The significance of Toll-like receptor (TLR) 2 and 9 gene polymorphisms in psoriasis

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.

The effect of secukinumab treatment on inflammatory parameters in patients with psoriasis: A multicentre restrospective study

AIM

Psoriasis is a common chronic inflammatory disease of the skin with remission and relapses. The aim of this study was to investigate the change in inflammatory parameters such as neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR) and mean platelet volume (MPV) in patients receiving secukinumab treatment for psoriasis vulgaris (PV).

MATERIALS AND METHODS

In this retrospective study, we evaluated the laboratory results of 40 patients who were followed up with a diagnosis of PV and received secukinumab treatment in three different dermatology clinics between July 2018 and September 2019.

RESULTS

Neutrophil count and leukocyte count were significantly decreased after secukinumab treatment. (P < .001) There was no statistically significant difference between lymphocyte count, platelet count, MPV, NLR and PLR values before treatment and at the 4th month of treatment (P values .230, .065, .110, .915 and .365, respectively).

CONCLUSION

In conclusion, it can be concluded that parameters such as NLR, PLR and MPV are not suitable parameters for monitoring the effects of secukinumab treatment on inflammation.

Going, Toll-like receptors in skin inflammation and inflammatory diseases

The Indian Ayurvedic physicians knew the concept of inflammation dating back to 1500 BC. The continuous progress in the immunology of inflammation has explained its undiscovered mechanisms. For example, the discovery of Toll-like receptor 4 (TLR4) in humans (1997) has revolutionized the field of infection biology and innate immunity. The laboratory mice have shown twelve TLRs and express TLR10 (CD290) as a disrupted pseudogene, and humans have ten functional TLRs. Now, it is well established that TLRs play a significant role in different infectious and inflammatory diseases. Skin inflammation and other associated inflammatory diseases, including atopic dermatitis (AD), acne vulgaris, and psoriasis, along with many skin cancers are major health problems all over the world. The continuous development in the immunopathogenesis of inflammatory skin diseases has opened the window of opportunity for TLRs in studying their role. Hence, the manuscript explores the role of different TLRs in the pathogenesis of skin inflammation and associated inflammatory diseases. The article starts with the concept of inflammation, its origin, and the impact of TLRs discovery on infection and inflammation biology. The subsequent section describes the burden of skin-associated inflammatory diseases worldwide and the effect of the geographical habitat of people affecting it. The third section explains skin as an immune organ and explains the expression of different TLRs on different skin cells, including keratinocytes, Langerhans cells (LCs), skin fibroblasts, and melanocytes. The fourth section describes the impact of TLRs on these cells in different skin-inflammatory conditions, including acne vulgaris, AD, psoriasis, and skin cancers. The article also discusses the use of different TLR-based therapeutic approaches as specific to these inflammatory skin diseases.

Clinical Impact of Inherited and Acquired Genetic Variants in Mastocytosis

Mastocytosis is a rare and complex disease characterized by expansion of clonal mast cells (MC) in skin and/or various internal organ systems. Involvement of internal organs leads to the diagnosis of systemic mastocytosis (SM). The WHO classification divides SM into indolent SM, smoldering SM and advanced SM variants, including SM with an associated hematologic neoplasm, aggressive SM, and MC leukemia. Historically, genetic analysis of individuals with pure cutaneous mastocytosis (CM) and SM have focused primarily on cohort studies of inherited single nucleotide variants and acquired pathogenic variants. The most prevalent pathogenic variant (mutation) in patients with SM is KIT p.D816V, which is detectable in most adult patients. Other somatic mutations have also been identified-especially in advanced SM-in TET2, SRSF2, ASXL1, RUNX1, CBL and JAK2, and shown to impact clinical and cellular phenotypes. Although only small patient cohorts have been analyzed, disease associations have also been identified in several germline variants within genes encoding certain cytokines or their receptors (IL13, IL6, IL6R, IL31, IL4R) and toll-like receptors. More recently, an increased prevalence of hereditary alpha-tryptasemia (HαT) caused by increased TPSAB1 copy number encoding alpha-tryptase has been described in patients with SM. Whereas HαT is found in 3-6% of general Western populations, it is identified in up to 17% of patients with SM. In the current manuscript we review the prevalence, functional role and clinical impact of various germline and somatic genetic variants in patients with mastocytosis.

Role of interferon regulatory factor-mediated signaling in psoriasis

Psoriasis is a chronic inflammatory disease that involves both the innate and adaptive immune systems. Type I interferons (IFNs), the production of which is partially regulated by toll-like receptors (TLRs), play an important role in the pathogenesis of psoriasis, especially psoriasis caused by skin trauma, known as the Koebner phenomenon. IFN regulatory factors (IRFs) function in both innate and adaptive immune responses, and their effect is associated with the regulation of type I IFNs. In this review, we focus on recent advances in understanding the expression of TLRs, IRFs, and type I IFNs in psoriasis. We also highlight the interplay among TLRs, IRFs, and type I IFNs.

