Kristina Callis Duffin

Genome-wide scan reveals association of psoriasis with IL-23 and NF-κB pathways.

Psoriasis is a common immune-mediated disorder that affects the skin, nails and joints. To identify psoriasis susceptibility loci, we genotyped 438,670 SNPs in 1,409 psoriasis cases and 1,436 controls of European ancestry. We followed up 21 promising SNPs in 5,048 psoriasis cases and 5,041 controls. Our results provide strong support for the association of at least seven genetic loci and psoriasis (each with combined P < 5 × 10−8). Loci with confirmed association include HLA-C, three genes involved in IL-23 signaling (IL23A, IL23R, IL12B), two genes that act downstream of TNF-α and regulate NF-κB signaling (TNIP1, TNFAIP3) and two genes involved in the modulation of Th2 immune responses (IL4, IL13). Although the proteins encoded in these loci are known to interact biologically, we found no evidence for epistasis between associated SNPs. Our results expand the catalog of genetic loci implicated in psoriasis susceptibility and suggest priority targets for study in other auto-immune disorders.

Phase 3 Studies Comparing Brodalumab with Ustekinumab in Psoriasis

BACKGROUND Early clinical studies suggested that the anti-interleukin-17 receptor A monoclonal antibody brodalumab has efficacy in the treatment of psoriasis. METHODS In two phase 3 studies (AMAGINE-2 and AMAGINE-3), patients with moderate-to-severe psoriasis were randomly assigned to receive brodalumab (210 mg or 140 mg every 2 weeks), ustekinumab (45 mg for patients with a body weight ≤100 kg and 90 mg for patients >100 kg), or placebo. At week 12, patients receiving brodalumab were randomly assigned again to receive a brodalumab maintenance dose of 210 mg every 2 weeks or 140 mg every 2 weeks, every 4 weeks, or every 8 weeks; patients receiving ustekinumab continued to receive ustekinumab every 12 weeks, and patients receiving placebo received 210 mg of brodalumab every 2 weeks. The primary aims were to evaluate the superiority of brodalumab over placebo at week 12 with respect to at least a 75% reduction in the psoriasis area-and-severity index score (PASI 75) and a static physicians global assessment (sPGA) score of 0 or 1 (clear or almost clear skin), as well as the superiority of brodalumab over ustekinumab at week 12 with respect to a 100% reduction in PASI score (PASI 100). RESULTS At week 12, the PASI 75 response rates were higher with brodalumab at the 210-mg and 140-mg doses than with placebo (86% and 67%, respectively, vs. 8% [AMAGINE-2] and 85% and 69%, respectively, vs. 6% [AMAGINE-3]; P<0.001); the rates of sPGA scores of 0 or 1 were also higher with brodalumab (P<0.001). The week 12 PASI 100 response rates were significantly higher with 210 mg of brodalumab than with ustekinumab (44% vs. 22% [AMAGINE-2] and 37% vs. 19% [AMAGINE-3], P<0.001). The PASI 100 response rates with 140 mg of brodalumab were 26% in AMAGINE-2 (P=0.08 for the comparison with ustekinumab) and 27% in AMAGINE-3 (P=0.007). Rates of neutropenia were higher with brodalumab and with ustekinumab than with placebo. Mild or moderate candida infections were more frequent with brodalumab than with ustekinumab or placebo. Through week 52, the rates of serious infectious episodes were 1.0 (AMAGINE-2) and 1.3 (AMAGINE-3) per 100 patient-years of exposure to brodalumab. CONCLUSIONS Brodalumab treatment resulted in significant clinical improvements in patients with moderate-to-severe psoriasis. (Funded by Amgen; AMAGINE-2 and AMAGINE-3 ClinicalTrials.gov numbers, NCT01708603 and NCT01708629.).

