Back pain in psoriatic arthritis: defining prevalence, characteristics and performance of inflammatory back pain criteria in psoriatic arthritis.

Objective: We aimed to determine the agreement between rheumatologist-judged inflammatory back pain (IBP) and criteria defining IBP in patients with psoriatic arthritis (PsA) and predictive value of IBP in identifying axial involvement in PsA.

Methods: Using prospectively collected data, we investigated the agreement between rheumatologist judgement of IBP and IBP criteria (Calin, Rudwaleit and Assessment of Spondyloarthritis International Society) using the kappa coefficient. We also determined the sensitivity, specificity and likelihood ratios of the presence of back pain, rheumatologist-judged IBP and the three IBP criteria for detecting axial PsA (AxPsA).

Association of variably expressed KIR3dl1 alleles with psoriatic disease.

The purpose of this study is to examine the genetic interaction of variably expressed killer cell immunoglobulin-like receptor (KIR) 3DL1 alleles with their cognate ligand, human leukocyte antigen (HLA)-Bw4, in susceptibility to psoriatic disease (PsD). A novel allelic typing system was developed to differentiate KIR3DL1 alleles (*High, *Low, *Null expression, and 3DS1), in PsD patients, including those with psoriatic arthritis (PsA) and cutaneous psoriasis without arthritis (PsC) and healthy controls. Frequencies of each KIR3DL1 allele, Bw4-80I and Bw4-80T, as well as the genetic interaction between the KIR3DL1 alleles and the Bw4 epitope were analyzed.

Magnetic Resonance Imaging in Psoriatic Arthritis: A Descriptive Study of Indications, Features and Effect on Treatment Change.

Objective: The aims of this study were to describe the indications for, and features of, axial/peripheral joint magnetic resonance imaging (MRI) in psoriatic arthritis (PsA) and to examine the influence of MRI findings on clinical practice.

Methods: All axial and peripheral (hand and/or foot) MRI scans on patients attending the Toronto PsA clinic l between 2003 and 2014 were included. Scan details were garnered from the radiologist's official report.

Attainment of Minimal Disease Activity Using Methotrexate in Psoriatic Arthritis.

Objective: An international task force has recommended that disease remission or minimal disease activity (MDA) be the target of treatment for psoriatic arthritis (PsA) and that remission or MDA should be attained within 6 months of initiating medication. The aim of this study was to establish the proportion of patients with PsA who achieve MDA after 6 months of methotrexate (MTX) treatment.

Methods: Patients who initiated MTX and were naive to biologics between 2004 and 2014 were included.

Psoriatic Arthritis Mutilans: Clinical and Radiographic Criteria. A Systematic Review.

Objective: Research on psoriatic arthritis mutilans (PAM), the most severe form of psoriatic arthritis, is impeded by the lack of an accepted classification criteria. We performed a systematic review of the literature to identify and synthesize clinical and radiographic features associated with the definition of PAM.

Methods: A systematic literature search limited to human studies was conducted without language restriction.

Investigational drugs for treating psoriatic arthritis.

Introduction: Psoriatic arthritis (PsA) is an inflammatory arthritis occurring in up to 30% of patients with psoriasis and can lead to progressive joint damage and disability. The emergence of 'biological' treatments, typified by the TNF inhibitors, has significantly advanced treatment of psoriatic disease over the last two decades and has led to an expanding field of drugs designed to target specific pathways identified in the pathogenesis of the disease.

Areas Covered: This review article describes current knowledge pertaining to genetic susceptibility and that gleaned from animal models.

Is the MAdrid Sonographic Enthesitis Index useful for differentiating psoriatic arthritis from psoriasis alone and healthy controls?

Objective: To assess the usefulness of the MAdrid Sonographic Enthesitis Index (MASEI) in classifying patients as having psoriatic arthritis (PsA) and comparing entheseal abnormalities between patients with PsA, psoriasis alone (PsC), and healthy controls (HC).

Methods: Patients with PsC were assessed to exclude inflammatory arthritis. The MASEI scoring system was used to quantify the extent of ultrasonographic (US) entheseal abnormalities.

