A preliminary study of new single polymorphisms in the T helper type 17 pathway for psoriasis in the Korean population

Association of IL-17F rs763780 polymorphism and risk of psoriasis in Turkish population: a case-control study

BACKGROUND

Psoriasis represents a chronic inflammatory phenotype shaped by genetic interactions, characterized by keratinocyte hyperproliferation and commonly affecting the skin and joints. Experimental and clinical studies suggest that the IL-17F gene locus plays a role as a central cytokine in the immunopathogenesis of psoriasis.

OBJECTIVES

Based on the central role of IL-17F in the pathogenesis of psoriasis, the authors thought that variations in this gene could affect the susceptibility and severity of this disease. Therefore, in this study, the authors aimed to analyze whether the IL-17F rs763780 variant has an effect on psoriasis pathogenesis in the Turkish population.

METHOD

In this case-control study, the study group consisted of 603 people (201 psoriasis patients (73 males/128 females)/402 controls (146 males/256 females) were genotyped in terms of IL-17F rs763780 polymorphism with TaqMan 5' Allelic Discrimination Test.

RESULTS

The genotype distributions of the IL-17F rs763780 polymorphism between patients and control groups were statistically different, and the TC (heterozygous genotype) and CC (homozygous mutant genotype) genotypes were more represented in the patients group than in the control group (24.9% vs. 10.2%; 2.0% vs. 0.2%, respectively). In addition, the variant C allele was higher in the patients group and this was statistically significant (p < 0.001), and the C allele carriage was associated with a 3.14-fold increased risk of psoriasis (95% CI 2.015‒24.921).

STUDY LIMITATIONS

The present study has some limitations. The first limitation is the relatively small sample size. The second limitation is that the authors could not measure IL-17F expression levels. However, the present study data draw attention to the importance of IL-17F which deserves to be studied in a larger sample group.

CONCLUSION

We report that IL-17F rs763780 TC and CC genotype and C allele are associated with an increased risk of psoriasis in the Turkish population.

Associations of A20, CYLD, Cezanne and JAK2 Genes and Immunophenotype with Psoriasis Susceptibility

Background and Objectives: Psoriasis is an immune-mediated chronic inflammatory skin disorder and commonly associated with highly noticeable erythematous, thickened and scaly plaques. Deubiquitinase genes, such as tumor necrosis factor-alpha protein 3 (TNFAIP3, A20), the cylindromatosis (CYLD) and Cezanne, function as negative regulators of inflammatory response through the Janus kinase/signal transducers and activators of transcription (JAK-STAT) pathways. In this study, polymorphisms and expressions of A20, CYLD and Cezanne genes as well as immunophenotype in psoriatic patients were determined. Materials and Methods: In total, 82 patients with psoriasis and 147 healthy individuals with well-characterized clinical profiles were enrolled. Gene polymorphisms were determined by direct DNA sequencing, gene expression profile by quantitative real time-polymerase chain reaction (PCR), immunophenotype by flow cytometry, and the secretion of cytokines and cancer antigen (CA) 125 by enzyme-linked Immunosorbent assay (ELISA). Results: The inactivation of A20, CYLD and Cezanne and increased levels of TNF-α, IFN-γ and CA 125 was observed in psoriatic patients. Importantly, patients with low A20 expression had significant elevations of triglyceride and total cholesterol concentrations and higher numbers of CD13+CD117- and CD19+CD23+ (activated B) cells than those with high A20 expression. Genetic analysis indicated that all rs4495487 SNPs in the JAK2 gene, rs200878487 SNPs in the A20 gene and four SNPs (c.1584-375, c.1584-374, rs1230581026 and p.W433R) in the Cezanne gene were associated with significant risks, while the rs10974947 variant in the JAK2 gene was at reduced risk of psoriasis. Moreover, in the Cezanne gene, p.W433R was predicted to be probably damaging by the Polyphen-2 prediction tool and an AA/CC haplotype was associated with a high risk of psoriasis. In addition, patients with higher CA 125 levels than the clinical cutoff 35 U/mL showed increased levels of IFN-γ than those with normal CA 125 levels. Conclusions: A20 expression was associated with lipid metabolism and the recruitment of CD13+ CD117- and activated B cells into circulation in psoriatic patients. Besides this, the deleterious effect of the p.W433R variant in the Cezanne gene may contribute to the risk of psoriasis.

