Project description:BackgroundAlopecia areata is marked by autoimmune assault on the hair follicle resulting in hair loss. T helper 17 cell subset has important roles in protecting the host against extracellular pathogens, however, also promotes inflammatory pathology in autoimmune disease, and it expresses both interleukin (IL)-17A and IL-17F, which can signal via the IL-17 receptor A.ObjectiveTo investigate the significance of IL17A and IL17RA gene polymorphisms in the susceptibility to alopecia areata.MethodsWe conducted case-control association study of 238 alopecia areata patients and 270 matched healthy controls. Allele frequency of total 2 single nucleotide polymorphims in the IL17A gene and 4 single nucleotide polymorphims in the IL17RA gene were studied. The statistical analyses were performed according to onset age, the presence of familyhistory, clinical subtypes, and presence of nail involvement or body hair involvement.ResultsOne single nucleotide polymorphim (rs879577) of IL17RA gene showed significant difference between alopecia areata patients group and controls group (p= 0.0288). One single nucleotide polymorphim (rs4819554) of IL17RA gene showed significant difference between the early onset and late onset alopecia areata (p=0.0421).ConclusionIL17RA gene polymorphism might contribute to the increased susceptibility to alopecia areata in Korean population, and IL17RA gene polymorphism may be associated with onset age.
Project description:Interleukin 18 (interferon gamma-inducing factor) (IL18) is an important proinflammatory cytokine that belongs to the IL1 family. This study investigated whether IL18 single-nucleotide polymorphisms (SNPs) are associated with the susceptibility to alopecia areata (AA) in a Korean population. Two hundred thirty-three AA patients and 243 healthy control subjects were recruited. One promoter SNP (rs187238, -137G/C) and exonic SNP (rs549908, Ser35Ser) in IL18 were genotyped using direct sequencing. SNPStats, SPSS 18.0, and Haploview version 4.2 programs were used to evaluate genetic data. Multiple logistic regression models were used to determine odds ratios, 95% confidence intervals, and P values. Tested 2 SNPs (rs187238 and rs549908) were associated with the development of AA (rs187238, P=0.002 in a codominant model 1, P=0.0048 in a dominant model, P=0.02 in a log-additive model, P=0.023 in allele distribution; rs549908, P=0.003 in a codominant model 1, P=0.0052 in a dominant model, P=0.016 in a log-additive model, P=0.015 in allele distribution). Our data suggest that the IL18 may be a risk factor for AA susceptibility.
Project description:Alopecia areata (AA) is a skin condition in which hair is lost from certain or all areas of the body. This condition has been described as an immune-mediated complex genetic disease, characterized by the presence of lymphocytes that are directed to the hair follicles in the anagen phase. The gene encoding the protein tyrosine phosphatase, non-receptor type 22 (PTPN22), which is exclusively expressed in immune cells, has been considered as a risk factor associated with a number of autoimmune diseases. In AA, the single nucleotide polymorphism, rs2476601, has been identified as a risk factor in several populations. The aim of the present study was to investigate the effect of PTPN22 C1858T inherited genetic polymorphism on the predisposition to severe forms of AA, in a case-control study on individuals. The study included 64 unrelated patients diagnosed with several types of AA, as well as 225 healthy unrelated subjects. The DNA samples were genotyped for PTPN22 C1858T polymorphism using the polymerase chain reaction-restriction fragment length polymorphism technique. Causal associations were determined by ?2 test and their respective odds ratio (OR) was assessed in a 2×2 contingency table. The results demonstrated a significant association of the T allele [P=0.040; OR=3.196; 95% confidence interval (CI), 0.094-10.279] and the CT genotype (P=0.038; OR=3.313; 95% CI, 1.008-10.892) with patchy AA. In conclusion, the results of the present study suggested the possible involvement of the T allele of the PTPN22 C1858T SNP as a genetic risk factor for this type of AA in the population studied.
Project description:ObjectivesAlopecia areata (AA) is a multifactorial autoimmune disease with a strong genetic predisposition. A variety of genes involved in immunity and inflammatory responses, such as cytokines, are suspected to increase the risk of developing AA. In which, different interleukin (IL) genes that associated with several autoimmune diseases and AA in varied populations. The objective of this study was to investigate the possible genetic association of AA with ten variants of single nucleotide polymorphism (SNP) in IL12B,IL13,IL16,IL17A, and IL18 genes among Jordanian patients.MethodsIn this case-control study, peripheral blood samples of 152 Jordanian AA patients and 150 controls (total of 302 subjects) were collected, genomic DNA extracted and genotyped, based on which their allele and genotype frequencies were assessed.ResultsIn the rs11073001 SNP located in the exon region of the IL16 gene, the A allele was distributed more frequently in AA patients (p =0.01). A difference was found between the patients and the controls for the rs17875491 SNP in the promoter region of the IL16 gene (p =0.04). The mean age of onset was 27.3±12.6 with male predominance. Most patients (68.4%) were asymptomatic but some reported experiencing associated sensations before the hair loss episodes. The patchy patterns of alopecia were the most common (90.3%). Nail changes were found in 7.3% of the patients.ConclusionsThe findings support the hypothesis of the involvement of IL16 gene in the etiology of AA. Moreover, it emphasizes the variations in the genetic component of AA, as well as the clinical phenotypes among different ethnic groups.
