Infliximab-induced psoriasis and psoriasiform skin lesions in pediatric Crohn disease and a potential association with IL-23 receptor polymorphisms

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.

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.

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.

Paradoxical Psoriasiform Eruptions in Children Receiving Tumor Necrosis Factor α Inhibitors

Importance

Tumor necrosis factor α (TNF) inhibitor-induced psoriasiform eruption is well recognized in adults, but few reports document this paradoxical effect in children.

Objective

To characterize the clinical features and the clinical time course of TNF inhibitor-induced psoriasiform eruptions in children.

Design, Setting, and Participants

A multicenter retrospective case series of children younger than 18 years seen between January 1, 2000, and December 31, 2016, who developed a new-onset psoriasiform eruption while taking a TNF inhibitor for a nondermatologic disorder. Participating sites were members of the Pediatric Dermatology Research Alliance. Data were entered into a Research Electronic Data Capture database at the Mayo Clinic (ie, the coordinating center).

Results

Psoriasiform eruptions were identified in 103 TNF inhibitor-treated patients (median age, 13.8 years [IQR, 11.7-16.4 years]; 52 female patients [50%]; 57 White patients [55%]), with 67 patients (65%) treated with infliximab, 35 (34%) with adalimumab, and 1 (1%) with certolizumab pegol. Most patients had no personal history (101 [98%]) or family history of psoriasis (60 patients [58%]). Inflammatory bowel disease was the most common indication for treatment with TNF inhibitor (94 patients [91%]). The primary extracutaneous disease was under control in 95 patients (92%) who developed the eruption. Most patients (n = 85 [83%]) developed psoriasiform eruptions at multiple anatomic sites, with scalp involvement being most common (65 patients [63%]). Skin disease developed at a median of 14.5 months (IQR, 9-24 months) after TNF inhibitor initiation. To treat the psoriasiform eruption, topical steroidal and nonsteroidal medication was prescribed for all patients. Systemic therapy was added for 30 patients (29%): methotrexate for 24 patients (23%), oral corticosteroids for 8 patients (8%), and azathioprine for 1 patient (1%). For 26 patients (25%), suboptimal effectiveness with topical medications alone prompted discontinuation of the initial TNF inhibitor and a change to a second-line TNF inhibitor with cutaneous improvement in 23 patients (88%) by a median of 3 months (IQR, 2-4 months). Eight patients (31%) who started a second-line TNF inhibitor developed a subsequent TNF inhibitor-induced psoriasiform eruption at a median of 6 months (IQR, 4-8 months). Persistent skin disease in 18 patients (17%) prompted discontinuation of all TNF inhibitors; 11 patients changed to a non-TNF inhibitor systemic therapy, and 7 discontinued all systemic therapy.

Conclusions and Relevance

In this case series, paradoxical TNF inhibitor-induced psoriasiform eruptions were seen in children treated with TNF inhibitors for any indication, and there appears to be a class effect among the varying TNF inhibitors. The majority of these children were able to continue TNF inhibitor therapy with adequate skin-directed and other adjuvant therapies.

Tumor necrosis factor-α inhibitor-related immune disorders

Biotechnological monoclonal antibodies and receptor antagonists capable of targeting specific inflammatory actors, such as cytokines, cytokines receptors, co-stimulatory molecules or leukocyte populations, have emerged as an alternative to conventional therapies for treating systemic inflammatory diseases with immune pathogenesis. However, there is no doubt that, with a frequency that is not exceptionally high but also not negligible, immunotherapies can favour the development of systemic and organ-specific immune-mediated disorders. It has become increasingly evident that interference with a specific immune pathway may favour the activation of opposing compensatory signalling, which may exacerbate underlying subclinical disorders or cause immune-mediated diseases completely different from the underlying disease. The 'compensatory immunological switch' has emerged primarily in patients treated with tumor necrosis factor (TNF) -α inhibitors, the first biological drugs approved for treating systemic inflammatory diseases with immune pathogenesis. In this Review, we describe the clinical features and predisposing factors of the main TNF-α inhibitor-related immune disorders, organising them into subclinical serological autoimmunity, autoimmune disorders other than those for which TNF-α inhibitors are indicated, and paradoxical reactions. We also discuss the underlying pathogenetic mechanisms and precautions for use in the therapeutic management of these patients. Better understanding of the complex phenomenon of the 'compensatory immunological switch', which TNF-α inhibitors and other biological drugs might trigger, can help not only appropriately managing immune-mediated disorders, but also better interpreting the heterogeneity of the pathogenetic mechanisms underlying certain chronic inflammatory conditions that, although different from each other, are arbitrarily placed in the context of overly generic nosological entities.

Immunosuppressant-associated eruptions in pediatric inflammatory bowel disease: A case-control study

Paradoxically, immunosuppressive therapy for inflammatory bowel disease (IBD) can induce psoriasiform or eczematous eruptions. This case-control study identified infliximab exposure, Crohn's disease, and history of inflammatory skin conditions as significant risk factors for these eruptions in children with IBD. Our results also showed possible trends in age and race.

Review article: paradoxical psoriasis as a consequence of tumour necrosis factor antagonists in patients with inflammatory bowel disease

BACKGROUND

Tumour necrosis factor (TNF) antagonists are an efficacious therapy used in the management of several immune-mediated inflammatory diseases, including inflammatory bowel disease (IBD) and psoriasis. However, since being prescribed more widely, reports of new-onset psoriatic lesions have began to emerge in the literature and are known as paradoxical psoriasis.

AIM

To review the evidence available in both the dermatology and gastroenterology literature pertaining to the entity known as paradoxical psoriasis as it relates to IBD and to create a comprehensive guide to assist clinicians who treat this challenging patient population.

METHODS

A literature search was conducted in PubMed to identify manuscripts that presented, discussed or summarised data pertaining to paradoxical psoriasis presenting in individuals with IBD.

RESULTS

Paradoxical psoriasis is now thought to be a contradictory effect of TNF antagonist therapy leading to psoriatic lesions often within the first year of treatment. The underlying pathogenesis, although not completely understood, is likely related to an imbalance of inflammatory cytokines. The histological appearance, while similar to classical psoriasis, does have unique features. The clinical presentation can vary among patients but often presents during maintenance therapy for inflammatory bowel disease. Treatment options should be determined based upon the severity of the skin lesion, activity of the underlying inflammatory bowel disease and the patient's unique clinical history.

CONCLUSIONS

The approach to paradoxical psoriasis in IBD should be discussed with a multidisciplinary team to optimise and preserve intestinal disease remission and to ensure the resolution of debilitating skin lesions.

