A systematic review of pharmacogenetic studies on the response to biologics in patients with psoriasis

Multi-failure psoriasis patients: characterization of the patients and response to biological therapy in a multicenter Italian cohort

INTRODUCTION

Patients with psoriasis who have failed multiple biologic drugs have been defined as "multi-failure," although there are no clear data on the characteristics, comorbidities, and best treatment strategies for this population. Nowadays, given the next generation and the number of biologics available, patients are considered multi-failure when ≥4 biologics fail to achieve a good response.

METHODS

Demographic characteristics and efficacy of anti-interleukin drugs in multi-failure patients were compared to a cohort of general psoriatic patients treated with IL-23 or IL-17 inhibitors.

RESULTS

In total 97 multi-failure patients (≥4 lines of biologics) were compared with 1,057 patients in the general cohort. The current drugs in the multi-failure group were risankizumab (34), ixekizumab (23), guselkumab (21), brodalumab (7), tildrakizumab (5), ustekinumab (4), secukinumab (2), and certolizumab pegol (1). A significant difference was found in the multi-failure cohort for age of psoriasis onset (mean 29.7 vs. 35.1, P < 0.001), concurrent psoriatic arthritis (45.4 vs. 26.9%, P < 0.001), diabetes mellitus (30.9 vs. 10.9%, P < 0.001), and cardiovascular comorbidity (54.6 vs. 39.8%, P = 0.005). In multi-failure patients, current biological therapy showed a good initial response (PASI 90 and 100 of 41.24 and 27.84%, respectively, at 16 weeks); the response tended to decline after 40 weeks. Anti-IL-17 agents showed clinical superiority over IL-23 agents in terms of achieving PASI90 at 28 weeks (P < 0.001) and 40 weeks (P = 0.007), after which they reached a plateau. In contrast, IL-23 agents showed a slower but progressive improvement that was maintained for up to 52 weeks. A similar trend was also seen for PASI100 (28 weeks P = 0.032; 40 weeks P = 0.121).

CONCLUSIONS

The multi-failure patient is characterized by many comorbidities and longstanding inflammatory disease that frequently precedes the introduction of systemic biologic therapy. Further studies are needed to identify more specific criteria that could be applied as a guideline by clinicians.

Rs1800629 polymorphism in TNF-alpha is associated with the susceptibility and initial short-term glucocorticoids efficacy in myasthenia gravis patients

Tumor necrosis factor-alpha (TNF-α) is a potent pro-inflammatory agent involved in various autoimmune and inflammatory diseases including myasthenia gravis (MG). In this study, we enrolled 409 adult MG patients and 487 healthy individuals to investigate the association between TNF-α polymorphism and MG. We found the rs1800629 A allele frequency was significantly higher in the MG group than in the control group. Subgroup analysis revealed that the A allele frequencies were significantly higher in the early-onset subgroup, non-thymoma subgroup, ocular-onset subgroup, and mild severity subgroup than in the control group. To minimize the interactions between clinical features, we used a comprehensive classification and found that the rs1800629 A allele frequency was significantly higher in the non-thymoma AChR-Ab negative subgroup than in the control group. In the analysis of initial short-term glucocorticoids (GC) efficacy in the treatment-naive patients, the rs1800629 A allele frequency was significantly higher in the unresponsive subgroup than in the responsive group and the control group. Logistic regression demonstrated the rs1800629 genotypes in the dominant model and disease duration prior to GC treatment independently contributed to initial short-term GC efficacy. In conclusion, our study revealed that in Chinese adult MG patients, rs1800629 polymorphism in TNF-α was associated with the susceptibility of MG and might indicate the initial short-term GC efficacy.

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.