Association between IL-17F, IL-17RA Gene Polymorphisms and Response to Biological Drugs in Psoriasis and Beyond

Psoriasis is a systemic inflammatory disease that associates with multiple comorbidities. It involves complex interactions between environmental factors and polygenic predisposition. The IL-17 family is one of the main actors in the pathogenesis of psoriasis. Secondary nonresponse is common, especially during the long-term use of TNF-α inhibitors, but it is not uncommon even for newer biologics, such as IL-17 inhibitors. Identification of clinically useful biomarkers of treatment efficacy and safety would enable optimal treatment selection, improve patient quality of life and outcome, and reduce healthcare costs. To our knowledge, this is the first study to evaluate the relationship between genetic polymorphism of IL-17F (rs763780) and IL-17RA (rs4819554) and response to biological treatment and other clinical data in bio-naive and secondary non-responders psoriasis patients in Romania and Southeastern Europe. We performed a prospective, longitudinal, analytical cohort study of 81 patients diagnosed with moderate-to-severe chronic plaque psoriasis who received biological treatments for the first time. Of the 79 patients treated with TNF-α inhibitors, 44 experienced secondary nonresponse. All patients were genotyped for the two SNPs in IL-17F and IL-17RA genes. The rs763780 polymorphism in the IL-17F gene could be an attractive candidate biomarker for predicting which patients will respond to anti-TNF-α therapies. Another emergent association of rs4819554 in IL-17RA with the risk of nail psoriasis and a higher BMI in moderate-to-severe plaque psoriasis patients is described.

Genetic Associations and Differential mRNA Expression Levels of Host Genes Suggest a Viral Trigger for Endemic Pemphigus Foliaceus

The long search for the environmental trigger of the endemic pemphigus foliaceus (EPF, fogo selvagem) has not yet resulted in any tangible findings. Here, we searched for genetic associations and the differential expression of host genes involved in early viral infections and innate antiviral defense. Genetic variants could alter the structure, expression sites, or levels of the gene products, impacting their functions. By analyzing 3063 variants of 166 candidate genes in 227 EPF patients and 194 controls, we found 12 variants within 11 genes associated with differential susceptibility (p < 0.005) to EPF. The products of genes TRIM5, TPCN2, EIF4E, EIF4E3, NUP37, NUP50, NUP88, TPR, USP15, IRF8, and JAK1 are involved in different mechanisms of viral control, for example, the regulation of viral entry into the host cell or recognition of viral nucleic acids and proteins. Only two of nine variants were also associated in an independent German cohort of sporadic PF (75 patients, 150 controls), aligning with our hypothesis that antiviral host genes play a major role in EPF due to a specific virus−human interaction in the endemic region. Moreover, CCL5, P4HB, and APOBEC3G mRNA levels were increased (p < 0.001) in CD4+ T lymphocytes of EPF patients. Because there is limited or no evidence that these genes are involved in autoimmunity, their crucial role in antiviral responses and the associations that we observed support the hypothesis of a viral trigger for EPF, presumably a still unnoticed flavivirus. This work opens new frontiers in searching for the trigger of EPF, with the potential to advance translational research that aims for disease prevention and treatment.

Psoriasis: An Immunogenetic Perspective

Psoriasis is an erythematous-squamous dermatosis with a polygenic inheritance history. Both environmental and genetic factors play a role in the etiology of the disease. Over the past two decades, numerous linkage analyzes and genome-wide association studies have been conducted to investigate the role of genetic variation in disease pathogenesis and progression. To date, >70 psoriasis susceptibility loci have been identified, including HLA-Cw6, IL12B, IL23R, and LCE3B/3C. Some genetic markers are used in clinical diagnosis, prognosis, treatment, and personalized new drug development that can further explain the pathogenesis of psoriasis. This review summarizes the immunological mechanisms involved in the etiopathogenesis of psoriasis and recent advances in susceptibility genes and highlights new potential targets for therapeutic intervention.