Incidence of and Risk Factors for Paradoxical Psoriasis or Psoriasiform Lesions in Inflammatory Bowel Disease Patients Receiving Anti-TNF Therapy: Systematic Review With Meta-Analysis

Background

Paradoxical psoriasis or psoriasiform lesions induced by anti-tumor necrosis factor (anti-TNF) therapies receive increasing attention worldwide. However, no comprehensive meta-analysis investigating the incidence estimates and risk factors for anti-TNF-induced psoriasis is currently available. We aimed to precisely quantify its incidence as well as risk factors in patients with inflammatory bowel disease (IBD).

Methods

This study was registered on PROSPERO database under review registration number CRD42021233695. The electronic databases PubMed, EMBASE, and the Cochrane library were comprehensively searched for observational studies published as full-length papers in English and reporting the incidence and/or predictors for psoriasis or psoriasiform lesions in IBD patients. A random-effects meta-analysis was performed to calculate the pooled incidence. Pooled odds ratio (OR) and 95% confidence interval for potential predictors were combined using a fixed-effects or random-effects model.

Results

In total, 30 articles comprising 24,547 IBD patients treated by anti-TNF were finally included. The overall pooled incidence of psoriasis and/or psoriasiform lesions following anti-TNF therapy was 6.0% (5.0–7.0%; I² = 93.9%), with 6.9% (5.1–8.7%; I² = 92.4%) for psoriasiform lesions and 4.6% (3.6–5.6%; I² = 93.9%) for psoriasis. Multivariable meta-regression analysis indicated regions and populations that significantly contributed to the heterogeneity. A statistically higher risk for psoriasis or psoriasiform lesions during anti-TNF therapy was observed in female patients (OR 1.46, 1.23–1.73), those who are at a younger age at anti-TNF initiation (OR 1.03, 1.00–1.05), smokers (OR 1.97, 1.56–2.48), ileocolonic Crohn’s disease patients (OR 1.48, 1.03–2.13), and those who are using adalimumab or certolizumab (vs. infliximab) (OR: 1.48 and 2.87 respectively).

Conclusions

The incidence of psoriasis or psoriasiform lesions was not uncommon in IBD patients following anti-TNF therapy. Female, younger age, smoker, ileocolonic Crohn’s disease, and the types of anti-TNF were significantly associated with such risk. These findings may help gastroenterologists to make more individualized decisions and understand the mechanisms of this paradoxical phenomenon.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=233695, identifier CRD42021233695.

Incidence Rates of Psoriasis in Children with Inflammatory Bowel Disease and Juvenile Arthritis Treated with TNFi Agents and DMARDs

Objective

To estimate the differential effect of tumor necrosis factor inhibitor (TNFi) therapies and presence/absence of conventional synthetic disease-modifying antirheumatic drug (DMARD) on the incidence of psoriasis in children with inflammatory bowel disease (IBD), juvenile idiopathic arthritis (JIA), and chronic nonbacterial osteomyelitis (CNO).

Methods

This was a retrospective cohort study from 2008 to 2020. TNFi and DMARD exposures were dichotomized as ever/never. The primary outcome was incident psoriasis. Incidence rates (IRs) of psoriasis were stratified by underlying diagnosis, TNFi agent, and DMARD use. Poisson regression was used to assess the IR ratios (IRR) between exposure groups.

Results

5088 children met inclusion criteria – 3794 (75%) had IBD, 1189 (23%) had JIA, and 105 (2%) had CNO. 613 (30%) and 1410 (70%) had TNFi exposure with or without a DMARD, respectively. IRR of developing psoriasis in patients exposed to adalimumab was 2.70 times higher (95% CI: 1.52-4.75; p<0.001) than those who did not receive any TNFi treatment, when controlling for DMARD, sex, and family history of psoriasis. IRR was lower, but not significantly different, for patients exposed to infliximab (IRR=2.34; 95% CI: 1.56-3.51; p<0.001) and etanercept (IRR=2.22; 95% CI: 1.17-4.21; p=0.006) compared to TNFi unexposed patients. IRR of TNFi exposure was lower by 0.25 (p<0.001) in DMARD exposed patients compared to non- DMARD exposed patients.

Conclusion

IRR of TNFi-induced psoriasis was not significantly different amongst adalimumab, infliximab, and etanercept. However, for patients with exposure to any of the TNFi evaluated, the IRR was significantly lower in those also exposed to a DMARD.

The relapse of psoriasis: what’s the veil of mystery?

Over the past decades, tremendous success in the treatment of psoriasis has been achieved using biologics, such as neutralizing antibodies against TNF/TNFR, IL-23, and IL-17A/IL-17RA. Although psoriatic skin lesions appear to resolve after treatment with these biologics, lesions often recur after therapy is discontinued or during therapy. Memory T cells residing in the skin have been considered as the major driver of psoriasis relapse. However, whether structural cells in the skin such as keratinocytes and fibroblasts are involved in the relapse of psoriasis is unknown. In this review, we outline the therapeutic rationale of biologics used in the treatment of psoriasis, summarize different clinical features of psoriasis relapse on the basis of preclinical and clinical data, and specifically discuss how memory T cells and structural cells in the skin are involved in psoriasis relapse. Finally, we discuss the future challenges in the basic or clinical research on psoriasis.

Psoriasis rate is increased by the exposure to TNF inhibition in children with JIA

OBJECTIVE

We aimed to investigate the relationship between tumour necrosis factor inhibitors (TNFi) therapy and the onset of new psoriasis in children with juvenile idiopathic arthritis (JIA) using Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry data.

METHODS

De-identified data were obtained from the CARRA Registry. Patients with inflammatory bowel disease or psoriasis documented on or prior to JIA diagnosis date or with incomplete data were excluded. Exposure to TNFi was categorised as: (1) ever use; (2) current use or (3) first use only. Adjusted HRs (aHRs) were calculated between exposed and unexposed groups adjusted for methotrexate exposure, sex, race, family history of psoriasis and initial JIA category.

RESULTS

A total of 8225 patients were included with a median follow-up of 3.9 years. Over half of the patients were prescribed TNFi (n=4437, 54%). The aHR of new onset of psoriasis after ever exposure to TNFi was 2.93 (2.15 to 3.98). The incidence rate of psoriasis was the highest in children ever receiving and actively receiving adalimumab. Ever concurrent methotrexate use (HR 0.45, 0.29 to 0.69) was associated with lower risk.

CONCLUSION

In a large prospective JIA patient registry, we observed a nearly threefold increased risk of psoriasis after TNFi exposureCite Now.

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.

