disease. In addition, the identification of novel infection-associated alleles in both TH1- and TH2-associated genes highlights the role of both in regulating and controlling responses to Schistosoma.

Single-nucleotide polymorphisms as important risk factors of diabetes among Middle East population

Diabetes is a chronic metabolic disorder that leads to the dysfunction of various tissues and organs, including eyes, kidneys, and cardiovascular system. According to the World Health Organization, diabetes prevalence is 8.8% globally among whom about 90% of cases are type 2 diabetes. There are not any significant clinical manifestations in the primary stages of diabetes. Therefore, screening can be an efficient way to reduce the diabetic complications. Over the recent decades, the prevalence of diabetes has increased alarmingly among the Middle East population, which has imposed exorbitant costs on the health care system in this region. Given that the genetic changes are among the important risk factors associated with predisposing people to diabetes, we examined the role of single-nucleotide polymorphisms (SNPs) in the pathogenesis of diabetes among Middle East population. In the present review, we assessed the molecular pathology of diabetes in the Middle East population that paves the way for introducing an efficient SNP-based diagnostic panel for diabetes screening among the Middle East population. Since, the Middle East has a population of 370 million people; the current review can be a reliable model for the introduction of SNP-based diagnostic panels in other populations and countries around the world.

Elevated X-Box Binding Protein1 Splicing and Interleukin-17A Expression Are Associated With Active Generalized Vitiligo in Gujarat Population

Vitiligo is an autoimmune skin disorder defined by the destruction of functional epidermal melanocytes. It is a multifactorial and polygenic disorder caused due to oxidative stress, endoplasmic reticulum (ER) stress, and autoimmunity, among other factors. In the present study, we aimed to investigate the association of X-box Binding Protein 1 (XBP1) and Interleukin-17A (IL-17A) polymorphisms and monitor their systemic as well as skin expression levels in vitiligo patients from Gujarat population in India. XBP1 rs2269577 G/C, IL17A rs2275913 G/A and IL17A rs8193036 C/T polymorphisms were genotyped by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) method in 312 controls and 276 vitiligo patients. Transcript levels of spliced (sXBP1), unspliced XBP1 (uXBP1) and IL17A from peripheral blood mononuclear cells (PBMCs) as well as spliced and unspliced XBP1 from skin samples were analyzed by qPCR. IL-17A protein levels in suction-induced blister fluid (SBF) from the skin of study subjects were estimated by ELISA. The results revealed that genotype (p=0.010) and allele (p=0.014) frequencies of XBP1 rs2269577 G/C polymorphism were significantly different, however, no significant difference was observed in frequencies of IL17A rs2275913 G/A and IL17A rs8193036 C/T polymorphisms in control and patient population. Gene expression analysis revealed that sXBP1 and IL17A levels were significantly higher in PBMCs of generalized (p=0.030 and p=0.039, respectively) and active (p=0.024 and p=0.017, respectively) vitiligo patients. Moreover, we observed a significantly elevated sXBP1 expression (p=0.037) as well as IL-17A protein levels (p=0.009) in perilesional skin of vitiligo patients as compared to controls. Overall, these findings suggest XBP1 and IL17A play an important role in vitiligo and further substantiate the involvement of ER stress in exacerbating immune-mediated vitiligo pathogenesis.

Meta-analysis for association of TNFA-308(G > A) SNP with vitiligo susceptibility

Vitiligo is an autoimmune progressive skin depigmenting disease. Tumor necrosis factor alpha (TNF-α) is a pro-inflammatory cytokine and plays a crucial role in vitiligo development. Since there are conflicting results and consensus is lacking for the association of the TNFA gene -308 G > A polymorphism with vitiligo susceptibility; we performed a meta-analysis of all the available studies to investigate the association of TNFA -308 G > A polymorphism with vitiligo risk. 11 studies involving 2199 vitiligo patients and 3083 controls were included in the meta-analysis. The meta-analysis revealed an increased vitiligo risk with "AA", "GA" and "AA" + "GA" genotypes and 'A' allele in the overall (p = 0.006, p = 0.003, p = 0.001 & p = 0.003) and Egyptian populations (p = 0.001, p < 0.00001, p < 0.00001 & p = 0.002). Moreover, we found association for "GA" and "AA" + "GA" genotypes in Asian population (p = 0.0009 & p = 0.005) and for 'A' allele in Asian and middle eastern populations (p = 0.04 & p = 0.0002). Interestingly the disease activity based analysis revealed significant association for "GA", "AA" + "GA" genotypes and 'A' allele with active vitiligo patients in the North American population (p = 0.02). Moreover, we found significant association for "GA", "AA" + "GA" genotypes and 'A' allele with localized vitiligo in overall (p = 0.02, p = 0.02 & p = 0.04) and Asian (p = 0.004, p = 0.003 & p = 0.01) populations. Overall, our meta-analysis suggests the involvement of susceptible 'A' allele with: i) vitiligo susceptibility in overall population and specifically with Asian, Middle Eastern and Egyptian populations; ii) vitiligo disease activity in North American population and iii) localized vitiligo in overall population and specifically in Asian population.