Pharmacogenomics on the Treatment Response in Patients with Psoriasis: An Updated Review

The efficacy and the safety of psoriasis medications have been proved in trials, but unideal responses and side effects are noted in clinical practice. Genetic predisposition is known to contribute to the pathogenesis of psoriasis. Hence, pharmacogenomics gives the hint of predictive treatment response individually. This review highlights the current pharmacogenetic and pharmacogenomic studies of medical therapy in psoriasis. HLA-Cw*06 status remains the most promising predictive treatment response in certain drugs. Numerous genetic variants (such as ABC transporter, DNMT3b, MTHFR, ANKLE1, IL-12B, IL-23R, MALT1, CDKAL1, IL17RA, IL1B, LY96, TLR2, etc.) are also found to be associated with treatment response for methotrexate, cyclosporin, acitretin, anti-TNF, anti-IL-12/23, anti-IL-17, anti-PDE4 agents, and topical therapy. Due to the high throughput sequencing technologies and the dramatic increase in sequencing cost, pharmacogenomic tests prior to treatment by whole exome sequencing or whole genome sequencing may be applied in clinical in the future. Further investigations are necessary to manifest potential genetic markers for psoriasis treatments.

Human leukocyte antigen association with azathioprine-induced drug hypersensitivity reactions in patients with anti-neutrophil cytoplasmic antibody associated vasculitis

Azathioprine (AZA) drug hypersensitivity reaction (DHR) is an uncommon yet potentially lethal condition that often goes unrecognised in patients with anti-Neutrophil Cytoplasmic Antibody (ANCA) associated vasculitis (AAV). We conducted a retrospective review of AAV patients on AZA maintenance therapy (N = 35). Participants were categorised into those who had experienced AZA-DHR (N = 15) and those who were AZA-tolerant (N = 20). Human leukocyte antigen (HLA) typing was performed in both groups. The primary endpoint was identification of a HLA gene association with AZA-DHR in the context of AAV. HLA-C*06:02, was solely expressed in AZA-DHR patients (33.3 %), whilst no patient who tolerated AZA carried this allele (0.0 %). This yielded a positive predictive value of 100 % for HLA-C*06:02 in predicting AZA-DHR in AAV patients, negative predictive value of 66.7 %, sensitivity of 33.3 % and specificity of 100 %. HLA-C*06:02 may predict the development of AZA-DHR in patients with AAV and inform safer therapeutic choice.

Pharmacogenetics of chemotherapy treatment response and -toxicities in patients with osteosarcoma: a systematic review

BACKGROUND

Osteosarcoma is the most common bone tumor in children and adolescents. Despite multiagent chemotherapy, only 71% of patients survives and these survivors often experience long-term toxicities. The main objective of this systematic review is to provide an overview of the discovery of novel associations of germline polymorphisms with treatment response and/or chemotherapy-induced toxicities in osteosarcoma.  METHODS: MEDLINE and Embase were systematically searched (2010-July 2022). Genetic association studies were included if they assessed > 10 germline genetic variants in > 5 genes in relevant drug pathways or if they used a genotyping array or other large-scale genetic analysis. Quality was assessed using adjusted STrengthening the REporting of Genetic Association studies (STREGA)-guidelines. To find additional evidence for the identified associations, literature was searched to identify replication studies.

RESULTS

After screening 1999 articles, twenty articles met our inclusion criteria. These range from studies focusing on genes in relevant pharmacokinetic pathways to whole genome sequencing. Eleven articles reported on doxorubicin-induced cardiomyopathy. For seven genetic variants in CELF4, GPR35, HAS3, RARG, SLC22A17, SLC22A7 and SLC28A3, replication studies were performed, however without consistent results. Ototoxicity was investigated in one study. Five small studies reported on mucosistis or bone marrow, nephro- and/or hepatotoxicity. Six studies included analysis for treatment efficacy. Genetic variants in ABCC3, ABCC5, FasL, GLDC, GSTP1 were replicated in studies using heterogeneous efficacy outcomes.

CONCLUSIONS

Despite that results are promising, the majority of associations were poorly reproducible due to small patient cohorts. For the future, hypothesis-generating studies in large patient cohorts will be necessary, especially for cisplatin-induced ototoxicity as these are largely lacking. In order to form large patient cohorts, national and international collaboration will be essential.