Risk factors for dermatological complications of anti-TNF therapy in a cohort of children with Crohn's disease

Studies showing a substantial frequency of dermatologic complications in paediatric Crohn's disease (CD) patients on anti-tumour necrosis factor (TNF) therapy preferentially include patients treated with infliximab. We aimed to identify risk factors for the cumulative incidence of skin complications in a paediatric cohort receiving either adalimumab or infliximab and found an association between current skin complications and the patient's current clinical condition. This study retrospectively evaluated dermatologic complications in an inception cohort of 100 paediatric CD patients receiving the first anti-TNF (Motol PIBD cohort). Patient data were collected every 3 months. The lesions were classified as psoriatic, atopic dermatitis, or others. We used Cox regression to evaluate the association between predefined variables and the time to complication and a generalised linear mixed model to assess the association between the patient's current condition and the occurrence of complications. Among the 89 included children, 35 (39%) presented with dermatologic lesions. The only predictor associated with any complication was infliximab (versus adalimumab) therapy (hazard ratio [HR]: 2.07; 95% confidence interval [CI]: 1.03-4.17; p = 0.04). Infliximab therapy (HR: 5.5; 95%CI: 1.59-19.06; p = 0.01) and a family history of atopy (HR: 3.4; 95%CI 1.35-8.57, p = 0.002) were associated with early manifestation of atopic dermatitis. Lower C-reactive protein levels (odds ratio [OR], 0.947; 95% CI, - 0.898 to 0.998; p = 0.046) and infliximab (versus adalimumab) were associated with the occurrence of any dermatologic complications (OR, 5.93; 95% CI, 1.59-22.07; p = 0.008).Conclusion: The frequency of skin complications seems high in paediatric CD patients treated with anti-TNF and is even higher in those treated with infliximab. What is Known: •The dermatologic complications occur during treatment with anti-tumour necrosis factor. •The frequency of skin complications in paediatric patients with Crohn's disease is high. What is New: •Infliximab (vs. adalimumab) was identified as a strong risk factor for the cumulative incidence of skin complications. •Lower C-reactive protein levels were associated with the current occurrence of dermatologic complications.

Paradoxical Psoriasis in Children Receiving Anti-TNFα Treatment for Inflammatory/autoimmune Disease

Tumor necrosis factor alpha inhibitors (TNFi) are widely used in children with autoimmune and autoinflammatory conditions. Although TNFi are approved to treat psoriasis, they have also been shown to paradoxically induce psoriasiform lesions. In this review, we aim to focus on the clinical presentation and management of paradoxical psoriasis after exposure to TNFi in children with juvenile idiopathic arthritis (JIA), inflammatory bowel disease (IBD), or chronic nonbacterial osteomyelitis (CNO). A narrative review of the literature was performed given the limited number of publications on this topic. Children with IBD, CNO, and JIA have a higher risk of developing psoriasis at baseline, which increases after TNFi use in those with JIA and IBD. Risk factors for paradoxical psoriasis remain incompletely defined, and patients with IBD and/or CNO develop paradoxical psoriasis more commonly than those with JIA. Sex, race, and family history were not significantly associated with paradoxical psoriasis. The most commonly implicated TNFi include infliximab and adalimumab. Paradoxical psoriasis occurs in a similar distribution on the body to isolated psoriatic lesions and is morphologically indistinguishable. In many instances, topical therapies are effective in treating psoriasis and children can continue on TNFi for their primary disease. If lesions are severe or unacceptable to patients, TNFi may be switched or discontinued. Further research is needed to better characterize risk factors and understand the mechanism of disease pathogenesis. Pediatric health care providers who prescribe TNFi should counsel families regarding the risk of paradoxical psoriasis prior to starting the medication and monitor for new cutaneous eruptions.

Psoriasis Associated With Tumor Necrosis Factor Inhibitors in Children With Inflammatory Diseases

OBJECTIVE

To estimate the incidence rate (IR) of psoriasis in children with inflammatory bowel disease (IBD), juvenile idiopathic arthritis (JIA), and chronic noninfectious osteomyelitis (CNO) with tumor necrosis factor inhibitor (TNFi) exposure as compared to children without TNFi exposure and to the general pediatric population.

METHODS

This was a single-center retrospective cohort study of children with IBD, JIA, or CNO from 2008 to 2018. TNFi exposure was defined as a prescription for adalimumab, etanercept, infliximab, certolizumab, or golimumab, and the primary outcome was incident psoriasis. IRs and standardized incidence ratios (SIRs) were calculated. Cox proportional hazards models were used to assess the association of psoriasis with TNFi exposure and other risk factors.

RESULTS

Of the 4,111 children who met inclusion criteria, 1,614 (39%) had TNFi exposure and 2,497 (61%) did not, with 4,705 and 6,604 person-years of follow-up, respectively. There were 58 cases (IR 12.3 per 1,000 person-years) and 25 cases (IR 3.8 per 1,000 person-years) of psoriasis in children with and without TNFi exposure, respectively. The SIR was 18 (95% confidence interval [95% CI] 15-22) overall, 30 (95% CI 23-39) for children with TNFi exposure, and 9.3 (95% CI 6.3-14) for children without TNFi exposure. The hazard ratio of psoriasis comparing TNFi exposure to no TNFi exposure was 3.84 (95% CI 2.28-6.47; P < 0.001).

CONCLUSION

Children with IBD, JIA, and CNO had an increased rate of psoriasis compared to the general pediatric population, with the highest rate in those with TNFi exposure.

Paradoxical eruptions to targeted therapies in dermatology: A systematic review and analysis

BACKGROUND

Antibody-based therapies that inhibit proinflammatory cytokine signaling are commonly used in dermatology. Paradoxically, these medications may induce or exacerbate inflammatory disorders.

OBJECTIVE

To summarize the spectrum of manifestations, incidence, timing, potential mechanisms of, and general management approaches to paradoxical cutaneous reactions induced by cytokine-targeted antibodies in dermatology.

METHODS

We performed a systematic review and analysis of published cases of cutaneous paradoxical reactions (PRs) reported in association with tumor necrosis factor α, interleukin (IL) 12/23 (p40), IL-17A/17R, IL-23 (p19), and IL-4Rα inhibitors.

RESULTS

We identified 313 articles reporting 2049 cases of PRs. Tumor necrosis factor α inhibitors resulted in 91.2% (1869/2049) of all cases, followed by IL-17/17R (3.5%), IL-4Rα (2.7%), IL-12/23 (2.4%), and IL-23 (0.01%) inhibitors. Psoriasiform and eczematous eruptions were the most commonly reported, but a wide spectrum of patterns were described. Phenotypically overlapping reaction patterns were common. Time to onset typically ranged from weeks to months but could occur more than a year later. Improvement or resolution upon discontinuation of the inciting drug was common.

LIMITATIONS

This was a retrospective analysis.

CONCLUSIONS

Familiarity with the clinical features of PRs from cytokine-blocking antibodies may facilitate efficient recognition and management.

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.