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.

Vitiligo skin T cells are prone to produce type 1- and type 2-cytokines to induce melanocyte dysfunction and epidermal inflammatory response through JAK signaling

Vitiligo is a T cell-mediated inflammatory skin disorder characterized by the loss of epidermal melanocytes. However, the contribution of melanocytes to the physiopathology of the disease in response to the T cell microenvironment remains unclear. Here, using NanoString technology and multiplex ELISA, we show that active vitiligo perilesional skin is characterized by prominent type 1 and 2 associated immune responses. The vitiligo skin T cell secretome downregulated melanocyte function and adhesion, while increasing melanocyte mitochondrial metabolism and expression of inflammatory cytokines and chemokines by epidermal cells. The JAK1/2 inhibitor ruxolitinib strongly inhibited such effects on epidermal cells. Our data highlight that vitiligo is more complex than previously thought with prominent combined activities of both Th1- and Th2-related cytokines inducing inflammatory responses of epidermal cells. Melanocytes do not appear only to be a target of T cells in vitiligo but could actively contribute to perpetuate inflammation. JAK inhibitors could prevent the impact of T cells on epidermal cells and pigmentation, highlighting their potential clinical benefit in vitiligo.

Differences in the skin microbial community between patients with active and stable vitiligo based on 16S rRNA gene sequencing

BACKGROUND/OBJECTIVE

Recent studies have described an association between altered skin microbial community and epidemiology of skin diseases, such as vitiligo, atopic dermatitis and psoriasis. In this study, we conducted microbiological analysis on patients at different stages of vitiligo to determine whether the dysbiosis is associated with disease progression.

METHODS

To characterise the skin microbes in vitiligo patients, we profiled samples collected from 40 patients with active and stable vitiligo using the Novaseq sequencer. Alpha diversity was used to measure richness and uniformity, while Beta diversity (Non-Metric Multi-Dimensional Scaling) analysis was used to show the differences. Moreover, the species differences were evaluated by LEfSe analysis and the flora gene function was predicted using Statistical Analysis of Metagenomic Profiles (STAMP).

RESULTS

The alpha diversity results showed no significant differences between active vitiligo and stable vitiligo, while beta diversity and LEfSe analysis results showed the differences in community composition. Streptomyces and Streptococcus were enriched in active vitiligo compared to stable vitiligo. In addition, the flora gene function of mixed acid fermentation was more pronounced in active vitiligo, while the function of lipid IVA biosynthesis was more significant in stable vitiligo.

CONCLUSION

This study has shown the differences in epidermal microbes between active vitiligo and stable vitiligo. Our results suggest that maintaining the flora balance might be a potential therapeutic target for vitiligo.

The IL-4, IL-13 and IL-31 pathways in atopic dermatitis

Introduction: Atopic dermatitis (AD) is the most common inflammatory skin disease. It has a complex pathophysiology, with a combination of immune dysregulation and intrinsic barrier defects driving cutaneous inflammation and allergic symptomatology. The IL-4, IL-13 and IL-31 inflammatory pathways have been identified as hallmark features in the pathogenesis of the disease, contributing uniquely and synergistically to immune and barrier abnormalities as well as the key symptoms, such as pruritis. Novel therapeutics that target these pathways have been under development to find treatments for AD.Areas covered: This review discusses the IL-4, IL-13 and IL-31 pathways in AD. We will also detail novel targeted therapeutics that have recently been or are currently in clinical trials for AD. A literature search was conducted by querying Scopus, Google Scholar, PubMed, and Clinicaltrials.gov up to January 2021 using combinations of the search terms 'IL-4' 'IL-13' 'IL-31' 'atopic dermatitis' 'immune pathway' 'biologics' 'novel therapeutics' 'JAK/STAT inhibitors.'Expert opinion: The complex pathophysiology of AD advocates for innovation. Novel minimally invasive sampling modalities such as tape stripping will allow for a broader characterization of the immunomechanisms behind AD pathophysiology. This will allow for the continued development of a personalized medicine approach to treat AD.

Polymorphisms of interleukin 4 and interleukin 4 receptor genes and bronchial asthma risk among Egyptian children

BACKGROUND

Interleukin 4 (IL4) is a key cytokine that regulates the inflammatory cascade in bronchial asthma. We investigated the association between the IL4 and IL4R polymorphisms and the susceptibility for bronchial asthma among Egyptian children.

METHODS

IL4 VNTR and IL4R c.1902 A>G p.(Q576R) polymorphisms were investigated among 100 children with bronchial asthma and 100 healthy controls using PCR method. Serum levels of IL4 and immunoglobulin E (IgE) were assessed by ELISA.

