Paradoxical psoriasiform reactions to anti-TNFα drugs are associated with genetic polymorphisms in patients with psoriasis

Paradoxical Psoriasis: An Updated Review of Clinical Features, Pathogenesis, and Treatment Options

The definition of paradoxical psoriasis (PP) encompasses 2 main scenarios, namely, (i) new-onset psoriasis in patients treated for a different disease and (ii) worsening as well as phenotypical change of pre-existing psoriasis. Originally restricted to the appearance of an untoward psoriasiform reaction under TNF inhibitors, the term has gained new meaning, with the progressive observation of psoriasis-like eruptions also with other medications. Although the conceptual framework of PP has expanded, a molecular and clinicotherapeutic classification is still lacking. In addition, a certain degree of confusion surrounds the correct terminology to indicate these eruptions. In this paper, evidence on the epidemiology, clinical features, pathogenesis, and treatment of PP is reviewed, providing a perspective on possible pathogenesis-driven therapeutic approaches.

The Role of Genetics on Psoriasis Susceptibility, Comorbidities, and Treatment Response

This review highlights advances made in psoriasis genetics, including findings from genome-wide association studies, exome-sequencing studies, and copy number variant studies. The impact of genetic variants on various comorbidities and therapeutic responses is discussed.

Paradoxical Psoriasis

Cytokine blocking therapies have revolutionized the management of psoriasis and atopic dermatitis but can lead to the development of paradoxic psoriasis (PP). Patients treated with biologics should be closely monitored for the development of PP and other paradoxical eruptions (including inflammatory joint disease, inflammatory bowel disease, eczematous eruptions, lupus like eruptions, sarcoidal eruptions, and others) and occasionally the development of cutaneous T-cell lymphoma. Further understanding the immunologic mechanism of these processes will ultimately drive our understanding of and ability to predict and manage PPs.

Paradoxical Psoriasis in Patients Receiving Therapy with Tumor Necrosis Factor Inhibitors: Potential Pathogenic Mechanisms and the Role of Genetic Factors

TNF inhibitors (TNFi) have revolutionized the therapeutic management of various chronic immune-mediated inflammatory diseases. Despite their known benefits, these therapies are related to paradoxical adverse effects (PAEs), including paradoxical psoriasis (PP). Although the underlying mechanism remains somewhat unclear, some theories suggest that genetic factors, particularly certain single-nucleotide polymorphisms (SNPs), may play an important role. The present review aimed to research and analyze recent findings regarding the pathomechanisms involved in the appearance of PP and the association between various genetic factors and PP in individuals treated with TNFi. We performed a literature search and found that certain genes (IL23R, TNF, FBXL19, CTLA4, SLC12A8, TAP1) are strongly associated with the occurrence of PP in pediatric and adult patients during therapy with TNFi. The identification of the specific SNPs involved in the appearance of PP and other PAEs in patients treated with TNFi for various diseases and in different populations may later favor the recognition of those patients at a high risk of developing such adverse effects and could guide personalized therapeutic strategies in future years.

Significant Correlation Between Cutaneous Abundance of Streptococcus and Psoriasis Severity in Patients with FBXL19 Gene Variants

Psoriasis results from both genetic predisposition and environmental triggers, such as Streptococcal infections. This study aimed to explore the correlation between the abundance of the Streptococcus genus on the skin and psoriasis severity in individuals carrying specific psoriasis-associated genetic variants. Studying 39 chronic plaque psoriasis patients, the elbow skin microbiome and 49 psoriasis-related single nucleotide polymorphisms (SNPs) were analysed using a MiSeq instrument for 16S rDNA sequencing, and CLC Genomic Workbench for processing and analysis. Through multivariate linear regression analysis, a positive correlation was found between Streptococcus genus abundance and psoriasis severity in patients with certain FBXL19 gene-related heterozygous SNPs (rs12924903, rs10782001, rs12445568). Conversely, a negative association was observed in patients with homozygous genotypes. Moreover, we identified an association between Streptococcus abundance and psoriasis severity in patients with genetic variants related to IL-22, ERAP1, NOS2, and ILF3. This is the first study highlighting a positive association between Streptococcus skin colonization and psoriasis severity in patients with heterozygous genotypes within the FBXL19 gene region. FXBL19 targets the IL-33/IL1RL1 axis, crucial in infectious diseases and innate immunity promotion. These novel results suggests an intricate interaction among host genetics, Streptococcus skin colonization, and psoriasis inflammation, offering potential avenues for novel treatment approaches.

Risk Factors for Psoriasis Flares: A Narrative Review

Psoriasis is a chronic inflammatory cutaneous disease with multifactorial pathogenesis involving both genetic and environmental factors as well as the innate and acquired immune response. Several triggering factors may exacerbate or worsen the disease. In this context, we performed a review manuscript with the aim of investigating current literature on psoriasis risk factors, also showing possible mechanisms by which they act on psoriasis. Globally, risk factors can be divided in classic risk factors (eg, mechanical stress, infections and dysbiosis of the skin, common drugs, environment and pollution, lifestyle, psychological stress, hormonal and metabolic alterations) which have long been known to be responsible for worsening and/or reoccurrence of psoriatic manifestations, and emerging risk factors (eg, biological drugs, immunotherapy for oncologic disease, Covid-19, and vaccines) defined as those newly identified risk factors. Accurate patient information and monitoring of risk factors as well as planned follow-ups may help to prevent and treat the worsening of psoriasis and consequently improve the quality of life of psoriatic patients.

Identification of immunological patterns characterizing immune-related psoriasis reactions in oncological patients in therapy with anti-PD-1 checkpoint inhibitors

Introduction

Immunotherapy with biologics targeting programmed cell death protein-1 (PD-1) is highly effective in the treatment of various malignancies. Nevertheless, it is frequently responsible for unexpected cutaneous manifestations, including psoriasis-like dermatitis. The pathogenesis of anti-PD-1-induced psoriasis has yet to be clarified, even though it is plausible that some innate and adaptive immunity processes are in common with canonical psoriasis. The genetic predisposition to psoriasis of patients could also be a contributing factor. Here, we investigated the immunological and genetic profiles of two patients with metastatic melanoma and one patient affected by lung cancer, who developed severe psoriasis after receiving anti-PD-1 nivolumab therapy.

