INTRODUCTION: Persistent pain is a major concern for patients with psoriatic arthritis (PsA). Pain may be due to inflammatory activity or augmented central pain processing. Unawareness of the origin and mechanisms of pain can lead to misinterpretation of disease activity (by composite scores) and erroneous treatments. Ultrasonography (US) is a highly sensitive method to detect tissue inflammation. Evaluating pain mechanisms in relation to US measures may prove valuable in predicting response to treatment in PsA.

AIMS: To study the association and prognostic value of pain mechanisms, ultrasonic activity and clinical outcomes in patients with PsA who intensify antirheumatic treatment.

METHODS AND ANALYSES: 100 participants >18 years of age with PsA who initiate or switch antirheumatic treatment (biologicals and/or conventional synthetic disease-modifying antirheumatic drugs (DMARDs)) will be prospectively recruited from outpatient clinics in Copenhagen. All data (demographics, clinical, imaging, blood samples and patient-reported outcomes) will be collected at baseline and after 4 months. Pain is assessed by the PainDETECT Questionnaire, Visual Analogue Scale for pain, Swollen to Tender Joint Count Ratio, Widespread Pain Index and tender point examination. The association between pain variables and clinical/US characteristics will be described by correlation analyses. The predictive value of pain measures and baseline US scores on treatment response will be analysed with regression models. Outcomes are composite and clinical, as well as patient reported.

ETHICS AND DISSEMINATION: The study is approved by the ethics committee of the Capital Region of Denmark (H-15009080) and has been designed in cooperation with patient research partners. The study is registered at clinicaltrials.gov (number NCT02572700). Results will be disseminated through publication in international peer-reviewed journals.

TRIAL REGISTRATION NUMBER: NCT02572700, Pre-results.

BACKGROUND: The effect of circumstances and exposures early in life on the risk of developing ankylosing spondylitis (AS) is largely unknown. The purpose of this study was to determine whether perinatal characteristics predict development of AS.

METHODS: AS cases (n = 1960; 59 % men) were defined as listed with a diagnosis of AS at least once in the Swedish National Patient Register and registered in the Swedish Medical Birth Register (born ≥1973). Population controls were retrieved from the Swedish Population Register (n = 8378; mean 4.3 controls/case), matched on birth year, sex and county. Odds ratios (OR) for developing AS were determined through conditional logistic regression, with regard to: birth weight, birth order, season of birth, maternal age, gestational length, size for gestational age, type of birth, mode of delivery, congenital malformations, mothers' country of birth, mothers' civil status and size of delivery unit.

RESULTS: In the univariate analyses statistically significant increases in risk for developing AS were observed for having older siblings (OR 1.18; 95 % Cl 1.06-1.30). No association was observed for the remainder of analysed exposures, although there was a weak association with birth weight below 3000 g (OR 1.19; 95 % CI 1.04-1.37), though not for "low birth weight" <2500 g (OR 0.90; 95 % CI 0.70-1.16). The increase in risk associated with having older siblings was consistent in a multivariate analysis adjusting for possible confounders (OR 1.23; 95 % Cl 1.09-1.39). The direction and magnitude of the point estimates were also consistent in several sensitivity analyses and when stratifying by sex.

CONCLUSIONS: Having older siblings was associated with an increased risk for developing AS. These results need to be repeated and confirmed in other cohorts.

OBJECTIVE: To investigate predictors of improvement in observed ability to manage activities of daily living as an outcome of rehabilitation in fibromyalgia.

METHODS: Exploratory analyses used data from the Interdisciplinary Rehabilitation and Evaluation Programme for Patients with Chronic Widespread Pain (the IMPROvE study); a randomized controlled trial including 191 females with fibromyalgia randomized (1:1) to rehabilitation or a waiting list. The primary outcome was observed activities of daily living ability evaluated with the Assessment of Motor and Process Skills (AMPS) 6 months post-intervention.

RESULTS: Overall, 38.7% of subjects were AMPS responders, i.e. having a clinically meaningful improvement in AMPS activities of daily living ability measures at 6 months post-intervention. In the exploratory analysis, only 4 baseline variables out of the 52 analysed showed a statistically significant interaction with treatment allocation (at the 0.05 level) indicating possible predictive value. Statistical analyses that used continuous variables dichotomized at the median suggested a predictive value of a low intake of weak and strong analgesics, and a high score of current pain and total score on the Pain Detect Questionnaire.

CONCLUSION: The results of this exploratory study suggest that several subgroups of patients, specifically those with a low baseline intake of weak and strong analgesics, and more pronounced clinical signs of central sensitization, may gain most clinical benefit from specialized rehabilitation when the outcome of interest is improvement in observed activity of daily living ability.

OBJECTIVE: Synovitis is a frequent condition in knee osteoarthritis (KOA) and has been associated with pain. This study investigated the links between the pressure hyperalgesia, the clinical pain, the degree of the synovitis, inflammatory biomarkers, and tissue-specific biomarkers in KOA patients.

MATERIALS AND METHODS: Fifty-eight KOA patients and 33 pain-free controls participated in this study. The patients were magnetic resonance imaging scanned, and the Boston-Leeds OA Knee Score (BLOKS, 0 to 3) was used to assess the degree of synovitis. The maximal knee pain intensity over the last 24 hours was scored on a visual analog scale (VAS). The pressure pain thresholds (PPTs) were assessed over the KOA-affected knee. Serological biomarkers were measured in fasting serum: high-sensitive C-reactive protein, matrix metalloproteinase-mediated degradation of CRP, and matrix metalloproteinase-mediated collagen type I, II, and III degradation (C1M [connective tissue], C2M [cartilage], C3M [synovial membrane]).

RESULTS: Compared with controls, the KOA patients showed increased levels of C1M (P<0.02), C2M (P<0.001), and high-sensitive C-reactive protein (P<0.02), decreased level of C3M (P<0.03), and reduced PPTs (P<0.03). Patients with no (BLOKS 0) and moderate to severe (BLOKS 2&3) synovitis had significantly lower PPTs compared with mild synovitis (BLOKS 1). Significantly negative correlations were found between VAS and PPTs. No correlations were found between BLOKS and the VAS, PPT, or biomarkers.

DISCUSSION: Patients without and with moderate to severe synovitis demonstrated local pressure hyperalgesia and increased degrees of: (1) systemic inflammation, (2) connective tissue degradation, (3) cartilage degradation, and (4) decreased synovial membrane degradation as compared with controls.

BACKGROUND: Women show increased risk of depressive symptoms in life phases where ovarian steroid hormone levels fluctuate or decline rapidly. The risk mechanisms may include changes in mental state and affective cognition possibly mediated by serotonergic neurotransmission.

METHODS: In a randomized controlled double-blinded trial, 61 healthy women (mean age 24.3±4.9 years) were tested with measures of affective verbal memory, reaction time, mental distress, and serotonin transporter binding at baseline and at follow-up after receiving gonadotropin-releasing hormone agonist (GnRHa) or placebo intervention. Women also reported daily mood profiles during intervention. We tested direct effects of intervention and indirect effects through changes in serotonin transporter binding on verbal affective memory, simple reaction time and self-reported measures of mental distress, and further effects of GnRHa on daily mood.

RESULTS: GnRHa induced an increase in simple reaction time (p=0.03) and more pronounced fluctuations in daily self-reported mood in a manner dependent on baseline mood (p=0.003). Verbal affective memory recall, overall self-perceived mental distress, and serotonin transporter binding were not affected.

CONCLUSIONS: In healthy women transient sex-steroid hormone fluctuations decrease speed of information processing and further produce more labile mood only in women with elevated levels of mood disturbances at baseline.