RESULTS

The frequencies of (A1A2 + A2A2) genotypes and A2-allele of the IL4 VNTR variant were significantly higher among asthmatic patients than controls (p = 0.01, OR = 2.34, 95% CI = 1.24-4.44; p = 0.01, OR = 2.27, 95% CI = 1.29-3.99, respectively). The frequencies of (AG + GG) genotypes and G-allele of the IL4R (A1902G) variant were significantly higher among asthmatic patients than controls (p = 0.003, OR = 2.52, 95% CI = 1.39-4.58; p = 0.002, OR = 2.25, 95% CI = 1.35-3.76, respectively). There was a significant association between (A1A2 + A2A2) genotypes of the IL4 VNTR variant and high serum IL4 level among asthmatic patients (p < 0.001). The (AG + GG) genotypes of the IL4R (A1902G) variant were significantly associated with exposure to triggers, atopic dermatitis and higher serum IgE level in asthmatic patients (p = 0.02, 0.04 and 0.01, respectively).

CONCLUSION

IL4 VNTR and IL4R (A1902G) polymorphisms could be associated with higher risks of bronchial asthma among Egyptian children.

Diversified Stimuli-Induced Inflammatory Pathways Cause Skin Pigmentation

The production of melanin pigments by melanocytes and their quantity, quality, and distribution play a decisive role in determining human skin, eye, and hair color, and protect the skin from adverse effects of ultraviolet radiation (UVR) and oxidative stress from various environmental pollutants. Melanocytes reside in the basal layer of the interfollicular epidermis and are compensated by melanocyte stem cells in the follicular bulge area. Various stimuli such as eczema, microbial infection, ultraviolet light exposure, mechanical injury, and aging provoke skin inflammation. These acute or chronic inflammatory responses cause inflammatory cytokine production from epidermal keratinocytes as well as dermal fibroblasts and other cells, which in turn stimulate melanocytes, often resulting in skin pigmentation. It is confirmed by some recent studies that several interleukins (ILs) and other inflammatory mediators modulate the proliferation and differentiation of human epidermal melanocytes and also promote or inhibit expression of melanogenesis-related gene expression directly or indirectly, thereby participating in regulation of skin pigmentation. Understanding of mechanisms of skin pigmentation due to inflammation helps to elucidate the relationship between inflammation and skin pigmentation regulation and can guide development of new therapeutic pathways for treating pigmented dermatosis. This review covers the mechanistic aspects of skin pigmentation caused by inflammation.

A Concise Review on the Role of Endoplasmic Reticulum Stress in the Development of Autoimmunity in Vitiligo Pathogenesis

Vitiligo is characterized by circumscribed depigmented macules in the skin resulting due to the autoimmune destruction of melanocytes from the epidermis. Both humoral as well as cell-mediated autoimmune responses are involved in melanocyte destruction. Several studies including ours have established that oxidative stress is involved in vitiligo onset, while autoimmunity contributes to the disease progression. However, the underlying mechanism involved in programing the onset and progression of the disease remains a conundrum. Based on several direct and indirect evidences, we suggested that endoplasmic reticulum (ER) stress might act as a connecting link between oxidative stress and autoimmunity in vitiligo pathogenesis. Oxidative stress disrupts cellular redox potential that extends to the ER causing the accumulation of misfolded proteins, which activates the unfolded protein response (UPR). The primary aim of UPR is to resolve the stress and restore cellular homeostasis for cell survival. Growing evidences suggest a vital role of UPR in immune regulation. Moreover, defective UPR has been implicated in the development of autoimmunity in several autoimmune disorders. ER stress-activated UPR plays an essential role in the regulation and maintenance of innate as well as adaptive immunity, and a defective UPR may result in systemic/tissue level/organ-specific autoimmunity. This review emphasizes on understanding the role of ER stress-induced UPR in the development of systemic and tissue level autoimmunity in vitiligo pathogenesis and its therapeutics.