Rare and Common Variants in CARD14, Encoding an Epidermal Regulator of NF-kappaB, in Psoriasis

Psoriasis is a common inflammatory disorder of the skin and other organs. We have determined that mutations in CARD14, encoding a nuclear factor of kappa light chain enhancer in B cells (NF-kB) activator within skin epidermis, account for PSORS2. Here, we describe fifteen additional rare missense variants in CARD14, their distribution in seven psoriasis cohorts (>6,000 cases and >4,000 controls), and their effects on NF-kB activation and the transcriptome of keratinocytes. There were more CARD14 rare variants in cases than in controls (burden test p value = 0.0015). Some variants were only seen in a single case, and these included putative pathogenic mutations (c.424G>A [p.Glu142Lys] and c.425A>G [p.Glu142Gly]) and the generalized-pustular-psoriasis mutation, c.413A>C (p.Glu138Ala); these three mutations lie within the coiled-coil domain of CARD14. The c.349G>A (p.Gly117Ser) familial-psoriasis mutation was present at a frequency of 0.0005 in cases of European ancestry. CARD14 variants led to a range of NF-kB activities; in particular, putative pathogenic variants led to levels >2.5× higher than did wild-type CARD14. Two variants (c.511C>A [p.His171Asn] and c.536G>A [p.Arg179His]) required stimulation with tumor necrosis factor alpha (TNF-α) to achieve significant increases in NF-kB levels. Transcriptome profiling of wild-type and variant CARD14 transfectants in keratinocytes differentiated probably pathogenic mutations from neutral variants such as polymorphisms. Over 20 CARD14 polymorphisms were also genotyped, and meta-analysis revealed an association between psoriasis and rs11652075 (c.2458C>T [p.Arg820Trp]; p value = 2.1 × 10(-6)). In the two largest psoriasis cohorts, evidence for association increased when rs11652075 was conditioned on HLA-Cw*0602 (PSORS1). These studies contribute to our understanding of the genetic basis of psoriasis and illustrate the challenges faced in identifying pathogenic variants in common disease.

A Phase 2 Trial of Guselkumab versus Adalimumab for Plaque Psoriasis

BACKGROUND Little is known about the effect of specific anti-interleukin-23 therapy, as compared with established anti-tumor necrosis factor therapies, for the treatment of moderate-to-severe plaque psoriasis. METHODS In a 52-week, phase 2, dose-ranging, randomized, double-blind, placebo-controlled, active-comparator trial, we compared guselkumab (CNTO 1959), an anti-interleukin-23 monoclonal antibody, with adalimumab in patients with moderate-to-severe plaque psoriasis. A total of 293 patients were randomly assigned to receive guselkumab (5 mg at weeks 0 and 4 and every 12 weeks thereafter, 15 mg every 8 weeks, 50 mg at weeks 0 and 4 and every 12 weeks thereafter, 100 mg every 8 weeks, or 200 mg at weeks 0 and 4 and every 12 weeks thereafter) through week 40, placebo, or adalimumab (standard dosage for psoriasis). At week 16, patients in the placebo group crossed over to receive guselkumab at a dose of 100 mg every 8 weeks. The primary end point was the proportion of patients with a Physicians Global Assessment (PGA) score of 0 (indicating cleared psoriasis) or 1 (indicating minimal psoriasis) at week 16. RESULTS At week 16, the proportion of patients with a PGA score of 0 or 1 was significantly higher in each guselkumab group than in the placebo group: 34% in the 5-mg group, 61% in the 15-mg group, 79% in the 50-mg group, 86% in the 100-mg group, and 83% in the 200-mg group, as compared with 7% in the placebo group (P≤0.002 for all comparisons). Moreover, the proportion was significantly higher in the 50-mg, 100-mg, and 200-mg guselkumab groups than in the adalimumab group (58%) (P<0.05 for all comparisons). At week 16, the proportion of patients with at least a 75% improvement in Psoriasis Area and Severity Index scores was significantly higher in each guselkumab group than in the placebo group (P<0.001 for all comparisons). At week 40, the proportion of patients with a PGA score of 0 or 1 remained significantly higher in the 50-mg, 100-mg, and 200-mg guselkumab groups than in the adalimumab group (71%, 77%, and 81%, respectively, vs. 49%) (P<0.05 for all comparisons). Between week 0 and week 16, infections were observed in 20% of the patients in the guselkumab groups, 12% in the adalimumab group, and 14% in the placebo group. CONCLUSIONS The results of this phase 2 trial suggest that guselkumab may be an effective therapy for plaque psoriasis and that control of psoriasis can be achieved with specific anti-interleukin-23 therapy. (Funded by Janssen Research and Development; X-PLORE ClinicalTrials.gov number, NCT01483599.).