Project description:Alopecia areata is an autoimmune disorder characterized by transient, non-scarring hair loss and preservation of the hair follicle. Hair loss can take many forms ranging from loss in well-defined patches to diffuse or total hair loss, which can affect all hair-bearing sites. Patchy alopecia areata affecting the scalp is the most common type. Alopecia areata affects nearly 2% of the general population at some point during their lifetime. Skin biopsies of affected skin show a lymphocytic infiltrate in and around the bulb or the lower part of the hair follicle in the anagen (hair growth) phase. A breakdown of immune privilege of the hair follicle is thought to be an important driver of alopecia areata. Genetic studies in patients and mouse models have shown that alopecia areata is a complex, polygenic disease. Several genetic susceptibility loci were identified to be associated with signalling pathways that are important to hair follicle cycling and development. Alopecia areata is usually diagnosed based on clinical manifestations, but dermoscopy and histopathology can be helpful. Alopecia areata is difficult to manage medically, but recent advances in understanding the molecular mechanisms have revealed new treatments and the possibility of remission in the near future.
Project description:The signalling of cytokine receptors plays a crucial role in regulating tolerance and immunity. Impaired immunological processes result in autoimmune inflammation that target the hair follicles, causing many hair disorders, mainly alopecia areata (AA). Therefore, polymorphisms in cytokine receptor genes are suggested to have a significant impact on the pathogenesis of AA, a disease with a multifactorial basis and uncertain etiology. In the present study, 152 AA patients of the Jordanian population were investigated for their genetic susceptibility to develop AA compared to 150 control subjects. Genomic DNA extraction and genotyping had conducted for IL17RA (rs879575, rs2229151, and rs4819554), IL2RA (rs3118470), IL23R (rs10889677), and IL31RA (rs161704) using the Sequenom MassARRAY® system. The allele frequency of IL17RA rs879575 is significantly higher in patients, while no statistical differences were found for IL2RA, IL23R, and IL31RA SNPs. Also, the recessive model of IL31RA rs161704 showing that AA genotype is significantly associated with AA development. To date, there is no published data regarding the association between AA and the selected genetic variants in our population. However, this study's findings assert that SNPs of IL17RA and IL31RA are linked to AA susceptibility in Jordanian patients.
Project description:ImportanceAlopecia areata (AA) is an autoimmune disease characterized by hair loss that can impose a substantial psychological burden on patients, including major depressive disorder (MDD), yet many patients report mental health symptoms prior to the onset of AA. As such, there may be an association between MDD and AA that acts in both directions.ObjectiveTo assess the bidirectional association between MDD and AA.Design, setting, and participantsThis population-based retrospective cohort study included patients 10 to 90 years of age registered with The Health Improvement Network in general practices in the United Kingdom between January 1, 1986, and May 16, 2012. Statistical analysis was conducted from August 17, 2017, to April 23, 2018. To assess the risk of AA, the following 2 cohorts were defined: patients with an incident diagnosis of MDD (exposure) and a reference general population cohort. To assess the risk of MDD, the following 2 cohorts were defined: patients with an incident diagnosis of AA (exposure) and a reference general population cohort. Person-time was partitioned into unexposed and exposed time in the exposure cohorts.Main outcomes and measuresIn the analysis of the risk of AA, development of incident AA during follow-up was considered the main outcome measure. In the analysis of the risk of MDD, development of incident MDD during follow-up was considered the primary outcome measure.ResultsIn the analysis of the risk of AA, 405 339 patients who developed MDD (263 916 women and 141 423 men; median age, 36.7 years [interquartile range, 26.6-50.5 years]) and 5 738 596 patients who did not develop MDD (2 912 201 women and 2 826 395 men; median age, 35.8 years [interquartile range, 25.3-52.6 years]) were followed up for 26 years. After adjustment for covariates, MDD was found to increase the risk of subsequently developing AA by 90% (hazard ratio, 1.90; 95% CI, 1.67-2.15; P < .001). Antidepressants demonstrated a protective effect on the risk of AA (hazard ratio, 0.57; 95% CI, 0.53-0.62; P < .001). In the analysis of the risk of MDD, 6861 patients who developed AA (3846 women and 3015 men; median age, 31.5 years [interquartile range, 18.2 years]) and 6 137 342 patients who did not develop AA (3 172 371 women and 2 964 971 men; median age, 35.9 years [interquartile range, 27.0 years]) were followed up for 26 years. After adjustment for covariates, AA was found to increase the risk of subsequently developing MDD by 34% (hazard ratio, 1.34; 95% CI, 1.23-1.46; P < .001).Conclusions and relevanceThese temporal analyses suggest that, while patients with AA are at risk for subsequently developing MDD, having MDD also appears to be a significant risk factor for development of AA, with antidepressant use confounding this risk.