Methods

The immune patterns of the three patients were compared with those detectable in classical, chronic plaque-type psoriasis or paradoxical psoriasis induced by anti-TNF-α therapy, mostly sustained by adaptive and innate immunity processes, respectively. Therefore, immunohistochemistry and mRNA analyses of innate and adaptive immunity molecules were conducted on skin biopsy of patients. Genetic analysis of polymorphisms predisposing to psoriasis was carried out by NGS technology.

Results

We found that anti-PD-1-induced psoriasis showed immunological features similar to chronic psoriasis, characterized by the presence of cellular players of adaptive immunity, with abundant CD3+, CD8+ T cells and CD11c+ dendritic cells infiltrating skin lesions, and producing IL-23, IL-6, TNF-α, IFN-γ and IL-17. On the contrary, a lower number of innate immunity cells (BDCA2+ plasmacytoid dendritic cells, CD15+ neutrophils, CD117+ mast cells) and reduced IFN-α/β, lymphotoxin (LT)-α/β, were observed in anti-PD-1-induced psoriasis lesions, as compared with anti-TNF-α-induced paradoxical psoriasis. Importantly, the disintegrin and metalloprotease domain containing thrombospondin type 1 motif-like 5 (ADAMTSL5) psoriasis autoantigen was significantly upregulated in psoriasis lesions of anti-PD-1-treated patients, at levels comparable with chronic plaque-type psoriasis. Finally, NGS analysis revealed that all patients carried several allelic variants in psoriasis susceptibility genes, such as HLA-C, ERAP1 and other genes of the major psoriasis susceptibility PSORS1 locus.

Discussion

Our study showed that adaptive immunity predominates over innate immunity in anti-PD-1-induced psoriasis lesions, consistently with the local ADAMTSL5 overexpression. The presence of numerous SNPs in psoriasis susceptibility genes of the three patients also suggested their strong predisposition to the disease.

Cellular and Molecular Determinants of Biologic Drugs Resistance and Therapeutic Failure in Inflammatory Bowel Disease

The advent of biologic drugs has revolutionized the treatment of Inflammatory Bowel Disease, increasing rates of response and mucosal healing in comparison to conventional therapies by allowing the treatment of corticosteroid-refractory cases and reducing corticosteroid-related side effects. However, biologic therapies (anti-TNFα inhibitors, anti-α4β7 integrin and anti-IL12/23) are still burdened by rates of response that hover around 40% (in biologic-naïve patients) or lower (for biologic-experienced patients). Moreover, knowledge of the mechanisms underlying drug resistance or loss of response is still scarce. Several cellular and molecular determinants are implied in therapeutic failure; genetic predispositions, in the form of single nucleotide polymorphisms in the sequence of cytokines or Human Leukocyte Antigen, or an altered expression of cytokines and other molecules involved in the inflammation cascade, play the most important role. Accessory mechanisms include gut microbiota dysregulation. In this narrative review of the current and most recent literature, we shed light on the mentioned determinants of therapeutic failure in order to pave the way for a more personalized approach that could help avoid unnecessary treatments and toxicities.

Developments in pharmacogenetics, pharmacogenomics, and personalized medicine

The development of Pharmacogenetics and Pharmacogenomics in Western Europe is highly relevant in the worldwide scenario. Despite the usually low institutional support, many research groups, composed of basic and clinical researchers, have been actively working for decades in this field. Their contributions made an international impact and paved the way for further studies and pharmacogenomics implementation in clinical practice. In this manuscript, that makes part of the Special Issue entitled Spanish Pharmacology, we present an analysis of the state of the art of Pharmacogenetics and Pharmacogenomics research in Europe, we compare it with the developments in Spain, and we summarize the most salient contributions since 1988 to the present, as well as recent developments in the clinical application of pharmacogenomics knowledge. Finally, we present some considerations on how we could improve translation to clinical practice in this specific scenario.

Paradoxical Psoriasis Induced by Ustekinumab: A Comprehensive Review and Case Report

Ustekinumab (UST), a biologic agent targeting interleukin-12 and interleukin-23, is widely used in the management of psoriasis and Crohn's disease. Despite its efficacy, there have been instances of paradoxical psoriasis induction or exacerbation in some patients during UST therapy. This paper offers a comprehensive review of reported cases of UST-induced paradoxical psoriasis, including a case from our clinic. We focus on a 39-year-old female patient with a history of long-standing Crohn's disease who developed a psoriasiform rash, as confirmed by biopsy, while undergoing UST treatment. The patient's clinical journey, from initial diagnosis through the complexities of treatment adjustments due to various complications including drug-induced lupus and the subsequent onset of psoriatic manifestations, provides insight into the challenges encountered in the clinical management of such cases. This review emphasizes the necessity for clinicians to recognize the possibility of paradoxical psoriasis in patients receiving UST treatment and calls for further research to better understand this phenomenon and devise effective management strategies.

Association between several immune response-related genes and the effectiveness of biological treatments in patients with moderate-to-severe psoriasis

Biological therapies are safer and more effective against psoriasis than conventional treatments. Even so, 30-50% of psoriatic patients show an inadequate response, which is associated with individual genetic heterogeneity. Pharmacogenetic studies have identified several single nucleotide polymorphisms (SNPs) as possible predictive and prognostic biomarkers for psoriasis treatment response. The objective of this study was to determine the link between several SNPs and the clinical response to biological therapies in patients with moderate-severe psoriasis. A set of 21 SNPs related to psoriasis and/or other immunological diseases were selected and analysed from salivary samples of patients (n = 88). Treatment effectiveness and patient improvement was assessed clinically through Relative Psoriasis Area and Severity Index (PASI), also called 'PASI response', as well as absolute PASI. Associations between SNPs and PASI factors were assessed at 3 and 12 months for every treatment category of IL-17, IL-23, IL-12&23 and TNF-α inhibitors. Multivariate correlation analysis and Fisher's exact test were used to analyse the relationship between SNPs and therapy outcomes. Several SNPs located in the TLR2, TLR5, TIRAP, HLA-C, IL12B, SLC12A8, TNFAIP3 and PGLYRP4 genes demonstrated association with increased short and long-term therapy-effectiveness rates. Most patients achieved values of PASI response ≥75 or absolute PASI<1, regardless of the biological treatment administered. In conclusion, we demonstrate a relationship between different SNPs and both short- and especially long-term effectiveness of biological treatment in terms of PASI. These polymorphisms may be used as predictive markers of treatment response in patients with moderate-to-severe psoriasis, providing personalized treatment.