Overview of the molecular determinants contributing to the expression of Psoriasis and Psoriatic Arthritis phenotypes

Psoriasis and psoriatic arthritis are multifactorial chronic disorders whose etiopathogenesis essentially derives from the alteration of several signalling pathways and the co-occurrence of genetic, epigenetic and non-genetic susceptibility factors that altogether affect the functional and structural property of the skin. Although shared and differential susceptibility genes and molecular pathways are known to contribute to the onset of pathological phenotypes, further research is needed to dissect the molecular causes of psoriatic disease and its progression towards Psoriatic Arthritis. This review will therefore be addressed to explore differences and similarities in the etiopathogenesis and progression of both disorders, with a particular focus on genes involved in the maintenance of the skin structure and integrity (keratins and collagens), modulation of patterns of recognition (through Toll-like receptors and dectin-1) and immuno-inflammatory response (by NLRP3-dependent inflammasome) to microbial pathogens. In addition, special emphasis will be given to the contribution of epigenetic elements (methylation pattern, non-coding RNAs, chromatin modifiers and 3D genome organization) to the etiopathogenesis and progression of psoriasis and psoriatic arthritis. The evidence discussed in this review highlights how the knowledge of patients' clinical and (epi)genomic make-up could be helpful for improving the available therapeutic strategies for psoriasis and psoriatic arthritis treatment.

The effect of biological agent treatment on neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, mean platelet volume, and C-reactive protein in psoriasis patients

Introduction

In recent years, the neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), mean platelet volume (MPV) and C reactive protein (CRP) have been shown to be important indicators of systemic inflammation. Studies have shown that NLR, PLR, MPV and CRP are higher in psoriasis patients than in the control group.

Aim

To investigate the NLR, PLR, MPV and serum CRP levels in patients who were treated with biological agents for psoriasis.

Material and methods

In our study, 75 patients who were followed up and had a diagnosis of psoriasis vulgaris and took a biological agent therapy between January 2014 and December 2017 in the Dermatology Clinic of the Dicle University Medical Faculty Hospital were evaluated before treatment, and 3 and 6 months after treatment.

Results

Neutrophil count, lymphocyte count, thrombocyte count, NLR, PLR, MPV and CRP values before the biological agent treatment were statistically higher than the values at 3 and 6 months of treatment. There was no statistically significant difference between pre-treatment neutrophil, lymphocyte, leukocyte, platelet, NLR, PLR, MPV, CRP values and values at 3 and 6 months after treatment when we compared four different biological agents.

Conclusions

It was seen that NLR, PLR, MPV and CRP values decreased independently of the type of the biological agent used in our study. Therefore, we think that these parameters can be used to evaluate the effects of biological agent treatment on systemic inflammation in psoriasis patients and to monitor the course 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.

Quo vadis, biological treatment for psoriasis and psoriatic arthritis?

Psoriasis is a chronic autoimmune disease that affects approximately 2-3% of the world's population. Although the cutaneous manifestations of the disease are the most prevalent, psoriasis is also associated with a systemic inflammation and various co-morbidities linked with autoinflammatory processes. One of those processes is psoriatic arthritis, an inflammatory, seronegative spondyloarthropathy that develops in 13.8-30% of psoriatic patients at some point of their lives. Over the past 15 years the therapeutic options for severe and generalized psoriasis have broadened immensely with the introduction of biological agents to everyday practice. We present a quick overview of current biological therapies in the treatment of psoriasis and prospects for forthcoming advancements in biological treatment.

ERAP1 and HLA-C*06 are strongly associated with the risk of psoriasis in the population of northern Poland

INTRODUCTION

HLA-C*06 is a major psoriasis genetic risk marker. Recent reports have been focused on the role of different polymorphisms within genes involved in the functioning of the epidermal barrier and antigen processing in the pathogenesis of psoriasis. Data on the association between genetic variants of LCE3B_LCE3C, CSTA, ERAP1, ZAP70 and this dermatosis in the population from Eastern Europe are lacking.

AIM

To compare the association between known genetic risk markers and psoriasis in a cohort of northern Polish patients with psoriasis and healthy controls.

MATERIAL AND METHODS

Based on previous studies' results, five susceptibility loci: HLA-C, LCE3C_LCE3B, ERAP1, ZAP70 and CSTA were selected for genotyping in 148 patients with chronic plaque psoriasis and 146 healthy controls. Each patient with this disease was clinically assessed with the Psoriasis Area and Severity Index.

RESULTS

The study population showed a significant association of psoriasis and a single nucleotide polymorphism in the ERAP1 - rs26653 (p = 3.11 × 10-5) and HLA-C*06 allele (p = 1.02 × 10-11) when compared with the control group. The presence of HLA-C*06 or rs26653 G allele significantly increased the risk of psoriasis by 2.4 times or twice, respectively. Carrying rs26653 C allele considerably decreased the risk of psoriasis by 1.5 times.

CONCLUSIONS

In the context of pathogenesis of psoriasis, our findings might give the evidence on disturbances in the proteolytic processing of N-terminal fragments of antigens presented via major histocompatibility complex class I to T cells.