Consensus Guidelines for the Management of Plaque Psoriasis

The Canadian Guidelines for the Management of Plaque Psoriasis were reviewed by the entire National Psoriasis Foundation Medical Board and updated to include newly approved agents such as ustekinumab and to reflect practice patterns in the United States, where the excimer laser is approved for psoriasis treatment. Management of psoriasis in special populations is discussed. In the updated guidelines, we include sections on children, pregnant patients or pregnant partners of patients, nursing mothers, the elderly, patients with hepatitis B or C virus infections, human immunodeficiency virus-infected patients, and patients with malignant neoplasms, as well as sections on tumor necrosis factor blockers, elective surgery, and vaccinations.

Obesity in early adulthood as a risk factor for psoriatic arthritis.

OBJECTIVE To study whether obesity increases the risk of psoriatic arthritis (PsA), given that obesity is a risk factor for psoriasis and is associated with more severe disease. DESIGN Case series. We used Cox regression analysis to study the relationship between obesity and PsA while controlling for age at psoriasis onset, current body mass index (BMI), sex, family history of psoriasis, worst-ever body surface area (BSA) involvement, Koebner phenomenon, and nail involvement. SETTING Dermatology clinics at the University of Utah School of Medicine. Patients Volunteer sample of patients with dermatologist-diagnosed psoriasis enrolled in the Utah Psoriasis Initiative from November 2002 to October 2008 (943 subjects; 50.2% women, 49.8% men). MAIN OUTCOME MEASURES Physician diagnosis of PsA from self-report questionnaire. RESULTS In our subjects, we found that BMI at age 18 years was predictive of PsA (odds ratio [OR], 1.06) (P < .01) over and above control variables. Other variables that were predictors of PsA included younger age at psoriasis onset (odds ratio [OR], 0.98) (P < .01), female sex (OR, 1.45) (P = .01), higher worst-ever BSA involvement with psoriasis (OR, 1.01) (P = .04), Koebner phenomenon (OR, 1.59) (P < .01), and nail involvement (OR, 1.76) (P < .01). Current BMI and family history of psoriasis were not significant predictors of PsA. CONCLUSIONS This study suggests that obesity at age 18 years increases the risk of developing PsA. Adiposity is associated with higher levels of inflammatory cytokines known to be associated with psoriasis. This inflammatory milieu could increase the risk of PsA in predisposed subjects. Prevention and early treatment of obesity may decrease the risk of PsA.

International multicenter psoriasis and psoriatic arthritis reliability trial for the assessment of skin, joints, nails, and dactylitis.

OBJECTIVE Clinical trials in psoriasis and psoriatic arthritis (PsA) involve assessment of the skin and joints. This study aimed to determine whether assessment of the skin and joints in patients with PsA by rheumatologists and dermatologists is reproducible. METHODS Ten rheumatologists and 9 dermatologists from 7 countries met for a combined physical examination exercise to assess 20 PsA patients (11 men, mean age 51 years, mean PsA duration 11 years). Each physician assessed 10 patients according to a modified Latin square design that enabled the assessment of patient, assessor, and order effect. Tender joint count (TJC), swollen joint count (SJC), dactylitis, physicians global assessment (PGA) of PsA disease activity (PGA-PsA), psoriasis body surface area (BSA), Psoriasis Area and Severity Index (PASI), Lattice System Physicians Global Assessment of psoriasis (LS-PGA), National Psoriasis Foundation Psoriasis Score (NPF-PS), modified Nail Psoriasis Severity Index (mNAPSI), number of fingernails with nail changes (NN), and PGA of psoriasis activity (PGA-Ps) were assessed. Variance components analyses were carried out to estimate the intraclass correlation coefficient (ICC), adjusted for the order of measurements. RESULTS There is excellent agreement (ICC >/=0.80) on the mNAPSI, substantial agreement (0.6 >/= ICC < 0.80) on the TJC, PASI, and NN, moderate agreement (0.4 >/= ICC < 0.60) on the PGA-Ps, LS-PGA, NPF-PS, and BSA, and fair agreement (0.2 >/= ICC < 0.40) on the SJC, dactylitis, and PGA-PsA. The only measure that showed a significant difference between dermatologists and rheumatologists was dactylitis (P = 0.0005). CONCLUSION There is substantial to excellent agreement on the TJC, PASI, NN, and mNAPSI among rheumatologists and dermatologists.