Cutaneous immune-related phenomena in patients with inflammatory arthritides treated with biological therapies: Clinical and pathophysiological considerations

In recent years, identifying the pathophysiologic mechanisms underlying autoimmune arthritides and systematic diseases has led to the use of biological drugs. The primary targets of those biological therapies are cytokines, B cells, and co-stimulation molecules. So far, these targeted therapies have shown good clinical improvement and an acceptable toxicity profile. However, by blocking components of an intact immune system, autoimmune phenomena and paradoxical inflammation have emerged, and among them many cutaneous immune-related adverse events (irAEs). In this article, we review the current state of knowledge on the clinical features and mechanisms of specific cutaneous irAEs observed during treatment with biological therapies. Among those, psoriatic skin lesions are the most commonly observed. Herein, we also report new cases of cutaneous irAEs recently seen in our clinic to help physicians treating inflammatory arthritides recognize cutaneous irAEs early and better manage patients receiving biologic therapies.

Paradoxical psoriasis: The flip side of idiopathic psoriasis or an autocephalous reversible drug reaction?

Psoriasis is a common, chronic skin disease that results mainly from the complex interplay between T cells, dendritic cells, and inflammatory cytokines including TNF-α, IL-17, IL-12, and IL-23. Successful therapy with anti-cytokine antibodies has proved the importance of these key cytokines, especially TNF-α. During the anti-TNF-α treatment of classical idiopathic psoriasis, a small portion of patients develop new psoriasiform lesions. This contradictory phenomenon was named paradoxical psoriasis which resembles idiopathic psoriasis clinically but presents overlapped histological patterns and distinct immunological processes. In this review, we discuss the differences between idiopathic psoriasis and paradoxical psoriasis with an emphasis on their innate immunity, as it is predominant in paradoxical psoriasis which exhibits type I IFN-mediated immunity without the activation of autoreactive T cells and memory T cells. We also put up an instructive algorithm for the management of paradoxical psoriasis. The decision on drug discontinuation or switching of biologics should be made based on the condition of underlying diseases and the severity of lesions.

FBXL19 promotes malignant behaviours by activating MAPK signalling and negatively correlates with prognosis in hepatocellular carcinoma

FBXL19 is a member of the Skp1-Cullin-F-box family of E3 ubiquitin ligases and is linked to a variety of vital biological processes, such as cell proliferation, migration, and differentiation. Previous studies have identified it as an oncogene in breast cancer and glioma. However, its role in hepatocellular carcinoma (HCC) remains unclear. To comprehensively elucidate its role in tumour biology and its underlying mechanisms, a variety of sophisticated methods, including bioinformatics analysis, RNA-sequencing technique, and in vitro cell biology experiments, were used. Here, we found that FBXL19 was upregulated in patients with HCC and correlated with poor prognosis. In in vitro experiments, the specific targeting of short hairpin RNAs via lentiviruses successfully induced the knockdown of FBXL19, resulting in notable inhibition of the proliferation, migration, and invasion of HCC cells. Furthermore, FBXL19 downregulation resulted in significant induction of G0/G1 phase cell cycle arrest. Importantly, FBXL19 knockdown inhibited tumour malignant behaviour primarily by inactivating extracellular signal-regulated protein kinase 1/2 and p38 mitogen-activated protein kinases. In conclusion, this study revealed that FBXL19 was upregulated in patients with HCC, and that its expression was negatively correlated with prognosis. Thus, FBXL19 displays oncogenic properties in HCC by activating mitogen-activated protein kinase signalling.

Childhood guttate psoriasis: an updated review

Background

Guttate psoriasis is common and affects 0.5-2% of individuals in the paediatric age group. This review aims to familiarize physicians with the clinical manifestations, evaluation, diagnosis and proper management of guttate psoriasis.

Methods

A search was conducted in July 2023 in PubMed Clinical Queries using the key term "guttate psoriasis". The search strategy included all observational studies, clinical trials and reviews published within the past 10 years. The information retrieved from the search was used in the compilation of the present article.

Results

Guttate psoriasis typically presents with an abrupt onset of numerous, small, scattered, tear-drop-shaped, scaly, erythematous, pruritic papules and plaques. Sites of predilection include the trunk and proximal extremities. There may be a history of preceding streptococcal infection. Koebner phenomenon is characteristic. Guttate psoriasis may spontaneously remit within 3-4 months with no residual scarring, may intermittently recur and, in 40-50% of cases, may persist and progress to chronic plaque psoriasis. Given the possibility for spontaneous remission within several months, active treatment may not be necessary except for cosmetic purposes or because of pruritus. On the other hand, given the high rates of persistence of guttate psoriasis and progression to chronic plaque psoriasis, some authors suggest active treatment of this condition.

Conclusion

Various treatment options are available for guttate psoriasis. Triggering and exacerbating factors should be avoided if possible. Topical corticosteroids alone or in combination with other topical agents (e.g. tazarotene and vitamin D analogues) are the most rapid and efficient treatment for guttate psoriasis and are therefore the first-line treatment for mild cases. Other topical therapies include vitamin D analogues, calcineurin inhibitors, anthralin, coal tar and tazarotene. Ultraviolet phototherapy is the first-line therapy for moderate-to-severe guttate psoriasis, as it is more practical than topical therapy when treating widespread or numerous small lesions. Systemic immunosuppressive and immunomodulatory therapies (e.g. methotrexate, cyclosporine, retinoids, fumaric acid esters and biologics) may be considered for patients with moderate-to-severe guttate psoriasis who fail to respond to phototherapy and topical therapies.