The HLA-Cw*06 allele may predict the response to methotrexate (MTX) treatment in Chinese arthritis-free psoriasis patients

MTX in genetically distinctive Chinese psoriatic patients remains less explored. The present study aimed to determine the impact of HLA-Cw*06 on MTX response in a Chinese psoriasis patient population. A total of 204 patients with psoriasis were enrolled in this study. Clinical data and DNA samples from all patients were collected. The allele of HLA-Cw*06 genotyping was detected using direct Sanger sequencing. This study enrolled 204 patients with psoriasis, including 47 (23.04%) psoriatic arthritis patients, 157 (76.96%) patients free of psoriatic arthritis. Overall, 110 (53.92%) of all patients carried the HLA-Cw*06 allele. This frequency in patients with arthritis-free psoriasis was higher than that in those with psoriatic arthritis (58.59 vs. 38.30%, P = 0.014). After 8 weeks of MTX treatment, the arthritis-free psoriasis patients, who tested positive for the HLA-Cw*06 allele, showed significant improvement compared to those who tested negative (For PASI50, 78.57 vs. 55.22%, P = 0.02, and for PASI75, 51.11 vs. 34.33%, P = 0.036). The psoriatic arthritis-free patients who carried the HLA-Cw*06 allele in combination with the ABCB1 rs1045642 CC genotype showed the highest improvement. A regression model containing HLA-Cw*06, rs1045642T > C, and initial PASI scores was used to construct the efficacy prediction model of MTX, which yielded AUC values of 73.2 and 75.6% for PASI50 and PASI75 to MTX, respectively, in arthritis-free psoriasis patients. The HLA-Cw*06 allele is associated with optimal response to MTX treatment in arthritis-free Chinese psoriasis patients. When combined with clinical indicators, the polymorphism explained more than 75% of the individual efficacy differences.

Towards Personalized Medicine in Psoriasis: Current Progress

Although innovative targeted therapies have positively revolutionized psoriasis treatment shifting treatment goals to complete or almost complete skin clearance, primary or secondary lack of efficacy is still possible. Hence, identifying robust biomarkers that reflect the various clinical psoriasis phenotypes would allow stratify patients in subgroups or endotypes, and tailor treatments according to the characteristics of each individual (precision medicine). To sum up the current progress in personalized medicine for psoriasis, we performed a review on the available evidence on biomarkers predictive of response to psoriasis treatments, with focus on phototherapy and systemic agents. Relevant literature published in English was searched for using the following databases from the last five years up to March 20, 2022: PubMed, Embase, Google Scholar, EBSCO, MEDLINE, and the Cochrane library. Currently, more evidence exists towards biologicals, as justified by the huge health care costs as compared to phototherapy or conventional systemic drugs. Among them, most of the studies focused on anti-TNF and IL12/23, with still few on IL17 (mainly secukinumab). The most discussed biomarker gene is the HLA-C*02:06 status that has been shown to be associated with psoriasis, and also differential response to biologicals. Although its positivity is associated with great response to MTX, debatable results were retrieved concerning both anti-TNF and IL12/23 while it seems not to affect secukinumab response. Personalized treatment in psoriasis would provide excellent outcome minimizing the risk of side effects. To date, although several candidates were proposed and assessed, the scarcity and heterogeneity of the results do not allow the identification of the gold-standard biomarker per each treatment. Anyway, the creation of a more comprehensive panel would be more reliable for the treatment decision process.

Biomarkers as predictors of treatment response to tricyclic antidepressants in major depressive disorder: A systematic review

Tricyclic antidepressants (TCAs) are frequently prescribed in case of non-response to first-line antidepressants in Major Depressive Disorder (MDD). Treatment of MDD often entails a trial-and-error process of finding a suitable antidepressant and its appropriate dose. Nowadays, a shift is seen towards a more personalized treatment strategy in MDD to increase treatment efficacy. One of these strategies involves the use of biomarkers for the prediction of antidepressant treatment response. We aimed to summarize biomarkers for prediction of TCA specific (i.e. per agent, not for the TCA as a drug class) treatment response in unipolar nonpsychotic MDD. We performed a systematic search in PubMed and MEDLINE. After full-text screening, 36 papers were included. Seven genetic biomarkers were identified for nortriptyline treatment response. For desipramine, we identified two biomarkers; one genetic and one nongenetic. Three nongenetic biomarkers were identified for imipramine. None of these biomarkers were replicated. Quality assessment demonstrated that biomarker studies vary in endpoint definitions and frequently lack power calculations. None of the biomarkers can be confirmed as a predictor for TCA treatment response. Despite the necessity for TCA treatment optimization, biomarker studies reporting drug-specific results for TCAs are limited and adequate replication studies are lacking. Moreover, biomarker studies generally use small sample sizes. To move forward, larger cohorts, pooled data or biomarkers combined with other clinical characteristics should be used to improve predictive power.

