The prevalence of neutropenia and association with infections in patients with systemic lupus erythematosus: a Swedish single-center study conducted over 14 years

Hematologic abnormalities are common manifestations of SLE, although neutropenia is observed less frequently and is not included in the classification criteria. Nonetheless, neutropenia is a risk factor for infections, especially those caused by bacteria or fungi. We aimed to evaluate the impact of neutropenia in SLE through a systematic investigation of all infections in a large cohort of well-characterized patients, focusing on neutropenia, lymphopenia, and hypocomplementemia. Longitudinal clinical and laboratory parameters obtained at visits to the Rheumatology Unit, Linköping University Hospital, and linked data on all forms of healthcare utilization for all the subjects included in our regional SLE register during 2008-2022 were assessed. Data regarding confirmed infections were retrieved from the medical records. Overall, 333 patients were included and monitored during 3,088 visits to a rheumatologist during the study period. In total, 918 infections were identified, and 94 occasions of neutropenia (ANC < 1.5 × 109/L) were detected in 40 subjects (12%). Thirty neutropenic episodes in 15 patients occurred in association with infections, of which 13 (43%) required in-hospital care, 4 (13%) needed intensive care, and 1 (3%) resulted in death. Bayesian analysis showed that patients with ≥ 1 occasion of neutropenia were more likely to experience one or more infections (OR = 2.05; probability of association [POA] = 96%). Both invasiveness (OR = 7.08; POA = 98%) and severity (OR = 2.85; POA = 96%) of the infections were significantly associated with the present neutropenia. Infections are common among Swedish SLE patients, 12% of whom show neutropenia over time. Importantly, neutropenia is linked to both the invasiveness and severity of infections. Awareness of the risks of severe infections in neutropenic patients is crucial to tailor therapies to prevent severe illness and death.

Obesity and tobacco smoking are independently associated with poor patient-reported outcomes in SLE: a cross-sectional study

We investigated associations of obesity and tobacco smoking with health-related quality of life (HRQoL), pain, fatigue, and functional impairment in systemic lupus erythematosus (SLE). Furthermore, we explored whether there was an effect modification between these two factors. We included adult SLE patients from the Linköping University Hospital (n = 325) in the present cross-sectional analysis. We further included population-based controls and performed cardinality matching to balance age and sex distributions with cases (n = 224). HRQoL was assessed with the EQ-5D index score; pain, fatigue, and overall SLE-related health state with visual analogue scales (VAS; 0 [best] to 100 [worst]); and functional impairment with the HAQ-DI. Unacceptable outcomes were defined as VAS scores corresponding to the 90th percentile derived from the matched controls. SLE patients reported worse scores than controls in all measures, and approximately 30% experienced unacceptable outcomes. When compared with normal-weight, obese SLE patients reported lower HRQoL, and greater functional impairment and risk of unacceptable pain (OR: 3.2; 95% CI 1.6-6.7) and fatigue (OR: 2.1; 95% CI 1.0-4.3). Similarly, the current smokers reported higher levels of functional impairment and a greater risk of unacceptable pain (OR: 3.8; 95% CI 1.8-8.2) and fatigue (OR: 2.8; 95% CI 1.3-5.9) than never smokers. The associations were independent of age, sex, disease duration, disease activity, and organ damage. There was no evidence of a synergistic effect between increased BMI and smoking on any outcome. In summary, obesity and smoking are risk factors for unacceptable patient-reported outcomes in SLE, regardless of clinical activity.

Factors associated with non-adherence to medications in systemic lupus erythematosus: Results from a Swedish survey

OBJECTIVE

To identify determinants of medication non-adherence in a Swedish population of systemic lupus erythematosus (SLE).

METHODS

Patients with SLE from Karolinska and Örebro University Hospitals participated in a survey-based cross-sectional study. Demographics, disease activity, organ damage, HRQoL (LupusQol, EQ-5D-5 L), medication non-adherence (<80% on CQR-19 or MASRI) and beliefs about medicines (BMQ) were registered. MASRI was used to report adherence to different drugs/drug classes, categorised into (i) antimalarial agents (AMA), (ii) glucocorticoids and (iii) other SLE medications. Multivariable logistic regression adjusted for age, sex, disease activity and organ damage.

RESULTS

Among 205 respondents, the median age was 52.0 years (IQR: 34.0-70.0), 86.3% were women, 66.8% were non-adherent to their medications according to CQR-19, and 6.6% and 6.3% were non-adherent to AMA and glucocorticoids, respectively, according to MASRI. Positive beliefs about glucocorticoids (OR; 95% CI: 0.77; 0.59-0.99; p = .039) and medications overall (0.71; 0.52-0.97; p = .029) were protective against non-adherence to glucocorticoids. Anxiety/depression (3.09; 1.12-8.54; p = .029), medication concerns (1.12; 1.05-1.20; p < .001) and belief that medications are overused (1.30; 1.15-1.46; p < .001) or harmful (1.36; 1.19-1.56; p < .001) were associated with medication non-adherence (CQR-19); beliefs in the necessity of medications (0.73; 0.65-0.82; p < .001) and positive beliefs in medications were protective (0.72; 0.60-0.86; p < .001). No associations were found between other investigated factors and medication non-adherence.

CONCLUSIONS

Beliefs about medications were a major determinant of medication non-adherence. Patient education may help alleviate the negative impact of misinformation/unawareness on adherence.

Osteosarcopenia: Prevalence and 10-Year Fracture and Mortality Risk - A Longitudinal, Population-Based Study of 75-Year-Old Women

Osteosarcopenia is the coexistence of low bone mass and sarcopenia. In older women, its prevalence is not well described, and it is unknown if sarcopenia is additive to low bone mass for fracture and mortality risk. The study investigated prevalence of osteosarcopenia and if osteosarcopenia is associated with higher fracture and mortality risk than low bone mass alone in older community-dwelling women. The longitudinal, population-based OPRA Cohort (n = 1044), all aged 75 at inclusion, followed for 10 years. Using WHO and EWGSOP2 definitions for low bone mass (T-score < -1.0 femoral neck) and sarcopenia (knee strength; appendicular lean muscle mass) women were categorized (1) Normal, (2) Low bone mass (LBM), and 3) Osteosarcopenia (probable; confirmed). Risk of hip, major osteoporotic fracture, and mortality were estimated. Osteosarcopeniaconfirmed prevalence increased from age 75 to 80 and 85 from 3.0% (29/970) to 4.9% (32/656) to 9.2% (33/358) but prevalence is potentially 2-4 times higher (11.8%, 13.4%, 20.3%) based on osteosarcopeniaprobable. Having osteosarcopeniaprobable significantly increased 10-year risk of hip fracture (HRadj 2.67 [1.34-5.32]), major osteoporotic fracture (HRadj 2.04 [1.27-3.27]), and mortality (HRadj 1.91 [1.21-3.04]). In contrast, LBM increased osteoporotic fracture risk (HRadj 2.08 [1.46-2.97], but not hip fracture (HRadj 1.62 [0.92-2.85]) or mortality (HRadj 0.94 [0.64-1.38]). Median time-to-hip fracture was 7.6 years (normal), 6.0 years (LBM), and 5.7 years (osteosarcopeniaprobable). Prevalence of confirmed osteosarcopenia is almost 10% at age 85. Probable osteosarcopenia significantly increased risk of hip and major osteoporotic fractures and mortality more so than low bone mass alone.

Apolipoproteins and the risk of giant cell arteritis-a nested case-control study

BACKGROUND

The etiology of giant cell arteritis (GCA) and its predictors are incompletely understood. Previous studies have indicated reduced risk of future development of GCA in individuals with obesity and/or diabetes mellitus. There is limited information on blood lipids before the onset of GCA. The objective of the study was to investigate the relation between apolipoprotein levels and future diagnosis of GCA in a nested case-control analysis.

METHODS

Individuals who developed GCA after inclusion in a population-based health survey (the Malmö Diet Cancer Study; N = 30,447) were identified by linking the health survey database to the local patient administrative register and the national patient register. A structured review of medical records was performed. Four controls for every validated case, matched for sex, year of birth, and year of screening, were selected from the database. Anthropometric measures, self-reported physical activity, based on a comprehensive, validated questionnaire, and non-fasting blood samples had been obtained at health survey screening. Concentrations of apolipoprotein A-I (ApoA-I) and apolipoprotein B (ApoB) in stored serum were measured using an immunonephelometric assay. Potential predictors of GCA were examined in conditional logistic regression models.