Dermatological Manifestations in Pediatric Inflammatory Bowel Disease

Background and Objectives: Over the last years, inflammatory bowel disease (IBD) has been reported on a high incidence in pediatric populations and has been associated with numerous extraintestinal manifestations, making its management a real challenge for the pediatric gastroenterologist. Dermatological manifestations in IBD are either specific, related to the disease activity or treatment-associated, or non-specific. This literature review aims to identify and report the dermatological manifestations of IBD in children, the correlation between their appearance and the demographical characteristics, the relationship between these lesions and disease activity, and to highlight the impact of dermatological manifestations on an IBD treatment regime. Materials and Methods: A systemic literature review was performed, investigating articles and case reports on dermatological manifestations in children with IBD starting from 2005. A total of 159 potentially suitable articles were identified and after the exclusion process, 75 articles were selected. Results: The most common dermatological manifestations reported in pediatric IBD are erythema nodosum and pyoderma gangrenosum. More rare cases of metastatic Crohn’s disease, epidermolysis bullosa acquisita, small-vessel vasculitis, necrotizing vasculitis, leukocytoclastic vasculitis, cutaneous polyarteritis nodosa, and Sweet’s syndrome have been reported. Oral manifestations of IBD are divided into specific (tag-like lesions, mucogingivitis, lip swelling with vertical fissures, aphthous stomatitis, and pyostomatitis vegetans) and non-specific. IBD treatment may present with side effects involving the skin and mucosa. Anti-tumor necrosis factor agents have been linked to opportunistic skin infections, psoriasiform lesions, and a potentially increased risk for skin cancer. Cutaneous manifestations such as acrodermatitis enteropathica, purpuric lesions, and angular cheilitis may appear secondary to malnutrition and/or malabsorption. Conclusions: The correct diagnosis of dermatological manifestations in pediatric IBD is of paramount importance because of their impact on disease activity, treatment options, and a patient’s psychological status.

Skin Manifestations in Pediatric Patients Treated With a TNF-Alpha Inhibitor for Inflammatory Bowel Disease: A Retrospective Study [Formula: see text]

BACKGROUND

Tumor necrosis factor (TNF) alpha inhibitors (anti-TNF) are effective in the treatment of inflammatory bowel disease (IBD) as well as psoriasis. Their increasing use has raised the identification of cutaneous side effects (CSEs). Evidence in children is limited.

OBJECTIVES

The objective of this study is to describe CSEs of anti-TNF treatment in a pediatric population with IBD.

METHODS

This is a retrospective single-center study of children with IBD under anti-TNF treatment between 2013 and 2016. A total of 40 patients with CSEs related to anti-TNF were referred to our pediatric dermatology clinic. A control group was randomly selected from patients receiving anti-TNF for IBD, who were referred to the dermatology clinic for other conditions unrelated to anti-TNF.

RESULTS

Of 343 patients with IBD, 40 (11.3%) presented CSEs potentially related to the treatment. No differences in sex, age, and underlying disease were found between those with and without CSEs. The most frequent CSEs were psoriasiform eruptions (41%) which were more exudative than usual, located especially in skin folds and on the scalp; skin infections (20%); and eczematous eruptions (10%). Only 5% of patients changed or discontinued the current anti-TNF because of CSEs.

CONCLUSION

This is one of the largest pediatric cohorts of IBD patients with CSEs. Psoriasiform eruptions were the most common CSEs, with predilection for skin folds and scalp, and frequent superimposed bacterial infection. Topical and/or systemic antibiotics were required in addition to topical corticosteroids in 25% of patients. The rate of discontinuation of anti-TNF therapy due to CSEs was low.

Global Prevalence and Bidirectional Association Between Psoriasis and Inflammatory Bowel Disease-A Systematic Review and Meta-analysis

BACKGROUND AND AIMS

Epidemiological studies have established an association between psoriasis and inflammatory bowel disease [IBD], i.e. ulcerative colitis [UC] and Crohn's disease [CD], but results are inconsistent. The aim of this study was therefore to quantify the prevalences and association between IBD and psoriasis.

METHODS

PubMed, Web of Science, and EMBASE were searched from database inception through April 2018 for studies reporting data on psoriasis among patients with IBD and vice versa. Meta-analysis was performed to estimate, respectively, the prevalences and association between IBD and psoriasis. Data extraction was according to the PRISMA guideline, and quality assessment was made using the Newcastle-Ottawa Scale. The main outcomes were the proportion of psoriasis patients with IBD and vice versa, as well as the association (odds ratio [OR]) of IBD in psoriasis and psoriasis in IBD, respectively.

RESULTS

Based on quantitative analysis of 93 studies, the prevalence of psoriasis in CD and in UC was 3.6% (95% confidence interval [CI] 3.1%-4.6%) and 2.8% [95% CI 2.0%-3.8%] respectively. The prevalence of CD and UC was 0.7% [95% CI 0.2%-1.3%] and 0.5% [95% CI 0.3%-0.8%], respectively, among patients with psoriasis. Presence of CD or UC was significantly associated with psoriasis, with OR 2.0 [95% CI 1.4-2.9] and OR 1.5 [95% CI 1.2-2.0], respectively. Presence of psoriasis was significantly associated with CD: OR 2.2 [95% CI 1.6-3.1] and with UC: OR 1.6 [95% CI 1.3-2.0].

CONCLUSIONS

We found significant bidirectional associations between psoriasis and IBD, warranting increased awareness among clinicians in the diagnostic process, especially in children and adolescents with IBD. Last, this study showed an increased frequency of paradoxical psoriasis in patients treated with biologics.

Tumor necrosis factor-α inhibitor-induced psoriasis in juvenile idiopathic arthritis patients

BACKGROUND/OBJECTIVES

The development of psoriasis while on tumor necrosis factor inhibitors (TNFi) is a paradoxical effect of agents that treat psoriasis. There is a paucity of data available on this entity in juvenile idiopathic arthritis (JIA). Our objectives were to determine the prevalence of TNFi-induced psoriasis in patients with JIA at two pediatric centers, and psoriasis response to therapeutic modifications.

METHODS

We performed retrospective chart review on patients with JIA treated with TNFi (adalimumab, etanercept, infliximab) who developed psoriasis. TNFi-induced psoriasis was defined as an incident diagnosis of psoriasis after starting a TNFi. Patients with personal histories of psoriasis prior to TNFi therapy were excluded. Following diagnosis, responses to medication changes were defined based on physician assessments.

RESULTS

Nine of 166 (5.4%) patients on TNFi for JIA were diagnosed with TNFi-induced psoriasis. All cases were female. One had a family history of psoriasis. The median age was 10 (range 2-16) years. Five (55%) patients experienced scalp psoriasis, including four (44%) with alopecia. Two (22%) patients achieved significant improvement after switching to different classes of biologic agents, while three (33%) patients had significant improvement following discontinuation of biologic therapy. One of five patients who switched to a different TNFi had complete resolution, while four had worsening symptoms or partial improvement.