Genetic Influence on Treatment Response in Psoriasis: New Insights into Personalized Medicine

Psoriasis is a chronic inflammatory disease with an established genetic background. The HLA-Cw*06 allele and different polymorphisms in genes involved in inflammatory responses and keratinocyte proliferation have been associated with the development of the disease. Despite the effectiveness and safety of psoriasis treatment, a significant percentage of patients still do not achieve adequate disease control. Pharmacogenetic and pharmacogenomic studies on how genetic variations affect drug efficacy and toxicity could provide important clues in this respect. This comprehensive review assessed the available evidence for the role that those different genetic variations may play in the response to psoriasis treatment. One hundred fourteen articles were included in this qualitative synthesis. VDR gene polymorphisms may influence the response to topical vitamin D analogs and phototherapy. Variations affecting the ABC transporter seem to play a role in methotrexate and cyclosporine outcomes. Several single-nucleotide polymorphisms affecting different genes are involved with anti-TNF-α response modulation (TNF-α, TNFRSF1A, TNFRSF1B, TNFAIP3, FCGR2A, FCGR3A, IL-17F, IL-17R, and IL-23R, among others) with conflicting results. HLA-Cw*06 has been the most extensively studied allele, although it has only been robustly related to the response to ustekinumab. However, further research is needed to firmly establish the usefulness of these genetic biomarkers in clinical practice.

CNVs Associated with Different Clinical Phenotypes of Psoriasis and Anti-TNF-Induced Palmoplantar Pustulosis

Background: Psoriasis can present different phenotypes and could affect diverse body areas. In contrast to the high effectiveness of biological drugs in the treatment of trunk and extremities plaque psoriasis, in palmoplantar phenotypes and in plaque scalp psoriasis, these same drugs usually have reduced efficacy. Anti-TNF drugs could induce the appearance of palmoplantar pustulosis (PPP) in patients with other inflammatory diseases. The objective of this study is to identify if there are DNA Copy Number Variations (CNVs) associated with these different clinical phenotypes, which could justify the differences found in clinical practice. Moreover, we intend to elucidate if anti-TNF-induced PPP has a similar genetic background to idiopathic PPP. Methods: Skin samples were collected from 39 patients with different patterns of psoriasis and six patients with anti-TNF-induced PPP. The CNVs were obtained from methylation array data (Illumina Infinium Human Methylation) using the conumee R package. Results: No significant CNVs were found between the different phenotypes and the locations of psoriasis compared. Nevertheless, we found two significant bins harboring five different genes associated with anti-TNF-induced PPP in patients with a different background other than psoriasis. Conclusions: Our results may help to predict which patients could develop anti-TNF-induced PPP.

Pharmacogenomics: An Update on Biologics and Small-Molecule Drugs in the Treatment of Psoriasis

Pharmacogenomic studies allowed the reasons behind the different responses to treatments to be understood. Its clinical utility, in fact, is demonstrated by the reduction in adverse drug reaction incidence and the improvement of drug efficacy. Pharmacogenomics is an important tool that is able to improve the drug therapy of different disorders. In particular, this review will highlight the current pharmacogenomics knowledge about biologics and small-molecule treatments for psoriasis. To date, studies performed on genes involved in the metabolism of biological drugs (tumor necrosis factor inhibitors and cytokines inhibitors) and small molecules (apremilast, dimethyl fumarate, and tofacitinib) have provided conflicting results, and further investigations are necessary in order to establish a set of biomarkers to be introduced into clinical practice.

Clinical Application of Pharmacogenetic Markers in the Treatment of Dermatologic Pathologies

Dermatologic pathologies are the fourth most common cause of non-fatal disease worldwide; however, they produce a psychosocial, economic, and occupational impact equal to or greater than other chronic conditions. The most prevalent are actinic keratosis, followed by basal-cell carcinoma, in a lesser proportion acne vulgaris, psoriasis, and hidradenitis suppurativa, among others, and more rarely dermatitis herpetiformis. To treat actinic keratosis and basal-cell carcinoma, 5-fluorouracil (5-FU) 0.5% is administered topically with good results, although in certain patients it produces severe toxicity. On the other hand, dapsone is a drug commonly used in inflammatory skin conditions such as dermatitis herpetiformis; however, it occasionally causes hemolytic anemia. Additionally, biologic drugs indicated for the treatment of moderate-to-severe psoriasis and hidradenitis suppurativa have proved to be effective and safe; nevertheless, a small percentage of patients do not respond to treatment with biologics in the long term or they are ineffective. This interindividual variability in response may be due to alterations in genes that encode proteins involved in the pathologic environment of the disease or the mechanism of action of the medication. Pharmacogenetics studies the relationship between genetic variations and drug response, which is useful for the early identification of non-responsive patients and those with a higher risk of developing toxicity upon treatment. This review describes the pharmacogenetic recommendations with the strongest evidence at present for the treatments used in dermatology, highlighting those included in clinical practice guides. Currently, we could only find pharmacogenetic clinical guidelines for 5-FU. However, the summary of product characteristics for dapsone contains a pharmacogenetic recommendation from the United States Food and Drug Administration. Finally, there is an enormous amount of information from pharmacogenetic studies in patients with dermatologic pathologies (mainly psoriasis) treated with biologic therapies, but they need to be validated in order to be included in clinical practice guides.

Paradoxical psoriasis in pediatric patients: A systematic review

BACKGROUND

Paradoxical psoriasis occurs in pediatric patients following treatment with biologic agents. These presentations are not well described, and optimal treatment strategies have not been established.

OBJECTIVE

To describe the reported rates, demographic characteristics, clinical presentation, and treatment options for TNF-α inhibitor-induced psoriasis.

METHODS

Systematic review of published cases and cohort studies of paradoxical psoriasis induced by biologic agents, with specific reference to TNF-α inhibitors.