RESULTS

There were 100 cases with a confirmed clinical diagnosis of GCA (81% female; mean age at diagnosis 73.6 years). The median time from screening to diagnosis was 12 years (range 0.3-19.1). The cases had significantly higher ApoA-I at baseline screening compared to controls (mean 168.7 vs 160.9 mg/dL, odds ratio [OR] 1.57 per standard deviation (SD); 95% confidence interval [CI] 1.18-2.10) (SD 25.5 mg/dL). ApoB levels were similar between cases and controls (mean 109.3 vs 110.4 mg/dL, OR 0.99 per SD; 95% CI 0.74-1.32) (SD 27.1 mg/dL). The ApoB/ApoA1 ratio tended to be lower in cases than in controls, but the difference did not reach significance. The association between ApoA-I and GCA development remained significant in analysis adjusted for body mass index and physical activity (OR 1.48 per SD; 95% CI 1.09-1.99).

CONCLUSION

Subsequent development of GCA was associated with significantly higher levels of ApoA-I. These findings suggest that a metabolic profile associated with lower risk of cardiovascular disease may predispose to GCA.

A human meniscus explant model for studying early events in osteoarthritis development by proteomics

Degenerative meniscus lesions have been associated with both osteoarthritis etiology and its progression. We, therefore, sought to establish a human meniscus ex vivo model to study the meniscal response to cytokine treatment using a proteomics approach. Lateral menisci were obtained from five knee-healthy donors. The meniscal body was cut into vertical slices and further divided into an inner (avascular) and outer region. Explants were either left untreated (controls) or stimulated with cytokines. Medium changes were conducted every 3 days up to Day 21 and liquid chromatography-mass spectrometry was performed at all the time points for the identification and quantification of proteins. Mixed-effect linear regression models were used for statistical analysis to estimate the effect of treatments versus control on protein abundance. Treatment by IL1ß increased release of cytokines such as interleukins, chemokines, and matrix metalloproteinases but a limited catabolic effect in healthy human menisci explants. Further, we observed an increased release of matrix proteins (collagens, integrins, prolargin, tenascin) in response to oncostatin M (OSM) + tumor necrosis factor (TNF) and TNF+interleukin-6 (IL6) + sIL6R treatments, and analysis of semitryptic peptides provided additional evidence of increased catabolic effects in response to these treatments. The induced activation of catabolic processes may play a role in osteoarthritis development.

The relation between synovitis of individual finger joints and grip force over the first 5 years in early rheumatoid arthritis - a cohort study

OBJECTIVE

The objective of this study was to investigate the relation between swelling and tenderness of individual finger joints and grip force in patients with early rheumatoid arthritis (RA).

METHODS

In an inception cohort of patients with early RA (symptom duration < 12 months), all patients were examined by the same rheumatologist, and grip force was measured using the Grippit instrument at inclusion, 1 and 5 years. The average grip force values of each hand were evaluated and expressed as % of expected values, based on age- and sex-specific reference values. Linear regression analyses were used to assess the cross-sectional relation between the involvement of individual finger joints and grip force. In generalized estimating equations, the impact of time-varying synovitis/tenderness on grip force over time was estimated. Analyses were adjusted for wrist involvement, erythrocyte sedimentation rate, and patient-reported pain.

RESULTS

In 215 patients with early RA, grip force was 39% of expected at diagnosis, and increased to 56% after 5 years. Synovitis of the first metacarpophalangeal (MCP) joint (60% and 69% at baseline in the right and left hand) was associated with reduced grip force at inclusion (adjusted ß - 9.2 percentage unit of expected grip force; 95% CI - 13.6 to - 4.8 for both hands combined) and at all follow-up evaluations. Synovitis of MCP I and MCP IV (12% at baseline) was significantly associated with reduced grip force over time in both hands. Proximal interphalangeal (PIP) joint swelling, and tenderness of MCP or PIP joints, had less impact on grip force.

CONCLUSION

MCP I synovitis is the major contributor to reduced grip force in patients with early RA. This underlines the importance of the involvement of the thumb for impaired hand function in RA. MCP IV synovitis, but not PIP involvement or finger joint tenderness, also has a substantial impact on grip force.

Register-based observational study of associations between inflammatory remission, formal treatment targets and the use of disease-modifying antirheumatic drugs among patients with early rheumatoid arthritis

OBJECTIVE

To assess associations between inflammatory remission, formal treatment targets and the likelihood of starting a new disease-modifying antirheumatic drug (DMARD), among patients with early rheumatoid arthritis (RA).

METHODS

Patients newly diagnosed with RA were identified in the Swedish Rheumatology Quality Register (n=11 784). Disease Activity Score 28 (DAS28) and DMARD-treatment were assessed at RA diagnosis and 3, 6, 12 and 24 months thereafter. Inflammatory remission was defined as: swollen joints (0-28)=0 and C reactive protein <10 mg/L and normal erythrocyte sedimentation rate. The primary treatment target was DAS28 remission (<2.6). The proportion of patients in inflammatory remission who failed to reach DAS28 targets was assessed at each follow-up visit, and their likelihood of starting a new DMARD was compared with patients in inflammatory remission who reached the treatment target. rate ratios (RR) and 95% CIs were estimated with modified Poisson regression.

RESULTS

Overall, 34%, 39%, 44% and 47% were in inflammatory remission at 3, 6, 12 and 24 months. Among these, 20%, 22%, 20% and 19%, respectively, failed to reach DAS28 remission. Patients who failed to reach DAS28 remission despite being in inflammatory remission were more likely to start a new DMARD treatment (RR (95% CI) at 6 months=1.59 (1.29 to 1.96), 12 months=1.52 (1.23 to 1.87)) and 24 months=1.47 (1.20 to 1.80).

CONCLUSION

Failing to reach formal treatment targets, despite being in inflammatory remission, is common among patients with early RA, and is associated with an increased likelihood of starting a new DMARD-treatment.

Empowerment and enablement and their associations with change in health-related quality of life after a supported osteoarthritis self-management programme - a prospective observational study

BACKGROUND

Osteoarthritis is a leading cause of disability worldwide. Current treatment supports coping strategies to improve health-related quality of life (HRQoL). The need to predict response to treatment has been raised to personalise care. This study aims to examine change in HRQoL from baseline to three and nine months follow-up after participating in a Supported Osteoarthritis Self-Management Programme (SOASP) and to examine if empowerment and/or enablement were associated with change in HRQoL after a SOASP.

METHODS

Patients participating in a SOASP were recruited consecutively between April 2016 and June 2018. The EQ-5D was used to measure HRQoL, the Swedish Rheumatic Disease Empowerment Scale (SWE-RES-23) (score range 1-5) to measure empowerment and the Patient Enablement Instrument (PEI) (score range 0-12) to measure enablement. The instruments were answered before (EQ-5D, SWE-RES-23) and after (EQ-5D, SWE-RES-23, PEI) the SOASP. A patient partner was involved in the research process to enhance the patient perspective. Changes in outcome were examined with paired sample t-test and standardized effect sizes (Cohen´s d). Multiple linear regression analysis was performed to assess potential associations.

RESULTS

One hundred forty-three patients participated in baseline measurement. Mean EQ-5D-5 L index score increased significantly from baseline to three months corresponding to a standardised effect size (Cohen´s d) of d = 0.43, 95% CI [0.24, 0.63] (n = 109), and from baseline to nine months d = 0.19, 95% CI [0.01, 0.37] (n = 119). The average EQ VAS score increased significantly from baseline to three months corresponding to a standardised effect size of d = 0.26, 95% CI [0.07, 0.45] (n = 109), and from baseline to nine months d = 0.18, 95% CI [0.00, 0.36] (n = 119). Neither SWE-RES-23 nor PEI at three months follow-up nor the change in the SWE-RES-23 score from baseline to three months follow-up were associated with change in either EQ-5D-5 L index (p > 0.05) or the EQ VAS (p > 0.05).

CONCLUSIONS

Health-related quality of life increased after participating in a SOASP. Empowerment and enablement as measured with the SWE-RES-23 and the PEI were not associated with change in HRQoL among patients participating in a SOASP.

TRIAL REGISTRATION

ClinicalTrials.gov. Identification number: NCT02974036. First registration 28/11/2016, retrospectively registered.

Anti-Ro52 positivity is associated with progressive interstitial lung disease in systemic sclerosis-an exploratory study

BACKGROUND

Interstitial lung disease (ILD) is the most common cause of death in patients with systemic sclerosis (SSc). Prognostic biomarkers are needed to identify SSc-ILD patients at risk for progressive pulmonary fibrosis. This study investigates autoantibodies measured in bronchoalveolar lavage (BAL) fluid and in serum in reference to the clinical disease course of SSc-ILD.