Association of Interleukin-17F Polymorphism and Mortality Predictors with the Risk of COVID-19

BACKGROUND

Th-17 cells, a proinflammatory subset of CD4 T lymphocytes, have been suggested as a possible cause of coronavirus disease-19 (COVID-19)-related immunological injuries. The aim of this study was to investigate the relationship between IL-17F (rs763780) polymorphism and the susceptibility to and outcomes of COVID-19 infection and to determine the clinical and laboratory predictors of COVID-19 death.

METHODS

This case-control study included 132 COVID-19 patients and 135 healthy age- and sex-matched controls. The participants were tested for IL-17F rs763780 polymorphism via TaqMan-based genotyping and for the expression of IL-17 by enzyme-linked immunosorbent assay. This study also investigated the predictors for COVID-19 mortality.

RESULTS

A non-statistically significant association was observed between IL-17F alleles and genotypes with COVID-19 (P=0.309, P=0.138, respectively). Moreover, no significant difference in the IL-17F genotypes was observed between non-survivors and survivors (P=0.482). In the multivariate analysis, the participants with the following characteristics had 17.7-, 11.2-, 8-, and 17.9-fold higher odds of exhibiting in-hospital mortality, respectively: (1) hypertension, (2) age of >57 years, (3) WBC count of >12.6 × 10³/mm³, and (4) D-dimer of >0.9 ng/ml. The ROC curve analysis showed that IL-17 at a cutoff point of >46 pg/ml was a perfect discriminator of COVID-19 patients from control subjects (AUC = 1.0).

CONCLUSION

The findings indicate that the IL-17F H161R variant does not influence the risk of COVID-19. However, the IL-17 level is a perfect discriminator of COVID-19 infection. Hypertension, age of >57 years, white blood cell count of >12.6 × 10³/mm³, and D-dimer of >0.9 ng/ml are the independent predictors for death among COVID-19 patients.

Evaluation of the relationship of IL-17A and IL-17F gene polymorphisms with the response to treatment in psoriatic patients using biological drugs: a case-control study in patients in Eastern Turkey

Introduction

IL-17A and IL-17F cytokines have important roles in the pathogenesis of psoriasis.

Aim

To examine the associations of IL-17A rs2275913 and IL-17F rs763780 variants with the development of psoriasis and whether these polymorphisms affect the responsiveness of biological agents.

Material and methods

In our case-controlled study, which included 83 psoriatic patients who were treated with different biological agents and 69 healthy controls, we genotyped IL-17A rs2275913 and IL-17F rs763780 variants using TaqMan probes.

Results

We did not observe statistically significant changes in genotype frequencies of IL-17A rs2275913 (p = 0.922) and IL-17F rs763780 (p = 0.621) variants between patient and control groups. Although we did not find any association between these polymorphisms and the development of psoriasis, statistical analyses showed that individuals with the IL-17A AA genotype had shorter disease duration (9.09 ±6.82, p = 0.020) and AA genotype frequency was higher in patients who used single conventional treatment (34.6%; p = 0.025). IL17A/rs2275913 variant in terms of disease duration, it was observed that individuals with AA genotype had a shorter disease duration (less than 10 years) (p = 0.009). For patients with PASI90 and PASI100 response, the IL-17A AA genotype was significantly higher (p = 0.015). On the other hand, we did not detect any statistically significant correlation between variants and response to biological agents.

Conclusions

According to our results, we may suggest that rs2275913 variant seems to be associated with disease duration, use of single conventional treatment and responsiveness of PASI90 and PASI100 however both variants have no effect on the susceptibility to psoriasis in the population of Eastern Turkey.