Investigation of the Role of Interleukin 6 in Vitiligo Pathogenesis

Interleukin-6 (IL6) is involved in pathogenesis of several autoimmune disorders including vitiligo. Hence, we aimed to investigate the association of IL6 -174 G/C and -572 G/C polymorphisms and its transcript levels with vitiligo; to evaluate the effect of IL-6 on normal human melanocyte (NHM) viability and expression of IL6R, MITF and TYR. IL6 -174 G/C and -572 G/C polymorphisms were genotyped by ARMS-PCR and PCR-RFLP respectively in 343 controls and 322 vitiligo patients. IL6 transcript levels were estimated from PBMCs (96 controls and 77 patients) and skin samples (15 controls and 15 patients) by qPCR. NHM viability was assessed by MTT; IL6R, MITF and TYR transcript and protein levels were monitored by qPCR and ICC respectively. Genetic analyses revealed no association of IL6 -174 G/C polymorphism (p> .05) with vitiligo. Analysis of IL6 -572 G/C revealed reduced risk of vitiligo in individuals with GC/CC genotypes compared to GG genotype (p = .010). IL6 expression was significantly increased (p = .0197) in PBMCs of patients. Further, IL6 expression was significantly higher in non-lesional skin compared to controls (p = .009). In-vitro NHM viability was decreased upon IL-6 exposure (10-50 ng/ml; p< .05), with significantly increased IL6R transcript (p = .042) and protein levels (p = .003) however, MITF transcript (p = .0003) and protein levels (p = .016), and TYR transcript levels (p = .001) were significantly decreased. The results suggest that IL6 -572 G/C polymorphism might be associated with vitiligo susceptibility in Gujarat population. Moreover, increased IL6 expression in vitiligo patients and its effect on NHM suggest a potential role in melanocyte biology.

CONCLUSION

The results suggest that IL6 - 572 G/C polymorphism might be associated with vitiligo susceptibility in Gujarat population. Moreover, increased IL6 expression in vitiligo patients and its effect on NHM suggest a potential role in melanocyte biology.

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.

Roles of inflammation factors in melanogenesis (Review)

The occurrence of hyperpigmentation or hypopigmentation after inflammation is a common condition in dermatology and cosmetology. Since the exact mechanism of its occurrence is not yet known, prevention and treatment are troublesome. Previous studies have confirmed that α-melanocyte-stimulating hormone, stem cell factor and other factors can promote melanogenesis-related gene expression through the activation of signaling pathways. Recent studies have revealed that a variety of inflammatory mediators can also participate in the regulation of melanogenesis in melanocytes. In this review, we summarized that interleukin-18, interleukin-33, granulocyte-macrophage colony stimulating factor, interferon-γ, prostaglandin E2 have the effect of promoting melanogenesis, while interleukin-1, interleukin-4, interleukin-6, interleukin-17 and tumor necrosis factor can inhibit melanogenesis. Further studies have found that these inflammatory factors may activate or inhibit melanogenesis-related signaling pathways (such as protein kinase A and mitogen activated protein kinase) by binding to corresponding receptors, thereby promoting or inhibiting the expression of melanogenesis-related genes and regulating skin pigmentation processes. This suggests that the development of drugs or treatment methods from the perspective of regulating inflammation can provide new ideas and new targets for the treatment of pigmented dermatosis. This review outlines the current understanding of the inflammation factors' roles in melanogenesis.

IL-4 polymorphism influences susceptibility to Pneumocystis jirovecii pneumonia in HIV-positive patients

OBJECTIVES

Pneumocystis jirovecii pneumonia (PJP) is an important cause of morbidity and mortality in HIV-positive patients. Polymorphisms in immune genes are increasingly reported to influence susceptibility to fungal infections. We analysed the role of 21 single nucleotide polymorphisms from 19 candidate genes on PJP development in patients from the Swiss HIV Cohort Study.

DESIGN AND METHODS

The analysis included patients with a nadir CD4 T-cell count less than 200 cells/μl, divided into a discovery (N = 1645) and a replication (N = 1861) cohort. The associations were analysed by using cumulative incidence curves as well as competing risk regression over 18 years, starting from the estimated date of HIV infection, considering death a competing risk, with censoring at lost follow-up, and assuming the dominant mode of inheritance.

RESULTS

The minor allele of rs2243250 in IL-4 was associated with the risk of PJP in the discovery cohort (cumulative incidence 0.18 versus 0.12, P = 0.002). This association was replicated in the validation cohort (0.16 versus 0.12, P = 0.02). It was still significant in multivariate models, adjusted for HIV transmission mode, viral load, CD4 T cells slope, age, antiretroviral therapy, tobacco smoking, hepatitis C virus coinfection, year of cohort entry and PJP prophylaxis (global subhazard ratio 1.42, 95% confidence interval 1.17-1.73, P = 0.0004).

CONCLUSION

Our data suggest rs2243250, a single nucleotide polymorphism known to influence IL-4 production, is associated with susceptibility to PJP in HIV-positive patients.

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.

