The association between Interleukin (IL)-4 gene intron 3 VNTR polymorphism and alopecia areata (AA) in Turkish population

Type-2 immunity associated with type-1 related skin inflammatory diseases: friend or foe?

Chronic inflammatory skin diseases are multifactorial diseases that combine genetic predisposition, environmental triggers, and metabolic disturbances associated with abnormal immune responses. From an immunological perspective, the better understanding of their physiopathology has demonstrated a large complex network of immune cell subsets and related cytokines that interact with both epidermal and dermal cells. For example, in type-1-associated diseases such as alopecia areata, vitiligo, and localized scleroderma, recent evidence suggests the presence of a type-2 inflammation that is well known in atopic dermatitis. Whether this type-2 immune response has a protective or detrimental impact on the development and chronicity of these diseases remains to be fully elucidated, highlighting the need to better understand its involvement for the management of patients. This mini-review explores recent insights regarding the potential role of type-2-related immunity in alopecia areata, vitiligo, and localized scleroderma.

Inheritance-Specific Dysregulation of Th1- and Th17-Associated Cytokines in Alopecia Areata

Autoimmune diseases tend to cluster in families, suggesting genetic predisposition to autoimmunity associated with familial background. We have previously reported similarities in gene expression patterns and PTPN22 polymorphisms between alopecia areata (AA) patients and their healthy relatives, but not unrelated healthy controls. However, the spectrum of disease promoting (or preventing) pathways that may be activated in blood relatives of AA patients remains to be defined. Here, we investigated the extent to which cytokines associated with the Th1 and Th17 pathway are differentially expressed in the blood of patients with AA and its clinical subtypes in comparison to both healthy relatives as well as unrelated healthy controls. A comprehensive set of Th1- and Th17-related cytokines were evaluated by ELISA. We found a significant elevation of the Th17 inducer IL-23, the Th17 product IL-17A, the Th1 hallmark cytokine IFNγ, and TNFα, a Th1 cytokine with relevance to the Th17 pathway in AA patients, regardless of disease subtype, compared to healthy individuals. On further examination, we found that healthy family members grouped together with patients in terms of elevated Th1- and Th17-pathway cytokines in an inheritance-specific manner, distinct from unrelated controls. The elevation of Th17-associated cytokines in healthy controls related to AA patients indicates that Th1 and Th17 dysregulation in AA may be genetically based. Of note, one unrelated control displayed elevated levels of IL-17A and IL-23 similar to those detected in patients. One year after initial blood draw, areas of beard hair loss consistent with the diagnosis of AA were reported by this individual, indicating that the elevation in Th17-related cytokines may have predictive value.

Interleukin-1 receptor antagonist (IL-1RA) and interleukin-4 (IL-4) variable number of tandem repeat polymorphisms in schizophrenia and bipolar disorder: an association study in Turkish population

Background

Pro-inflammatory/anti-inflammatory cytokine imbalance in cerebrospinal fluid or plasma of schizophrenia (SCZ) and bipolar disorder (BD) patients has been documented over the last decade. We aim to examine the interleukin-1 receptor antagonist (IL-1RA) and IL-4 variable number of tandem repeat (VNTR) polymorphisms in SCZ and BD patients by comparing them with healthy controls.

Methods

Two hundred and thirty-four unrelated patients (127 patients with SCZ, 107 patients with BD) and 204 healthy controls were included. The Structured Clinical Interview for DSM-IV Axis I Disorders was used to confirm the diagnosis. In addition, the polymerase chain reaction technique was used to investigate IL-1RA and IL-4 VNTR polymorphisms.

Results

Our results showed that the distributions of IL-1RA and IL-4 genotype and the allele frequencies of SCZ or BD patients were not significantly different from the healthy control group. IL-1RA allele 2 homozygous genotype and IL-1RA allele 2 frequencies were non-significantly higher among SCZ patients than in controls.

Conclusions

Our study indicates that the IL-1RA and IL-4 VNTR polymorphisms are not considered risk factors for developing SCZ and BD among Turkish patients.

