Prevalence and Factors Associated With Osteoporosis and Bone Mineral Density Testing in Psoriatic Arthritis.

OBJECTIVE: To determine bone mineral density (BMD) in psoriatic arthritis (PsA) patients, factors associated with undergoing BMD testing, and the effect of PsA clinical activity on BMD. METHODS: Patients attending the University of Toronto PsA Clinic with BMD testing results from cohort inception to January 2019 were included. Descriptive statistics summarized lumbar spine, femoral neck, and total hip T scores. Cox proportional hazards regression identified predictors for BMD testing. Logistic regression analysis determined odds of having normal (T score -1.0 or more) versus osteoporotic-range BMD (T score -2.5 or less). A multistate model determined factors associated with BMD state changes over time. RESULTS: Of the 1,479 patients, 214 had BMD tests performed. The mean ± SD T scores at the lumbar spine, femoral neck, and total hip were -0.30 ± 0.32, -1.10 ± 1.04, and -0.45 ± 0.42, respectively. Osteopenia and osteoporosis occurred in 45.27% and 12.94% of patients. Increasing age, menopause, elevated acute-phase reactants, and biologics, methotrexate, and systemic glucocorticoids use were associated with a higher chance of undergoing BMD testing. Increased body mass index (BMI) and biologics use were associated with a lower chance of having osteoporotic-range BMD test results. In multistate analysis, polyarthritis may portend lower BMD results over time, although this did not achieve statistical significance due to low patient numbers. CONCLUSION: The prevalence of osteopenia and osteoporosis in the PsA cohort was similar to that of the general population. Clinicians are using osteoporosis risk factors and PsA disease severity markers to select patients for BMD testing. Polyarticular disease may portend worse BMD test results. Biologic use and increased BMI appear to have a protective effect.

The association between synovial fluid serine proteinase activity and response to intra-articular corticosteroid injection in psoriatic arthritis.

INTRODUCTION/OBJECTIVES: Intra-articular corticosteroid (IAS) injections are often used for the immediate relief of pain and inflammation in the joint of psoriatic arthritis (PsA) patients. However, studies identifying factors that predict response to the IAS injections are lacking. We aimed to assess the usefulness of serine proteinase activity measurements in PsA synovial fluid (SF) samples obtained at the time of injection in predicting clinical response. METHODS: The PsA patients with available SF samples from the knee joint were identified from the University of Toronto PsA cohort. Clinical response was defined as an absence of tenderness or swelling in the injected joint at the first post-injection visit, at either 3 or 6 months. SF proteinase activity was determined by measuring cleavage of fluorogenic tri-peptide substrates for trypsin-like (VPR-AMC and VLK-AMC) and chymotrypsin-like (AAPF-AMC) serine proteinases. Generalized estimating equation (GEE) models were used to investigate factors associated with response. RESULTS: A total of 32 patients with 60 injected joints and data available for follow-up at 3 or 6 months were included in the analysis, with 25 (41.7%) injected joints resulting in clinical response. Age, sex, active joint count, systemic medications and SF serine proteinase activity at the time of injection were included as covariates. Only treatment with biologics was significantly associated with response at 3 or 6 months in the multivariate reduced model (OR 3.02, p = 0.027). CONCLUSIONS: We could not demonstrate an association between SF serine proteinase activity and response to IAS injection. Biologic agents significantly improve the likelihood of achieving clinical response.

Liver Abnormalities in Patients with Psoriatic Arthritis.

