Validity of the Brief Illness Perception Questionnaire in people with knee pain: a Rasch analysis.

OBJECTIVE: The Brief Illness Perception Questionnaire (B-IPQ) is a frequently used measure of illness perception (IP). The aim of this study was to explore the psychometric properties of the questionnaire when used in elderly people with knee pain. METHOD: Based on data from the Frederiksberg Cohort on elderly people reporting knee pain (N = 836), the psychometric properties of the eight B-IPQ items (1 'Consequences', 2 'Timeline', 3 'Personal control', 4 'Treatment control', 5 'Identity', 6 'Concern', 7 'Coherence', and 8 'Emotions') were analysed using Rasch analysis to establish whether the questionnaire provides reliable and valid measures of IP. RESULTS: Threshold disordering was found on the 1-10 rating scale in all items. When rescaling to a 0-2 rating scale, disordering was resolved in six items. Item goodness-of-fit analyses revealed that two items displayed underfit misfit and four items overfit misfit; hence, the B-IPQ does not present unidimensionality. The person separation index indicated that items separate respondents into only two IP levels. Finally, floor and ceiling effects were found, indicating that the B-IPQ may not fully describe the extent of IP in this population. CONCLUSION: The 1-10 rating scale used in the Danish B-IPQ targeting knee pain is suboptimal, while a 0-2 scale improves the psychometric properties of the scale. The B-IPQ does not present unidimensionality and the use of a sum score is therefore not recommended when assessing IP. The B-IPQ may not cover the extent of IP in elderly people with knee pain.

Exercise and education vs intra-articular saline for knee osteoarthritis: a 1-year follow-up of a randomized trial.

OBJECTIVE: To assess the longer-term effect of the Good Life with osteoarthritis in Denmark (GLAD) exercise and education program relative to open-label placebo (OLP) on changes from baseline in core outcomes in individuals with knee osteoarthritis (OA). METHODS: In this 1-year follow-up of an open-label, randomized trial, patients with symptomatic and radiographically confirmed knee OA were monitored after being randomized to either the 8-week GLAD program or OLP given as 4 intra-articular saline injections over 8 weeks. The primary outcome was the change from baseline in the Knee injury and Osteoarthritis Outcome Score questionnaire (KOOS) pain subscale after 1 year in the intention-to-treat population. Key secondary outcomes were the KOOS function and quality of life subscales, and Patients' Global Assessment of disease impact. RESULTS: 206 adults were randomly assigned: 102 to GLAD and 104 to OLP, of which only 137 (63/74 GLAD/OLP) provided data at 1 year. At one year the mean changes in KOOS pain were 8.4 for GLAD and 7.0 for OLP (Difference: 1.5 points; 95% CI -2.6 to 5.5). There were no between-group differences in any of the secondary outcomes. CONCLUSIONS: In this 1-year follow-up of individuals with knee OA, the 8-week GLAD program and OLP both provided minor longer-term benefits with no group difference. These results require confirmation given the significant loss to follow-up. TRIAL REGISTRATION NUMBER: NCT03843931.

Who are likely to benefit from the Good Life with osteoArthritis in Denmark (GLAD) exercise and education program? An effect modifier analysis of a randomised controlled trial.

OBJECTIVE: To identify contextual factors that modify the treatment effect of the 'Good Life with osteoArthritis in Denmark' (GLAD) exercise and education programme compared to open-label placebo (OLP) on knee pain in individuals with knee osteoarthritis (OA). METHODS: Secondary effect modifier analysis of a randomised controlled trial. 206 participants with symptomatic and radiographic knee OA were randomised to either the 8-week GLAD programme (n = 102) or OLP given as 4 intra-articular saline injections over 8 weeks (n = 104). The primary outcome was change from baseline to week 9 in the Knee injury and Osteoarthritis Outcome Score questionnaire (KOOS) pain subscale (range 0 (worst) to 100 (best)). Subgroups were created based on baseline information: BMI, swollen study knee, bilateral radiographic knee OA, sports participation as a young adult, sex, median age, a priori treatment preference, regular use of analgesics (NSAIDs or paracetamol), radiographic disease severity, and presence of constant or intermittent pain. RESULTS: Participants who reported use of analgesics at baseline seem to benefit from the GLAD programme over OLP (subgroup contrast: 10.3 KOOS pain points (95% CI 3.0 to 17.6)). Participants with constant pain at baseline also seem to benefit from GLAD over OLP (subgroup contrast: 10.0 points (95% CI 2.8 to 17.2)). CONCLUSIONS: These results imply that patients who take analgesics or report constant knee pain, GLAD seems to yield clinically relevant benefits on knee pain when compared to OLP. The results support a stratified recommendation of GLAD as management of knee OA. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03843931. EudraCT number 2019-000809-71.