Genetic Variations and mRNA Expression of Goat DNAH1 and Their Associations with Litter Size

Dynein Axonemal Heavy Chain 1 (DNAH1) encodes proteins which provide structural support for the physiological function and motor structure of spermatozoa (hereafter referred to as sperm) and ova. This study found that three single nucleotide polymorphisms (SNPs), the 27-bp insertion/deletion (InDel) mutations and three exonic copy number variations (CNVs) within DNAH1 were significantly associated with litter size of Shaanbei white cashmere goats (n = 1101). Goats with the wildtypes of these three SNPs had higher litter sizes than other carriers (p < 0.05). II genotype of the 27-bp InDel had the highest litter size compared with ID carriers (p = 0.000022). The gain genotype had the largest litter sizes compared with the loss or medium carriers for the three CNV mutations (p < 0.01). Individuals with the AA-TT-CC-II-M1-M2-M3 and AA-TT-CC-II-G1-G2-M3 combination genotypes had larger litter sizes compared with the other genotypes. This study also showed the DNAH1 expression in mothers of multiple kids was higher than mothers of single kids. These three SNPs, the 27-bp InDel and three CNVs in DNAH1 could be used as molecular markers for the selection of goat reproductive traits.

The current state of knowledge of the immune ecosystem in alopecia areata

Alopecia areata (AA) is an autoimmune disease that affects approximately 2% of the general population. Patients with AA most commonly present with one or more patches of hair loss on the scalp in defined circular areas. A fraction of patients progress to more severe forms of the disease, in some cases with involvement of all body surfaces. The healthy anagen stage hair follicle is considered an immune privileged site, described as an environment that suppresses inflammatory immune responses. However, in AA, this immune privileged state collapses and marks the hair follicle as a target for the immune system, resulting in peri- and intrafollicular infiltration by lymphocytes. The complexity of the inflammatory ecosystem of the immune response to the hair follicle, and the relationships between the cellular and soluble participants, in AA remains incompletely understood. Many studies have demonstrated the presence of various immune cells around diseased hair follicles; however, often little is known about their respective contributions to AA pathogenesis. Furthering our understanding of the mechanisms of disease in AA is essential for the novel identification of targeted therapeutics that are efficacious and have few unintended effects.

Alopecia areata: Current understanding of the pathophysiology and update on therapeutic approaches, featuring the Japanese Dermatological Association guidelines

Alopecia areata (AA) is a relatively common nonscarring hairloss disease characterized by an autoimmune response to anagen hair follicles (HFs). Accumulated evidence suggests that collapse of the HF immune privilege subsequent to triggering events, represented by viral infection, leads to autoimmune response in which autoreactive cytotoxic CD8+NKG2D+ T cells mainly target exposed HF autoantigens. AA had been recognized as type 1 inflammatory disease, but recent investigations have suggested some roles of type 2- and Th17-associated mediators in AA pathogenesis. The significance of psychological stress in AA pathogenesis is less emphasized nowadays, but psychological comorbidities, such as depression and anxiety, attract greater interest in AA management. In this regard, the disease severity may not solely be evaluated by the extent of hair loss. Use of trichoscopy markedly improved the resolution of the diagnosis and evaluation of the phase of AA, which is indispensable for the optimization of treatment. For the standardization of AA management, the establishment of guidelines/expert consensus is pivotal. Indeed, the Japanese Dermatological Association (JDA) and other societies and expert groups have published guidelines/expert consensus reports, which mostly recommend intralesional/topical corticosteroid administration and contact immunotherapy as first-line treatments, depending on the age, disease severity, and activity of AA. The uniqueness of the JDA guidelines can be found in their descriptions of intravenous corticosteroid pulse therapy, antihistamines, and other miscellaneous domestically conducted treatments. Considering the relatively high incidence of spontaneous regression in mild AA and its intractability in severe subsets, the importance of course observation is also noted. Evidenced-based medicine for AA is currently limited, however, novel therapeutic approaches, represented by JAK inhibitors, are on their way for clinical application. In this review, the latest understanding of the etiopathogenesis and pathophysiology, and update on therapeutic approaches with future perspectives are summarized for AA, following the current version of the JDA AA management guidelines.