The Potential of Polygenic Risk Scores to Predict Antidepressant Treatment Response in Major Depression: A Systematic Review

BACKGROUND

Understanding the genetic underpinnings of antidepressant treatment response in unipolar major depressive disorder (MDD) can be useful in identifying patients at risk for poor treatment response or treatment resistant depression. A polygenic risk score (PRS) is a useful tool to explore genetic liability of a complex trait such as antidepressant treatment response. Here, we review studies that use PRSs to examine genetic overlap between any trait and antidepressant treatment response in unipolar MDD.

METHODS

A systematic search of literature was conducted in PubMed, Embase, and PsycINFO. Our search included studies examining associations between PRSs of psychiatric as well as non-psychiatric traits and antidepressant treatment response in patients with unipolar MDD. A quality assessment of the included studies was performed.

RESULTS

In total, eleven articles were included which contained PRSs for 30 traits. Studies varied in sample size and endpoints used for antidepressant treatment response. Overall, PRSs for attention-deficit hyperactivity disorder, the personality trait openness, coronary artery disease, obesity, and stroke have been associated with antidepressant treatment response in patients with unipolar MDD.

LIMITATIONS

The endpoints used by included studies differed significantly, therefore it was not possible to perform a meta-analysis.

CONCLUSIONS

Associations between a PRS and antidepressant treatment response have been reported for a number of traits in patients with unipolar MDD. PRSs could be informative to predict antidepressant treatment response in this population, given advances in the field. Most importantly, there is a need for larger study cohorts and the use of standardized outcome measures.

Potential Differences in the Cardiometabolic Risk Profile of Patients with Psoriatic Disease according to Their HLA-C ∗ 06 Status

The human leukocyte antigen-C∗06 (HLA-C∗06, formerly HLA-Cw6) is the main genetic biomarker in psoriatic disease. It has been related to several phenotypic traits in psoriatic disease, but its role in relation to cardiometabolic comorbidities is unknown at present. Here, we analyze the potential connections between this biomarker and the cardiometabolic profile of these patients. We carried out a cross-sectional observational study including 400 patients recruited at a single university hospital. Clinical and classical cardiometabolic factors were compared between HLA-C∗06-positive and HLA-C∗06-negative individuals (OR with 95% CI). Multivariate regression analyses were carried out to check for disease traits associated with different cardiometabolic risk factors. The study population included 215 men (53.8%) and 185 women (46.2%), mean age of 46 ± 15 years, and an average disease evolution of 17 ± 12.6 years. Ninety-three (23.3%) patients met CASPAR criteria for psoriatic arthritis. HLA-C∗06 carriers (n: 160, 40%) showed an earlier age at disease onset, psoriasis family history, and more severe skin disease (type I disease). After correcting for age, sex, and disease duration, they also showed less hypertension (13.8% vs. 24.2%, OR 0.7 (95% CI: 0.42-0.78), p = 0.025), lower waist circumference (94.4 ± 13.7 vs. 98.3 ± 13.8 cm), and lower BMI (27 ± 4.4 vs. 28.1 ± 4.8, p < 0.05). We confirmed the well-known association between HLA-C∗06 and type I psoriatic disease. As a novel finding, patients carrying HLA-C∗06 showed a better cardiometabolic profile. In any case, these findings need further confirmation.