METHODS

Fifteen patients with new onset SSc-ILD underwent bronchoscopy. Autoantibody levels were analyzed using addressable laser bead immunoassay from BAL fluid and the serum. In a separate longitudinal cohort of 43 patients with early SSc-ILD, autoantibodies in serum were measured at baseline and pulmonary function tests were performed at least 2 times over the course of at least 2 or more years. Linear mixed effect models were created to investigate the relationship between specific autoantibodies and progression of SSc-ILD. Finally, lung tissue from healthy controls and from subjects with SSc was analyzed for the presence of the Ro52 antigen using immunohistochemistry.

RESULTS

Among SSc-ILD patients who were positive for anti-Ro52 (N = 5), 3 (60%) had enrichment of anti-Ro52 in BAL fluid at a ratio exceeding 50x. In the longitudinal cohort, 10/43 patients (23%) were anti-Ro52 positive and 16/43 (37%) were anti-scl-70 positive. Presence of anti-Scl-70 was associated with a lower vital capacity (VC) at baseline (-12.6% predicted VC [%pVC]; 95%CI: -25.0, -0.29; p = 0.045), but was not significantly associated with loss of lung function over time (-1.07%pVC/year; 95%CI: -2.86, 0.71; p = 0.230). The presence of anti-Ro52 was significantly associated with the loss of lung function over time (-2.41%pVC/year; 95% CI: -4.28, -0.54; p = 0.013). Rate of loss of lung function increased linearly with increasing anti-Ro52 antibody levels (-0.03%pVC per arbitrary units/mL and year; 95%CI: -0.05, -0.02; p < 0.001). Immunohistochemical staining localized the Ro52 antigen to alveolar M2 macrophages in peripheral lung tissue both in subjects with and without SSc.

CONCLUSIONS

This study suggests that antibodies targeting Ro52 are enriched in the lungs of patients with new-onset SSc-ILD, linking Ro52 autoimmunity to the pulmonary pathology of SSc. Clinical and immunohistochemical data corroborates these findings and suggest that anti-Ro52 may serve as a potential biomarker of progressive SSc-ILD.

Use of non-surgical treatments on the journey to knee replacement in patients with knee osteoarthritis: a 10-year population-based case-control study

AIM

To investigate temporal trends in primary care visits, physiotherapy visits, dispensed non-steroidal anti-inflammatory drugs (NSAIDs) and opioids in knee osteoarthritis (OA) patients who have and have not undergone knee replacement.

METHODS

We analysed 5665 OA patients from the Skåne Healthcare Register, Sweden, who underwent knee replacement between 2015 and 2019. Controls were OA patients without knee replacement, matched 1:1 by sex, age, time and healthcare level of initial OA diagnosis, and assigned a pseudo-index date corresponding to their case's knee replacement date. Annual prevalence and prevalence ratio of primary care and physiotherapy visits, dispensed NSAIDs and opioids (all for any cause) in the 10 years before knee replacement were estimated using Poisson regression.

RESULTS

The annual prevalence of all-cause primary care visits, physiotherapy visits and opioid use was similar between cases and controls until 3 years before the index date when it started to increase among the cases. The year before the index date, the prevalence ratio (cases vs controls) for physiotherapy use was 1.8 (95% CI 1.7, 1.8), while for opioid use 1.6 (1.5, 1.7). NSAID use was consistently higher among cases, even 10 years before the index date when the prevalence ratio versus controls was 1.3 (1.2, 1.3), increasing to 1.8 (1.7, 1.9) in the year preceding the index date.

CONCLUSIONS

Management of OA patients who have and have not undergone knee replacement appears largely similar except for higher use of NSAIDs in knee replacement cases. Symptomatic treatments start to increase a few years before the surgery in knee replacement cases.

Can active sun exposure decrease the risk of giant cell arteritis and polymyalgia rheumatica in women?

Objectives

To study if active sun exposure among women affects the risk of developing GCA or PMR in a prospective cohort study with restricted latitudinal variability.

Methods

We linked the response to questions relating to sun exposure from the Melanoma Inquiry in Southern Sweden (MISS) prospective cohort study in women to the risk of developing GCA or PMR. Healthcare data were gathered from the Skåne Healthcare Register (SHR), covering all public healthcare consultations. The direct effect of active sun exposure on the risk of developing GCA or PMR was assessed using Cox proportional hazards models adjusted for covariates based on a directed acyclic graph.

Results

A total of 14 574 women were included in the study; 601 women were diagnosed with GCA or PMR (144 and 457, respectively) during the follow-up time. Women with moderate or high sun exposure were not less likely to develop GCA or PMR compared with women that indicated they avoided sun exposure [hazard ratio (HR) 1.2 (CI 0.9, 1.6) and 1.3 (0.9, 1.9), respectively] when adjusted for diabetes, hyperlipidaemia, hypertension, smoking, obesity and stratified by age. Similar patterns were observed when studying only GCA [HR 1.2 (CI 0.7, 2.3) and 1.3 (0.7, 2.6)] and only PMR [HR 1.3 (CI 0.9, 1.8) and 1.4 (0.9, 2.0)].

Conclusion

Active sun exposure did not affect the risk of developing GCA or PMR in women in a cohort with restricted latitudinal variability.

An explorative study on proteomic analyses related to inflammation and pain in children with juvenile idiopathic arthritis

BACKGROUND

Our aim was attempting to find proteins involved in the pain process and correlating with pain but not degree of inflammation in children with juvenile idiopathic arthritis (JIA), using a proteomics panel.

METHODS

A total of 87 plasma samples were collected from 51 children with JIA (51 at diagnosis in a higher disease activity state, 18 at follow-up in a lower disease activity state) and 18 healthy controls. Relative levels of 92 proteins related to a wide range of biological processes in inflammation were obtained using a proximity extension assay panel. Comparisons between children with and without JIA, in different disease categories, by juvenile disease activity score (JADAS27) and degree of pain on a visual analogue scale (VAS), were performed using parametric and non-parametric statistical methods.

RESULTS

Nineteen proteins involved in arthritic inflammation, such as interleukin 6 (IL-6) and S100 protein A12, were higher in patients with JIA than controls, seven decreased significantly during treatment, and 18 correlated significantly with JADAS27. Three proteins correlated with pain VAS scores in unadjusted analyses: the glial cell line-derived neurotrophic factor (GDNF), transforming growth factor beta, and IL-18R1. Levels of GDNF correlated significantly with pain VAS scores but not with JADAS27.

CONCLUSIONS

Plasma levels of 18 of 92 tested proteins correlated with degree of disease activity. Levels of three proteins correlated with pain, and levels of one, GDNF, originating from neural cells, correlated with pain without correlating with inflammatory degree, suggesting that it may play a role in pain in JIA. Further studies in larger cohorts are warranted.

Serum levels of soluble urokinase plasminogen activator receptor in juvenile idiopathic arthritis: a single-center Swedish case-control study

OBJECTIVES

Reliable biomarkers in the early stages of idiopathic arthritis (JIA) are scarce and the disease heterogeneity makes it clinically challenging to predict the risk of joint damage. Biomarkers with prognostic potential are warranted in order to individualize treatment and follow-up in JIA. The soluble urokinase plasminogen activator receptor (suPAR) has been reported as an easily measurable biomarker for prognosis and severity in several rheumatic diseases but it has never been studied in JIA.

METHODS

Sera from 51 well-characterized patients with JIA and 50 age- and sex-matched control subjects were collected and stored for later analysis of suPAR. Patients were carefully followed clinically over 3 years and analysis of erythrocyte sedimentation rate, C-reactive protein, rheumatoid factor (RF) and antibodies against cyclic citrullinated peptides (anti-CCP) were analyzed as part of clinical routine. Signs of joint erosions were evaluated by radiography.

RESULTS

Overall, the levels of suPAR did not differ significantly between JIA patients and controls but those with polyarticular involvement showed higher suPAR (p = 0.013). In addition, elevated suPAR were associated with joint erosions (p = 0.026). Two RF/anti-CCP negative individuals with erosions showed high levels of suPAR.

CONCLUSIONS

We present new data on the biomarker suPAR in JIA. Our results indicate that, apart from RF and anti-CCP, analysis of suPAR could be of additional value in assessing the risk of erosions. Analysis of suPAR early could potentially guide treatment decision-making in JIA, but our observations should be confirmed in prospective studies.