Evaluation of the level of serum Interleukins (IL-2, IL-4, IL-15 andIL-17) and its relationship with disease severity in patients with alopecia areata

Background

Alopecia areata (AA) is a hair disease that causes hair loss without scarring. The etiopathogenesis of AA has not been fully understood yet.

Objective

To determine serum interleukin levels (IL-2, IL-4, IL-15, and IL-17) in patients diagnosed with alopecia areata and to investigate the relationship of IL levels with the duration and severity of alopecia areata and the response to tofacitinib therapy.

Methods

Patients (≥16 years old) diagnosed with alopecia areata and healthy individuals as a control group was enrolled. Baseline serum interleukin levels of the patients and controls were measured. In the patient group receiving tofacitinib therapy, serum interleukin levels were measured again after 6 months. Disease severity for alopecia areata was assessed using the Severity of Alopecia Tool.

Results

Sixty-one AA patients and 30 healthy individuals were included; they were comparable regarding age and sex. The mean disease duration for AA was 7 ± 6 years and the baseline mean Severity of Alopecia Tool score was 71 ± 30 (range, 20–100). Baseline IL-2, IL-4 and IL-15 levels were significantly higher in the patient group than those in the control group (p < 0.001 for each). No significant correlation was found between the baseline interleukin levels and either disease duration or disease severity (baseline Severity of Alopecia Tool score). Among the patients receiving tofacitinib (n = 22), all interleukin levels significantly decreased after treatment. However, no significant relationship between the change in interleukin levels and the change in the Severity of Alopecia Tool scores was observed after tofacitinib treatment.

Study limitations

This is a monocentric study conducted in a single university hospital.

Conclusion

High interleukin levels in alopecia areata patients and the significant decrease with treatment support the idea that interleukins have a role in pathogenesis. Nevertheless, no relationship could be demonstrated between IL levels and disease duration or severity.

The Association between Alopecia and Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis

IMPORTANCE

The link between autoimmune gut disorders and different types of hair loss conditions has been recently investigated with an increased interest. With acknowledgement of the connection between immune dysregulation and the gut microbiome, this pathway is now becoming recognized as playing an important role in hair growth. The inflammatory cascade that results from the disruption of gut integrity such as seen in inflammatory bowel diseases (IBD) has been associated with certain types of alopecia.

OBJECTIVE

The aim of this work was to evaluate the association between alopecia and IBD.

EVIDENCE REVIEW

A primary literature search was conducted using the PubMed, Embase, and Web of Science databases to identify articles on co-occurring alopecia and IBD from 1967 to 2020. A total of 79 studies were included in the review. A one-way proportional meta-analysis was performed on 19 of the studies to generate the pooled prevalence of alopecia and IBD.

FINDING

The pooled prevalence of non-scarring alopecia among IBD patients was 1.12% (k = 7, I2 = 98.6%, 95% CI 3.1-39.9); the prevalence of IBD among scarring and non-scarring alopecia was 1.99% (k = 12; I2 = 99%, 95% CI 6.2-34). The prevalence of non-scarring alopecia areata (AA) among IBD was compared to the prevalence of AA in the general population (0.63 vs. 0.1%; p < 0.0001). Similarly, the prevalence of IBD among the scarring and non-scarring alopecia groups was compared to the prevalence of IBD in the general population (1.99 vs. 0.396%; p = 0.0004).

CONCLUSION

IBD and alopecia, particularly AA, appear to be strongly associated. Dermatology patients with alopecia may benefit from screening for IBD.

Alopecia Areata Is Associated with Atopic Diathesis: Results from a Population-Based Study of 51,561 Patients

BACKGROUND

Evidence of T_H1/IFN-γ overactivation as a major pathogenic driver somewhat conflicts with data supporting robust allergic background in patients with alopecia areata (AA). Previous investigations of immunological dysregulations show that both T_H1- and T_H2-related markers are overexpressed in AA. Clinical correlations in large populations may shed light on the immune pathways most likely to result in the clinical phenotype of AA.