RESULTS

We identified 4564 pediatric patients treated with TNF-α inhibitors, of whom 210 (4.6%) developed paradoxical psoriasis. Infliximab was the drug most likely to induce psoriasis (8.3%), followed by adalimumab (3.3%). Individual-level data were acquired from 129 individuals with a mean age of 13.6 years (SD: 4.0); 45.0% were male. The scalp was the most commonly affected area (47.5%), followed by the ears (30.8%). Most (63.3%) patients were continued on TNF-α inhibitor therapy. Among those who switched TNF-α inhibitors, only 32.0% had complete clearance of their skin lesions. Among patients who were switched to a non-TNF-α inhibitor, 81% had complete clearance of their paradoxical psoriasis.

LIMITATIONS

Data were acquired from retrospective studies including case reports and case series.

CONCLUSION

TNF-α inhibitor-induced psoriasis is a common adverse effect; however, most patients can continue their original therapy and be managed with skin-directed topical or systemic medications. If a patient requires medication discontinuation, switching to a new TNF-α inhibitor is unlikely to lead to resolution of their skin lesions.

Expression of microRNA-21 and TIMP-3 in paradoxical psoriasiform reactions during treatment with antitumor necrosis factor agents

BACKGROUND

Expression of microRNA-21 (miR-21) is increased in psoriasis, leading to reduced levels of epidermal tissue inhibitor of matrix metalloproteinase 3 (TIMP-3), a highly potent inhibitor of the tumor necrosis factor alpha (TNFα) sheddase TACE (TNFα-converting enzyme)/ADAM17. We described the profile of miR-21 and TIMP-3 in paradoxical psoriasiform reactions induced by anti-TNFα drugs and in a control group to elucidate the pathogenesis of this reactions.

METHODS

We performed an analytic, cross-sectional, prospective, experimental case-control study. We compared our findings with those of non-induced psoriasis.

RESULTS

We included 15 patients with a change of morphology (plaque to guttate psoriasis) and 10 patients with induced psoriasis (six palmoplantar pustulosis and four plaque psoriasis). Consecutive patients with different subtypes of non-induced, non-systemically treated psoriasis were included as a control group. We found that most cases with guttate psoriasis and with induced plaque psoriasis cases showed high expression of TIMP-3 expression and decreased or poorly increased levels of miR-21. The expression pattern was not homogeneous in the cases of induced palmoplantar pustulosis. These profiles differ from those of non-induced psoriasis.

CONCLUSION

We conclude that various pro-inflammatory cytokine profiles are involved in the pathogenesis of paradoxical psoriasiform reactions and non-induced psoriasis.

Influence of Genetic Polymorphisms on Response to Biologics in Moderate-to-Severe Psoriasis

Psoriasis is a chronic inflammatory skin pathology of autoimmune origin and unknown etiology. There are various therapies for treating it, including a wide range of biopharmaceuticals indicated in moderate-to-severe psoriasis. Depending on their therapeutic target, they are classified as tumor necrosis factor inhibitors (anti-TNF) or cytokine inhibitors (interleukin-12, 23, and 17 antagonists). Although they have proved effective and safe, in clinical practice, many patients show a short- and long-term suboptimal response and even varying degrees of toxicity. This variability in response may be influenced by genetic factors, such as polymorphisms in the genes involved in the pathological environment, metabolism or mechanism of action of the drug that could affect the effectiveness and toxicity of biological therapies. This review assesses pharmacogenetic studies of the impact of genetic factors on response to biopharmaceuticals and toxicity in patients diagnosed with moderate-to-severe psoriasis. The results suggest that polymorphisms detected in the HLA genes, in genes that encode cytokines (TNF, IL genes, TNFAIP3), transporters (PDE3A-SLCO1C1, SLC12A8), receptors (TNFRSF1B, CD84, FCGR2A and FCGR3A, IL17RA, IL23R, TLR genes, PGLYRP4) and associated proteins (TNFAIP3, LY96, TIRAP, FBXL19), as well as other genes implicated in the pathogenesis of psoriasis (CDKAL1, CARD14, PTTG1, MAP3K1, ZNF816A, GBP6, CTNNA2, HTR2A, CTLA4, TAP1) can be used in the future as predictive markers of treatment response and/or toxicity with biological therapies in patients diagnosed with moderate-to-severe psoriasis, tailoring treatment to the individual patient.

Pharmacogenetics Update on Biologic Therapy in Psoriasis

Background and objectives: Psoriasis is a chronic immune-mediated skin disease caused by several complex factors, both environmental and genetic, many of which are still not fully understood. Nowadays, several groups of biological drugs are being used for psoriasis treatment. Although these therapies are very effective, they show significant variability in efficacy among individuals. Therefore, there is a need for biomarkers to predict treatment outcomes in order to guide personalized therapeutic decisions. Pharmacogenetics is the study of variations in DNA sequences related to drug response. Materials and Methods: In this article, we review pharmacogenetics studies on the treatment of moderate-to-severe psoriasis focusing on anti-interleukin (IL) 12/23 (ustekinumab) and anti-IL17 drugs (secukinumab and ixekizumab), as well as recent studies concerning anti-TNF drugs. Results: Several polymorphisms have been studied over the years in reference to anti-TNF drugs; some of the most recent studies included the performance of a genome-wide association study (GWAS) and pharmacogenetics studies focused on the optimization of a treatment regimen. Various polymorphisms in different genes have been related to ustekinumab response; among them, the most commonly studied is the HLA-C*06:02 allele. Conclusions: Although not confirmed in some studies, most studies have shown that patients carrying this allele present a significantly higher response rate to ustekinumab. Some polymorphisms have been studied in patients treated with anti-IL17 drugs, mostly related to secukinumab; however, up to now, no association has been found between any of these polymorphisms and response. Nevertheless, further studies involving larger cohorts are needed in order to confirm these results before the implementation of this biomarker in clinical practice.