Poor replicability of recommended exercise interventions for knee osteoarthritis: a descriptive analysis of evidence informing current guidelines and recommendations.

OBJECTIVE: To examine the reporting completeness of exercise-based interventions for knee osteoarthritis (OA) in studies that form the basis of current clinical guidelines, and examine if the clinical benefit (pain and disability) from exercise is associated with the intervention reporting completeness. DESIGN: Review of clinical OA guidelines METHODS: We searched MEDLINE and EMBASE for guidelines published between 2006 and 2016 including recommendations about exercise for knee OA. The studies used to inform a recommendation were reviewed for exercise reporting completeness. Reporting completeness was evaluated using a 12-item checklist; a combination of the Template for Intervention Description and Replication (TIDieR) and Consensus on Exercise Reporting Template (CERT). Each item was scored 'YES' or 'NO' and summarized as a proportion of interventions with complete descriptions and each intervention's completeness was summarized as the percentage of completely described items. The association between intervention description completeness score and clinical benefits was analyzed with a multilevel meta-regression. RESULTS: From 10 clinical guidelines, we identified 103 original studies of which 100 were retrievable (including 133 interventions with 6,926 patients). No interventions were completely described on all 12 items (median 33% of items complete; range 17-75%). The meta-regression analysis indicated that poorer reporting was associated with greater effects on pain and no association with effects on disability. CONCLUSION: The inadequate description of recommended interventions for knee OA is a serious problem that precludes replication of effective interventions in clinical practice. By consequence, the relevance and usability of clinical guideline documents and original study reports are diminished. PROSPERO: CRD42016039742.

Day-to-Day Reliability of Nonlinear Methods to Assess Walking Dynamics.

The present study investigated the day-to-day reliability (quantified by the absolute and relative reliability) of nonlinear methods used to assess human locomotion dynamics. Twenty-four participants of whom twelve were diagnosed with knee osteoarthritis completed 5 min of treadmill walking at self-selected preferred speed on two separate days. Lower limb kinematics were recorded at 100 Hz and hip, knee, and ankle joint angles, three-dimensional (3D) sacrum marker displacement and stride time intervals were extracted for 170 consecutive strides. The largest Lyapunov exponent and correlation dimension were calculated for the joint angle and sacrum displacement data using three different state space reconstruction methods (group average, test-retest average, individual time delay and embedding dimension). Sample entropy and detrended fluctuation analysis (DFA) were applied to the stride time interval time series. Relative reliability was assessed using intraclass correlation coefficients and absolute reliability was determined using measurement error (ME). For both joint angles and sacrum displacement, there was a general pattern that the group average state space reconstruction method provided the highest relative reliability and lowest ME compared to the individual and test-retest average methods. The DFA exhibited good reliability, while the sample entropy showed poor reliability. The results comprise a reference material that can inspire and guide future studies of nonlinear gait dynamics.

In silico and in vitro immunogenicity assessment of B-domain-modified recombinant factor VIII molecules.