CONCLUSIONS

Our findings demonstrate the prevalence of TNFi-induced psoriasis in JIA at two centers. Though larger studies are needed, our data suggest discontinuation of TNFi or biologic class switching should be considered as treatment strategies in select patients.

Infliximab Paradoxical Psoriasis in a Cohort of Children With Inflammatory Bowel Disease

OBJECTIVES

In adult inflammatory bowel disease (IBD) treated by anti-TNF antibodies, paradoxical psoriasis has an estimated prevalence of 1.6 to 22%, especially in infliximab (IFX)-treated patients. Little is known in the pediatric IBD (PIBD) populations.

METHODS

All patients ages from 2 to 18 years with Crohn disease (CD) or ulcerative colitis (UC) and treated for the first time by IFX between January 2002 and March 2014, were considered for inclusion in this retrospective study performed in a tertiary PIBD centre. Paradoxical psoriasis events together with clinical and biological data were collected in all patients. Comparisons between psoriasis and control groups were performed using univariate statistical analyses.

RESULTS

One hundred and twenty-three CD patients and 24 UC patients were treated with IFX. Twenty patients (13.6%) experienced a paradoxical psoriasis. All of them were affected by CD. Perianal CD was more frequent in the psoriasis group (P = 0.033). Fourteen patients (70%) were in remission when skin lesions occurred. Paradoxical psoriasis was diagnosed 355 days (median, interquartile range [IQR] 239; 532) after the initiation of IFX corresponding to the eighth injection (median, IQR: 6; 15). Psoriasis lesions were controlled by local steroids in all cases and no patients discontinued IFX therapy.

CONCLUSIONS

13.6% of our IBD patients treated with IFX developed psoriasis during a median follow-up of 23.9 months (IQR: 11.6; 36.5). Crohn disease patients with perianal disease were at a higher risk to develop this common side effect.

Infliximab and biosimilar infliximab in psoriasis: efficacy, loss of efficacy, and adverse events

Psoriasis is a chronic immune-mediated skin disease affecting multiple systems, and tumor necrosis factor-α (TNF-α) plays a significant role in the initiation and progression of the disease process. Psoriasis has a high prevalence rate in the Western world, especially in the USA and Australia; in China, although the prevalence rate is much lower, there is still a large number of patients suffering from psoriasis and its comorbidities. As TNF-α is thought to be crucial in the pathogenesis of psoriasis, specific therapy blocking TNF-α may be beneficial in the treatment of this disease. Infliximab, a murine-human monoclonal antibody, is highly efficacious in the treatment of moderate-to-severe psoriasis, with better skin clearance and faster onset of action than topical medications such as methotrexate, narrow-band ultraviolet B, and calcipotriol. Lack of adherence to infliximab therapy is mainly due to loss of response (LOR) over time and adverse events, particularly because infusion reactions are usually encountered. Anti-infliximab antibody is thought to be responsible for the LOR and infusion reactions. However, the mechanism underlying the formation of anti-infliximab antibody and its side effects remains unclear. Further studies identifying patients at risk for LOR will probably help clinicians to select the right patients for anti-TNF-α therapy and to increase the durability of the treatment. This review discusses the efficacy of infliximab as demonstrated by various clinical trials, LOR to infliximab, combatting LOR, as well as the adverse events usually faced during the use of infliximab therapy and the infliximab biosimilar Remsima^®. We hope that we can discover a better way to use infliximab in the therapy of psoriasis from the current research data.

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.

Risks associated with use of TNF inhibitors in children with rheumatic diseases

Introduction: Tumor necrosis factor alpha (TNF-α) is a pro-inflammatory cytokine involved in the pathogenesis of many inflammatory diseases. Several drugs blocking TNF-α are employed in clinical practice in pediatrics. Given their action on the immune system, TNF-α inhibitors have raised concerns on their safety profile since their introduction. A broad spectrum of side effects related to TNF inhibition has been reported: immunogenicity, infectious diseases, malignancies, and others. Areas covered: In order to assess the risk related to the use of anti-TNF-α agents in children with rheumatic diseases we analyzed data obtained from retrospective and prospective safety studies, case reports and case series, and controlled trials. Expert commentary: Anti-TNF-α agents have shown a remarkably good safety profile in the pediatric population so far. However, there are lots of questions to be answered and maintaining active surveillance on these drugs is necessary in order to not overlook any possible unexpected adverse effects.

TNF Inhibitor-Induced Psoriasis: Proposed Algorithm for Treatment and Management

Tumor necrosis factor a (TNF-α)-targeted therapies have expanded the therapeutic options for patients with inflammatory bowel disease (IBD), rheumatoid arthritis (RA), psoriasis, and psoriatic arthritis (PsA) and have significantly improved patients' quality of life. Paradoxically, anti-TNF-α agents may induce psoriatic eruptions or worsen preexisting psoriatic skin disease. Currently, there is no standard approach for the management of TNF inhibitor-induced psoriasis. Here, we conduct a literature review on TNF inhibitor-induced psoriasis and introduce a novel treatment algorithm for maintaining otherwise effective anti-TNF therapy versus switching to a different class as appropriate in the management of patients with IBD, RA, psoriasis, or PsA.

Paradoxic eczema in infants after heart transplantation

New-onset psoriasis in patients receiving tumor necrosis factor inhibitors is well recognized in children and adults. We describe three children who underwent cardiac transplantation and developed an analogous form of paradoxic eczema occurring 2-48 months after starting systemic tacrolimus, a drug widely used topically to treat eczema. Anecdotal reports and our experience suggest that tacrolimus taper with alternative systemic antirejection immunosuppressant may lead to skin clearance. Pending additional insight, treatment should include optimizing skin barrier function, minimizing microbial and allergic triggers, and coordinating care to choose the best-tolerated systemic immunosuppressant regimen at the lowest effective dose.

Biologics in pediatric psoriasis - efficacy and safety

INTRODUCTION

Childhood psoriasis is a special situation that is a management challenge for the treating dermatologist. As is the situation with traditional systemic agents, which are commonly used in managing severe psoriasis in children, the biologics are being increasingly used in the recalcitrant disease despite limited data on long term safety.

AREAS COVERED

We performed an extensive literature search to collect evidence-based data on the use of biologics in pediatric psoriasis. The relevant literature published from 2000 to September 2017 was obtained from PubMed, using the MeSH words 'biologics', 'biologic response modifiers' and 'treatment of pediatric/childhood psoriasis'. All clinical trials, randomized double-blind or single-blind controlled trials, open-label studies, retrospective studies, reviews, case reports and letters concerning the use of biologics in pediatric psoriasis were screened. Articles covering the use of biologics in pediatric psoriasis were screened and reference lists in the selected articles were scrutinized to identify other relevant articles that had not been found in the initial search. Articles without relevant information about biologics in general (e.g. its mechanism of action, pharmacokinetics and adverse effects) and its use in psoriasis in particular were excluded. We screened 427 articles and finally selected 41 relevant articles.