Paradoxical Psoriasis Induced by Anti-TNFα Treatment: Evaluation of Disease-Specific Clinical and Genetic Markers

Paradoxical psoriasis (PP) may occur during treatment with anti-tumor necrosis factor-alpha (TNF-α) drugs in various chronic immune-mediated diseases, mainly inflammatory bowel diseases (IBD) and psoriasis. In this study, clinical and genetic characteristics of PP arising in IBD and psoriatic patients were investigated to identify disease-specific markers of the paradoxical effect. A total of 161 IBD and psoriatic patients treated with anti-TNF-α drugs were included in the study. Of these patients, 39 developed PP. All patients were characterized for the main clinical–pathologic characteristics and genotyped for six candidate single nucleotide polymorphisms (SNPs) selected for their possible role in PP susceptibility. In IBD patients, the onset of PP was associated with female sex, presence of comorbidities, and use of adalimumab. IBD patients with PP had a higher frequency of the TNF-α rs1799964 rare allele (p = 0.006) compared with cases without the paradoxical effect, and a lower frequency of the human leucocyte antigen (HLA)-Cw06 rs10484554 rare allele (p = 0.03) compared with psoriatic patients with PP. Overall, these findings point to specific clinical and genetic characteristics of IBD patients with PP and provide data showing that genetic variability may be related to the paradoxical effect of anti-TNF-α drugs with possible implications into clinical practice.

Family history of psoriasis, psychological stressors, and tobacco use are associated with the development of tumor necrosis factor-α inhibitor-induced psoriasis: A case-control study

BACKGROUND

Tumor necrosis factor-α inhibitor-induced psoriasis (TNFI psoriasis) is a paradoxical reaction characterized by development of a psoriasiform rash that mimics psoriasis vulgaris. Temporal onset variability and low incidence rates suggest that underlying risk factors or outside triggers have a role in TNFI psoriasis initiation.

OBJECTIVES

We aimed to identify underlying risk factors and outside triggers associated with TNFI psoriasis onset.

METHODS

This case-control study included 97 patients at a tertiary care center between 2003 and 2013 who developed TNFI psoriasis. Ninety-seven control patients were matched to age, sex, disease, TNF-α inhibitor, and length of time on treatment before TNFI psoriasis onset. Patient medical records were reviewed ≥6 months immediately preceding TNFI psoriasis onset (similar equivalent time point for matched controls) for information about potential risk factors and outside factors categorized as: (1) serologic abnormalities, (2) acute events, and (3) social factors.

RESULTS

Compared with those of matched controls, odds ratios (ORs) were significantly higher in the TNFI psoriasis group for psoriasis family history (OR, 16.0) and acute psychological stressors (OR, 3.14) and marginally associated with tobacco use (OR, 1.76).

CONCLUSIONS

Our results suggest that psoriasis family history, psychological stressors, and tobacco use might be risk factors for developing TNFI psoriasis. Performing detailed patient histories when considering TNFI therapy may be useful in identifying patients at risk for TNFI-psoriasis.

Paradoxical Skin Reaction to Certolizumab, an Overlap of Pyoderma Gangrenosum and Psoriasis in a Young Woman Treated for Ankylosing Spondylitis: Case Report with Literature Review

Introduction

Biologic agents form an indispensable part of modern therapeutic regimens for the treatment of severe inflammatory diseases, especially in the fields of rheumatology, dermatology and gastroenterology. They are favoured by both physicians and patients due to their high effectiveness, good patient tolerance and safety. However, interference in the regulation and dynamics of inflammatory cytokines can on occasion lead to an onset of a dermatological condition also known as paradoxical skin reaction. Here, we present a case of paradoxical skin reaction induced by certolizumab.

Case Report

A young woman with ankylosing spondylitis developed a severe and complex cutaneous reaction after 6 months of otherwise successful treatment with certolizumab. The diagnosis of a rare paradoxical cutaneous reaction post anti-tumour necrosis factor alpha treatment was based on overlapping features of pyoderma gangrenosum and palmoplantar pustular psoriasis. Alopecia developed and there was also nail involvement. Treatment proved to be challenging as the disease did not remit after the patient ceased treatment with certolizumab. The patient was started on a combination of secukinumab and methotrexate to control the symptoms, with a promising outcome.

Conclusion

Paradoxical skin reactions are an emerging clinical entity that require further research in order to establish risk factors and best personalized treatment.

Genetic influences on susceptibility to rheumatoid arthritis in African-Americans

Large meta-analyses of rheumatoid arthritis (RA) susceptibility in European (EUR) and East Asian (EAS) populations have identified >100 RA risk loci, but genome-wide studies of RA in African-Americans (AAs) are absent. To address this disparity, we performed an analysis of 916 AA RA patients and 1392 controls and aggregated our data with genotyping data from >100 000 EUR and Asian RA patients and controls. We identified two novel risk loci that appear to be specific to AAs: GPC5 and RBFOX1 (PAA < 5 × 10-9). Most RA risk loci are shared across different ethnicities, but among discordant loci, we observed strong enrichment of variants having large effect sizes. We found strong evidence of effect concordance for only 3 of the 21 largest effect index variants in EURs. We used the trans-ethnic fine-mapping algorithm PAINTOR3 to prioritize risk variants in >90 RA risk loci. Addition of AA data to those of EUR and EAS descent enabled identification of seven novel high-confidence candidate pathogenic variants (defined by posterior probability > 0.8). In summary, our trans-ethnic analyses are the first to include AAs, identified several new RA risk loci and point to candidate pathogenic variants that may underlie this common autoimmune disease. These findings may lead to better ways to diagnose or stratify treatment approaches in RA.