OBJECTIVE

To investigate the atopic comorbidities among patients with AA in a large population-based study.

METHODS

This is a cross-sectional retrospective study of patients with AA and a matched comparison group, analyzing the associations between AA and 4 atopic comorbidities: asthma, atopic dermatitis (AD), allergic rhinitis, and allergic conjunctivitis. χ² and t tests were used for univariate analysis, and logistic regression model was used for multivariate analysis. The study was performed using the computerized database of the Clalit Health Services, encompassing more than 4.4 million subjects.

RESULTS

The study population included 51,561 patients with AA and 51,410 matched control subjects. The prevalence of asthma (7.8% vs 6.5%; odds ratio [OR], 1.22; 95% CI, 1.17-1.28; P < .001), AD (3.9% vs 2.6%; OR, 1.55; 95% CI, 1.44-1.66; P < .001), allergic rhinitis (16.0% vs 12.8%; OR, 1.29; 95% CI, 1.25-1.34; P < .001), and allergic conjunctivitis (23.5% vs 19.6%; OR, 1.27; 95% CI, 1.23-1.30; P < .001) was significantly higher among patients with AA as compared with matched control subjects. Patients with AA also had a significantly higher probability of having more than 1 atopic comorbidity, with increasing OR as the number of concomitant atopic conditions increased.

CONCLUSIONS

Our analysis supports the previous literature and provides strong generalizability of significant atopy in patients with AA, suggesting T_H2 pathogenicity in AA, and challenging the traditional view of AA as a single-axis, T_H1-centered disease.

IL-1RN VNTR, IL-2(-330), and IL-4 VNTR gene polymorphisms in patients with chronic rhinosinusitis with sinonasal polyposis

Background/aim

Sinonasal polyposis is a complex chronic disease displaying contributions from multiple genetic and environmental factors. In this study, we analyzed possible genetic factors that increase susceptibility to this widespread inflammatory disease.

Materials and methods

A total of 176 adult patients, including 78 patients with sinonasal polyposis and 98 healthy controls, were analyzed for IL-1RN VNTR, IL-2(-330), and IL-4 VNTR gene polymorphisms using polymerase chain reaction and enzyme restriction.

Results

IL-1RN and IL-4 VNTR polymorphisms were notably associated with sinonasal polyposis (P = 0.0001 and P = 0.036, respectively); however, regarding the IL-2(-330) gene polymorphism, no significant difference was shown between the patient and control groups (P = 0.235).

Conclusions

Our study indicates that the RN2 allele of IL-1RN and the RP1 allele of IL-4 might be risk factors for developing sinonasal polyposis.

Alopecia areata: a review of disease pathogenesis

BACKGROUND

Alopecia areata is a disorder that results in nonscarring hair loss. The psychological impact can be significant, leading to feelings of depression and social isolation. Objectives In this article, we seek to review the pathophysiological mechanisms proposed in recent years in a narrative fashion.

METHODS

We searched MEDLINE and Scopus for articles related to alopecia areata, with a particular emphasis on its pathogenesis.

RESULTS

The main theory of alopecia areata pathogenesis is that it is an autoimmune phenomenon resulting from a disruption in hair follicle immune privilege. What causes this breakdown is an issue of debate. Some believe that a stressed hair follicle environment triggers antigen presentation, while others blame a dysregulation in the central immune system entangling the follicles. Evidence for the latter theory is provided by animal studies, as well investigations around the AIRE gene. Different immune-cell lines including plasmacytoid dendritic cells, natural killer cells and T cells, along with key molecules such as interferon-γ, interleukin-15, MICA and NKG2D, have been identified as contributing to the autoimmune process.

CONCLUSIONS

Alopecia areata remains incurable, although it has been studied for years. Available treatment options at best are beneficial for milder cases, and the rate of relapse is high. Understanding the exact mechanisms of hair loss in alopecia areata is therefore of utmost importance to help identify potential therapeutic targets.