Protective association exhibited by a single nucleotide polymorphism of the IFIH1 gene in patients with psoriasis: A case-control study

Introduction

Psoriasis is a chronic inflammatory dermatosis, a with variable clinical presentation and whose multifactorial etiology carries an essential genetic component. Multiple genetic variations associated with psoriasis have been described around the world. However, these variants are unknown among the Colombian population. This study aimed to evaluate the single nucleotide polymorphism rs10930046 (His460Arg) in the IFIH1 gene and its ssociation with the development of psoriasis in a Colombian population.

Methods

An observational, unmatched, case-control study was performed, including 51 patients with psoriasis and 151 population controls, all with self-reported Paisa ancestry (from the Antioquia region). All individuals were genotyped for the single nucleotide polymorphism rs10930046 (His460Arg) in the IFIH1 gene, and its association with psoriasis was pursued. Both groups were demographically characterized, and cases were also assessed for clinical variables.

Results

Through the allelic association analysis, cases were found to have a lower frequency of the single nucleotide polymorphism rs10930046 (His460Arg) in the IFIH1 gene than controls; 5% versus 22.67%, respectively. There were no significant differences in age or sex. We also found that psoriasis vulgaris was the most common variant (78%), that about half of the cases had nail psoriasis (56%), 19.6% had psoriatic arthritis, and that 45% had some comorbidity.

Conclusions

The results obtained from this study confirm that carriers of the single nucleotide polymorphism rs10930046 (His460Arg) in the IFIH1 gene have a decreased risk of developing psoriasis.

New Frontiers in Psoriatic Disease Research, Part I: Genetics, Environmental Triggers, Immunology, Pathophysiology, and Precision Medicine

Psoriasis is a chronic inflammatory condition characterized by systemic immune dysregulation. Over the past several years, advances in genetics, microbiology, immunology, and mouse models have revealed the complex interplay between the heritable and microenvironmental factors that drive the development of psoriatic inflammation. In the first of this two-part review series, the authors will discuss the newest insights into the pathogenesis of psoriatic disease and highlight how the evolution of these scientific fields has paved the way for a more personalized approach to psoriatic disease treatment.

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.

Progress to Date in Advancing Stratified Medicine in Psoriasis

Stratified medicine is the tailoring of treatment to the individual characteristics of each patient. This is a challenging task in the context of psoriasis, a complex disease with a variety of phenotypic presentations and a comorbidity burden that extends beyond cutaneous manifestations. In recent years, considerable progress has been made in understanding the immunology of psoriasis, and this has informed the development of increasingly precise and efficacious therapies. However, not all patients respond to biologic therapy, and access is limited to patients with moderate to severe disease. However, subpopulations of patients are emerging with distinct patterns of response to therapy, largely determined by clinical and pharmacogenomic factors. Despite progress to date, the natural history of psoriasis remains poorly understood. It is likely that disease onset, progression, development of comorbidities and response to therapy are due to a combination of genetic, inflammatory and environmental factors. We envision that a greater understanding of the natural history of psoriasis will be a key factor in progressing a stratified medicine approach to patient care, as will earlier intervention in the course of the disease.

The HLA-Cw6 Dilemma: Is It Really an Outcome Predictor in Psoriasis Patients under Biologic Therapy? A Monocentric Retrospective Analysis

HLA-Cw6 is one of the most strongly associated psoriasis susceptibility alleles. Data regarding correlation between HLA-Cw6 status and biologic treatment outcomes are divergent. The aim of our study in our cohort of psoriatic patients was to explore if the HLA-Cw6 status influences the response rate to biologic therapies at 16 and 48 weeks. One hundred and one psoriatic patients eligible for biologic therapies were enrolled. HLA-C*06 alleles were detected from their blood samples. The effectiveness of antipsoriatic treatments was reported as 90% Psoriasis Area and Severity Index reduction (PASI90). All biologics showed efficacy at week 16, without significant differences between one another. HLA-Cw6 status did not seem to affect baseline characteristics, or treatment response at week 16. At week 48, IL-12/23 and IL-17 targeting drugs were more effective on Cw6-positive patients than on Cw6-negative patients. Conversely, TNF-targeting drugs seemed to be more effective on Cw6- negative patients than on Cw6-positive patients. The HLA-Cw6 test could well deserve to be integrated into the clinical laboratory work-up supporting the choice of the correct biologic.