Paradoxical psoriasis induced by TNF-α blockade shows immunological features typical of the early phase of psoriasis development

Immunomodulation with anti‐TNF‐α is highly effective in the treatment of various immune‐mediated inflammatory diseases, including hidradenitis suppurativa (HS). However, this may be responsible for unexpected paradoxical psoriasiform reactions. The pathogenic mechanisms underlying the induction of these events are not clear, even though the involvement of innate immune responses driven by plasmacytoid dendritic cells (pDC) has been described. In addition, the genetic predisposition to psoriasis of patients could be determinant. In this study, we investigated the immunological and genetic profiles of three HS patients without psoriasis who developed paradoxical psoriasiform reactions following anti‐TNF‐α therapy with adalimumab. We found that paradoxical psoriasiform skin reactions show immunological features common to the early phases of psoriasis development, characterized by cellular players of innate immunity, such as pDC, neutrophils, mast cells, macrophages, and monocytes. In addition, IFN‐β and IFN‐α2a, two type I IFNs typical of early psoriasis, were highly expressed in paradoxical skin reactions. Concomitantly, other innate immunity molecules, such as the catheledicin LL37 and lymphotoxin (LT)‐α and LT‐β were overproduced. Interestingly, these innate immunity molecules were abundantly expressed by keratinocytes, in addition to the inflammatory infiltrate. In contrast to classical psoriasis, psoriasiform lesions of HS patients showed a reduced number of IFN‐γ and TNF‐α‐releasing T lymphocytes. On the contrary, IL‐22 immunoreactivity was significantly augmented together with the IL‐36γ staining in leukocytes infiltrating the dermis. Finally, we found that all HS patients with paradoxical reactions carried allelic variants in genes predisposing to psoriasis. Among them, SNPs in ERAP1, NFKBIZ, and TNFAIP genes and in the HLA‐C genomic region were found.

Histone modifications associated with biological drug response in moderate-to-severe psoriasis

INTRODUCTION

Epigenetic factors play an important role in psoriasis onset and development. Biological drugs are used to treat moderate-to-severe psoriasis patients resistant to conventional systemic drugs. Although they are safe and effective, some patients do not respond to them. Therefore, it is necessary to find biomarkers that could predict response to these therapies.

OBJECTIVE

To find epigenetic biomarkers that could predict response to biological drugs (ustekinumab, secukinumab, adalimumab, ixekizumab).

MATERIALS AND METHODS

Peripheral blood mononuclear cells (PBMCs) were isolated from 39 psoriasis patients treated with biological therapies before and after drug administration and from 42 healthy subjects. Afterwards, histones were extracted from PBMCs. Four histone modifications (H3 and H4 acetylation, H3K4 and H3K27 methylation) were determined by ELISA. Data were analysed by IBM-SPSS v.23.

RESULTS AND CONCLUSIONS

Psoriasis patients presented reduced levels of acetylated H3 and H4 and increased levels of methylated H3K4 compared to controls. Non-significant changes were observed after treatment administration in any of the histone modifications analysed. Nevertheless, significant changes in methylated H3K27 were found between responders and non-responders to biological drugs at 3 months. As 28% of these patients also presented psoriatic arthritis (PsA), the former analysis was repeated in the subsets of patients with or without PsA. In patients without PsA, significant changes in methylated H3K4 were found between responders and non-responders to biological drugs at 3 and 6 months. Although further studies should confirm these results, these findings suggest that H3K27 and H3K4 methylation may contribute to patients' response to biological drugs in psoriasis.

Pharmacogenetics: A strategy for personalized medicine for autoimmune diseases

For many years, a considerable number of patients with autoimmune diseases (ADs) have suffered from a lack of drug response and drug-related toxicity. Despite the emergence of new therapeutic options such as biological agents, patients continue to struggle with these problems. Unfortunately, new challenges, including the paradoxical effects of biological drugs, have complicated the situation. In recent decades, efforts have been made to predict drug response as well as drug-related side effects. Thanks to the many advances in genetics, evaluation of markers to predict drug response/toxicity before the initiation of treatment may be an avenue toward personalizing treatments. Implementing pharmacogenetics and pharmacogenomics in the clinic could improve clinical care; however, obstacles remain to effective personalized medicine for ADs. The present study attempted to clarify the concept of pharmacogenetics/pharmacogenomics for ADs. After an overview on the pathogenesis of the most common types of treatments, this paper focuses on pharmacogenetic studies related to the selected ADs. Bridging the gap between pharmacogenetics and personalized medicine is also discussed. Moreover, the advantages, disadvantages and recommendations related to making personalized medicine practical for ADs have been addressed.

Paradoxical Skin Reactions to Biologics in Patients With Rheumatologic Disorders

Targeted immune-modulating treatment with biological agents has revolutionized the management of immune-mediated inflammatory diseases, including rheumatologic conditions. The efficacy and tolerability of biological agents, from the initial tumour necrosis factor (TNF)-α inhibitors to the new anti-cytokine monoclonal antibodies, have dramatically changed the natural history of debilitating conditions such as rheumatoid arthritis and seronegative spondyloarthropathies. The widening use of biologics across several rheumatologic diseases has been associated with a new class of adverse events, the so-called paradoxical reactions. These events are inflammatory immune-mediated tissue reactions, developing paradoxically during treatment of rheumatologic conditions with targeted biologics that are commonly used for treating the idiopathic counterparts of these drug-induced reactions. The skin is frequently involved, and, even if considered rare to uncommon, these cutaneous manifestations are an important cause of biologic agent discontinuation. TNF-α antagonist-induced psoriasis, which can manifest de novo or as exacerbation of a pre-existing form, is the prototypic and most frequent paradoxical skin reaction to biologics while other reactions, such as eczematous and lichenoid eruptions, hidradenitis suppurativa, pyoderma gangrenosum, Sweet’s syndrome and granulomatous skin diseases, occur much more rarely. Management of these reactions consists of topical or systemic skin-directed therapies, depending on the severity and extension of the cutaneous picture, and it is generally associated with switching over to other disease-modifying regimens for treating the underlying rheumatologic condition. Here, we review in detail the current concepts and controversies on classification, pathogenesis and clinical management of this new class of cutaneous adverse events induced by biologics in rheumatologic patients.