Serum IL 4 and its gene polymorphism (rs79071878) in Egyptian children with familial Mediterranean fever

Familial Mediterranean fever (FMF) is an autoinflammatory disorder. It is caused by mutations in the MEFV gene encoding the pyrin protein, which regulates the innate inflammatory response. The aim of the current study was to investigate the relationship between serum Interleukin-4 (IL-4) and its gene polymorphism, namely rs79071878, and FMF occurrence, severity, and response to treatment in Egyptian children harboring the disease. Fifty Egyptian children diagnosed as having FMF were included in this study. They were divided equally into two groups according to disease activity. Forty controls, age- and gender-matched, were also included. Serum IL-4 levels were measured by enzyme-linked immunosorbent assay (ELISA). The IL-4 rs79071878 polymorphism was determined by polymerase chain reaction (PCR) analysis. There was no significant difference in genotype distribution of IL-4 gene rs79071878 between patients and controls (p = 0.286) and had no correlation with FMF severity or response to colchicine therapy. Serum IL-4 level had no significant difference between children with FMF attack and those in attack-free period compared to controls (p = 0. 794) and had no correlation with any of demographic, or clinical characteristics, disease severity, or response to colchicine therapy. Serum IL-4 level and its gene polymorphism were not found to have any increase risk of FMF occurrence, disease severity, or response to treatment in the Egyptian children. Further studies are needed to verify these results.

Cancer risk by the subtype of alopecia

The cancer risk in patients with alopecia areata (AA) or alopecia totalis (AT)/alopecia universalis (AU) remains unknown. In this study, national statistical data were used to study the association between these forms of alopecia and the risk of cancer. We enrolled 668,604 patients who were treated for alopecia from 2007 to 2014, and age- and sex-matched control subjects. AA and AT/AU patients had slightly higher overall cancer risks (hazard ratio (HR), 1.043; 95% confidence interval (CI), 1.022-1.065 and HR, 1.07; 95% CI, 1.013-1.129, respectively) than controls, after adjusting for confounding factors. The risks of oral cavity, esophagus, liver, biliary tract, pancreas, larynx, lung, kidney, breast, cervix, ovary, uterus, testis, nerve, and skin cancers; and lymphoma, multiple myeloma, and leukemia, were not increased in alopecia patients. In AA or AT/AU patients, the only increased risk was that of thyroid cancer. In AA patients alone, the risks of bladder and prostate cancers were increased. Thus, the cancer risks varied by the alopecia subtype. Careful monitoring is needed to explore if the actual risks of thyroid, bladder, and prostate cancers are increased in alopecia patients.

Genetic analysis of interleukin 18 gene polymorphisms in alopecia areata

BACKGROUND

Alopecia areata (AA), which appears as nonscarring hair shedding on any hair-bearing area, is a common organ-specific autoimmune condition. Cytokines have important roles in the development of AA. Interleukin (IL) 18 is a significant proinflammatory cytokine that was found higher in the patients with AA. We aimed to investigate whether the IL-18 (rs187238 and rs1946518) single nucleotide polymorphisms (SNPs) may be associated with AA and/or clinical outcome of patients with AA in Turkish population.

METHODS

Genotyping of rs187238 and rs1946518 SNPs were detected using sequence-specific primer-polymerase chain reaction (SSP-PCR) method in 200 patients with AA and 200 control subjects.

RESULTS

The genotype distribution of rs1946518 (-607C>A) SNP was found to be statistically significantly different among patients with AA and controls (P = .0008). Distribution of CC+CA genotypes and frequency of -607/allele C of rs1946518 SNP were higher in patients with AA (P = .001, P = .001, respectively). The genotype distribution of rs187238 (-137G>C) SNP was found to be statistically significantly different among patients with AA and control subjects (P = .0014). Distribution of GG genotype and frequency of -137/allele G of rs187238 SNP were higher in patients with AA (P = .0003, P = .001, respectively).