Project description:Purpose: Epidermal growth factor (EGF) has been found to be associated with the development and repair mechanisms of several renal diseases. In this study, we hypothesized that single nucleotide polymorphisms (SNPs) in EGF or its receptor genes might have an association with end-stage renal disease (ESRD) or acute renal allograft rejection (AR) in a Korean population.Methods: Three-hundred and forty seven recipients of the first renal transplants for ESRD, including 63 AR patients along with 289 healthy adults were included in the study. Five EGF gene SNPs (rs11568835, rs11568943, rs2237051, rs11569017, and rs3756261) and four EGFR gene SNPs (rs1140475, rs2293347, rs1050171, and rs6965469) were analyzed. The genotypes of these SNPs were analyzed using the AxiomTM genome-wide human assay. Statistical analysis was performed using SNPStats and Haploview version 4.2 software. Multiple logistic regression models (codominant, dominant, recessive, and Log-additive) were used to estimate the odds ratio (OR), 95% confidence interval (CI), and P value.Results: One SNP (rs11569017) in the EGF gene showed significant association with ESRD but not with AR. Another SNP (rs11568835) in the EGF gene showed significant association with susceptibility to AR but not with ESRD. One SNP (rs1050171) in the EGFR gene showed significant association with susceptibility to AR but not with ESRD.Conclusion: Our findings suggest that SNPs in the EGF and EGFR gene may be associated with the risk of ESRD and AR development in the Korean population.
Project description:ImportanceAlopecia areata is associated with diverse systemic and psychiatric diseases. However, whether all-cause and cause-specific mortality in patients with alopecia areata differs from that of the general population remains unclear.ObjectiveTo investigate all-cause and cause-specific mortality risk in patients with alopecia areata.Design, setting, and participantsUsing the National Health Insurance Service database and National Death Registry of Korea, a retrospective cohort study of participants identified in 2006, with investigation of mortality until 2016, was carried out. Patients with alopecia areata with at least 3 documented visits to a dermatologist with an International Statistical Classification of Diseases (tenth revision) code of L63 during 2002 to 2006 were included. For comparison, 1:10 age- and sex-matched controls without documented visits with a code of L63 until 2016 were included.ExposuresPatients with alopecia areata and controls without alopecia areata.Main outcomes and measuresThe study population was followed from January 1, 2007, for a period of 10 years to estimate all- and cause-specific mortality.ResultsThe study comprised 73 107 patients with alopecia areata and 731 070 age- and sex-matched controls. Of these, 6023 were patients with alopecia totalis/universalis. No differences in all-cause mortality risk between the cohorts were found (HR, 0.97; 95% CI, 0.87-1.09). However, mortality associated with intentional self-harm/psychiatric diseases was greater in patients than in participants in the control group (HR, 1.21; 95% CI, 1.04-1.41). Adult patients aged 35 years or younger (HR, 1.68; 95% CI, 1.32-2.12) and those with alopecia totalis/universalis (HR, 1.85; 95% CI, 1.25-2.75) were particularly affected. Mortality associated with lung cancer was greater in patients with alopecia totalis/universalis (HR, 2.16; 95% CI, 1.41-3.33). However, mortality associated with diabetes mellitus was significantly lower in patients with alopecia areata (HR, 0.53; 95% CI, 0.36-0.79).Conclusions and relevancePatients with alopecia areata have a higher risk of mortality associated with self-harm, psychiatric diseases, and smoking-associated malignant diseases including lung cancer. For better outcomes, clinicians should appropriately treat patients to ensure emotional and psychological well-being.
Project description:BackgroundMany patients with asthma experience alopecia areata (AA) in their lives. However, it is unclear whether asthma causes or results from AA. Our objective was to investigate the genetic causal relationship between asthma and AA.MethodsTwo-sample Mendelian randomization (MR) was used to assess the causal relationship between asthma and AA based on the largest publicly available genome-wide association study summary statistics. Androgenetic alopecia (AGA) and cicatricial alopecia (CA) were chosen as the control groups for AA. The main estimates were obtained using inverse variance weighting meta-analysis (IVW), Mendelian randomization-Egger (MR-Egger), maximum likelihood estimation, and the weighted median. Sensitivity analyses were conducted using Cochran's Q test, MR-Egger, and leave-one-out methods. Lastly, we conducted a reverse MR analysis to evaluate the possibility of reverse causation.ResultsGenetically, asthma is associated with an increased risk of AA, while the association between genetically predicted AGA or CA and asthma was negative. The risk of AA increased by 1.86 times in patients with asthma under the IVW method (OR = 1.86, 95% CI = 1.31-2.629, p < 0.001). The reverse MR analysis did not find evidence supporting reverse causality from three phenotypes of alopecia to asthma. Sensitivity analyses yielded consistent causal estimates.ConclusionThis study suggests that asthma is causally associated with AA. The findings deepen our understanding of the role of asthma in the pathology of AA, which emphasizes the potential for opening a new vista for the prevention and diagnosis of AA.