INTRODUCTION: B-domain modification can improve production of recombinant factor VIII (rFVIII) proteins. However, the engineered junction results in non-native peptide sequences with the potential to elicit immune responses via major histocompatibility complex class-II (MHC-II)-binding and CD4+ T cell activation. AIM: Assess the immunogenic potential of B-domain junction peptides of turoctocog alfa and other B-domain-modified rFVIII proteins using in silico and in vitro immunogenicity assessment techniques. METHODS: Peptides with amino acid sequences identical to the B-domain junction of turoctocog alfa, simoctocog alfa and moroctocog alfa were evaluated by in silico peptide-MHC-II binding prediction, in vitro peptide-MHC-II-binding measurement and in vitro T cell-activation assays. Moreover, turoctocog alfa was assessed for peptide presentation on dendritic cells (DCs) using MHC-associated peptide proteomics. RESULTS: In silico analysis predicted virtually no neo-epitopes in the B-domain junction for turoctocog alfa, whereas some were predicted for simoctocog alfa and moroctocog alfa. Turoctocog alfa and moroctocog alfa peptides showed minimal capacity to bind high-frequency MHC-II molecules in vitro, whereas simoctocog alfa peptide demonstrated some degree of binding to approximately half of the MHC-II molecules tested. In line with this, no B-domain peptides from turoctocog alfa were found to be presented on MHC-II complexes on DCs. B-domain junction peptides from all 3 compounds induced T cell responses in only a few percentages of donors. CONCLUSION: All 3 junction peptides were found to have a low immunogenicity potential, suggesting that modification of the B-domain does not constitute an increased immunogenicity risk for any of the products examined.

The effect of intra-articular glucocorticosteroids and exercise on symptoms and bone marrow lesions in knee osteoarthritis: a secondary analysis of results from a randomized controlled trial.

OBJECTIVE: To evaluate if the relative volume of bone marrow lesions (BMLs) changed in patients with knee osteoarthritis (OA) during a therapeutic study. DESIGN: This study is a sub-study to a larger clinical trial which compared the clinical effects of intra-articular corticosteroid injection in knee OA to placebo injection, both given prior to exercise therapy. Clinical assessment using the Knee injury and Osteoarthritis Outcome Score (KOOS) and magnetic resonance imaging (MRI) examinations with BML assessments were performed at baseline and follow-up after 14 weeks and 26 weeks, respectively. The BML volume was determined using a computer assisted method focusing on participants with valid baseline and follow-up MRI examinations. Any changes in BML and KOOS were analyzed and investigated for associations. RESULTS: Fifty participants received steroid and placebo injection, respectively, of which 41 and 45 had complete MRI examinations at week 14, and 36 and 33 at week 26, respectively. All participants received 12 weeks of exercise. A significant change in relative BML volume was observed between the corticosteroid group and the placebo group after 14 weeks [-1.1% vs 2.7%; between-group difference, 3.8% (95% CI 0.5-7.0)] but not after 26 weeks [0.8% vs 1.6%; between-group difference, 0.8% (95% CI -2.8 to 4.4)]. No significant association was found between changes in relative BML volume and KOOS. CONCLUSIONS: Despite the statistically significant difference in BML volume at 14 weeks after corticosteroid injection and 12 weeks exercise therapy compared to placebo injection and exercise, there is very little evidence on a relationship between corticosteroids and BML volume. EU CLINICAL TRIALS REGISTER: EudraCT number: 2012-002607-18.

The effects of intra-articular glucocorticoids and exercise on pain and synovitis assessed on static and dynamic magnetic resonance imaging in knee osteoarthritis: exploratory outcomes from a randomized controlled trial.

OBJECTIVE: The aims of the present knee osteoarthritis (KOA)-study were to: (1) describe and compare the changes in magnetic resonance imaging (MRI)-measures of synovitis following an exercise program preceded by an intra-articular injection of either corticosteroid or isotonic saline and (2) investigate if any of the changes in patient reported outcome measures (PROMs) were associated with changes in MRI-measures of synovitis. DESIGN: We performed a randomized, double-blinded, placebo-controlled clinical trial evaluating the effects of intra-articular corticosteroid vs placebo injections given before exercise therapy in KOA-patients. PROMs were assessed using the KOOS (knee injury and osteoarthritis outcome score). Synovitis was assessed on conventional non-contrast-enhanced, conventional contrast-enhanced (CE) and dynamic contrast-enhanced (DCE) MRI. PROMs and MRIs were obtained prior to the intra-articular injection, after termination of the exercise program (week 14-primary time point) and week 26. RESULTS: Of 100 randomized participants (50 in each allocation group), 91 had complete MRI-data at baseline (63% female, mean age: 62 years, median Kellgren-Lawrence-grade: 3). There were no statistically significant differences between the two interventions in regards of changes in MRI-measures of synovitis at any time-point. At week 14, we found no statistical significant MRI-explanatory variables of either of the PROMs. CONCLUSIONS: The present study does not justify the use of intra-articular corticosteroids over intra-articular saline when combined with an exercise program for reduction of synovitis in KOA. The improvement in pain and function following the intervention with intra-articular corticosteroids/saline and exercise could not be explained by a decrease in synovitis on MRI indicating other pain causing/relieving mechanisms in KOA.