EXPERT OPINION

The available literature on the use of biologics such as anti-tumor necrosis factor (TNF)-α agents, and anti-IL-12/23 agents like ustekinumab suggests that these are effective and safe in managing severe pediatric psoriasis although there is an urgent need to generate more safety data. Dermatologists must be careful about the potential adverse effects of the biologics before administering them to children with psoriasis. It is likely that with rapidly evolving scenario of biologics in psoriasis, these will prove to be very useful molecules particularly in managing severe and recalcitrant psoriasis in pediatric age group.

Psoriasis and Psoriasiform Eruptions in Pediatric Patients with Inflammatory Bowel Disease Treated with Anti-Tumor Necrosis Factor Alpha Agents

BACKGROUND

Anti-tumor necrosis factor alpha (TNF-α) agents are used to treat a variety of autoimmune and inflammatory conditions, including psoriasis. Paradoxically, numerous reports have documented new-onset or exacerbation of psoriasis or psoriasiform skin lesions (PSO) in patients treated with these agents for conditions other than PSO-particularly in adults with inflammatory bowel disease (IBD). Not much is known regarding similar cases in children.

METHODS

A retrospective chart review was performed on children younger than 19 years of age with IBD seen at the Mayo Clinic between 2003 and 2015 who developed new-onset or recurrent PSO while undergoing anti-TNF-α therapy.

RESULTS

Fourteen children developed PSO while undergoing anti-TNF-α therapy for IBD. All three anti-TNF-α agents (infliximab, adalimumab, certolizumab) used to treat IBD in this series led to induction or recurrence of PSO lesions. The median time to development of PSO was 11 months (range 0-48 mos), the median age was 15 years (range 12.5-17.5 yrs), and 57% of patients were male. IBD activity was quiescent in 93% of cases at PSO onset. Seven patients (50%) discontinued their initial anti-TNF-α therapy because of their skin disease. Ultimately, four patients (29%) had to discontinue all anti-TNF-α therapy to induce PSO resolution.

CONCLUSION

TNF-α antagonist-induced PSO in children with IBD is a rarely reported adverse reaction. PSO onset has a variable latency, but usually occurs during IBD remission, with a slight male bias. Nearly half of patients required a change in their initial anti-TNF-α agent despite conventional skin-directed therapies, and one-third of patients discontinued all anti-TNF-α therapy because of PSO.

Tumor necrosis factor-α inhibitor-induced psoriasis: Systematic review of clinical features, histopathological findings, and management experience

BACKGROUND

Tumor necrosis factor-α (TNF-α) inhibitors have been reported to induce new-onset psoriasis.

OBJECTIVE

To better define the demographic, clinical features, and treatment approach of TNF-α inhibitor-induced psoriasis.

METHODS

Systematic review of published cases of TNF-α inhibitor-induced psoriasis.

RESULTS

We identified 88 articles with 216 cases of new-onset TNF-α inhibitor-induced psoriasis. The mean age at psoriasis onset was 38.5 years. The most common underlying diseases were Crohn disease (40.7%) and rheumatoid arthritis (37.0%). Patients underwent TNF-α therapy for an average of 14.0 months before psoriasis onset with 69.9% of patients experiencing onset within the first year. The majority of patients received skin-directed therapy, though patients who discontinued TNF therapy had the greatest resolution of symptoms (47.7%) compared with those who switched to a different TNF agent (36.7%) or continued therapy (32.9%).

LIMITATIONS

Retrospective review that relies on case reports and series.

CONCLUSION

While TNF-α inhibitor cessation may result in resolution of induced psoriasis, lesions may persist. Decisions regarding treatment should be weighed against the treatability of TNF-α inhibitor-induced psoriasis, the severity of the background rheumatologic or gastrointestinal disease, and possible loss of efficacy with cessation followed by retreatment. Skin-directed therapy is a reasonable initial strategy except in severe cases.

Infliximab-induced skin manifestations in patients with inflammatory bowel disease

OBJECTIVE

The use of infliximab in rheumatoid and inflammatory bowel diseases (IBD) has been associated with a variety of adverse skin reactions, including paradoxical psoriatic lesions. The prevalence and possible predictors for these lesions were under observation in our cross-sectional prospective study.

MATERIAL AND METHODS

Nurses screened the skin of 118 adult patients with IBD during infliximab infusions between 4 September 2013 and 30 September 2014 based on the structured questionnaire. Data on skin manifestations, concomitant medications, extraintestinal manifestations and inflammatory markers were collected for analysis.

RESULTS

Non-infectious skin manifestations were observed in 27 (22.9%) patients during the study period, of which eight (29.6%) were new-onset, eight (29.6%) were exacerbations of existing lesions and 11 (40.7%) were baseline lesions that did not worsen during the study. Scaling eczema was the most commonly described skin manifestation (n = 8; 29.6%), followed by exacerbated atopic eczema (n = 5; 18.5%) and plausible infliximab-induced psoriasiform lesions (n = 5; 18.5%). The strongest associating factor for skin manifestations was Crohn's disease, in nearly 80% of afflicted patients.

CONCLUSIONS

Anti-TNF-α therapy is frequently associated with newly onset skin reactions, most commonly in patients with Crohn's disease. Non-infectious skin manifestations can be treated topically and do not require cessation of anti-TNF-α therapy.

Health Care Maintenance for the Pediatric Patient With Inflammatory Bowel Disease

Nearly one-quarter of patients with inflammatory bowel disease (IBD) are younger than 20 years of age at diagnosis. Furthermore, the incidence of IBD in children continues to increase. Nevertheless, variation in management exists within the care of patients with IBD with regards to disease screening and preventive care. A multidisciplinary approach that involves the general practitioner and pediatric gastroenterologist is needed to routinely monitor growth, bone health, vitamin and mineral deficiencies, vaccination status, and endoscopic surveillance. It is also important to monitor for extraintestinal manifestations of IBD that may affect the liver, joints, skin, and eyes. The purpose of this article is to provide an updated overview of comprehensive care for pediatric patients with IBD.

Anti-Tumor Necrosis Factor α-Related Psoriatic Lesions in Children with Inflammatory Bowel Disease: Case Report and Systematic Literature Review

We report a child with Crohn's disease and infliximab-induced guttate psoriasis. We also performed a systematic literature review on this intriguing paradoxical phenomenon in children with inflammatory bowel disease.