Association between IL13 Polymorphisms and Psoriatic Arthritis Is Modified by Smoking

Genetic and environmental factors influence the development of psoriasis (Ps) and psoriatic arthritis (PsA). Recently, we reported that three IL13 polymorphisms, rs1800925, rs20541, and rs848, on chromosome 5q31 conferred the risk for Ps. IL13 encodes IL-13, a Th2 cytokine, and rs1800925 and rs20541 confer risk of asthma. Further, smoking may increase the risk of developing Ps. We examined the association between IL13 polymorphisms, smoking, and PsA in two Ps sample sets genotyped for rs1800925, rs20541, and rs848. We found that the minor alleles (rs1800925*T, rs20541*A, and rs848*A) were significantly associated with protection from PsA versus controls, and that no association with Ps is seen when the PsA cases are excluded. This effect was strongest with rs1800925*T (odds ratio (OR) 0.40, P(allelic) 0.000067). The prevalence of PsA in cases with the rs1800925*CT or TT genotype is about half that of those with the CC genotype (15.5 vs 32.1%, P=0.0002). However, smoking appears to abrogate this effect (CT/TT/non-smoker, prevalence of PsA 13%, OR 0.20, P=0.0001; CT/TT/smoker, prevalence 38%, OR 0.88, P=0.74, CC/non-smoker, prevalence 42% (reference), CC/smoker prevalence 47%, OR 1.21, P=0.47). This study suggests that IL13 polymorphisms associate most strongly with PsA and that smoking may modulate this effect.

Genetic Variations in Cytokines and Cytokine Receptors Associated with Psoriasis Found by Genome-Wide Association

Genetic variants have long been suspected to be important in psoriasis. Recent work has suggested that HLA-Cw6 on chromosome 6 is the risk variant in the PSORS1 [MIM 177900] susceptibility locus that confers the greatest risk for early onset of psoriasis. Although numerous minor susceptibility loci have been identified by linkage analysis, few biologically relevant candidates have been discovered within these intervals. Recent large-scale genome-wide association studies have yielded new candidates in genes encoding cytokines with functional relevance to psoriasis. Polymorphisms within the genes encoding the IL-12 p40 subunit, IL12B, and one of the IL-23 receptor subunits, IL23R, have been replicated in US and European populations and overlap with risk of Crohns disease. Polymorphisms within the gene encoding IL-13, a Th2 cytokine, also confer risk for psoriasis. Variants of the gene IL15 encoding IL-15 have been identified that associate with psoriasis in a Chinese population. These discoveries pose the challenge of elucidating the role of common genetic variants in susceptibility to and manifestations of psoriasis.

Limitations in screening instruments for psoriatic arthritis: a comparison of instruments in patients with psoriasis.

Objective. To compare the abilities of 3 validated screening instruments to predict the diagnosis of psoriatic arthritis (PsA) in patients with psoriasis. Methods. Prior to a rheumatologic evaluation, 213 participants in the Utah Psoriasis Initiative completed the Psoriasis Epidemiology Screening project (PEST), the Toronto Psoriatic Arthritis Screen (ToPAS), and the Psoriatic Arthritis Screening and Evaluation (PASE). Previously established instrument cutoff scores were used to designate positive and negative classifications. Sensitivities and specificities were determined by comparing instrument classifications to the rheumatologist’s diagnosis. Phenotypic features and alternative diagnoses were compared between participants who screened positively and negatively on each instrument. Discrepancies between the rheumatologist’s examination findings and responses to specific instrument questions were compared. Results. The sensitivities of PEST, ToPAS, and PASE were 85%, 75%, and 68%, and the specificities were 45%, 55%, and 50%, respectively. The instruments were less sensitive in patients with lower disease activity, fewer PsA features, and shorter disease duration. The instruments did not consistently differentiate between PsA and other types of musculoskeletal disease. Discrepancies between examination findings and responses to instrument questions occurred more frequently with ToPAS than with PEST and PASE. Conclusion. Sensitivities and specificities for PEST, ToPAS, and PASE were lower than previously reported. This population included patients with PsA and other types of musculoskeletal disease and may represent those most likely to complete a screening instrument and follow through with a rheumatology referral. Further analyses may enable the development of more successful screening strategies for PsA in psoriasis patients with musculoskeletal complaints.