Ethnic variation of IL-4 intron 3 VNTR gene polymorphism; its association with type 2 diabetes mellitus and its complication (neuropathy) in Egyptian subjects

Type 2 diabetes mellitus (T2DM) has multigenetic and environmental interactive factors. Although diabetic neuropathies (DPN) are the most common, but at the same time, the least recognized and understood long-term complication of diabetes. This study aimed to investigate the association of IL-4 VNTR gene polymorphism with T2DM complicated with neuropathy in Egyptian subjects. This is a case control study including 102 T2DM Egyptian patients, plus 188 unrelated healthy individuals as controls. They were evaluated for variable number tandem repeat (VNTR); 70 base pair repeats located in the intron 3; of IL-4 gene using the PCR technique. Homozygote frequency of the three-repeat allele (A1/A1) genotype of IL-4 VNTR was nearly equal among diabetic cases and controls (60.8% vs. 62.2%, respectively). Heterozygous frequency of (A1/A2) genotype was higher among controls compared to cases (33.5% vs. 19.6%, respectively) but not statistically significant. The (A2) allele had a significantly higher frequency in diabetic cases compared to controls (29.3% vs. 21.0%, respectively) while the (A1) allele had lower frequency but not significant one (70.7% vs. 79.0%, respectively). Comparing cases complicated with diabetic neuropathy vs. noncomplicated cases regarding their polymorphic IL-4 (VNTR) genotypes revealed a nonsignificant lower frequency of (A1A1) genotype (57.1% vs. 65.1%, respectively, p = .57) with a higher combined (A2A2 + A1/A2) genotype frequency (42.9% vs. 34.9%, respectively). Only two haplotypes (A1) & (A2) of IL-4 (VNTR) gene were recognized among Egyptian population; (A2) allele may influence in diabetes but not its complication (neuropathy) among Egyptian diabetic patients.

Association of interleukin 1 receptor antagonist intron 2 variable number of tandem repeats polymorphism with vitiligo susceptibility in Gujarat population

Background

Vitiligo is a multifactorial, polygenic, autoimmune skin disorder caused by selective destruction of melanocytes. Interleukin 1 receptor antagonist intron 2 polymorphism was found to be associated with various autoimmune disorders.

Aims

We aimed to investigate the association of interleukin 1 receptor antagonist intron 2 variable number of tandem repeats polymorphism (rs2234663) with vitiligo to assess interleukin 1 receptor antagonist transcript levels and to perform possible genotype-phenotype correlation.

Methods

Three hundred and seven vitiligo patients and 316 controls were enrolled in the study, genotyping of interleukin 1 receptor antagonist rs2234663 was performed by polymerase chain reaction, and relative gene expression of interleukin 1 receptor antagonist was carried out in peripheral blood mononuclear cells from patients (n = 36) and controls (n = 36) by real-time-PCR.

Results

A significant difference was observed in the frequency of interleukin 1 receptor antagonist *A (1/2) genotype among patients with active and stable vitiligo (P = 0.0172). Interleukin 1 receptor antagonist*A (2/2) genotype and allele frequencies were significantly different between SV patients and controls (P = 0.0246 and P = 0.0046, respectively). Significant difference was also observed for interleukin 1 receptor antagonist*A2 (allele) in active and stable vitiligo patients (P = 0.0060). However, other comparisons did not show any significant difference in genotype and allele frequencies. Moreover, interleukin 1 receptor antagonist*A (3/2) genotype was observed only in patients whereas interleukin 1 receptor antagonist*A (5/2) was observed only in controls. Gene expression analysis showed no significant difference in interleukin 1 receptor antagonist transcript levels in patients compared to controls (P = 0.5962). Interestingly, genotype-phenotype correlation analysis revealed that individuals with IL1RN*A (2/2) exhibited higher interleukin 1 receptor antagonist expression compared to other major genotypes interleukin 1 receptor antagonist*A (1/2) (P = 0.01) and interleukin 1 receptor antagonist*A (1/1) (P = 0.03).

Limitations

More case-control studies on interleukin 1 receptor antagonist rs2234663 polymorphism and gene expression from different ethnic populations are required to explore the impact of interleukin 1 receptor antagonist in vitiligo susceptibility.

Conclusion

Interleukin 1 receptor antagonist*A2 might be a risk factor for progressive vitiligo.

The role of interleukins in vitiligo: a systematic review

Vitiligo is a disorder of the skin that causes depigmentation and asymptomatic macules whose exact cause is still unclear. Although its aetiology is not fully elucidated, the main theory of its pathomechanism is that it is associated with the autoimmune process. There is few summarized information about the role of inflammatory mediators, as interleukins, in vitiligo, so our aim was to present a systematic review of the role of interleukins in vitiligo, focusing on interleukins. In this review, we included all studies assessing interleukin levels in vitiligo patients conducted up to June 2017. Quality assessment of these studies was performed using the Newcastle-Ottawa Scale (NOS). The interleukins mainly involved were IL-2, IL-4, IL-6, IL-10 and IL-17. The studies highlight the crucial role of IL-17 in the onset and progression of the disease, and its synergistic action with IL-2, IL-6 and IL-33. Dysregulated levels of the interleukins were also correlated with the stage of disease, the affected skin surface area, and indicated as the main factor for lymphocyte infiltration found in depigmented regions. These findings illustrate the growing need for new therapies targeting vitiligo and further research into the role of interleukins as an area of particular interest.