CONCLUSION

The rs1946518 (-607C>A) and rs187238 (-137G>C) polymorphisms were found associated with alopecia areata disease. The study suggests that IL-18 rs187238 and rs1946518 SNPs may be the cause of the AA susceptibility.

Cytokine Targeted Therapeutics for Alopecia Areata: Lessons from Atopic Dermatitis and Other Inflammatory Skin Diseases

Alopecia areata is a T-cell-mediated disease that shares phenotypic similarities with other inflammatory diseases, particularly atopic dermatitis, and lacks safe, effective, mechanism-specific treatments. Increasing data suggests that alopecia areata harbors contributions of T helper type 1, T helper type 2, T helper type 17/IL-23, and phosphodiesterase pathways. Antagonism of these axes is undergoing evaluation, and might elucidate the underlying molecular circuitry of alopecia areata, advancing the translational revolution for this disease.

The Changing Landscape of Alopecia Areata: The Therapeutic Paradigm

Alopecia areata (AA), a prevalent inflammatory cause of hair loss, lacks FDA-approved therapeutics for extensive cases, which are associated with very poor rates of spontaneous hair regrowth and major psychological distress. Current treatments for severe cases include broad immune-suppressants, which are associated with significant adverse effects, precluding long-term use, with rapid hair loss following treatment termination. As a result of the extent of the disease in severe cases, topical contact sensitizers and intralesional treatments are of limited use. The pathogenesis of AA is not yet fully understood, but recent investigations of the immune activation in AA skin reveal Th1/IFN-γ, as well as Th2, PDE4, IL-23, and IL-9 upregulations. Tissue analyses of both animal models and human lesions following broad-acting and cytokine-specific therapeutics (such as JAK inhibitors and ustekinumab, respectively) provide another opportunity for important insights into the pathogenesis of AA. As reviewed in this paper, numerous novel therapeutics are undergoing clinical trials for AA, emphasizing the potential transformation of the clinical practice of AA, which is currently lacking. Dermatologists are already familiar with the revolution in disease management of psoriasis, stemming from better understanding of immune dysregulations, and atopic dermatitis will soon follow a similar path. In light of these recent developments, the therapeutic arena of AA treatments is finally getting more exciting. AA will join the lengthening list of dermatologic diseases with mechanism-targeted drugs, thus changing the face of AA.

Interleukin-4 -590 T>C and interleukin-4 receptor Q551R A>G gene polymorphisms in Saudi cases with alopecia areata

OBJECTIVES

Immunogenetic factors are known to play a role in the pathogenesis of alopecia areata (AA). This study aimed at investigating the association between AA with the polymorphisms of interleukin-4 (IL-4) promoter and receptor (IL-4R) genes.

PATIENTS AND METHODS

This work is a case-control study that was conducted on 76 AA patients from Qassim region, Saudi Arabia. Patients were compared with 93 normal healthy controls from the same locality. Genomic DNA was extracted and processed using real-time PCR amplification for characterization of IL-4 -590 T>C and IL-4R Q551R A>G gene polymorphisms.

RESULTS

Cases of AA showed a higher frequency of the IL-4 -590 CC homozygous genotype compared with controls (63.2 vs. 53.8%, P>0.05) with a lower frequency of the TT genotype (5.3 vs. 10.8%); yet, both were statistically nonsignificant (P>0.05). Regarding the IL-4R Q551R A>G polymorphism, cases and controls showed nearly equal frequencies of all variants, that is, with no significant difference. Although the frequency of the IL-4 C and the IL-4R A alleles was higher among cases than among controls (78.9 vs. 71.5% and 78.8 vs. 72.6%, respectively), this was also statistically nonsignificant (P>0.05). Comparing case subgroups in terms of their age of onset, sex, disease severity, consanguinity, and family history showed no statistically significant difference regarding the studied genetic variant.

CONCLUSION

IL-4 -590 and IL-4R Q551R gene polymorphisms are not associated with the susceptibility and the clinical pattern of AA in Saudi patients. We recommend further research studies involving the estimation of cytokines both in the serum and in the local skin lesions or in cultured skin cells to figure out whether Th1 or Th2 pathways play a specific role in the pathogenesis of AA.