Identification and quantification of degradome components in human synovial fluid reveals an increased proteolytic activity in knee osteoarthritis patients vs controls

Synovial fluid (SF) may contain cleavage products of proteolytic activities. Our aim was to characterize the degradome through analysis of proteolytic activity and differential abundance of these components in a peptidomic analysis of SF in knee osteoarthritis (OA) patients versus controls (n = 23). SF samples from end-stage knee osteoarthritis patients undergoing total knee replacement surgery and controls, that is, deceased donors without known knee disease were previously run using liquid chromatography mass spectrometry (LC-MS). This data was used to perform new database searches generating results for non-tryptic and semi-tryptic peptides for studies of degradomics in OA. We used linear mixed models to estimate differences in peptide-level expression between the two groups. Known proteolytic events (from the MEROPS peptidase database) were mapped to the dataset, allowing the identification of potential proteases and which substrates they cleave. We also developed a peptide-centric R tool, proteasy, which facilitates analyses that involve retrieval and mapping of proteolytic events. We identified 429 differentially abundant peptides. We found that the increased abundance of cleaved APOA1 peptides is likely a consequence of enzymatic degradation by metalloproteinases and chymase. We identified metalloproteinase, chymase, and cathepsins as the main proteolytic actors. The analysis indicated increased activity of these proteases irrespective of their abundance.

eEF2 improves dense connective tissue repair and healing outcome by regulating cellular death, autophagy, apoptosis, proliferation and migration

Outcomes following human dense connective tissue (DCT) repair are often variable and suboptimal, resulting in compromised function and development of chronic painful degenerative diseases. Moreover, biomarkers and mechanisms that guide good clinical outcomes after DCT injuries are mostly unknown. Here, we characterize the proteomic landscape of DCT repair following human Achilles tendon rupture and its association with long-term patient-reported outcomes. Moreover, the potential regulatory mechanisms of relevant biomarkers were assessed partly by gene silencing experiments. A mass-spectrometry based proteomic approach quantified a large number (769) of proteins, including 51 differentially expressed proteins among 20 good versus 20 poor outcome patients. A novel biomarker, elongation factor-2 (eEF2) was identified as being strongly prognostic of the 1-year clinical outcome. Further bioinformatic and experimental investigation revealed that eEF2 positively regulated autophagy, cell proliferation and migration, as well as reduced cell death and apoptosis, leading to improved DCT repair and outcomes. Findings of eEF2 as novel prognostic biomarker could pave the way for new targeted treatments to improve healing outcomes after DCT injuries.Trial registration: NCT02318472 registered 17 December 2014 and NCT01317160 registered 17 March 2011, with URL http://clinicaltrials.gov/ct2/show/NCT02318472 and http://clinicaltrials.gov/ct2/show/study/NCT01317160 .

Bone Turnover Marker Profiling and Fracture Risk in Older Women: Fracture Risk from Age 75 to 90

PURPOSE

A major challenge in osteoporosis is to identify individuals at high fracture risk. We investigated six bone turnover markers (BTMs) to determine association with specific fracture types; the time-frame for risk prediction and whether these are influenced by age at assessment.

METHODS

Population-based OPRA cohort (n = 1044) was assessed at ages 75, 80, 85 and fractures documented for up to 15 years. Six BTMs were analyzed at each time-point (N-terminal propeptide of type I collagen, PINP; total osteocalcin, OC; bone-specific alkaline phosphatase, BALP; C-terminal telopeptide of type I collagen, CTX; tartrate-resistant acid phosphatase 5b, TRAcP5b; urinary osteocalcin). Hazard ratios (HR) for any, major osteoporotic, vertebral and hip fractures were calculated as short (1, 2, 3 years) and long-term risk (5, 10, 15 years).

RESULTS

At 75 year, high CTX levels were associated with an increased risk of all fractures, including major osteoporotic fractures, across most time-frames (HRs ranging: 1.28 to 2.28). PINP was not consistently associated. Urinary osteocalcin was consistently associated with elevated short-term risk (HRs ranging: 1.83-2.72). Other BTMs were directionally in accordance, though not all statistically significant. BTMs were not predictive for hip fractures. Association of all BTMs attenuated over time; at 80 year none were associated with an increased fracture risk.

CONCLUSION

CTX, urinary OC and TRAcP5b are predictive for fracture in a 1 to 3 year, perspective, whereas in the long-term or above age 80 years, BTMs appear less valuable. Resorption markers, particularly CTX, were more consistently associated with fracture risk than formation markers in the very elderly.

Cohort profile: the Halland osteoarthritis (HALLOA) cohort-from knee pain to osteoarthritis: a longitudinal observational study in Sweden

PURPOSE

The overall objective in this study is to investigate the early development of radiographic knee osteoarthritis (OA) and its association with hand or/and knee OA, metabolic diseases, biomarkers, chronic pain, physical function and daily physical activity types.

PARTICIPANTS

The Halland osteoarthritis (HALLOA) cohort is a longitudinal cohort study that includes individuals with knee pain in the southwest of Sweden. Enrolment took place from 2017 to 2019. The inclusion criteria were current knee pain, with no former known radiographic knee OA and no cruciate ligament rupture or rheumatological disorder. The participants were recruited: (1) when seeking care for knee pain in primary healthcare or (2) by advertisements in local newspapers. There are 306 individuals included in the study, mean age (SD) 51.7 (8.7) years and 69% are women. The baseline and follow-ups include clinical tests, radiographical examinations, blood samples, metabolic measures, pain pressure thresholds, tests of physical functions, daily physical activity types and patient-reported outcomes.

FINDINGS TO DATE

There were associations between metabolic factors and radiographic knee OA, even in those with normal body mass index at baseline. In addition, clinical hand OA was positively associated with fasting plasma glucose. We also found that modifiable factors as increased visceral fat and total body fat were associated with increased pain sensitivity among individuals with knee pain.

FUTURE PLANS

By studying possible pathophysiological mechanisms of OA over time, we aim to provide new insights on OA progression, identify usable preventive measures helping the clinicians in the management of the disease and improve health for the patients. It is also important to study the development of chronic pain in OA, to get tools to identify individuals at risk and to be able to offer them treatment.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov (NCT04928170).

Factors associated with changes in volumetric bone mineral density and cortical area in men with ankylosing spondylitis: a 5-year prospective study using HRpQCT

Patients with ankylosing spondylitis (AS) have impaired volumetric bone mineral density (vBMD) assessed with high-resolution peripheral computed tomography (HRpQCT). This first longitudinal HRpQCT study in AS shows that cortical and trabecular vBMD decreased at tibia and that signs of inflammation were associated with cortical bone loss at tibia and radius.

INTRODUCTION

Patients with ankylosing spondylitis (AS) have reduced volumetric bone mineral density (vBMD) in the peripheral skeleton assessed with high-resolution peripheral quantitative computed tomography (HRpQCT). The aims were to investigate longitudinal changes in vBMD, cortical area, and microarchitecture and to assess factors associated with changes in vBMD and cortical area in men with AS.

METHODS

HRpQCT of radius and tibia was performed in 54 men with AS at baseline and after 5 years. Univariate and multivariable linear regression analyses were used.

RESULTS

At tibia, there were significant decreases exceeding least significant changes (LSC) in cortical and trabecular vBMD, mean (SD) percent change -1.0 (1.9) and -2.7 (5.0) respectively (p<0.001). In multivariable regression analyses, increase in disease activity measured by ASDAS_CRP from baseline to follow-up was associated with decreases in cortical vBMD (β -0.86, 95% CI -1.31 to -0.41) and cortical area (β -1.66, 95% CI -3.21 to -0.10) at tibia. At radius, no changes exceeded LSC. Nonetheless, increase in ASDAS_CRP was associated with decreases in cortical vBMD, and high time-averaged ESR was associated with decreases in cortical area. Treatment with TNF inhibitor ≥ 4 years during follow-up was associated with increases in cortical vBMD and cortical area at tibia, whereas exposure to bisphosphonates was associated with increases in cortical measurements at radius. No disease-related variables or treatments were associated with changes in trabecular vBMD.

CONCLUSION

The findings in this first longitudinal HRpQCT study in patients with AS strengthen the importance of controlling disease activity to maintain bone density in the peripheral skeleton.

Prevalence and factors related to sleep apnoea in ankylosing spondylitis

An increased prevalence of obstructive sleep apnoea (OSA) has been suggested in patients with ankylosing spondylitis (AS) in a few controlled studies. We aimed to study the prevalence of OSA compared to controls and to investigate if disease-related and non-disease-related factors were determinants of OSA in AS patients. One hundred and fifty-five patients with AS were included in the Backbone study, a cross-sectional study that investigates severity and comorbidities in AS. Controls were recruited from the Swedish CArdioPulmonary bioImage Study. To evaluate OSA, the participants were asked to undergo home sleep-monitoring during one night’s sleep. For each AS patient 45–70 years old, four controls were matched for sex, age, weight, and height. OSA was defined as an apnoea-hypopnoea index (AHI) ≥ 5 events/hour. Sixty-three patients with AS were examined with home sleep-monitoring, and 179 controls were matched with 46 patients, 45–70 years. Twenty-two out of 46 (47.8%) patients with AS vs. 91/179 (50.8%) controls had OSA (AHI ≥ 5 events/hour), P = 0.72. No differences in the sleep measurements were noted in AS patients vs. controls. In logistic regression analysis adjusted for age and sex, higher age, higher BMI, and lesser chest expansion were associated with the presence of OSA in the 63 AS patients. In the current study, patients with AS did not have a higher prevalence of OSA compared to matched controls. AS patients with OSA had higher BMI, were older, and had lesser chest expansion because of more severe AS compared to patients without OSA.