Genetic variants in IL-17A rs10484879 and serum levels of IL-17A are associated with psoriasis risk

Psoriasis is an inflammatory skin disease characterized by keratinocyte hyperproliferation with effective environmental and genetic factors. Recent studies showing that the IL-23/IL-17 axis plays a central role in the pathogenesis of the disease. Experimental and clinical studies suggest that IL-17A, an important regulatory effector cytokine in this pathway and triggers changes mainly in affected tissues. Based on the central role of IL-17A in the pathogenesis of psoriasis, we thought that variations in this gene could affect the susceptibility and severity of this disease. Therefore, in this study, we aimed to analyze whether IL-17A rs10484879 variant has an effect on psoriasis pathogenesis in Turkish population. In this case-control study, the study group consisting of 564 patient (188 psoriasis patients (66 males/122 females)/376 controls (132 males/244 females) and they were genotyped in terms of IL-17A (rs10484879) polymorphism with TaqMan 5 'Allelic Discrimination Test. IL-17A serum levels were measured with the Enzyme-linked immunosorbent assay (ELISA). The genotype distributions of the IL-17A rs10484879 polymorphism between the patient and control groups were statistically different in the TT genotype and it was observed more commonly in the patient group compared to the controls (p < 0.001). Similarly, the T allele was observed with a higher prevalence in the patient group compared to the controls (p = 0.007). IL-17A serum levels were associated with increased serum concentration, respectively, TT > GT > GG in all study groups (p < 0.05). We would like to report that IL-17A rs10484879 TT genotype and T allele are associated with increased risk of psoriasis in the Turkish population.

Association between interleukin-17F rs763780 polymorphism and psoriasis risk: A meta-analysis

BACKGROUND

The polymorphism of interleukin-17F rs763780 has been found to have a probable association with increased risk of developing psoriasis.

AIMS

This study aims to get a more convincing estimation of the association between the interleukin-17F rs763780 T /C polymorphism and psoriasis risk.

METHODS

Two authors independently searched the databases including PubMed, EMBASE, Cochrane Central Register of Controlled Trials, Chinese National Knowledge Infrastructure, Wanfang and Chinese Biomedical Literature Databases for case-control studies which reported the odds ratios with 95% confidence intervals comparing genotype and allele frequencies of the interleukin-17F rs763780 polymorphism in patients with psoriasis versus participants without psoriasis.

RESULTS

A total of seven case-control studies incorporating 1824 cases and 1585 controls were identified. The pooled odds ratios indicated that interleukin-17F rs763780 C allele was a risk factor for psoriasis in allele frequency, recessive model and homozygote model (P < 0.05). Subgroup analysis by ethnicity further indicated that the C allele was closely related to increased risk of psoriasis in Asian populations (P < 0.05), but not in Caucasians.

LIMITATIONS

Only a few studies on the interleukin-17F rs763780 polymorphism in psoriasis have been reported till date, thus the data is insufficient. Only one gene polymorphic site was selected for this study, and it is not clear whether other genetic mutation functional sites affect the gene. Further studies on confounding effects of other genetic polymorphisms are needed.

CONCLUSION

The present meta-analysis results suggested that the interleukin-17F rs763780 T /C is significantly associated with psoriasis risk in Asians.

Targeted Therapies in Autoimmune Skin Diseases

Unlike the established anti-inflammatory drugs with a broad range, new-targeted therapeutic approaches have emerged in the management of autoimmune skin diseases to increase efficacy and decrease adverse reactions on the basis of an improved molecular understanding of pathogenesis. Most inflammatory dermatoses are driven by misled immune responses physiologically directed at exogenous pathogens, that is, type 1 immunity against viral pathogens, type 2 immunity against parasites, and type 3 immunity against fungi and bacteria. Pathogenic hallmarks of these major immune reaction patterns are characterized within this article, and a comprehensive overview of current clinical trials evaluating targeted therapeutics for respective dermatoses is outlined.

Association between IL-17A, IL-17F and IL-17RA gene polymorphisms and susceptibility to psoriasis and psoriatic arthritis: a meta-analysis

BACKGROUND

Psoriasis (Ps) is a chronic dermatosis characterized by erythematous-squamous plaques derived from an inflammatory response. The effect of polymorphisms in the genes that encode the members of the IL-17 family and their receptors has been studied to find an association with the susceptibility to Ps. However, the findings have not been conclusive.

OBJECTIVES

To describe the association between IL-17A, IL-17F and IL-17RA gene polymorphisms and susceptibility to Ps.

METHOD

A systematic review was conducted using the PubMed and Scopus databases to identify studies that evaluated the association between IL-17A, IL-17F, and IL-17RA gene polymorphisms and Ps susceptibility. This meta-analysis included reports published until June 2021. Heterogeneity was assessed using Cochran's Q-statistic test and I² statistics. The associations between polymorphisms and Ps susceptibility were determined by pooled OR with a 95% CI.