Changes in ultrasound assessed markers of inflammation following intra-articular steroid injection combined with exercise in knee osteoarthritis: exploratory outcome from a randomized trial.

OBJECTIVE: Knee osteoarthritis (KOA) is a multifactorial joint disease affecting many people worldwide. Recommended treatments for KOA include exercise and steroid injections, or a combination of these. The objective of this exploratory outcome analysis of a randomized trial was to assess changes in inflammation markers assessed by ultrasound imaging (US) in KOA secondary to intra-articular corticosteroid injection given prior to exercise therapy. DESIGN: This study is a sub-study to a larger clinical trial which compared the clinical effects of steroid injection in KOA to placebo injection, both given prior to exercise therapy. The US outcomes were changes from baseline in US-assessed synovial size, Doppler activity presence in the synovial membrane, and numbers of US-detected Baker's cysts. US was performed at baseline, week 14 (exercise stop), and week 26 (follow-up). RESULTS: Fifty participants received steroid injection, and 50 received placebo injection. All participants received 12 weeks of exercise. Forty-five and 44, respectively, completed the study. At week 14, the group difference in the change in synovium thickness was 2.2 mm (95%, confidence interval (CI) -0.5 to 4.8), P = 0.11. There were no group differences in the changes in distribution of patients with presence of synovial Doppler activity (P = 0.98) or Baker's cysts (P = 0.35). There were no statistically significant differences between groups at week 26 in any outcome. CONCLUSION: Intra-articular steroid injection of KOA-patients prior to a 3 months exercise programme did not reduce synovial hypertrophy, synovial Doppler activity, or Baker's cyst presence more than a placebo saline injection according to US-assessments. TRIAL REGISTRATION: EudraCT: 2012-002607-18.

IFNγ and perforin cooperate to control infection and prevent fatal pathology during persistent gammaherpesvirus infection in mice.

Infection with murine gammaherpesvirus 68 has become an accepted model for studying the virus/host interactions with regard to gammaherpesvirus infections. Previous studies using gene-deficient mice have revealed that neither IFNγ nor perforin is essential in controlling the outcome of infection or the virus load during chronic infection in C57BL/6 mice. However, pronounced multiorgan fibrosis and splenic atrophy are observed in mice lacking IFNγ or the IFNγ receptor. To study the interplay between perforin and IFNγ in controlling the virus-induced pathology and the viral load during chronic gammaherpesvirus infection, we infected IFNγ/perforin double-deficient C57BL/6 mice and followed the course of infection. While absence of perforin prevented the splenic atrophy in IFNγ-deficient mice, fibrosis did not disappear. Moreover, double-deficient mice developed extreme splenomegaly, were unable to control the viral load and displayed chronic immune activation. Thus, IFNγ and perforin act in concert to minimize pathology and control the viral load in mice chronically infected with MHV68. Furthermore, while certain aspect of the virus-induced pathology in IFNγ-deficient mice may be alleviated in double-deficient mice, other aspects are exaggerated, and the normal architecture of the spleen is completely destroyed. We believe that these findings add to the understanding of the virus/host interaction during chronic gammaherpes virus infection.

Depletion of CD4+ T cells precipitates immunopathology in immunodeficient mice infected with a noncytocidal virus.