Biomarkers of alopecia areata disease activity and response to corticosteroid treatment

Alopecia areata (AA) is a common inflammatory disease targeting the anagen-stage hair follicle. Different cytokines have been implicated in the disease profile, but their pathogenic role is not yet fully determined. We studied biopsies of pretreatment lesional and non-lesional (NL) scalp and post-treatment (intra-lesional steroid injection) lesional scalp of 6 patchy patients with AA using immunohistochemistry and gene expression analysis. Immunohistochemistry showed increases in CD3(+) , CD8(+) T cells, CD11c(+) dendritic cells and CD1a(+) Langerhans cells within and around hair follicles of pretreatment lesional scalp, which decreased upon treatment. qRT-PCR showed in pretreatment lesional scalp (compared to NL) significant increases (P < 0.05) in expression of inflammatory markers (IL-2, IL-2RA, JAK3, IL-15), Th1 (CXCL10 and CXCL9), Th2 (IL-13, CCL17 and CCL18), IL-12/IL-23p40 and IL-32. Among these, we observed significant downregulation with treatment in IL-12/IL-23p40, CCL18 and IL-32. We also observed significant downregulation of several hair keratins in lesional scalp, with significant upregulation of KRT35, KRT75 and KRT86 in post-treatment lesional scalp. This study shows concurrent activation of Th1 and Th2 immune axes as well as IL-23 and IL-32 cytokine pathways in lesional AA scalp and defined a series of response biomarkers to corticosteroid injection. Clinical trials with selective antagonists coupled with cytokine-pathway biomarkers will be necessary to further dissect pathogenic immunity.

Association between PTPN22 C1858T polymorphism and alopecia areata risk

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 χ² 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.

Alopecia areata profiling shows TH1, TH2, and IL-23 cytokine activation without parallel TH17/TH22 skewing

BACKGROUND

Alopecia areata (AA) is a common T cell-mediated disorder with limited therapeutics. A molecular profile of cytokine pathways in AA tissues is lacking. Although studies have focused on TH1/IFN-γ responses, several observations support a shared genetic background between AA and atopy.

OBJECTIVE

We sought to define the AA scalp transcriptome and associated biomarkers with comparisons with atopic dermatitis (AD) and psoriasis.

METHODS

We performed microarray and RT-PCR profiling of 27 lesional and 17 nonlesional scalp samples from patients with AA for comparison with normal scalp samples (n = 6). AA gene expression was also compared with samples from patients with lesional or nonlesional AD and those with psoriasis. A fold change of greater than 1.5 and a false discovery rate of less than 0.05 were used for differentially expressed genes (DEGs).

RESULTS

We established the AA transcriptomes (lesional vs nonlesional: 734 DEGs [297 upregulated and 437 downregulated]; lesional vs normal: 4230 DEGs [1980 upregulated and 2250 downregulated]), including many upregulated immune and downregulated hair keratin genes. Equally impressive as upregulation in TH1/interferon markers (IFNG and CXCL10/CXCL9) were those noted in TH2 (IL13, CCL18, CCL26, thymic stromal lymphopoietin, and periostin), TH9/IL-9, IL-23 (p40 and p19), and IL-16 mediators (all P < .05). There were no increases in TH17/TH22 markers. Hair keratin (KRT) expressions (ie, KRT86 and KRT85) were significantly suppressed in lesional skin. Greater scalp involvement (>25%) was associated with greater immune and keratin dysregulation and larger abnormalities in nonlesional scalp samples (ie, CXCL10 and KRT85).

CONCLUSIONS

Our data associate the AA signature with TH2, TH1, IL-23, and IL-9/TH9 cytokine activation, suggesting consideration of anti-TH2, anti-TH1, and anti-IL-23 targeting strategies. Similar to psoriasis and AD, clinical trials with selective antagonists are required to dissect key pathogenic pathways.