RESULTS

Fifteen studies were included. The frequency of the T allele of the IL-17F rs763780 polymorphism was significantly lower in patients with vulgar Ps (OR = 0.732, p = 0.026). The TT genotype of the IL-17F rs763780 polymorphism was significantly associated with a decreased frequency in individuals with Ps and psoriatic arthritis (PsA) (TT:TC + CC OR = 0.664, p = 0.046). Regarding IL-17RA polymorphisms, the AG genotype of the rs4819554 polymorphism showed a near-significant decrease in psoriasis risk compared to the GG genotype (AG:GG OR = 0.604, p = 0.050). Other polymorphisms in IL-17A, IL-17F and IL-17RA showed no association with Ps.

CONCLUSIONS

The T allele and TT genotype of the IL-17F rs763780 polymorphism may be associated with a decreased risk of psoriasis. Therefore, the implications of this variant on psoriasis pathogenesis and treatment require further investigation.

Apremilast Pharmacogenomics in Russian Patients with Moderate-to-Severe and Severe Psoriasis

One of the target drugs for plaque psoriasis treatment is apremilast, which is a selective phosphodiesterase 4 (PDE4) inhibitor. In this study, 34 moderate-to-severe and severe plaque psoriasis patients from Russia were treated with apremilast for 26 weeks. This allowed us to observe the effectiveness of splitting patient cohorts based on clinical outcomes, which were assessed using the Psoriasis Area Severity Index (PASI). In total, 14 patients (41%) indicated having an advanced outcome with delta PASI 75 after treatment; 20 patients indicated having moderate or no effects. Genome variability was investigated using the Illumina Infinium Global Screening Array. Genome-wide analysis revealed apremilast therapy clinical outcome associations at three compact genome regions with undefined functions situated on chromosomes 2, 4, and 5, as well as on a single single-nucleotide polymorphism (SNP) on chromosome 23. Pre-selected SNP sets were associated with psoriasis vulgaris analysis, which was used to identify four SNP-associated targeted therapy efficiencies: IL1β (rs1143633), IL4 (IL13) (rs20541), IL23R (rs2201841), and TNFα (rs1800629) genes. Moreover, we showed that the use of the global polygenic risk score allowed for the prediction of onset psoriasis in Russians. Therefore, these results can serve as a starting point for creating a predictive model of apremilast therapy response in the targeted therapy of patients with psoriasis vulgaris.

JAK1 rs310241 and JAK3 rs3008 Genotypes May Increase Susceptibility to Psoriasis: A Case Control Study

BACKGROUND

Janus kinases (JAKs) are a family of non-receptor protein tyrosine kinases that are expressed in a variety of tissues. Several JAK-controlled cytokine receptor pathways are incriminated in the initiation and progression of psoriasis. Genetic polymorphisms influencing JAK expression would be anticipated to have a great impact on disease activity.

OBJECTIVE

The aim of the study was to evaluate the association between JAK1 rs310241 and JAK3 rs3008 polymorphisms and the risk of developing psoriasis.

METHODS

Blood samples of 150 patients and 120 controls were screened for nucleotide polymorphisms in JAK1 rs310241 and JAK3 rs3008 genes by using polymerase chain reaction (PCR)-restriction fragment length polymorphism technique.

RESULTS

The GG genotype of the JAK1 rs310241 and JAK3 rs3008 genes was significantly associated with an increase in psoriasis risk (p = 0.000, OR = 7.7, 95% CI = 2.8-21.5; p = 0.003, OR = 3.3, 95% CI = 1.5-6.9, respectively). The G allele of both genes was also associated with psoriasis susceptibility (p = 0.000, OR = 2.0, 95% CI = 1.4-2.8; p = 0.002, OR = 1.7, 95% CI = 1.2-2.4, respectively).

CONCLUSION

The results indicate a possible association between JAK1 rs310241 and JAK3 rs3008 gene polymorphisms and susceptibility to psoriasis. These findings validate the importance of these molecules in psoriasis and may enable the identification of the individuals most susceptible to the disease.