IFN-gamma-deficient (IFN-gamma(-/-)) mice inoculated with intermediate doses of a slowly replicating strain of lymphocytic choriomeningitis virus become chronically infected. In such mice a hypercompensated CTL response is observed that partially controls virus replication. Here we have investigated whether CD4(+) Th cells are required to establish and maintain this new equilibrium. The absence of IFN-gamma does not impair the generation of IL-2-producing CD4(+) cells, and depletion of these cells precipitates severe CD8(+) T cell-mediated immunopathology in IFN-gamma(-/-) mice, indicating an important role of CD4(+) T cells in preventing this syndrome. Analysis of organ virus levels revealed a further impairment of virus control in IFN-gamma(-/-) mice following CD4(+) cell depletion. Initially the antiviral CTL response did not require CD4(+) cells, but with time an impaired reactivity toward especially the glycoprotein 33--41 epitope was noted. Enumeration of epitope-specific (glycoprotein 33--41 and nucleoprotein 396--404) CD8(+) T cells by use of tetramers gave similar results. Finally, limiting dilution analysis of CTL precursors reveal an impaired capacity to sustain this population in CD4(+)-depleted mice, especially in mice also deficient in IFN-gamma. Thus, our findings disclose that T cell help is required to sustain the expanded CTL precursor pool required in IFN-gamma(-/-) mice. This interpretation is supported by mathematical modeling that predicts an increased requirement for help in IFN-gamma(-/-) hosts similar to what is found with fast replicating virus strains in normal hosts. Thus, the functional integrity of CD8(+) effector T cells is one important factor influencing the requirement for T cell help during viral infection.

Persistent virus infection despite chronic cytotoxic T-lymphocyte activation in gamma interferon-deficient mice infected with lymphocytic choriomeningitis virus.

The role of gamma interferon (IFN-gamma) in the permanent control of infection with a noncytopathic virus was studied by comparing immune responses in wild-type and IFN-gamma-deficient (IFN-gamma -/-) mice infected with a slowly invasive strain of lymphocytic choriomeningitis virus (LCMV Armstrong). While wild-type mice rapidly cleared the infection, IFN-gamma -/- mice became chronically infected. Virus persistence in the latter mice did not reflect failure to generate cytotoxic T-lymphocyte (CTL) effectors, as an unimpaired primary CTL response was observed. Furthermore, while ex vivo CTL activity gradually declined in wild-type mice, long-standing cytolytic activity was demonstrated in IFN-gamma -/- mice. The prolonged effector phase in infected IFN-gamma -/- mice was associated with elevated numbers of CD8(+) T cells. Moreover, a higher proportion of these cells retained an activated phenotype and was actively cycling. However, despite the increased CD8(+) T-cell turnover, which might have resulted in depletion of the memory CTL precursor pool, no evidence for exhaustion was observed. In fact, at 3 months postinfection we detected higher numbers of LCMV-specific CTL precursors in IFN-gamma -/- mice than in wild-type mice. These findings indicate that in the absence of IFN-gamma, CTLs cannot clear the infection and are kept permanently activated by the continuous presence of live virus, resulting in a delicate new balance between viral load and immunity. This interpretation of our findings is supported by mathematical modeling describing the effect of eliminating IFN-gamma-mediated antiviral activity on the dynamics between virus replication and CTL activity.

CCR2+ and CCR5+ CD8+ T cells increase during viral infection and migrate to sites of infection.

Chemokines and their receptors play a critical role in the selective recruitment of various leukocyte subsets. In this study, we correlated the expression of multiple chemokine and CC chemokine receptor (CCR) genes during the course of intracerebral (i.c.) infection with lymphocytic choriomeningitis virus (LCMV) and vesicular stomatitis virus (VSV), which are prototypic of a noncytopathic and a cytopathic virus, respectively. Infection of mice with either virus resulted in rapid activation and overlapping cerebral expression of a number of chemokine genes. Infection with VSV i.c. causes a rapidly lethal, T cell-independent encephalitis, and infection resulted in a dramatic early up-regulation of chemokine gene expression. Similar marked up-regulation of chemokine expression was not seen until late after LCMV infection and required the presence of activated T cells. Cerebral CCR gene expression was dominated by CCR1, CCR2 and CCR5. However, despite a stronger initial chemokine signal in VSV-infected mice, only LCMV-induced T cell-dependent inflammation was found to be associated with substantially increased expression of CCR genes. Virus-activated CD8+ T cells were found to express CCR2 and CCR5, whereas activated monocytes/macrophages expressed CCR1 in addition to CCR2 and CCR5. Together, these CCR profiles readily account for the CCR profile prominent during CD8+-dependent CNS inflammation.

Migration of activated CD8(+) T lymphocytes to sites of viral infection does not require endothelial selectins.