A case-control study on association of proteasome subunit beta 8 (PSMB8) and transporter associated with antigen processing 1 (TAP1) polymorphisms and their transcript levels in vitiligo from Gujarat

BACKGROUND

Autoimmunity has been implicated in the destruction of melanocytes from vitiligo skin. Major histocompatibility complex (MHC) class-II linked genes proteasome subunit beta 8 (PSMB8) and transporter associated with antigen processing 1 (TAP1), involved in antigen processing and presentation have been reported to be associated with several autoimmune diseases including vitiligo.

OBJECTIVES

To explore PSMB8 rs2071464 and TAP1 rs1135216 single nucleotide polymorphisms and to estimate the expression of PSMB8 and TAP1 in patients with vitiligo and unaffected controls from Gujarat.

METHODS

PSMB8 rs2071464 polymorphism was genotyped using polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP) and TAP1 rs1135216 polymorphism was genotyped by amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) in 378 patients with vitiligo and 509 controls. Transcript levels of PSMB8 and TAP1 were measured in the PBMCs of 91 patients and 96 controls by using qPCR. Protein levels of PSMB8 were also determined by Western blot analysis.

RESULTS

The frequency of 'TT' genotype of PSMB8 polymorphism was significantly lowered in patients with generalized and active vitiligo (p = 0.019 and p = 0.005) as compared to controls suggesting its association with the activity of the disease. However, TAP1 polymorphism was not associated with vitiligo susceptibility. A significant decrease in expression of PSMB8 at both transcript level (p = 0.002) as well as protein level (p = 0.0460) was observed in vitiligo patients as compared to controls. No significant difference was observed between patients and controls for TAP1 transcripts (p = 0.553). Interestingly, individuals with the susceptible CC genotype of PSMB8 polymorphism showed significantly reduced PSMB8 transcript level as compared to that of CT and TT genotypes (p = 0.009 and p = 0.003 respectively).

CONCLUSIONS

PSMB8 rs2071464 was associated with generalized and active vitiligo from Gujarat whereas TAP1 rs1135216 showed no association. The down-regulation of PSMB8 in patients with risk genotype 'CC' advocates the vital role of PSMB8 in the autoimmune basis of vitiligo.

Recent advances in exploring the genetic susceptibility to diabetic neuropathy

Diabetic polyneuropathy and cardiovascular autonomic neuropathy are common and disabling complications of diabetes. Although glycaemic control and cardiovascular risk factors are major contributory elements in its development, diabetic neuropathy recognizes a multifactorial influence and a multiplicity of pathogenetic mechanisms. Thus genetic and environmental factors may contribute to its susceptibility, each with a modest contribution, by targeting various metabolic and microvascular pathways whose alterations intervene in diabetic neuropathy pathogenesis. This review is aimed at describing major data from the available literature regarding genetic susceptibility to diabetic neuropathies. It provides an overview of the genes reported as associated with the development or progression of these complications, i.e. ACE, MTHFR, GST, GLO1, APOE, TCF7L2, VEGF, IL-4, GPX1, eNOS, ADRA2B, GFRA2, MIR146A, MIR128A. The identification of genetic susceptibility can help in both expanding the comprehension of the pathogenetic mechanisms of diabetic nerve damage and identifying biomarkers of risk prediction and response to therapeutic intervention.

Enhanced Th1 and Th17 responses in peripheral blood in active non-segmental vitiligo

Accumulating studies have indicated that vitiligo, especially non-segmental vitiligo (NSV), is one kind of autoimmune diseases and CD4⁺ T cells play important roles in the pathogenesis. However, there have been very limited data on the detailed changes of each of the CD4⁺ T cell subsets in periphery in active NSV. To clarify this issue, we collected the peripheral blood mononuclear cells (PBMCs) from 30 patients with active NSV and 30 age- and sex-matched healthy controls. The percentages of circulating Th1, Th2, Th17 and Tregs were evaluated using flow cytometry and the expressions of their specific transcription factors T-bet, GATA3, RORγt and FOXP3 at mRNA level and protein levels were qualified by qPCR and flow cytometry, respectively. Meanwhile, the expression levels of IFN-γ, IL-4, TGF-β, and IL-17A in serum were measured. We found that in patients with NSV, the percentages and absolute numbers of circulating Th1 and Th17 were both significantly higher than those of healthy controls, while the percentages of Th2 and Tregs and absolute numbers showed no significant difference compared to healthy controls. Moreover, the ratios of Th1/Tregs and Th17/Tregs in circulation were both statistically elevated in active NSV. Similar results were got in qualification of their corresponding transcription factors at mRNA level and protein levels. Compared with healthy controls, the expression level of IL-17A was significantly increased in serum of patients with NSV, while the productions of IFN-γ, IL-4, TGF-β had no significant change. These data suggested that in circulating CD4⁺ T cell subsets, Th1 and Th17 played the major role in cellular immunity in the progression of vitiligo. The immune lever in circulation was inclined to effector CD4⁺ T cells not suppressor CD4⁺ T cells that may result in the loss of self-tolerance to melanocytes.