Key points
• Patients with ankylosing spondylitis did not have a higher prevalence of obstructive sleep apnoea versus matched controls.
• Patients with ankylosing spondylitis and obstructive sleep apnoea were older and had higher body mass index versus patients without obstructive sleep apnoea.
• Patients with ankylosing spondylitis and obstructive sleep apnoea had lesser chest expansion versus patients without obstructive sleep apnoea.

Usefulness of Clinical and Laboratory Criteria for Diagnosing Autoimmune Liver Disease among Patients with Systemic Lupus Erythematosus: An Observational Study

Abnormal liver function tests are frequently observed during follow-up of patients with systemic lupus erythematosus (SLE) but data on co-existence with autoimmune liver diseases (AILD) are scarce. This retrospective study aimed to describe the prevalence of autoimmune hepatitis (AIH) and primary biliary cholangitis (PBC) among well-characterized subjects with SLE. We also evaluated whether the presence of autoantibodies to complement protein 1q (C1q) and/or ribosomal P protein (anti-ribP) are, directly or inversely, associated with AIH, as proposed in some reports. The number of screened patients was 287 (86% females), and all cases were included in a regional Swedish cohort. Each subject of the study population met the 1982 American College of Rheumatology classification criteria and/or the Fries' diagnostic principle. By applying the simplified diagnostic AIH criteria combined with persistent transaminasemia, 40 (13.9%) cases reached at least "probable AIH". However, merely 8 of these had been diagnosed with AIH (overall AIH prevalence 2.8%). Neither anti-C1q nor anti-ribP associated significantly with AIH. By applying the recent PBC guidelines, 6 (2.1%) cases were found, but only 3 of them had actually been diagnosed with PBC and one additional subject was not identified by the guidelines (overall PBC prevalence 1.4%). Compared to prevalence data from the general Swedish population, both AIH and PBC were highly overrepresented in our study population. The sensitivity of the diagnostic AIH criteria was impeccable but the specificity was less impressive, mainly due to positive ANA and hypergammaglobulinemia. Based on our findings, among subjects with SLE, the AIH criteria are less useful and liver biopsy combined with detection of other AILD-associated autoantibodies should be performed.

Understanding interactions between risk factors, and assessing the utility of the additive and multiplicative models through simulations

Understanding the genetic background of complex diseases requires the expansion of studies beyond univariate associations. Therefore, it is important to use interaction assessments of risk factors in order to discover whether, and how genetic risk variants act together on disease development. The principle of interaction analysis is to explore the magnitude of the combined effect of risk factors on disease causation. In this study, we use simulations to investigate different scenarios of causation to show how the magnitude of the effect of two risk factors interact. We mainly focus on the two most commonly used interaction models, the additive and multiplicative risk scales, since there is often confusion regarding their use and interpretation. Our results show that the combined effect is multiplicative when two risk factors are involved in the same chain of events, an interaction called synergism. Synergism is often described as a deviation from additivity, which is a broader term. Our results also confirm that it is often relevant to estimate additive effect relationships, because they correspond to independent risk factors at low disease prevalence. Importantly, we evaluate the threshold of more than two required risk factors for disease causation, called the multifactorial threshold model. We found a simple mathematical relationship (square root) between the threshold and an additive-to-multiplicative linear effect scale (AMLES), where 0 corresponds to an additive effect and 1 to a multiplicative. We propose AMLES as a metric that could be used to test different effects relationships at the same time, given that it can simultaneously reveal additive, multiplicative and intermediate risk effects relationships. Finally, the utility of our simulation study was demonstrated using real data by analyzing and interpreting gene-gene interaction odds ratios from a rheumatoid arthritis case-control cohort.

Intermediate monocytes correlate with CXCR3+ Th17 cells but not with bone characteristics in untreated early rheumatoid arthritis

Background

Rheumatoid arthritis (RA) is associated with development of generalized osteoporosis. Bone-degrading osteoclasts are derived from circulating precursor cells of monocytic lineage, and the intermediate monocyte population is important as osteoclast precursors in inflammatory conditions. T cells of various subsets are critical in the pathogenesis of both RA and associated osteoporosis, but so far, no studies have examined associations between circulating intermediate monocytes, T cell subsets and bone characteristics in patients with RA. The aim of this study was to investigate the frequency of intermediate monocytes in patients with untreated early rheumatoid arthritis (ueRA) compared to healthy controls (HC), and to explore the correlation between intermediate monocytes and a comprehensive panel of T helper cell subsets, bone density and bone microarchitecture in ueRA patients.

Methods

78 patients with ueRA fulfilling the ACR/EULAR 2010 criteria were included and compared to 29 age- and sex-matched HC. Peripheral blood samples were obtained before start of treatment and proportions of monocyte subsets and CD4⁺ helper and regulatory T cell subsets were analyzed by flow cytometry. Bone densitometry was performed on 46 of the ueRA patients at inclusion using DXA and HR-pQCT.

Results

Flow cytometric analyses showed that the majority of ueRA patients had frequencies of intermediate monocytes comparable to HC. The intermediate monocyte population correlated positively with CXCR3⁺ Th17 cells in ueRA patients but not in HC. However, neither the proportions of intermediate monocytes nor CXCR3⁺ Th17 cells were associated with bone density or bone microarchitecture measurements.

Conclusions

Our findings suggest that in early RA, the intermediate monocytes do not correlate with bone characteristics, despite positive correlation with circulating CXCR3⁺ Th17 cells. Future longitudinal studies in patients with longer disease duration are required to fully explore the potential of intermediate monocytes to drive bone loss in RA.

Patient-related outcome, fracture displacement and bone mineral density following distal radius fracture in young and older men

BACKGROUND

Distal radius fractures can adversely affect wrist function; for men with this fracture, the role played by fracture severity, age and osteoporosis on fracture outcome has not been sufficiently studied.

OBJECTIVE

To describe patient-reported outcome and the association with bone integrity, fracture severity and future fracture risk among young and older men with distal radius fracture.

METHODS

This prospective study includes 133 men with acute distal radius fracture, mean age 54 (range 21-88), who were followed for 12 months. They were categorized as younger (< 65) and older (65+). Main outcome was DASH (Disability of the Arm, Shoulder and Hand) at 12 months; DASH > 15 was defined as poor outcome. Fractures were classified and radiographic displacement identified at initial presentation and follow-up. BMD was measured and FRAX 10-year probability of fracture calculated.

RESULTS

Disability was higher in older men (DASHmedian 10 vs 2; p = 0.002); a clinically meaningful difference (ΔDASH = 10, p = 0.017) remained after adjustment for displacement, fracture classification and treatment method. Almost 50% of older men vs 14% in younger had poor outcome, p < 0.001. Bone mineral density did not independently predict outcome. Older men with a displaced fracture at initial presentation had greater disability (DASHmedian, IQR 45, 14;73) and risk of fracture (FRAXmajor osteoporotic 14, 8;21).

CONCLUSION

Men over the age of 65 with a distal radius fracture are more likely to have post-fracture disability regardless of radiographic appearance. Fracture displacement, indicating impaired bone strength, is also more common and associated with an increased risk of fracture within 10-years. Secondary fracture prevention should therefore be considered in men presenting with distal radius fracture.

Function of multiple sclerosis-protective HLA class I alleles revealed by genome-wide protein-quantitative trait loci mapping of interferon signalling

Interferons (IFNs) are cytokines that are central to the host defence against viruses and other microorganisms. If not properly regulated, IFNs may contribute to the pathogenesis of inflammatory autoimmune, or infectious diseases. To identify genetic polymorphisms regulating the IFN system we performed an unbiased genome-wide protein-quantitative trait loci (pQTL) mapping of cell-type specific type I and type II IFN receptor levels and their responses in immune cells from 303 healthy individuals. Seven genome-wide significant (p < 5.0E-8) pQTLs were identified. Two independent SNPs that tagged the multiple sclerosis (MS)-protective HLA class I alleles A*02/A*68 and B*44, respectively, were associated with increased levels of IFNAR2 in B and T cells, with the most prominent effect in IgD^–CD27⁺ memory B cells. The increased IFNAR2 levels in B cells were replicated in cells from an independent set of healthy individuals and in MS patients. Despite increased IFNAR2 levels, B and T cells carrying the MS-protective alleles displayed a reduced response to type I IFN stimulation. Expression and methylation-QTL analysis demonstrated increased mRNA expression of the pseudogene HLA-J in B cells carrying the MS-protective class I alleles, possibly driven via methylation-dependent transcriptional regulation. Together these data suggest that the MS-protective effects of HLA class I alleles are unrelated to their antigen-presenting function, and propose a previously unappreciated function of type I IFN signalling in B and T cells in MS immune-pathogenesis.