Using mice deficient of E-selectin and E/P-selectin, we have studied the requirement for endothelial selectins in extravasation of leukocytes at sites of viral infection, with major emphasis on the recruitment of virus-specific T(C)1 cells. Lymphocytic choriomeningitis virus (LCMV)-induced meningitis was used as our primary experimental model. Additionally, localized subdermal inflammation and virus clearance in internal organs were analyzed during LCMV infection. The generation of CD8(+) effector T cells in infected mutants was unimpaired. Quantitative and qualitative analysis of the inflammatory exudate cells in intracerebrally infected mice gave identical results in all strains of mice. Expression of endothelial selectin was also found to be redundant regarding the ability of effector cells to eliminate virus in nonlymphoid organs. Concerning LCMV-induced footpad swelling, absent or marginal reduction was found in E/P-sel -/- mice, compared with wild-type mice after local challenge with virus or immunodominant viral MHC class I restricted peptide, respectively. Similar results were obtained after adoptive transfer of wild-type effector cells into E/P-sel -/- recipients, whereas footpad swelling was markedly decreased in P-sel/ICAM-1 -/- and ICAM-1 -/- recipients. LCMV-induced footpad swelling was completely inhibited in ICAM-deficient mice transfused with donor cell preincubated with soluble VCAM-1-Ig chimeric protein. Taken together, the current findings strongly indicate that the migration of T(C)1 effector cells to sites of viral infection can proceed in the absence of endothelial selectins, whereas ligands of the Ig superfamily are critically involved in this process. (Blood. 2000;95:1362-1369)

Inducible nitric-oxide synthase plays a minimal role in lymphocytic choriomeningitis virus-induced, T cell-mediated protective immunity and immunopathology.

By using mice with a targetted disruption in the gene encoding inducible nitric-oxide synthase (iNOS), we have studied the role of nitric oxide (NO) in lymphocytic choriomeningitis virus (LCMV)-induced, T cell-mediated protective immunity and immunopathology. The afferent phase of the T cell-mediated immune response was found to be unaltered in iNOS-deficient mice compared with wild-type C57BL/6 mice, and LCMV- induced general immunosuppression was equally pronounced in both strains. In vivo analysis revealed identical kinetics of virus clearance, as well as unaltered clinical severity of systemic LCMV infection in both strains. Concerning the outcome of intracerebral infection, no significant differences were found between iNOS-deficient and wild-type mice in the number or composition of mononuclear cells found in the cerebrospinal fluid on day 6 post-infection. Likewise, NO did not influence the up-regulation of proinflammatory cytokine/chemokine genes significantly, nor did it influence the development of fatal meningitis. However, a reduced virus-specific delayed-type hypersensitivity reaction was observed in iNOS-deficient mice compared with both IFN-gamma-deficient and wild-type mice. This might suggest a role of NO in regulating vascular reactivity in the context of T cell-mediated inflammation. In conclusion, these findings indicate a minimal role for iNOS/NO in the host response to LCMV. Except for a reduced local oedema in the knockout mice, iNOS/NO seems to be redundant in controlling both the afferent and efferent phases of the T cell-mediated immune response to LCMV infection.

Soluble tumour necrosis factor (TNF)-receptor levels in serum as markers of anti-viral host reactivity.

The role of soluble receptors for TNF-alpha (sTNF-Rs) as markers of virus-induced host responses was studied by the use of murine model infections. A marked elevation in serum levels of sTNF-R75, but not sTNF-R55, was found 1 day after infection with vesicular stomatitis virus (VSV). In mice infected with lymphocytic choriomeningitis virus (LCMV), an early increase was also revealed, but peak levels of sTNF-R75 were observed later temporally related to maximal T cell-mediated anti-viral activity. Analysing different well characterized knockout mice, it was found that elevated release of sTNF-R75 into serum early after VSV infection was independent of T cells, whereas interferon (IFN)-alpha/beta seemed to be a major mediator. In contrast, increased release of sTNF-R75 into serum 8 days post-LCMV infection was mediated via T cells but independently of both CD40 ligand and IFN-gamma. A simple correlation between release of sTNF-Rs in vivo and macrophage activation in vitro was not present. These findings indicate that sTNF-R75 is indeed a sensitive marker of both innate and specific cell-mediated host reactivity during viral infection, but it is not correlated to a single immunological parameter.