Psoriasis: Classical vs. Paradoxical. The Yin-Yang of TNF and Type I Interferon

Chronic plaque psoriasis is a common debilitating skin disease. The identification of the pathogenic role of the TNF/IL-23/T_H17 pathway has enabled the development of targeted therapies used in the clinic today. Particularly, TNF inhibitors have become a benchmark for the treatment of numerous chronic inflammatory diseases such as psoriasis. Although being highly effective in psoriasis treatment, anti-TNFs can themselves induce psoriasis-like skin lesions, a side effect called paradoxical psoriasis. In this review, we provide a comprehensive look at the different cellular and molecular players involved in classical plaque psoriasis and contrast its pathogenesis to paradoxical psoriasis, which is clinically similar but immunologically distinct. Classical psoriasis is a T-cell mediated autoimmune disease driven by TNF, characterised by T-cells memory, and a relapsing disease course. In contrast, paradoxical psoriasis is caused by the absence of TNF and represents an ongoing type-I interferon-driven innate inflammation that fails to elicit T-cell autoimmunity and lacks memory T cell-mediated relapses.

Complications of Treatments for Pediatric Rheumatic Diseases

Medications to treat children with rheumatic disease include disease-modifying antirheumatic drugs, glucocorticosteroids, and biologic response modifiers that target mediators and cells involved in autoimmunity and inflammation. Although usually well-tolerated, such medications have many possible side effects, of which primary care and emergency providers should be aware. Both disease and immunosuppression contribute to susceptibility to unusual and opportunistic infections, in addition to usual childhood infections for which these children should receive all applicable nonlive vaccines. Close coordination between the rheumatologist and other medical care providers is essential, because medication side effects, infections, and disease flares are difficult to distinguish, and may occur together.

Paradoxical Reactions to Biologic Therapy in Psoriasis: A Review of the Literature

Biologic drugs, which are molecules designed to act on specific immune system targets, have been shown to be very effective in treating various dermatological, rheumatological, and systemic diseases. As a group, they have an acceptable safety profile, but their use has been associated with the onset of both systemic and organ-specific inflammatory conditions. True paradoxical reactions are immune-mediated disorders that would usually respond to the biologic agent that causes them. There is still debate about whether certain other adverse reactions can be said to be paradoxical. The hypotheses proposed to explain the pathogenesis of such reactions include an imbalance in cytokine production, with an overproduction of IFN-α and altered lymphocyte recruitment and migration (mediated in part by CXCR3), and the production of autoantibodies. Some biologic therapies favor granulomatous reactions. While most of the paradoxical reactions reported have been associated with the use of TNF-α inhibitors, cases associated with more recently introduced biologic therapies -such as ustekinumab, secukinumab, and ixekizumab- are increasingly common. The study of paradoxical adverse events not only favors better management of these reactions in patients receiving biologic therapy, but also improves our knowledge of the pathogenesis of chronic inflammatory diseases and helps to identify potential therapeutic targets.

Paradoxical skin lesions induced by anti-TNF-α agents in SAPHO syndrome

The objectives of the study were to characterize the clinical picture of paradoxical skin lesions in SAPHO patients treated with anti-TNF-α agents and to explore its pathogenesis. Patients treated with anti-TNF-α therapy were identified from a cohort of 164 SAPHO patients. The clinical data and skin biopsies were collected. The usage, efficacy, and side effects of anti-TNF-α therapy were recorded. Forty-one (25.0%) patients received anti-TNF-α therapy, of which seven (17.1%) developed paradoxical skin lesions after 1 to 14 infusions. Patients with such lesions were older at onset of skin lesions than those without (p = 0.034). Expression of TNF-α in palmoplantar pustulosis increased after anti-TNF-α therapy in the two examined patients with exacerbated skin lesions. Anti-TNF-α therapy induces paradoxical skin lesions in 17.1% SAPHO patients. Late onset of skin manifestations is associated with an increased risk of such lesions. The paradoxical elevation of TNF-α expression in lesions may contribute to this phenomenon.

Psoriasiform Eruption and Worsening of Pustulosis Palmoplantaris After Treatment with Two Anti-TNF-α Inhibitors, Followed by Successful Treatment with Ustekinumab

Introduction

Tumor necrosis factor (TNF)-α inhibitors are widely used for the treatment of inflammatory diseases. One of the side effects of TNF-inhibitors is the development of a psoriatiform eruption, also known as paradoxical psoriasis. In this case report, we describe a patient with this side effect after treatment with adalimumab and etanercept.

Case Report

A 45-year-old female was treated with adalimumab 40 mg once every 2 weeks for pustulosis palmoplantaris and psoriatic arthritis. After 2 injections, the patient developed a psoriatiform eruption on her body, which improved after discontinuation of adalimumab but worsened after treatment with etanercept 50 mg twice weekly. Eventually, the patient was treated with topical corticosteroids and ustekinumab 45 mg once every 3 months with a complete remission of the psoriatiform eruption.

Discussion

Several case reports and reviews have been published in recent years which describe patients with a psoriatiform eruption after treatment with TNF-α inhibitors. The pathogenesis that causes this psoriatic eruption is unclear. In conclusion, we describe a patient with a psoriatiform eruption after treatment with adalimumab and etanercept. This patient had to discontinue the treatment and eventually had a complete response after treatment with topical corticosteroids and treatment with ustekinumab.

Pharmacogenetics and pharmacogenomics in psoriasis treatment: current challenges and future prospects

INTRODUCTION

Topical, systemic, oral disease modifying, and biologic agents are part of the armamentarium to manage psoriatic disease. The choice of therapy depends upon disease severity, relevant co-morbidities and patient preference. There is great variability in patient response with these agents, and there is still no clear method of selecting the preferred therapeutic agent for efficacy or lack of adverse events.

AREAS COVERED

This article will review the pharmacogenetic and pharmacogenomic targets that are currently known with respect to psoriasis vulgaris, and the most frequent co-morbidity of psoriasis, psoriatic arthritis.

EXPERT OPINION

Presently, no clinically actionable biomarker exists for any therapeutic agent used to treat psoriasis or psoriatic arthritis. The lack of validated outcome measures and conflicting results of open-label studies conducted may be attributed to a multitude of issues that confound discovery. Consequently, studies have been underpowered to identify genes or genetic variants worth translating to clinical practice. In order to achieve a pharmacogenetic/pharmacogenomic signature, improvements in study design of future investigations are required, including carefully designed prospective studies. It is imperative to combine known clinical, serological, and molecular markers with consistent outcomes and an adequate health economic evaluation before they can be adopted widely in clinical practice.