Not your average joint: Towards precision medicine in psoriatic arthritis

Precision medicine, propelled by advances in multi-omics methods and analytics, aims to revolutionize patient care by using clinically-actionable molecular markers to guide diagnostic and therapeutic decisions. We describe the applications of precision medicine in risk stratification, drug selection, and treatment response prediction in psoriatic arthritis, for which targeted, personalized approaches are steadily emerging.

Reduced Efficacy of Biological Drugs in Psoriatic Patients with HLA-A Bw4-80I KIR Ligands

BACKGROUND

Biological drugs (biologics) are a highly effective therapy for the moderate to severe form of psoriasis, an immune-mediated dermatosis with a strong immunogenetic component. The interaction between human leukocyte antigen (HLA) class I ligands and killer immunoglobulin-like receptors (KIR) has a functional significance in the education of natural killer (NK) cells, and can thus influence the response to biologics.

OBJECTIVE

In this study, we investigated the impact of HLA-A and -B KIR ligands in the response to biologics in a cohort of psoriatic patients.

METHODS

Eighty-five patients with moderate to severe psoriasis treated with biologics (adalimumab, etanercept, infliximab, ustekinumab and secukinumab) were enrolled in the study. Clinical response was evaluated as patients attaining 50%, 75% or 90% reduction in the Psoriasis Area and Severity Index (PASI) (PASI 50, 75 or 90, respectively) over 6 months' follow-up. Poor response was defined as PASI 50, and in this case patients shifted to treatment with a different biologic. Fifty-two patients (61.2%) showed excellent response (PASI 90) to the first biologic, while 33 patients (38.8%), needed two or more biologics before reaching an excellent response (PASI 90) and were considered difficult to treat.

RESULTS

Only HLA-A Bw4-80I ligands were associated with the response to biologics; in particular, they were linked with reduced response both at univariable analysis (odds ratio [OR] 3.11, 95% confidence interval [CI] 1.19-8.07; p = 0.019) and multivariable analysis (OR 5.02, 95% CI 1.40-17.97; p = 0.013).

CONCLUSION

We suggest that the HLA-A Bw4-80I epitope could be a marker of reduced responsiveness to biologics. The possible reason for this is an increase of tumour necrosis factor (TNF)-α and the silencing of NK cells through the predominant interaction with the KIR3DL/S pair. HLA-KIR affinities might lead to a more efficient way to prescribe biologics.

Association of HLA-C*06:02 Status With Differential Response to Ustekinumab in Patients With Psoriasis: A Systematic Review and Meta-analysis

Importance

Previous research showed a differential response to ustekinumab therapy based on HLA-C*06:02 status in patients with psoriasis but consisted mostly of small (and sometimes inconclusive) cohort studies.

Objective

To assess whether HLA-C*06:02 status is associated with a differential response to ustekinumab therapy in patients with psoriasis through a systematic review and a meta-analysis of available data.

Data Sources

A comprehensive search was conducted using MEDLINE, Embase, the Cochrane Library, Web of Science, and gray literature sources. Databases were searched from January 1, 2000, to May 14, 2018. Search strategies included terms and synonyms for psoriasis, HLA-C, and ustekinumab. Languages were restricted to English, French, German, and Dutch.

Study Selection

Studies were included if they reported the association between HLA-C*06:02 status and 75% improvement in Psoriasis Area and Severity Index (PASI75) response to ustekinumab therapy in patients with plaque psoriasis after 6 and/or 3 months of treatment. Randomized clinical trials and observational studies were included. Screening and selection were performed independently by 2 reviewers.

Data Extraction and Synthesis

HLA-C*06:02 genotype status and PASI75 response rates were extracted by 2 reviewers. Data were pooled using random-effects models. Heterogeneity was assessed using the τ2 and I2 statistic. Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) and Meta-Analysis of Observational Studies in Epidemiology (MOOSE) reporting guidelines were followed.