Obesity is associated with a lower probability of achieving sustained minimal disease activity state among patients with psoriatic arthritis.

Aim: To assess whether overweight and obese patients with psoriatic arthritis (PsA) are less likely to achieve sustained minimal disease activity (MDA) state compared to patients with normal weight.

Methods: A cohort of patients was assessed at the University of Toronto PsA clinic at 6-12-month intervals according to a standard protocol from 2003 to 2012. Patients were categorised into the following groups according to their body mass index (BMI): normal (<25), overweight (25-30), and obese (>30).

The Framingham Risk Score underestimates the extent of subclinical atherosclerosis in patients with psoriatic disease.

Aim: To investigate the usefulness of carotid atherosclerosis assessment in cardiovascular risk stratification of patients with psoriatic disease compared with the Framingham Risk Score (FRS).

Methods: Patients with psoriatic arthritis (PsA) and psoriasis alone (PsC), who had no previous history of cardiovascular disease, chronic kidney disease or diabetes mellitus were recruited. They underwent assessment of their cardiovascular risk factors and the FRS was calculated.

Tumour necrosis factor α blockers are more effective than methotrexate in the inhibition of radiographic joint damage progression among patients with psoriatic arthritis.

Aim: To determine whether tumour necrosis factor α (TNFα) blockers are more effective than methotrexate in inhibiting the progression of radiographic joint damage in patients with psoriatic arthritis (PsA).

Methods: A cohort analysis of patients followed prospectively in a large PsA clinic was conducted. Patients who received a TNFα blocker were compared to those treated with methotrexate.

Differential human leucocyte allele association between psoriasis and psoriatic arthritis: a family-based association study.

Objective: A recent population-based study identified several HLA alleles as conferring a risk for psoriatic arthritis (PsA) among patients with psoriasis. The authors aimed to confirm these results using a family-based association study.

Methods: PsA probands, psoriasis probands and their first-degree family members were included.

IL13 gene polymorphism is a marker for psoriatic arthritis among psoriasis patients.

Aim: To study the association between smoking and IL13 gene polymorphisms with psoriatic arthritis (PsA) and psoriasis.

Methods: The authors genotyped three groups of Caucasians: those with PsA, those with psoriasis without arthritis (PsC) and healthy controls for the rs20541 and rs848 IL13 single nucleotide polymorphisms (SNPs). An additional SNP, rs1800925, was genotyped only in the PsA and PsC groups.

Incidence of arthritis in a prospective cohort of psoriasis patients.

Objective: Epidemiologic studies about the incidence of psoriatic arthritis (PsA) are limited to a few population-based studies. There are limited data regarding the incidence of PsA in patients with psoriasis. We aimed to determine the incidence of PsA among a prospective cohort of psoriasis patients.

Is ASDAS better than BASDAI as a measure of disease activity in axial psoriatic arthritis?

Objective: To assess the discriminative ability and correlation of the Ankylosing Spondylitis Disease Activity Score (ASDAS) and Bath Ankylosing Spondylitis Activity Disease Activity Index (BASDAI) with disease activity in axial psoriatic arthritis (AxPsA).

Methods: Patients with AxPsA were selected from a large prospective cohort study of psoriatic arthritis. Patient and physician global scores were used as constructs of disease activity.

Reappraisal of the effectiveness of methotrexate in psoriatic arthritis: results from a longitudinal observational cohort.

Objective: In a previous study in our clinic, methotrexate (MTX) conferred no advantage with respect to clinical response or progression of damage after 24 months in patients with psoriatic arthritis (PsA). Our aim was to determine if MTX is being used earlier in the course of PsA and in a higher dose and whether that has led to improved outcomes.

Methods: All patients treated with MTX for at least 24 months in our clinic, between 1994 and 2004, were included in the study.

Relationship between spinal mobility and radiographic damage in ankylosing spondylitis and psoriatic spondylitis: a comparative analysis.

Objective: To correlate measures of spinal mobility used in the assessment of spondyloarthritis with radiographic severity, and to compare ankylosing spondylitis (AS) and psoriatic spondylitis (Ps-Sp) in this clinical-radiographic correlation.