Activation of the interleukin-23/interleukin-17 signalling pathway in autoinflammatory and autoimmune uveitis

Uveitis is a group of diseases characterized by intraocular inflammation, of which some are driven by autoinflammatory or autoimmune responses, such as Vogt-Koyanagi-Harada disease, Behçet's disease, uveitis associated with spondyloarthritis, ocular sarcoidosis, sympathetic ophthalmia and birdshot chorioretinopathy. These entities have various clinical forms, but genetic and biomarker data suggest that they share a common molecular basis, activation of the Interleukin (IL)-23/IL-17 pathway. Multiple factors including genetic predisposition, various cytokine imbalances, infectious agents and gut alterations are found to trigger an aberrant response of this pathway. The enhanced activity of the IL-23/IL-17 pathway is committed to the expansion and pathogenicity of Th17 cells. Evidence from animal models demonstrates that the development of pathogenic Th17 cells is responsible for the induction of experimental autoimmune uveitis. Further findings indicate that retinal pigment epithelium (RPE) cells may be a target of IL-17. IL-17 triggers downstream inflammatory cascades and causes dysfunction of RPE cells, which may affect retinal barrier function and thereby promote intraocular inflammation. Currently, several emerging drugs blocking the IL-23/IL-17 pathway have been assessed for the treatment of uveitis in pilot studies. The purpose of this is to summarize updated biological knowledge and preliminary clinical data, providing the rationale for further development and evaluation of novel drugs targeting the IL-23/IL-17 pathway in autoinflammatory and autoimmune uveitis. Future studies may focus on translational medicine targeting the IL-23/IL-17 pathway for the improvement of diagnosis and treatment of uveitis. In conclusion, activation of the IL-23/IL-17 pathway is a critical biological event and can be an important target for the treatment of autoinflammatory and autoimmune uveitis.

Genetic Signature of Acute Lymphoblastic Leukemia and Netherton Syndrome Co-incidence-First Report in the Literature

The aim of the following case report is to provide a description of acute lymphoblastic leukemia (ALL) in a patient with Netherton syndrome (NS). A 15-year-old male with NS was referred with suspicion of acute leukemia. Severe anemia, leukocytosis, thrombocytopenia, and elevated CRP level were demonstrated in pre-hospital laboratory tests. Physical examination revealed generalized ichthyosiform erythroderma. ALL was diagnosed on the basis of bone marrow biopsy. The patient was initially classified as CNS3 status. No signals indicating fusion of BCR/ABL1, ETV6, and RUNX1 genes and MLL gene rearrangement were found in the cytogenetic analysis. The patient was qualified for chemotherapy and treated according to ALL IC-BFM 2009 protocol for high-risk ALL. During induction therapy, severe skin toxicity occurred (WHO grade III), which prompted the modification of treatment down to intermediate-risk strategy. In the course of reinduction therapy, severe chemotherapy-induced adverse drug reactions occurred, including progression of skin toxicity to WHO grade IV. The patient achieved complete remission. In view of life-threatening toxicities and the confirmed complete remission, intensive chemotherapy regimen was discontinued and maintenance treatment was started. Because of the baseline CNS3 status, the patient received cranial radiotherapy. Whole exome sequencing (WES) was used to identify disease-associated mutations. WES revealed two germline mutations: a novel premature termination variant in SPINK5 (p.Cys510^*), along with a novel potentially pathogenic variant in NUP214 (p.Arg815Gln). Somatic mutations were known pathogenic variants of JAK2 (p.Arg683Gly), IL17RC (p.Ala303Thr), and potentially pathogenic non-synonymous variants of TTN (p.Gly1091Arg and p.Pro17245Leu), ACTN2 (p.Ile143Leu), TRPV3 (p.Arg729^*), and COL7A1 (p.Glu2842fs) genes. Currently, the patient continues maintenance chemotherapy, with stable status of skin lesions and no features of ALL relapse. To our knowledge, this is the first report of ALL in a patient with NS. As has been presented, in such patients, optimal treatment according to the current protocols is extremely difficult. WES was used to confirm the diagnosis of Ph-like ALL in our patient. The detection of JAK2 gene mutation offers the possibility of therapy personalization. A specific signature of rare germline variants and somatic mutations can be proposed as a factor predisposing to the co-incidence of ALL and NS.