Serum Antibodies against Helicobacter pylori Neutrophil Activating Protein in Carriers of IL-4 C-590T Genetic Polymorphism Amplify the Risk of Gastritis and Gastric Cancer

BACKGROUND

Gastric cancer arises, mainly, on an inflammatory background. Helicobacter pylori neutrophil activating (HP-NAP) protein functions as a potent pro-inflammatory mediator. Similarly, IL-4 plays a critical role in the inflammation pathway, the levels of which are altered by C to T transition at position -590 in its promoter region. Here, we have aimed to assess the risk of gastritis and gastric cancer in the co-presence of these two inflammation modulating mediators.

METHODS

Gastritis (n=58) and gastric cancer (n=31) patients were evaluated and compared with H. pylori-positive asymptomatic controls (n=46), for serum antibodies against recombinant HP-NAP and IL-4 C-590T single nucleotide polymorphism using immunoblotting and PCR-RFLP, respectively. Multivariable logistic regression, adjusting for age, gender and ethnicity, was used for data analysis.

RESULTS

In terms of susceptibility to gastritis, seropositivity to HP-NAP projected a risk impact of 4.62 fold (OR=4.62, 95% CI=1.50-14.22), which when present in IL-4 -590 T carriers augmented the risk up to 9.7 fold (OR=9.70, 95% CI=2.06-45.69). A similar pattern, but of a stronger magnitude, occurred for the risk of gastric cancer, which was estimated at 9.07 fold (OR=9.07, 95% CI=1.99-42.0) for HP-NAP-seropositive subjects and was drastically amplified (OR=33.64, 95% CI=2.06-548.68), when double-positive (HP-NAP seropositive/IL-4 -590 T carrier) subjects were examined against double negatives (HP-NAP seronegative/IL-4 -590 CC).

CONCLUSION

Our preliminary data indicate that serum antibodies against HP-NAP represent a state of risk, which is further exacerbated in IL-4 -590 T carriers. These biomarkers, if validated in larger prospective studies, can be used to screen for gastric cancer susceptibility.

Vitiligo in association with vernal keratoconjunctivitis

Vernal keratoconjunctivitis (VKC) is a chronic allergic inflammation of ocular surface involving the tarsal and/or bulbar conjunctiva. Signs of VKC are confined to the conjunctiva and cornea. The skin of the lid remains uninvolved. Here we report a case of 17 year-old male suffering from VKC who develops vitiligo of lid skin and lash poliosis. All ocular and systemic causes of localized skin and lash depigmentation were excluded in our patient by thorough clinical examination and investigations. During regular follow-up for two-year patient did not develop any ocular and systemic illness presenting as vitiligo and poliosis. We believe that VKC was the most possible etiology of Vitiligo of lid and lash poliosis in this patient.

Differential expression of mRNA for T-bet and GATA-3 transcription factors in peripheral blood mononuclear cells of patients with vitiligo

BACKGROUND

There is accumulating evidence that aberrant T helper (Th)1 and Th2 cell responses play critical roles in the pathogenesis of autoimmune diseases. However, their importance in the pathobiology of vitiligo have yet to be elucidated.

AIM

To evaluate the expression profile of two transcription factors, namely, T-bet, a Th1-specific T box transcription factor and GATA binding protein 3 (GATA-3), a Th2-specific transcription factor, and to measure expression levels of interferon (IFN)-γ and interleukin (IL)-4 mRNAs as the signature cytokines of Th1 and Th2 cells, respectively.

METHODS

Gene expression analysis of peripheral blood mononuclear cells (PBMCs) was performed using real-time reverse transcriptase PCR.

RESULTS

In patients with vitiligo compared with controls, mRNA expression was significantly higher for T-bet and IFN-γ, and significantly lower for GATA-3 and IL-4 mRNAs (P ≤ 0.05).

CONCLUSION

These data suggest additional implications for the role of Th1/Th2 balance in the immunopathogenesis of vitiligo.

The homeostatic role of neuropeptide Y in immune function and its impact on mood and behaviour

Neuropeptide Y (NPY), one of the most abundant peptides in the nervous system, exerts its effects via five receptor types, termed Y1, Y2, Y4, Y5 and Y6. NPY's pleiotropic functions comprise the regulation of brain activity, mood, stress coping, ingestion, digestion, metabolism, vascular and immune function. Nerve-derived NPY directly affects immune cells while NPY also acts as a paracrine and autocrine immune mediator, because immune cells themselves are capable of producing and releasing NPY. NPY is able to induce immune activation or suppression, depending on a myriad of factors such as the Y receptors activated and cell types involved. There is an intricate relationship between psychological stress, mood disorders and the immune system. While stress represents a risk factor for the development of mood disorders, it exhibits diverse actions on the immune system as well. Conversely, inflammation is regarded as an internal stressor and is increasingly recognized to contribute to the pathogenesis of mood and metabolic disorders. Intriguingly, the cerebral NPY system has been found to protect against distinct disturbances in response to immune challenge, attenuating the sickness response and preventing the development of depression. Thus, NPY plays an important homeostatic role in balancing disturbances of physiological systems caused by peripheral immune challenge. This implication is particularly evident in the brain in which NPY counteracts the negative impact of immune challenge on mood, emotional processing and stress resilience. NPY thus acts as a unique signalling molecule in the interaction of the immune system with the brain in health and disease.