Methods: As part of the International SPondyloarthritis Interobserver Reliability Exercise (INSPIRE) study, 20 spondyloarthropathy (SpA) experts met for an examination exercise assessing 19 patients with SpA -- 10 with Ps-Sp (9 men, mean age 52 yrs, mean disease duration 17 yrs) and 9 with AS (7 men, mean age 38 yrs, mean disease duration 16 yrs). Spearman correlation with bias correction was used to correlate median values of the spinal measurements obtained in the INSPIRE study with modified Stoke AS spinal score (mSASSS) and Bath AS Radiology Index-spine (BASRI-s) scores calculated by consensus of 2 assessors.

Treatment of refractory psoriatic arthritis with infliximab: a 12 month observational study of 16 patients.

Objective: To evaluate the effectiveness and toxicity of infliximab in patients with recalcitrant psoriatic arthritis (PsA).

Methods: Patients with treatment resistant PsA and at least six actively inflamed joints, who had failed to respond to at least two disease modifying agents, were included. Infliximab (5 mg/kg) was given at weeks 0, 2, 6, and every 6-8 weeks pending response.

Comparison of radiological severity in psoriatic arthritis and rheumatoid arthritis.

Objective: To compare the radiological severity of patients with psoriatic arthritis (PsA) and rheumatoid arthritis (RA).

Methods: Patients were identified from the University of Toronto PsA and RA databases. Using the earliest available radiographs, each RA patient was matched to a single PsA patient on the basis of sex, age, and disease duration.

Psoriatic arthritis.

Psoriatic arthritis occurs in 5 - 42% of patients with psoriasis. It is an inflammatory arthritis distinct from rheumatoid, being usually sero-negative, asymmetrical and often affecting the spine, sacro-iliac and distal interphalangeal joints. It runs a very variable course, from a mild non-destructive disease to a severe rapidly progressive erosive arthropathy, producing an 'arthritis mutilans' with a combination of bone lysis and joint ankylosis.

Comparison of clinical and immunogenetic features in familial versus sporadic psoriatic arthritis.

Objective: To compare patients with familial versus sporadic psoriatic arthritis (PsA) with respect to clinical, radiological and immunogenetic features.

Methods: All patients were identified from the University of Toronto Psoriatic Arthritis Clinic. Familial and sporadic PsA were distinguished based on the proband's self-reported history.

Progression in psoriatic arthritis: role of time varying clinical indicators.

Objective: We have shown that the presence of 5 or more effusions and high medication use at first clinic visit predicted clinical progression in patients with psoriatic arthritis (PsA), while a low erythrocyte sedimentation rate (ESR) was "protective." These clinical indicators will change over the course of a patient's disease. We investigated whether there is additional prognostic information available through monitoring these indicators at each clinic visit.

Validity assessment of the disabilities of arm, shoulder, and hand questionnaire (DASH) for patients with psoriatic arthritis.

Objective: To determine whether patients' perception of their functional ability, as measured by the disabilities of arm, shoulder. and hand (DASH) questionnaire, correlates with clinical measures of articular status in patients with psoriatic arthritis (PsA).

Methods: Patients attending the University of Toronto Psoriatic Arthritis Clinic between June and August 1997 were asked to complete a DASH questionnaire during their visits.

The use of sulfasalazine in psoriatic arthritis: a clinic experience.

Objective: To assess the tolerability of sulfasalazine in a clinic setting and determine its longterm effectiveness with respect to articular disease and prevention of radiographic progression in patients with psoriatic arthritis (PsA).

Methods: Patients who were given sulfasalazine during their attendance at the University of Toronto Psoriatic Arthritis Clinic were enrolled in the study. For patients that were able to tolerate sulfasalazine for at least 3 months a matched control was identified who did not receive sulfasalazine.

Coexistence of Fabry's disease and systemic lupus erythematosus.

This report describes a case of a female with systemic lupus erythematosus, who was subsequently diagnosed with Fabry's disease. Due to similarities in the organs involved by these two multisystem disorders, difficulties were encountered in establishing a prompt diagnosis of Fabry's disease. That and subsequent management of this patient are discussed.