Main Outcome and Measure

The primary outcome was the risk difference of achieving PASI75 after 6 months of ustekinumab therapy between HLA-C*06:02-positive and HLA-C*06:02-negative patients.

Results

A total of 8 studies were reviewed; 1048 patients were included for meta-analyses, and 937 patients were included for the primary analysis of PASI75 response after 6 months of treatment. Random-effects meta-analysis showed a risk difference of 0.24 (95% CI, 0.14-0.35; P < .001) in favor of HLA-C*06:02-positive patients. The median PASI75 response rate in the HLA-C*06:02-positive group was 92% (pooled, 89%; range, 62%-98%). For HLA-C*06:02-negative patients, the median response rate was 67% (pooled, 62%; range, 40%-84%). Substantial heterogeneity may have been present, with an I2 of 82%.

Conclusions and Relevance

The meta-analysis showed a differential response to ustekinumab therapy based on HLA-C*06:02 status in patients with psoriasis. Although HLA-C*06:02-positive patients had high PASI75 response rates after 6 months, the PASI75 response rate was also high in the HLA-C*06:02-negative group. There appears to be no rationale for excluding patients from ustekinumab treatment based on a negative HLA-C*06:02 status.

Response to IL-17A inhibitors secukinumab and ixekizumab cannot be explained by genetic variation in the protein-coding and untranslated regions of the IL-17A gene: results from a multicentre study of four European psoriasis cohorts

BACKGROUND

Genetic predictors for treatment response could optimize allocation of biological treatment in patients with psoriasis. There is minimal knowledge about pharmacogenetics of anti-IL-17 agents.

OBJECTIVES

To assess whether genetic variants in the protein-coding region or untranslated regions of the IL-17A gene are associated with response to IL-17A inhibitors in patients with psoriasis.

METHODS

This was a multicenter European cohort study investigating pharmacogenetics of IL-17A inhibitors in patients with psoriasis. Patients with plaque psoriasis treated with secukinumab or ixekizumab in daily practice were included. For all participants, the protein-coding region and untranslated regions of the IL-17A gene were analysed using Sanger sequencing. Identified genetic variants were tested for association with response to secukinumab/ixekizumab, measured as ∆PASI, after 12 weeks (primary outcome) and after 24 weeks (secondary outcome). Association was tested using a linear regression model with correction for baseline PASI as a fixed covariate and for biological naivety and body mass index as additional covariates.

RESULTS

In total, 134 patients treated with secukinumab or ixekizumab were included. Genotyping of the cohort identified genetic variants present in untranslated regions and intronic DNA, but not in the protein-coding region of the IL-17A gene. Five genetic variants in non-coding DNA with a known or suspected functional effect on IL-17A expression were selected for association analyses: rs2275913, rs8193037, rs3819025, rs7747909 and rs3748067. After 12 weeks, 62% of patients achieved PASI75 and 39% achieved PASI90. At week 24, PASI75 and PASI90 response rates were 72% and 62%, respectively. No associations were found between the five genetic variants and ∆PASI, PASI75 or PASI90 after 12 and 24 weeks of anti-IL-17A treatment.

CONCLUSIONS

Response to IL-17A inhibitors secukinumab and ixekizumab cannot be explained by genetic variation in the protein-coding and untranslated regions of the IL-17A gene. Pharmacogenetics of IL-17A inhibitors in the treatment of psoriasis requires further exploration.

Epigenome-wide association studies in asthma: A systematic review

OBJECTIVE

Asthma is a common chronic respiratory airway disease influenced by environmental factors and possibly their interaction with the human genome causing epigenetic changes. Epigenome-wide association studies (EWAS) have mainly investigated DNA methylation and its association with disease or traits, exposure factors or gene expression. This systematic review aimed to identify all EWAS assessing differentially methylated sites associated with asthma in humans.

DESIGN

Structured systematic literature search following PRISMA guidelines, Newcastle-Ottawa Scale (NOS) for cohort studies was used for bias assessment.

DATA SOURCES

We searched PubMed and Embase databases from 2005 to 2019.