Juvenile generalized pustular psoriasis with IL36RN mutation treated with short-term infliximab

A 8-year-old Chinese boy with generalized pustular psoriasis (GPP) refractory to cyclosporine and methylprednisolone was treated successfully with two infusions of infliximab 3.3 mg/kg. He remained in remission for 21 months. Direct sequencing of IL36RN gene showed a homozygous mutation, c.115 + 6T>C. Juvenile GPP is a rare severe form of psoriasis occasionally associated with life-threatening complications. Like acitretin, cyclosporine and methotrexate, infliximab has been reported to be effective for juvenile GPP in case reports. However, there is a lack of data in the optimal treatment course of infliximab for juvenile GPP. Prolonged administration of these medications may cause toxic or fatal complications. We suggest that short-term infliximab regimen should be recommended as a choice for acute juvenile GPP refractory to traditional systemic therapies. WBC count and CRP are sensitive parameters to reflect the disease activity and evaluate the effectiveness of treatment. Monitoring CD4 T lymphocyte count, preventing and correcting CD4 lymphocytopenia are important in the treatment course of juvenile GPP.

Genetics of Inflammatory Bowel Diseases

In this review, we provide an update on genome-wide association studies (GWAS) in inflammatory bowel disease (IBD). In addition, we summarize progress in defining the functional consequences of associated alleles for coding and noncoding genetic variation. In the small minority of loci where major association signals correspond to nonsynonymous variation, we summarize studies defining their functional effects and implications for therapeutic targeting. Importantly, the large majority of GWAS-associated loci involve noncoding variation, many of which modulate levels of gene expression. Recent expression quantitative trait loci (eQTL) studies have established that the expression of most human genes is regulated by noncoding genetic variations. Significant advances in defining the epigenetic landscape have demonstrated that IBD GWAS signals are highly enriched within cell-specific active enhancer marks. Studies in European ancestry populations have dominated the landscape of IBD genetics studies, but increasingly, studies in Asian and African-American populations are being reported. Common variation accounts for only a modest fraction of the predicted heritability and the role of rare genetic variation of higher effects (ie, odds ratios markedly deviating from 1) is increasingly being identified through sequencing efforts. These sequencing studies have been particularly productive in more severe very early onset cases. A major challenge in IBD genetics will be harnessing the vast array of genetic discovery for clinical utility through emerging precision medical initiatives. In this article, we discuss the rapidly evolving area of direct-to-consumer genetic testing and the current utility of clinical exome sequencing, especially in very early onset, severe IBD cases. We summarize recent progress in the pharmacogenetics of IBD with respect to partitioning patient responses to anti-TNF and thiopurine therapies. Highly collaborative studies across research centers and across subspecialties and disciplines will be required to fully realize the promise of genetic discovery in IBD.

Pharmacogenetics of inflammatory bowel disease

Pharmacogenetic studies have been performed for almost all classes of drugs that have been used in IBD but very few have generated consistent findings or have been replicated. The genetic test that has been approved for clinical practice is TPMT testing prior to starting treatment with thiopurine drugs. Research in IBD pharmacogenetics has focused on prediction of drug efficacy and toxicity by identifying polymorphisms in the genes encoding enzymes that are involved in metabolic pathways. Recent research has mainly focused on therapeutic agents such as azathioprine, methotrexate, aminosalicylates, corticosteroids, infliximab and adalimumab. Future pharmaceutical trials should include pharmacogenetic research to test appropriate candidate genes in a prospective manner and correlate genetic associations with trial outcomes and relevant functional data.

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

Paradoxical psoriasiform reactions to anti-tumor necrosis factor α (TNFα) agents have been described. We aimed to study the association between these reactions and polymorphisms in genes previously associated with psoriasis or other autoimmune diseases. A total of 161 patients with plaque-type psoriasis treated with anti-TNFα drugs were genotyped for 173 single-nucleotide polymorphisms (SNPs) using the Illumina Veracode genotyping platform. Among the 161 patients, 25 patients developed a paradoxical psoriasiform reaction consisting of a change in morphology, mostly to guttate psoriasis (88%). These lesions developed 9.20±13.52 months after initiating treatment, mainly with etanercept (72%). Psoriasis type and a Psoriasis Area and Severity Index (PASI) 75 response to treatment were not associated with lesions. Multivariate logistic regression revealed that five SNPs (rs11209026 in IL23R, rs10782001 in FBXL19, rs3087243 in CTLA4, rs651630 in SLC12A8 and rs1800453 in TAP1) were associated with paradoxical reactions. This is the first study to show an association between genetic polymorphisms and paradoxical reactions in patients with psoriasis treated with anti-TNFα drugs.The Pharmacogenomics Journal advance online publication, 21 July 2015; doi:10.1038/tpj.2015.53.

Biologic response modifiers and pediatric psoriasis

The efficacy and safety of biologic response modifiers such as etanercept, adalimumab, infliximab, and ustekinumab have been demonstrated in the treatment of psoriasis in adults, but none are currently approved for the treatment of psoriasis in children in the United States, and only etanercept is approved for the treatment of psoriasis in children in the European Union. Through case reports, case series, and a large clinical trial of the use of etanercept, the literature supports the use of these agents to treat psoriasis in children. Data on the use of the tumor necrosis factor-α antagonists etanercept, adalimumab, and infliximab in the treatment of other inflammatory diseases in children-namely Crohn's disease, juvenile arthritis, and uveitis--support their safety profile in children.

Concomitant use of azathioprine/6-mercaptopurine decreases the risk of anti-TNF-induced skin lesions

BACKGROUND

Anti-tumor necrosis factor (anti-TNF) agents are widely used to treat patients with moderate-to-severe inflammatory bowel disease (IBD). We aimed to identify the risk factors for adverse skin lesions in patients with IBD receiving anti-TNF agents and assess the effect of concomitant use of azathioprine/6-mercaptopurine (AZA/6 MP).

METHODS

A total of 500 patients (404 with Crohn's disease, 96 with ulcerative colitis) who received anti-TNF agents between June 2002 and July 2013 were identified and retrospectively investigated. We compared 47 patients with IBD with skin lesions with 443 patients with IBD without skin lesions to identify risk factors by univariate and multivariate analysis. The Kaplan-Meier method was used to estimate the cumulative incidence of adverse skin lesions in relation to the concomitant use of AZA/6 MP.

RESULTS

Eczematiform eruptions (n = 18, 38%) were the most common skin lesion type, followed by psoriasiform lesions (n = 13, 28%). A response to topical steroids was seen in 70% (33/47) of patients with skin lesions, and anti-TNF agents had to be discontinued in 9% (4/47). Concomitant use of AZA/6 MP decreased the risk of skin lesions in univariate (hazard ratio, 0.452; 95% CI, 0.251-0.814; P = 0.008) and multivariate (hazard ratio, 0.437; 95% CI, 0.242-0.790; P = 0.006) analysis. In addition, the cumulative incidence of adverse skin lesions was lower in patients on concomitant maintenance with AZA/6 MP (P = 0.009) than in those on anti-TNF monotherapy.