Genetic association studies have been very successful in identifying disease-associated single nucleotide polymorphisms (SNPs), but it has been challenging to define the molecular mechanisms underlying these associations. As interferons (IFNs) have a central role in the immune system, we hypothesized that some of the SNPs associated to immune-mediated diseases would affect the IFN system. By combining genetic data with characterization of interferon receptor levels and their responses on the protein level in immune cells from 303 genotyped healthy individuals, we show that two SNPs tagging the HLA class I alleles A*02/A*68 and B*44 are associated with a decreased response to type I IFN stimulation in B cells and T cells. Notably, both HLA-A*02 and HLA-B*44 confer protection from developing multiple sclerosis (MS), which is a chronic inflammatory neurologic disease. In addition to suggesting a pathogenic role of enhanced type I interferon signalling in B cells and T cells in MS, our data emphasize the fact that genetic associations in the HLA locus can affect functions not directly associated to antigen presentation, which conceptually may be important for other diseases genetically associated to the HLA locus.

Long-time follow up of physical activity level among older adults with rheumatoid arthritis

BACKGROUND

Physical activity and exercise are acknowledged as important parts in the management of rheumatoid arthritis (RA). However, long-term maintenance of exercise is known to be difficult. The aim of this study was to evaluate change in physical activity and physical fitness after four years in older adults with RA who had previously participated in exercise with person-centred guidance compared to controls.

METHOD

A follow-up study was performed where older adults (> 65 years) who had participated in a randomized controlled trial where they were allocated to either exercise with person-centred guidance or home-based, light-intensity exercise (controls) were invited to one visit and assessed with performance-based test, blood-sampling and self-reported questionnaires. Forty-seven out of 70 older adults accepted participation, 24 from the exercise group and 23 from the control group. Comparisons of the result with baseline values were performed and explanatory factors for increase of physical activity were examined with logistic regression.

RESULTS

The result show that there was no significant difference in weekly hours of physical activity when groups where compared. However, participants in the exercise group rated significantly increased weekly hours of physical activity after four years (p = 0.004) when compared to baseline. Higher levels of fatigue, BMI and physical activity, at baseline were negatively associated with increased physical activity after four years. There was no significant difference in change of physical fitness between the groups. Within group analysis showed that the control group reported increased pain (p = 0.035), fatigue (p = 0.023) increased number of tender joints (p = 0.028) higher disease activity (p = 0.007) and worsening of global health (p = 0.004) when compared to baseline while the exercise group remained at the same level as at baseline.

CONCLUSION

These results indicate that introducing moderate- to high intensity exercise with person-centred guidance might favor increased physical activity after four years in older adults with RA. Previous partaking in moderate- to high intensity exercise might also be protective against increased disease activity, pain and fatigue over time.

Identification of Clec4b as a novel regulator of bystander activation of auto-reactive T cells and autoimmune disease

The control of chronic inflammation is dependent on the possibility of limiting bystander activation of autoreactive and potentially pathogenic T cells. We have identified a non-sense loss of function single nucleotide polymorphism in the C-type lectin receptor, Clec4b, and have shown that it controls chronic autoimmune arthritis in rat models of rheumatoid arthritis. Clec4b is specifically expressed in CD4⁺ myeloid cells, mainly classical dendritic cells (DCs), and is defined by the markers CD4⁺/MHCII^hi/CD11b/c⁺. We found that Clec4b limited the activation of arthritogenic CD4+αβT cells and the absence of Clec4b allowed development of arthritis already 5 days after adjuvant injection. Clec4b sufficient CD4⁺ myeloid dendritic cells successfully limited the arthritogenic T cell expansion immediately after activation both in vitro and in vivo. We conclude that Clec4b expressed on CD4+ myeloid dendritic cells regulate the expansion of auto-reactive and potentially pathogenic T cells during an immune response, demonstrating an early checkpoint control mechanism to avoid autoimmunity leading to chronic inflammation.

To identify early disease regulatory mechanisms in autoimmune diseases such as rheumatoid arthritis (RA) is challenging not only because of the genetic and environmental complexity but also because of the critical autoimmune time-period that precedes the clinical diagnosis. Therefore, we set out to study the complex disease pathways in a more restricted setting. Through genetic segregation of rat crosses, followed by the selection of recombinants to produce minimal congenic strains, we have identified a single nucleotide polymorphism regulating the expression of Clec4b2 that in turn controls the development of arthritis. The Clec4b gene is normally expressed in a population of antigen-presenting cells that can limit enhanced activation of bystander autoreactive T cells during an immune-priming response. This previously unknown type of immune regulation reveals the existence of a mechanism protecting against autoimmune dieases by the avoidance of bystander activation of autoreactive T cells during a normal immune response to foreign antigen.

Autoantibody and Cytokine Profiles during Treatment with Belimumab in Patients with Systemic Lupus Erythematosus

We investigated whether belimumab treatment impacts on levels of autoantibodies and cytokines of interest in systemic lupus erythematosus (SLE). Longitudinally collected serum samples from 78 belimumab-treated Swedish SLE patients were analysed. Serum cytokine levels were determined using Luminex xMAP technology, and nuclear antigen autoantibody specificities using addressable laser bead immunoassay. In patients with detectable levels at baseline, interferon (IFN)-α2 levels were lower at month 6 (median; interquartile range (IQR): 8.9; 1.5-54.9 pg/mL) versus baseline (28.4; 20.9-100.3 pg/mL; p = 0.043). Interleukin (IL)-6 (baseline: 7.1; 2.9-16.1 pg/mL) decreased from month 6 (0.5; 0.5-6.3 pg/mL; p = 0.018) and throughout a 24 month follow-up. IL-10 (baseline: 12.6; 2.8-29.7 pg/mL) showed more rapid decreases from month 3 (1.8; 0.6-9.1 pg/mL; p = 0.003). Levels of anti-dsDNA (p < 0.001), anti-Smith antigen (Sm) (p = 0.002), anti-U1 small nuclear ribonucleoprotein (U1RNP) (p < 0.001), anti-Sm-U1RNP complex (p = 0.028), and anti-ribosomal P (p = 0.012) antibodies decreased from month 3 and remained decreased. Anti-Sm positivity at baseline was associated with higher probability and/or shorter time to achieve sustained SLE responder index-4 response (hazard ratio (HR): 2.52; 95% CI: 1.20-5.29; p = 0.015), independently of other factors. Decline of IL-6 levels through month 3 was greater in responders. In summary, belimumab treatment lowered IFN-α2, IL-6, and IL-10 levels, as well as levels of multiple autoantibodies, however after different time spans. Notably, anti-Sm positivity and early decline in IL-6 levels were associated with favorable treatment outcome.

Prediction of prognosis and renal outcome in lupus nephritis

Lupus nephritis (LN) is a severe manifestation of SLE, characterised by subendothelial and/or subepithelial immune complex depositions in the afflicted kidney, resulting in extensive injury and nephron loss during the acute phase and eventually chronic irreversible damage and renal function impairment if not treated effectively. The therapeutic management of LN has improved during the last decades, but the imperative need for consensual outcome measures remains. In order to design trials with success potentiality, it is important to define clinically important short-term and long-term targets of therapeutic and non-therapeutic intervention. While it is known that early response to treatment is coupled with favourable renal outcomes, early predictors of renal function impairment are lacking. The information gleaned from kidney biopsies may provide important insights in this direction. Alas, baseline clinical and histopathological information has not been shown to be informative. By contrast, accumulating evidence of pronounced discrepancies between clinical and histopathological outcomes after the initial phase of immunosuppression has prompted investigations of the potential usefulness of per-protocol repeat kidney biopsies as an integral part of treatment evaluation, including patients showing adequate clinical response. This approach appears to have merit. Hopefully, clinical, molecular or genetic markers that reliably reflect kidney histopathology and portend the long-term prognosis will be identified. Novel non-invasive imaging methods and employment of the evolving artificial intelligence in pattern recognition may also be helpful towards these goals. The molecular and cellular characterisation of SLE and LN will hopefully result in novel therapeutic modalities, maybe new taxonomy perspectives, and ultimately personalised management.