Association of neuropeptide Y (NPY), interleukin-1B (IL1B) genetic variants and correlation of IL1B transcript levels with vitiligo susceptibility

BACKGROUND

Vitiligo is a depigmenting disorder resulting from loss of functional melanocytes in the skin. NPY plays an important role in induction of immune response by acting on a variety of immune cells. NPY synthesis and release is governed by IL1B. Moreover, genetic variability in IL1B is reported to be associated with elevated NPY levels.

OBJECTIVES

Aim of the present study was to explore NPY promoter -399T/C (rs16147) and exon2 +1128T/C (rs16139) polymorphisms as well as IL1B promoter -511C/T (rs16944) polymorphism and to correlate IL1B transcript levels with vitiligo.

METHODS

PCR-RFLP method was used to genotype NPY -399T/C SNP in 454 patients and 1226 controls; +1128T/C SNP in 575 patients and 1279 controls and IL1B -511C/T SNP in 448 patients and 785 controls from Gujarat. IL1B transcript levels in blood were also assessed in 105 controls and 95 patients using real-time PCR.

RESULTS

Genotype and allele frequencies for NPY -399T/C, +1128T/C and IL1B -511C/T SNPs differed significantly (p<0.0001, p<0.0001; p = 0.0161, p = 0.0035 and p<0.0001, p<0.0001) between patients and controls. 'TC' haplotype containing minor alleles of NPY polymorphisms was significantly higher in patients and increased the risk of vitiligo by 2.3 fold (p<0.0001). Transcript levels of IL1B were significantly higher, in patients compared to controls (p = 0.0029), in patients with active than stable vitiligo (p = 0.015), also in female patients than male patients (p = 0.026). Genotype-phenotype correlation showed moderate association of IL1B -511C/T polymorphism with higher IL1B transcript levels. Trend analysis revealed significant difference between patients and controls for IL1B transcript levels with respect to different genotypes.

CONCLUSION

Our results suggest that NPY -399T/C, +1128T/C and IL1B -511C/T polymorphisms are associated with vitiligo and IL1B -511C/T SNP influences its transcript levels leading to increased risk for vitiligo in Gujarat population. Up-regulation of IL1B transcript in patients advocates its possible role in autoimmune pathogenesis of vitiligo.

Interleukin-1beta -511T>C genetic variant contributes to recurrent pregnancy loss risk and peripheral natural killer cell proportion

OBJECTIVE

To identify whether interleukin gene polymorphisms are risk factors for idiopathic recurrent pregnancy loss (RPL) in Korean women.

DESIGN

Case-control study.

SETTING

Hospital-based study.

PATIENT(S)

A cohort of 385 idiopathic RPL patients and 232 controls with Korean ethnicity.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Genotyping was assessed with a polymerase chain reaction-restriction fragment length polymorphism assay. We examined polymorphisms in three interleukin (IL) genes: IL-1β, IL-4, and IL-10.

RESULT(S)

The IL-1β -511T>C polymorphism was associated with RPL (-511TT vs. -511CC: adjusted odds ratio 1.826; 95% confidence interval 1.130-2.953). Allelic gene-gene interaction analysis revealed that the T/B2/G (IL-1β/IL-4/IL-10) allele combination was only detected in the RPL group (adjusted odds ratio 20.046; 95% confidence interval 1.188-338.204). The proportion of peripheral natural killer cells was higher in patients with the IL-1β -511C allele compared with the -511T allele.

CONCLUSION(S)

According to these results, IL-1β -511T>C may be a predisposing factor to RPL susceptibility. However, the mechanism underlying the function of IL-1β -511T>C in RPL remains to be determined, and further studies are needed to improve understanding of the roles of IL-1β -511T>C, using a larger and more heterogeneous cohort.

Modern vitiligo genetics sheds new light on an ancient disease

Vitiligo is a complex disorder in which autoimmune destruction of melanocytes results in white patches of skin and overlying hair. Over the past several years, extensive genetic studies have outlined a biological framework of vitiligo pathobiology that underscores its relationship to other autoimmune diseases. This biological framework offers insight into both vitiligo pathogenesis and perhaps avenues towards more effective approaches to treatment and even disease prevention.