ELIGIBILITY CRITERIA

Epigenome-wide association studies testing association between differential methylation and asthma in humans.

RESULTS

Overall, we identified 16 EWAS studies complying with our search criteria. Twelve studies were conducted on children, and 10 were conducted on sample sizes <150 subjects. Four hundred and nineteen CpGs were reported in children studies after correction for multiple testing. In the adult studies, thousands of differentially methylated sites were identified. Differential methylation in inflammatory-related genes correlated with higher levels of gene expressions of inflammatory modulators in asthma. Differentially methylated genes associated with asthma included SMAD3, SERPINC1, PROK1, IL13, RUNX3 and TIGIT. Forty-one CpGs were replicated at least once in blood samples, and 28 CpGs were replicated in nasal samples.

CONCLUSION

Although many differentially methylated CpGs in genes known to be involved in asthma have been identified in EWAS to date, we conclude that further studies of larger sample sizes and analyses of differential methylation between different phenotypes are needed in order to comprehensively evaluate the role of epigenetic factors in the pathophysiology and heterogeneity of asthma, and the potential clinical utility to predict or classify patients with asthma.

Psoriasis in Skin of Color: Insights into the Epidemiology, Clinical Presentation, Genetics, Quality-of-Life Impact, and Treatment of Psoriasis in Non-White Racial/Ethnic Groups

Psoriasis is a chronic inflammatory skin condition affecting diverse racial/ethnic groups throughout the world. Large population-based studies suggest that psoriasis occurs most often in individuals of European ancestry, followed by black and Hispanic individuals, although the true prevalence of psoriasis in non-white individuals is likely underestimated. Despite similarities in psoriasis between ethnic groups, there are notable differences in the presentation, quality-of-life impact, and treatment of psoriasis with important implications for the management of non-white individuals. Overall, heterogeneity in psoriasis susceptibility alleles, in combination with cultural and socioeconomic factors, may explain these differences. In this article, we review the epidemiology, clinical presentation, genetic polymorphisms, quality-of-life impact, and treatment nuances of psoriasis in patients with skin of color.

Alteration of serum thymus and activation-regulated chemokine level during biologic therapy for psoriasis: Possibility as a marker reflecting favorable response to anti-interleukin-17A agents

Biologics show great efficacy in treating psoriasis, a chronic inflammatory skin disease. The high cost and side-effects of biologics, dose-reduction, elongation of administration interval and suspension are possible options. However, there has been no reliable biomarker we can use when we consider these moderations in therapy. This study was conducted to test the possibility of using serum thymus and activation-regulated chemokine (TARC) level as an indicator for step down of biologic therapy. Serum TARC level was measured in 70 psoriatic patients at Asahikawa Medical University, and a correlation of TARC and severity of skin lesions was analyzed. Referring to serum TARC level, psoriatic patients can be divided into two groups. One is a population in which serum TARC level is positively correlated with severity of skin lesions, and the other is a population with low psoriatic severity and high TARC level. Serum TARC level was higher in the group that achieved PASI-clear with biologics than in the group which did not achieve PASI-clear. Among biologics, the group treated with secukinumab, an anti-interleukin (IL)-17A agent, showed significantly higher TARC level compared with the group treated with anti-tumor necrosis factor agents. In certain populations achieving PASI-clear, serum TARC level may be a potent marker reflecting better response to IL-17A inhibitors, and in this case step down of treatment for psoriasis is possible.

The Genetic Basis of Psoriasis

Psoriasis is widely regarded as a multifactorial condition which is caused by the interaction between inherited susceptibility alleles and environmental triggers. In the last decade, technological advances have enabled substantial progress in the understanding of disease genetics. Genome-wide association studies have identified more than 60 disease susceptibility regions, highlighting the pathogenic involvement of genes related to Th17 cell activation. This pathway has now been targeted by a new generation of biologics that have shown great efficacy in clinical trials. At the same time, the study of rare variants of psoriasis has identified interleukin (IL)-36 cytokines as important amplifiers of Th17 signaling and promising targets for therapeutic intervention. Here, we review these exciting discoveries, which highlight the translational potential of genetic studies.