The diagnostic accuracies of the 2012 SLICC criteria and the proposed EULAR/ACR criteria for systemic lupus erythematosus classification are comparable

In a joint effort, the European League Against Rheumatism (EULAR) and the American College of Rheumatology (ACR) recently proposed new criteria for the classification of systemic lupus erythematosus (SLE) with the overarching goal to identify potential participants for clinical studies. Herein, we present the first independent evaluation of these criteria in comparison with older classification grounds using an adult Scandinavian study population of confirmed SLE cases and individuals with SLE-mimicking conditions. We included 56 confirmed SLE cases meeting the 1982 ACR criteria (ACR-82) and/or the Fries "diagnostic principle" (antinuclear antibodies on at least one occasion plus involvement of at least two defined organ systems) and 55 controls with possible systemic autoimmune disease, including the presence of any SLE-related autoantibody. The proposed EULAR/ACR criteria showed a diagnostic sensitivity of 93% (95% confidence interval (CI), 0.83-0.98) compared with 83% (95% CI, 0.72-0.91) for the updated ACR criteria from 1997. The diagnostic accuracy of all tested classification grounds was fairly similar, achieving approximately 85%. However, the disease specificity of the EULAR/ACR criteria reached only 73% (95% CI, 0.59-0.83), which was comparable with the 2012 Systemic Lupus International Collaborating Clinics (SLICC) criteria, 75% (95% CI, 0.61-0.85), but clearly lower than for ACR-82, 94% (95% CI, 0.83-0.99). In this first independent evaluation of a limited number of cases, we found comparable results with respect to diagnostic sensitivity, specificity and accuracy regarding the SLICC-12 and the proposed EULAR/ACR classification criteria. However, their specificity for SLE appeared to be lower compared with ACR-82.

A qualitative study examining the validity and comprehensibility of physical activity items: developed and tested in children with juvenile idiopathic arthritis

BACKGROUND

Not all physical activity (PA) questionnaires (PAQ) gather information regarding PA intensity, duration, and modes and only a few were developed specifically for children. We assessed children's comprehensibility of items derived from two published PAQs used in children along with three items designed to ascertain PA intensity in order to assess comprehensibility of items and identify response errors. We modified items to create a new PAQ for children (ASCeND). We hypothesized that children would have comprehension difficulties with some original PAQ items and that ASCeND would be easier to comprehend, and would improve recall and reporting of PA.

METHODS

For this qualitative study, we recruited 30 Swedish children [ages 10-16 years; mean age = 13.0 (SD = 1.8)]; median disease activity score = 4.5 (IQR 2.2-9.0); median disease duration = 5.0 (IQR 2.6-10.8) with juvenile idiopathic arthritis (JIA) from a children's hospital-based rheumatology clinic. We conducted cognitive interviews to identify children's comprehension of PAQ items. Interviews were audiotaped, transcribed, and independently analyzed. In phase one, 10 children were interviewed and items modified based on feedback. In phase two, an additional 20 children were interviewed to gather more feedback and further refine the modified items, to create the ASCeND.

RESULTS

The median interview time was 41 min (IQR 36-56). In phase one, 219 comments were generated regarding directions for recording PA duration, and transportation use, walking, dancing, weight-bearing exercise and cardio fitness. Based on feedback we modified the survey layout, clarified directions and collapsed or defined items to reduce redundancy. In phase two, 95 comments were generated. Most comments related to aerobic fitness and strenuous PA. Children had difficulty recalling total walking and other activities per day. Children used the weather on a particular day, sports practice, or gym schedules to recall time performing activities. The most comments regarding comprehension were generated about the 3-item PA intensity survey, suggesting children had problems responding to intensity items.

CONCLUSIONS

The newer layout facilitated recall of directions or efficiency in answering items. The 3-item intensity survey was difficult to answer. Sports-specific items helped children more accurately recall the amount of daily PA. The ASCeND appeared to be easy to answer and to comprehend.

Physiotherapists' Adoption of a Theory-Based Skills Training Program in Guiding People with Rheumatoid Arthritis to Health-Enhancing Physical Activity

Purpose

To describe physiotherapists’ (PTs’) adoption of a theory-based skills training program preparing them to guide people with rheumatoid arthritis (RA) to health-enhancing physical activity (HEPA) within a 1-year intervention trial.

Method

This was a longitudinal case study. Ten female PTs (age 25–59), delivering the HEPA intervention, participated. Data were collected on five occasions over a 19-month period: once before the training course, once after 4 course days, twice during the HEPA intervention and once after the HEPA intervention. Knowledge on about physical activity (score 0–6) and behavior change techniques (BCTs) (score 0–18), fear-avoidance beliefs (score 8–48) and self-efficacy to guide behavior change (score 9–54) were assessed with a questionnaire. Structured logbooks were used to register PTs’ self-reported guiding behavior. Criteria for PTs’ adherence to the protocol were pre-set.

Results

PTs’ knowledge on about BCTs and their self-efficacy increased significantly (p < 0.05) from median 9 to 13 and from median 38 to 46.5, respectively. Knowledge on about physical activity was high and fear-avoidance beliefs were low before the education (median 6 and 13.5, respectively) and did not change over time. Two out of ten PTs fulfilled the pre-set criteria for adherence throughout the intervention.

Conclusion

The results suggest that a theory-based skills training program improves PTs’ knowledge on about behavior change techniques and their self-efficacy to guide people with RA to HEPA. PTs’ adherence to the protocol was not complete but the clinical relevance of the adherence criteria need to be validated against observed PT behavior and patient outcomes.

Challenges in Fabrication of Tissue-Engineered Cartilage with Correct Cellular Colonization and Extracellular Matrix Assembly

A correct articular cartilage ultrastructure regarding its structural components and cellularity is important for appropriate performance of tissue-engineered articular cartilage. Various scaffold-based, as well as scaffold-free, culture models have been under development to manufacture functional cartilage tissue. Even decellularized tissues have been considered as a potential choice for cellular seeding and tissue fabrication. Pore size, interconnectivity, and functionalization of the scaffold architecture can be varied. Increased mechanical function requires a dense scaffold, which also easily restricts cellular access within the scaffold at seeding. High pore size enhances nutrient transport, while small pore size improves cellular interactions and scaffold resorption. In scaffold-free cultures, the cells assemble the tissue completely by themselves; in optimized cultures, they should be able to fabricate native-like tissue. Decellularized cartilage has a native ultrastructure, although it is a challenge to obtain proper cellular colonization during cell seeding. Bioprinting can, in principle, provide the tissue with correct cellularity and extracellular matrix content, although it is still an open question as to how the correct molecular interaction and structure of extracellular matrix could be achieved. These are challenges facing the ongoing efforts to manufacture optimal articular cartilage.

Variation in pain related to systemic lupus erythematosus (SLE): a 7-year follow-up study

We have previously shown that most patients with systemic lupus erythematosus (SLE) reported low degree of SLE-related pain. However, 24% of the patients reported high degree of SLE-related pain, more fatigue, anxiety and depression, and worse health-related quality of life (HRQoL). To explore SLE-related pain, the presence of long-standing widespread pain, and patient-reported outcomes (PROs) after 7 years. Sixty-four out of 84 patients participated in a 7-year follow-up of the original survey and completed the same questionnaires answered at inclusion: pain (VAS 100 mm), fatigue (MAF), HRQoL (SF-36), anxiety and depression (HADS), and, if appropriate, a pain-drawing. Differences between inclusion and follow-up (change) were calculated. The patients with a low degree of SLE-related pain at inclusion reported no changes at follow-up in pain and PROs except for worsening in physical function in SF-36, median change (IQR) 0 (- 10 to 5), p = 0.024. Half of the patients with high degree of pain at inclusion reported decreased pain at follow-up, median change (IQR) 45 (35 to 65), p = 0.021; fatigue, 8 (8 to 17), p = 0.018; anxiety, 4 (1 to 4), p = 0.035; and depression, 4 (2 to 5), p = 0.018 and improvements in most dimensions of SF-36. The remaining half of the patients reported no changes regarding pain and PROs except for a worsening in vitality in SF-36, 20 (15 to 35), p = 0.0018. All patients with remaining high level of pain indicated long-standing widespread pain. After 7 years, a subgroup of patients with SLE reported remaining high level of SLE-related pain and a high symptom burden, including long-standing widespread pain. Such patients require more observant attention to receive appropriate treatment.