OBJECTIVE: We aimed to determine the prevalence and incidence, and to identify the factors associated with liver abnormalities in patients with psoriatic arthritis (PsA). METHODS: From a longitudinal cohort study, we identified PsA patients with either elevated serum transaminase or alkaline phosphatase levels or liver disease after the first visit to the PsA clinic (cases). Controls were subjects from the same cohort who never had such abnormalities or liver disease. Cases and controls were matched 1:1 by sex, age at the first clinic visit, and followup duration; variables at the onset of the first appearance of liver test abnormality associated with liver abnormalities were identified using univariate logistic and multivariate logistic regression analyses. RESULTS: Among 1061 patients followed in the PsA clinic, 343 had liver abnormalities. Two hundred fifty-six patients who developed liver abnormalities after the first visit were identified as cases, and 718 patients were identified as controls. The prevalence of liver abnormalities was 32% and the incidence was 39/1000 patient-years where there were 256 cases over 6533 total person-years in the PsA cohort. Liver abnormalities were detected after a mean (SD) followup duration of 8.3 ± 7.8 years. The common causes of liver abnormalities were drug-induced hepatitis and fatty liver. Independent factors associated with liver abnormalities were higher body mass index (BMI), daily alcohol intake, higher damaged joint count, elevated C-reactive protein, and use of methotrexate, leflunomide, or tumor necrosis factor inhibitors. CONCLUSION: Liver abnormalities are common among patients with PsA and are associated with higher BMI, more severe disease, and certain therapies.

Is axial psoriatic arthritis distinct from ankylosing spondylitis with and without concomitant psoriasis?

OBJECTIVE: The aim of this study was to compare patients with ankylosing spondylitis with psoriasis (ASP) and without psoriasis (AS), to axial PsA (axPsA) patients. METHODS: Two adult cohorts were recruited from the AS clinic: ASP and AS. These two cohorts were compared with two adult cohorts recruited from the PsA clinic: axPsA (radiographic sacroiliitis: ⩾bilateral grade 2 or unilateral grade 3 or 4); and Peripheral PsA. All patients were followed prospectively according to the same protocol. The demographic, clinical and radiographic variables were compared. Adjusted means were used to account for varying intervals between visits. A logistic regression was performed and adjusted for follow-up duration. RESULTS: There were 477 axPsA patients, 826 peripheral PsA, 675 AS and 91 ASP patients included. AS patients were younger (P < 0.001), more male and HLA-B*27 positive (76%, 72% vs 64%, P ⩽ 0.001, 82%, 75%, vs 19%, P = 0.001). They had more back pain at presentation (90%, 92% vs 19%, P = 0.001), worse axial disease activity scores (bath ankylosing spondylitis disease activity index: 4.1, 3.9 vs 3.5 P = 0.017), worse back metrology (bath ankylosing spondylitis metrology index: 2.9, 2.2 vs 1.8, P < 0.001), worse physician global assessments (2.4, 2.2 vs 2.1, P < 0.001), were treated more with biologics (29%, 21% vs 7%, P = 0.001) and had a higher grade of sacroiliitis (90%, 84% vs 51%, P < 0.001). Similar differences were detected in the comparison of ASP to axPsA and in a regression model. CONCLUSION: AS patients, with or without psoriasis, seem to be different demographically, genetically, clinically and radiographically from axPsA patients. axPsA seems to be a distinct entity.

Late onset psoriatic arthritis in a longitudinal cohort: Disease presentation, activity over time and prognosis.

AIMS: To evaluate disease activity of late onset psoriatic arthritis (LoPsA) patients at presentation, during follow-up, and after 5years of follow-up, compared to young onset PsA patients (YoPsA). METHODS: The study included patients with PsA followed prospectively within 2years from diagnosis. Patients were divided into two groups: (1) LoPsA - defined as disease onset ≥ 50 years, (2) YoPsA - defined as disease onset < 50 years. Descriptive statistics are provided and multivariable logistic regression models were developed to compare these groups. RESULTS: Five hundred and sixty-six patients were included at presentation. Regression analysis showed that the LoPsA group at presentation was characterized by: less males (OR 0.4, p = 0.001), less HLA-C*06 (OR 0.3, p = 0.005), longer psoriasis duration (OR 1.04, p = 0.0005), higher BMI (OR 1.1, p = 0.005) and higher modified Steinbrocker score (mSS) (OR 1.1, p = 0.005). Regression analysis adjusted for gender, BMI, psoriasis duration, HLA and treatments after 5years of follow-up revealed a trend toward higher adjusted mean active joint count (OR 7.98, p = 0.052) and higher mean mSS score (OR 13.39, p = 0.007) in the LoSpA group compared to the YoPsA group. During 5years of follow-up, the YoPsA patients were treated with more NSAIDs (96% vs. 88%, p = 0.04), while there were no significant differences in the DMARDs and biologic drugs. CONCLUSION: The LoPsA patients at presentation are characterized by female predominance, higher BMI, more damage and less HLA-C*06. After 5years of follow-up the LoPsA patients have worse prognosis manifested by a trend toward higher disease activity burden and significantly more damage.