The IL17F His161Arg polymorphism, a potential risk locus for psoriasis, increases serum levels of interleukin-17F in an Asian population

Interleukin 17 (IL-17) plays pivotal role in the pathogenesis of psoriasis. In a previous study, we identified a locus in the IL17F gene that is associated with psoriasis, the IL17F rs763780 (His161Arg) T/C variant. The current study aimed to elucidate the association between this polymorphism and psoriasis, and to determine its effect on serum levels of cytokine. A total of 116 psoriasis patients and 97 healthy volunteers were recruited. Genotyping analysis was performed using quantitative polymerase chain reaction, and serum levels of cytokine were measured using a multiplex immunoassay. The IL17F His161Arg polymorphism was significantly associated with psoriasis based on the genotype and allele analyses. Psoriasis patients harbouring the mutant allele had significantly increased serum levels of IL-17F. Our results suggest that this polymorphism is a potential risk locus for psoriasis and that it results in a direct increase in IL-17F production.

Psoriasis: Association of interleukin-17 gene polymorphisms with severity and response to treatment

Psoriasis is a chronic, inflammatory disease with a complex pathogenesis that is not yet fully understood. Although it is a multifactorial disease, the genetic factor has a major role in the pathogenesis of psoriasis. Genome wide association studies have identified over 50 genetic loci associated with psoriasis risk. Beside TNF-α or IL-23, the IL-17 family is a newer group that has proven implications in the pathogenesis of psoriasis. The most important members of the family, with pro-inflammatory qualities, are IL-17A and IL-17F. These interleukins are produced by a varied number of cells, but by far the most important are Th17 cells. Of the patients 20-30% present moderate-to-severe psoriasis, therefore, systemic medication (phototherapy, methotrexate, cyclosporine, acitretin or biologic agents) is mandatory. The necessity of an individualized treatment plan, for each patient, is imperative in order to establish the best strategy for non-responders to classical treatment or to other biologic treatments. The discovery of Th17 pathway improved the treatment and prognosis of psoriasis. Anti-psoriatic agents against IL-17 or its receptors are a novel group of biologic agents; these include ixekizumab, secukinumab and brodalumab. Polymorphisms of IL-17 family have been correlated with the severity and response to treatment in psoriasis, and also with the risk of inflammatory, infectious, autoimmune or neoplastic pathologies. The significant difference in the presence or absence of susceptibility loci in different population is due to genetic background and environmental factors that have a major impact on disease predisposition. In this study, we reviewed the importance and influence of the IL-17 polymorphisms as predictors of response to treatment and severity of the disease.

The Possible Role of Gene Variant Coding Nonfunctional Toll-Like Receptor 2 in the Pathogenesis of Mastocytosis

BACKGROUND

Data on the genetic predisposition to mastocytosis are scarce. The aim of this work was to study the association of single nucleotide polymorphisms of Toll-like receptor (TLR)-2, TLR-4, and TLR-9 genes in Polish patients with mastocytosis.

OBJECTIVES

The study comprised 137 patients with mastocytosis (102 cutaneous [60 children and 42 adults] and 35 systemic cases); 171 disease-free individuals were used as controls.

METHOD

The frequency of polymorphisms R753Q (rs5743708) of TLR-2, 896 A>G (rs496790) of TLR-4, and -1237C>T (rs5743836) of TLR-9 genes were determined with the use of the amplification refractory mutation system polymerase chain reaction method.

RESULTS

It was found that the R753Q TLR-2 gene polymorphism was significantly more frequent in patients with mastocytosis in comparison to healthy controls (p = 0.037) and in the group of SM versus controls (p = 0.0076). The presence in the genotype 753Q variant of TLR-2 gene increased the risk of mastocytosis more than 2-fold (OR 2.51; p = 0.04), and the risk of SM more than 4-fold (OR 4.22; p = 0.01). TLR-4 and TLR-9 polymorphisms were not associated with mastocytosis.

CONCLUSIONS

Our results suggest that the R753Q polymorphism of the TLR-2 gene may be involved in the pathogenesis of mastocytosis.