Microsomal prostaglandin E synthase-1 gene deletion impairs neuro-immune circuitry of the cholinergic anti-inflammatory pathway in endotoxaemic mouse spleen

The cholinergic anti-inflammatory pathway (CAP) is an innate neural reflex where parasympathetic and sympathetic nerves work jointly to control inflammation. Activation of CAP by vagus nerve stimulation (VNS) has paved way for novel therapeutic strategies in treating inflammatory diseases. Recently, we discovered that VNS mediated splenic acetylcholine (ACh) release and subsequent immunosuppression in response to LPS associated inflammation is impaired in mice lacking microsomal prostaglandin E synthase-1 (mPGES-1) expression, a key enzyme responsible for prostaglandin E2 synthesis. Here, we have further investigated the consequences of mPGES-1 deficiency on various molecular/cellular events in the spleen which is critical for the optimal functioning of VNS in endotoxaemic mice. First, VNS induced splenic norepinephrine (NE) release in both mPGES-1 (+/+) and (-/-) mice. Compared to mPGES-1 (+/+), immunomodulatory effects of NE on cytokines were strongly compromised in mPGES-1 (-/-) splenocytes. Interestingly, while LPS increased choline acetyltransferase (ChAT) protein level in mPGES-1 (+/+) splenocytes, it failed to exert similar effects in mPGES-1 (-/-) splenocytes despite unaltered β₂ AR protein expression. In addition, nicotine inhibited TNFα release by LPS activated mPGES-1 (+/+) splenocytes in vitro. However, such immunosuppressive effects of nicotine were reversed both in mPGES-1 (-/-) mouse splenocytes and human PBMC treated with mPGES-1 inhibitor. In summary, our data implicate PGE2 as an important mediator of ACh synthesis and noradrenergic/cholinergic molecular events in the spleen that constitute a crucial part of the CAP immune regulation. Our results suggest a possible link between cholinergic and PG system of CAP that may be of clinical significance in VNS treatment.

Temporal trends and regional disparity in rheumatoid arthritis and gout hospitalizations in Sweden, 1998-2015

Hospitalization is an important component of rheumatoid arthritis (RA) and gout economic burden. This study aimed to assess temporal trends and regional disparities in RA and gout hospitalizations among people aged ≥ 20 years in Sweden during 1998–2015. Data on hospital admissions with a principal diagnosis of RA or gout were collected from the National Patient Register. Age-standardized hospitalization rates (ASHRs) were calculated by means of direct standardization. The absolute and relative regional disparities were assessed. The temporal trends in ASHR and proportion of RA and gout hospitalizations from all and musculoskeletal disorders hospitalizations were analyzed using joinpoint regression. Between 1998–2000 and 2013–2015, the ASHR for RA declined by 78.9% from 109.9 to 23.2 per 100,000 Swedish adults, while it almost doubled for gout (from 10.5 to 20.8 per 100,000 Swedish adults). While in 1998–2000, RA hospitalizations were 10.3 times more frequent than gout (0.54 vs 0.05% of all hospitalizations), this ratio declined to 1.1 in 2013–2015 (0.13 vs 0.11% of all hospitalizations). The joinpoint regression revealed that, on average, the ASHR for RA declined by 10.2% (95% CI: 9.3–11.1) per year whereas for gout, it rose by 4.3% (3.2–5.4) per year during 1998–2015. While the relative regional disparities were stable, the absolute regional disparity declined for RA and increased for gout over the study period. While substantial decline in RA hospitalization is encouraging, the substantial rise in gout hospitalization is of concern, reflecting potential increase in prevalence of gout and suboptimal management of the disease.

H1N1 vaccination in Sjögren's syndrome triggers polyclonal B cell activation and promotes autoantibody production

OBJECTIVES

Vaccination of patients with rheumatic disease has been reported to result in lower antibody titres than in healthy individuals. However, studies primarily include patients on immunosuppressive therapy. Here, we investigated the immune response of treatment-naïve patients diagnosed with primary Sjögren's syndrome (pSS) to an H1N1 influenza vaccine.

METHODS

Patients with Sjögren's syndrome without immunomodulatory treatment and age-matched and gender-matched healthy controls were immunised with an H1N1 influenza vaccine and monitored for serological and cellular immune responses. Clinical symptoms were monitored with a standardised form. IgG class switch and plasma cell differentiation were induced in vitro in purified naïve B cells of untreated and hydroxychloroquine-treated patients and healthy controls. Gene expression was assessed by NanoString technology.

RESULTS

Surprisingly, treatment-naïve patients with Sjögren's syndrome developed higher H1N1 IgG titres of greater avidity than healthy controls on vaccination. Notably, off-target B cells were also triggered resulting in increased anti-EBV and autoantibody titres. Endosomal toll-like receptor activation of naïve B cells in vitro revealed a greater propensity of patient-derived cells to differentiate into plasmablasts and higher production of class switched IgG. The amplified plasma cell differentiation and class switch could be induced in cells from healthy donors by preincubation with type 1 interferon, but was abolished in hydroxychloroquine-treated patients and after in vitro exposure of naïve B cells to chloroquine.

CONCLUSIONS

This comprehensive analysis of the immune response in autoimmune patients to exogenous stimulation identifies a mechanistic basis for the B cell hyperactivity in Sjögren's syndrome, and suggests that caution is warranted when considering vaccination in non-treated autoimmune patients.

Neuromuscular electrical stimulation prevents skeletal muscle dysfunction in adjuvant-induced arthritis rat

Skeletal muscle weakness is a prominent feature in patients with rheumatoid arthritis (RA). In this study, we investigated whether neuromuscular electrical stimulation (NMES) training protects against skeletal muscle dysfunction in rats with adjuvant-induced arthritis (AIA). AIA was produced by intraarticular injection of complete Freund’s adjuvant into the knees of Wistar rats. For NMES training, dorsiflexor muscles were stimulated via a surface electrode (0.5 ms pulse, 50 Hz, 2 s on/4 s off). NMES training was performed every other day for three weeks and consisted of three sets produced at three min intervals. In each set, the electrical current was set to achieve 60% of the initial maximum isometric torque and the current was progressively increased to maintain this torque; stimulation was stopped when the 60% torque could no longer be maintained. After the intervention period, extensor digitorum longus (EDL) muscles were excised and used for physiological and biochemical analyses. There was a reduction in specific force production (i.e. force per cross-sectional area) in AIA EDL muscles, which was accompanied by aggregation of the myofibrillar proteins actin and desmin. Moreover, the protein expressions of the pro-oxidative enzymes NADPH oxidase, neuronal nitric oxide synthase, p62, and the ratio of the autophagosome marker LC3bII/LC3bI were increased in AIA EDL muscles. NMES training prevented all these AIA-induced alterations. The present data suggest that NMES training prevents AIA-induced skeletal muscle weakness presumably by counteracting the formation of actin and desmin aggregates. Thus, NMES training can be an effective treatment for muscle dysfunction in patients with RA.

IgM antibodies to oxidized phosphatidylserine as protection markers in cardiovascular disease among 60-year olds

Objective

Phosphatidylserine is exposed on apoptotic cells and is prone to oxidation (OxPS). Here we analyze the association of IgM antibodies against OxPS (anti-OxPS) with the risk of cardiovascular disease (CVD).

Methods

Among sixty-year olds from Stockholm County in Sweden, previously screened for cardiovascular risk factors (2039 men, 2193 women), there were 210 incident CVD-cases identified during a 5-year follow-up. Using a nested case-control design, 622 age- and sex-matched controls were selected. Odds ratios (OR) with 95% intervals (CI) were calculated by conditional logistic regression. IgM anti-OxPS was measured by ELISA. Phagocytosis of apoptotic Jurkat-cells by macrophages was studied by flow cytometry.

Results

Anti-OxPS levels were lower among cases (median (interquartile range): 80.7 (60.9–101.0 vs. 84.6 (65.8–109.6); p = 0.047); among men (76.6 (55.8–99.2) vs. 82.0 (63.1–105.1); p = 0.022) and among women 89.6 (72.3–110.1) vs. 89.8 (69.9–114.4); p = 0.79).

After adjustment for smoking, BMI, diabetes mellitus type II, hypercholesterolaemia and hypertension, and dividing into quartiles, using the highest quartile (quartile 4) as reference, quartile 3 was associated with a OR of 1.74 (CI 1.08–2.81). Quartiles 2 and 1 had similar associations, the later reaching statistical significance. Among men associations were stronger whereas no significant associations were observed in women. The OR of MI/angina comparing quartile 3 with quartile 4 was 2.31 (CI 1.30–4.11). The OR for quartile 2 and 1, respectively, were similar as for quartile 3.

Total IgM increased uptake of apoptotic cells, which was reversed if incubated with OxPS.

Conclusions

IgM anti-OxPS is a novel potential protection marker for CVD, in particular in men. Increased phagocytosis of dying/dead cells could be one potential underlying mechanism.