Prediction of Psoriatic Arthritis in Patients With Psoriasis Using DNA Methylation Profiles.

OBJECTIVE: Psoriatic arthritis (PsA) is an immune-mediated inflammatory arthritis, associated with psoriasis, that significantly increases morbidity and mortality risk. We currently lack the means of predicting which patients with psoriasis will develop PsA, and a large number of patients remain undiagnosed. Regulation of gene expression through DNA methylation can potentially trigger and maintain PsA pathophysiological processes. We aimed to identify DNA methylation markers that can predict which patients with psoriasis will develop PsA prior to the onset of musculoskeletal symptoms. METHODS: Genome-wide DNA methylation was assessed in blood samples from patients with psoriasis who went on to develop arthritis (converters) and patients with psoriasis who did not (biologic naive, matched for age, sex, psoriasis duration, and duration of follow-up). Methylation differences between converters and nonconverters were identified by a multivariate linear regression model including clinical covariates (age, sex, body mass index, smoking). Predictive performance of methylation markers was assessed by developing support vector machine classification models with and without the addition of clinical variables. RESULTS: We identified a set of 36 highly relevant methylation markers (false discovery rate: adjusted P < 0.05 and a minimum change in methylation of 0.05) across 15 genes and several intergenic regions. A classification model relying on these markers identified converters and nonconverters with an area under the receiver operating characteristic curve of 0.9644. CONCLUSION: This study shows that DNA methylation patterns at an early stage of psoriatic disease can distinguish between patients who will develop PsA from those who will not during the same follow-up.

Exploring cannabis use and perspectives among psoriatic disease patients.

OBJECTIVE: To assess the correlation between cannabis use and psoriatic disease severity, health-related quality of life, pain, psychosocial outcomes, and cytokine levels in psoriasis (PsC) and psoriatic arthritis (PsA) patients. METHODS: PsC and PsA patients enrolled in the International Psoriasis and Arthritis Research Team (IPART) program were surveyed on cannabis use and were asked to provide a serum and urine sample. Demographic and clinical variables were compared between users and non-users using Student's t-test or Mann-Whitney U test for continuous variables, and chi-square or Fisher's exact test for categorical variables. RESULTS: Of 151 respondents, 30% reported current cannabis use within the last year. Compared to non-users, cannabis users were younger and had a shorter PsA duration and poorer mental health as measured by the SF-36. Other measures of health-related quality of life and pain were comparable between the groups. Respondents' primary perceived benefits of cannabis use were aid in sleep and arthritis pain relief, but there was no difference in pain between users and non-users. No THC was detected in the urine of non-users while users had a mean level of 19.6 ng/ml. Serum IL-23 levels were statistically significantly higher in non-users than in users. CONCLUSION: A third of the patients used cannabis within the past year, and 54.3% of users reported the use of cannabis for arthritis pain relief. However, there was no difference in pain scores. Comprehensive education for providers on the current body of evidence and further studies on cannabis use and outcomes in psoriatic disease are needed. Key Points • A third of patients with psoriatic arthritis have used cannabis in the past year. • Most used it for better sleep and control of pain. • There was no difference in pain scores between users and non-users. • IL-23 levels were significantly higher in non-users.

Macrophage migration inhibitory factor drives pathology in a mouse model of spondyloarthritis and is associated with human disease.

Spondyloarthritis (SpA), a type 3 immunity-mediated inflammatory arthritis, is a systemic rheumatic disease that primarily affects the joints, spine, gut, skin, and eyes. Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine, yet MIF's pathological role in SpA is unknown. Here, we observed that the expression of MIF and its receptor CD74 is increased in blood and tissues of curdlan (ß-glucan)­treated SKG mice, a mouse model of SpA. We found that neutrophils substantially expanded and produced MIF in curdlan-treated SKG mice and that human neutrophils from SpA patients secreted higher concentrations of MIF compared to healthy individuals. Although genetic deletion of Mif (Mif−/−) substantially suppressed the severity of SpA features, adoptive transfer of inflammatory neutrophils induced SpA pathology in curdlan-treated Mif−/− SKG mice; in contrast, blocking the function of neutrophils with anti­Gr-1 antibody suppressed the curdlan-induced SpA-like phenotype. We also determined that systemic MIF overexpression was sufficient to induce SpA-like clinical features in SKG mice with enhanced type 3 immunity, whereas SKG mice treated with a MIF antagonist prevented or attenuated curdlan-induced SpA manifestations. Mechanistically, we identified that MIF intensifies type 3 immunity by boosting human and mouse T regulatory cell (Treg) acquisition of a TH17 cell­like phenotype, including the up-regulation of interleukin-17 (IL-17) and IL-22 in vitro. Tregs in blood and synovial fluids from SpA patients have a pathologic TH17 phenotype. These results indicate that MIF is a crucial regulator and a potential therapeutic target in type 3 immunity-mediated arthritis.

Variation in telangiectasia predisposing genes is associated with overall radiation toxicity.

PURPOSE: In patients receiving radiotherapy for breast cancer where the heart is within the radiation field, cutaneous telangiectasiae could be a marker of potential radiation-induced heart disease. We hypothesized that single nucleotide polymorphisms (SNPs) in genes known to cause heritable telangiectasia-associated disorders could predispose to such late, normal tissue vascular damage. METHODS AND MATERIALS: The relationship between cutaneous telangiectasia as a late normal tissue radiation injury phenotype in 633 breast cancer patients treated with radiotherapy was examined. Patients were clinically assessed for the presence of cutaneous telangiectasia and genotyped at nine SNPs in three candidate genes. Candidate SNPs were within the endoglin (ENG) and activin A receptor, type II-like 1 (ACVRL1) genes, mutations in which cause hereditary hemorrhagic telangiectasia and the ataxia-telangiectasia mutated (ATM) gene associated with ataxia-telangiectasia. RESULTS: A total of 121 (19.1%) patients exhibited a degree of cutaneous telangiectasiae on clinical examination. Regression was used to examine the associations between the presence of telangiectasiae in patients who underwent breast-conserving surgery, controlling for the effects of boost and known brassiere size (n=388), and individual geno- or haplotypes. Inheritance of ACVRL1 SNPs marginally contributed to the risk of cutaneous telangiectasiae. Haplotypic analysis revealed a stronger association between inheritance of a ATM haplotype and the presence of cutaneous telangiectasiae, fibrosis and overall toxicity. No significant association was observed between telangiectasiae and the coinheritance of the candidate ENG SNPs. CONCLUSIONS: Genetic variation in the ATM gene influences reaction to radiotherapy through both vascular damage and increased fibrosis. The predisposing variation in the ATM gene will need to be better defined to optimize it as a predictive marker for assessing radiotherapy late effects.