CONCLUSIONS

Concomitant use of AZA/6 MP may decrease the occurrence of adverse skin lesions in patients receiving anti-TNF therapy.

Skin reactions during anti-TNFα therapy for pediatric inflammatory bowel disease: a 2-year prospective study

BACKGROUND

Although the development of therapy-related skin reactions is common along with an increase in the number of adult patients receiving anti-TNFα, there are few studies on pediatric inflammatory bowel disease; hence, this prospective study focuses on skin reactions related to infliximab therapy.

METHODS

All pediatric patients with inflammatory bowel disease undergoing infliximab therapy were prospectively screened for the presence of skin manifestations at the time of each infusion between March 1, 2011 and March 31, 2011 at Children's Hospital, Helsinki, Finland. Blood inflammatory markers and fecal calprotectin levels were measured at the time of infusions.

RESULTS

During the study period, 84 children with inflammatory bowel disease (Crohn's n = 64) received infliximab infusions (the median duration of therapy 12.2 mo). Almost every other patient (n = 40; 47.6%) presented chronic skin reactions, 23% with lesions considered severe. Most commonly, the patient's ear lobes and scalp were affected with psoriasis-like manifestations, followed by their eyelids, perioral and pubic area, trunk, and the extremities. However, an HLA-Cw*0602 genotype associating with psoriasis was rare. Interestingly, most patients with skin reactions had a low degree of intestinal inflammation based on their fecal calprotectin levels (median level, 133 μg/g versus 589 in unaffected patients; P < 0.016). Seven patients (8.3% of all patients but 17% of those with skin lesions) discontinued the given therapy due to a skin reaction.

CONCLUSIONS

Skin reactions are common during maintenance therapy with infliximab in pediatric patients. For most patients, skin reactions seem to correlate with a low level of intestinal inflammation. Although potentially harsh, skin lesions mostly allow continuation of infliximab.

Infliximab maintains durable response and facilitates catch-up growth in luminal pediatric Crohn's disease

BACKGROUND

Infliximab induces and maintains clinical remission in children with Crohn's disease (CD), but specifically pediatric long-term data remain sparse.

METHODS

Patients (N = 195) who received infliximab ± immunomodulator for luminal CD were retrospectively reviewed. Outcomes included clinical response, linear growth, and mucosal healing. Durability of response was assessed using Cox proportional hazards models. Levels of infliximab and antibodies (antibodies to infliximab) were measured when response was lost.

RESULTS

Among 195 patients (median age, 13.9 yr; median CD duration, 1.6 yr), 81% experienced complete response (judged by physician global assessment and pediatric Crohn's disease activity index ≤10). Longer duration of diagnosed CD and female gender were associated with lower response. During first year of follow-up, 35% of subjects had regimen individualized through dose escalation/interval shortening. Despite regimen optimization, 16/157 complete responders experienced loss of response at a rate of 2% to 6% per year over 5 years, associated with development of antibodies to infliximab. Concurrent immunomodulation for ≥30 weeks significantly decreased loss of response (hazard ratio = 0.25, 95% confidence interval, 0.08-0.76; P = 0.014). Follow-up endoscopic examination was performed in 40 responders, of whom 22 (73%) demonstrated complete resolution of mucosal ulceration. Patients with growth potential (Tanner 1/2 at induction) demonstrated significant improvements in mean height z-score from induction to years 1 and 2 of follow-up (P < 0.001). With infliximab initiation within the first 18 months after diagnosis, mean height z-score normalized to 0 after 3 years.

CONCLUSIONS

These data demonstrate sustained effectiveness of infliximab in children and adolescents with luminal CD. Durability of response is increased by concomitant immunomodulation. Clinical response is associated with enhanced linear growth, particularly when therapy is initiated early.

Advances in IBD genetics

IBD is a spectrum of chronic disorders that constitute an important health problem worldwide. The hunt for genetic determinants of disease onset and course has culminated in the Immunochip project, which has identified >160 loci containing IBD susceptibility genes. In this Review, we highlight how genetic association studies have informed our understanding of the pathogenesis of IBD by focusing research efforts on key pathways involved in innate immunity, autophagy, lymphocyte differentiation and chemotaxis. Several of these novel genetic markers and cellular pathways are promising candidates for patient stratification and therapeutic targeting.

Tnfa signaling through tnfr2 protects skin against oxidative stress-induced inflammation

A new zebrafish model of skin inflammatory disease explains new-onset and worsening psoriasis and lichen planus in patients receiving anti-TNFα therapy.

TNFα overexpression has been associated with several chronic inflammatory diseases, including psoriasis, lichen planus, rheumatoid arthritis, and inflammatory bowel disease. Paradoxically, numerous studies have reported new-onset psoriasis and lichen planus following TNFα antagonist therapy. Here, we show that genetic inhibition of Tnfa and Tnfr2 in zebrafish results in the mobilization of neutrophils to the skin. Using combinations of fluorescent reporter transgenes, fluorescence microscopy, and flow cytometry, we identified the local production of dual oxidase 1 (Duox1)-derived H₂O₂ by Tnfa- and Tnfr2-deficient keratinocytes as a trigger for the activation of the master inflammation transcription factor NF-κB, which then promotes the induction of genes encoding pro-inflammatory molecules. In addition, pharmacological inhibition of Duox1 completely abrogated skin inflammation, placing Duox1-derived H₂O₂ upstream of this positive feedback inflammatory loop. Strikingly, DUOX1 was drastically induced in the skin lesions of psoriasis and lichen planus patients. These results reveal a crucial role for TNFα/TNFR2 axis in the protection of the skin against DUOX1-mediated oxidative stress and could establish new therapeutic targets for skin inflammatory disorders.

Psoriasis and lichen planus are chronic, debilitating skin diseases that affect millions of people worldwide. TNFα is a multifunctional cytokine that mediates acute and chronic inflammation. While TNFα antagonist therapy is used for autoimmune or chronic inflammatory diseases, such as inflammatory bowel disease (IBD), numerous studies have reported new-onset psoriasis and lichen planus following such therapy. We have used the unique advantages of the zebrafish embryo to identify a novel phenotype that mirrors this unexplained and paradoxical onset of psoriasis and lichen planus. We found that depletion of Tnfa or its receptor Tnfr2 caused skin inflammation and hyperproliferation of keratinocytes through the activation of a Duox1/H₂O₂/NF-κB positive feedback inflammatory loop. Strikingly, DUOX1 was drastically induced in the skin lesions of psoriasis and lichen planus patients, and pharmacological inhibition of Duox1 abrogated skin inflammation, placing Duox1-derived H₂O₂ upstream of this inflammatory loop. Our results suggest that therapies targeting DUOX1 and H₂O₂ could provide innovative approaches to the management of skin inflammatory disorders.