Outcome of pregnancy in women with psoriatic arthritis compared to healthy controls.

OBJECTIVES: The mean age at onset of psoriatic arthritis (PsA) ranges between the 4th-6th decades of life. However, little is known about fertility and pregnancy outcome in PsA patients. The aim of this study was to examine whether fertility and pregnancy outcome of PsA patients are different from healthy controls and to evaluate PsA and psoriasis disease activity perception during pregnancy and the year postpartum. METHODS: A questionnaire-based study, including demographic, fertility, pregnancy outcome, and disease activity questions, was conducted in PsA patients and healthy controls. The inclusion criterion was diagnosis of PsA before at least 1 pregnancy. Descriptive statistics are provided. T tests and Pearson chi-square tests were used to analyze the differences between continuous and categorical variables, respectively. RESULTS: The 74 PsA patients and 74 healthy controls were not significantly different in most of the demographic variables. The mean number of pregnancies, children, and infertility diagnosis were not significantly different between the groups. The pregnancy outcomes in the PsA group (n = 151) and in the control group (n = 189) were similar in: live birth (76% vs. 76%, P = 0.3), vaginal delivery (48% vs. 51%, P = 0.6), gestation age (38.5 vs. 38.3, P = 0.3), weight at birth (3.4 kg vs. 3.4 kg, P = 0.5), low rate of maternal and fetal complications, and the duration and rate of breastfeeding. Most (58%) patients reported favorable joint activity during pregnancy and 50% reported worsening during the 1st postpartum year. CONCLUSIONS: PsA patients do not have more infertility or worse pregnancy outcomes compared to healthy controls.

Characteristic and Outcome of Psoriatic Arthritis Patients with Hyperuricemia.

OBJECTIVE: To determine the characteristics of patients with psoriatic arthritis (PsA) who have hyperuricemia (HUC) and their outcomes, especially cardiovascular (CVD) and kidney diseases. METHODS: Patients have been followed prospectively at the PsA clinic according to a standard protocol at 6- to 12-month intervals. We defined HUC in men > 450 µmol/l or women > 360 µmol/l. We matched patients with HUC based on sex and age ± 5 years with normal uric acid patients. Demographics information and disease characteristics were reviewed. Outcomes of patients with HUC, especially CVD and kidney diseases, were recorded. Conditional logistic regression was performed to determine factors independently associated with HUC in patients with PsA. RESULTS: There were 325 (31.9%) out of 1019 patients with PsA who had HUC. Of these, 318 cases were matched to 318 controls. There were 11 (3.4%) out of 325 patients with HUC who had gout. Patients with HUC had longer disease duration and a higher Psoriasis Area and Severity Index. They had more concurrent comorbidities, including CVD and metabolic diseases, as well as higher prevalence of kidney stones and higher creatinine. Only 1 patient with HUC was treated with allopurinol at first evaluation visit and 7 patients during followup. Over the followup, 163 of the 318 patients had persistent HUC (pHUC) for more than 2 visits. Patients with pHUC developed more myocardial infarction, heart failure, and renal impairment. Multivariate analysis showed an association between pHUC, PsA disease duration, and obesity. CONCLUSION: HUC is common in patients with PsA, especially in those with longer disease duration and obesity. Proper control of HUC and metabolic diseases may play a preventive role in improving PsA outcomes.