Association of rheumatoid factor, anti-citrullinated protein antibodies and shared epitope with clinical response to initial treatment in patients with early rheumatoid arthritis: data from a randomised controlled trial.

OBJECTIVES: To investigate whether rheumatoid factor (RF), anti-citrullinated protein antibodies (ACPAs) and shared epitope (SE) allele-related genetic markers associate with treatment response to abatacept, certolizumab pegol or tocilizumab versus active conventional treatment (ACT). METHODS: Patients with treatment-naïve early rheumatoid arthritis were randomised in the NORD-STAR trial to ACT, certolizumab pegol, abatacept or tocilizumab, all with methotrexate. Centralised laboratory analyses for ACPA, RF and SE were performed. Clinical Disease Activity Index remission was analysed longitudinally with logistic generalised estimating equations. Differences in treatment effect across RF, ACPA and SE subgroups were assessed with interaction terms at 24 and 48 weeks, adjusted for sex, country, age, body mass index, Disease Activity Score of 28 joints based on C-reactive protein and smoking. RESULTS: In total, 778 patients were included. At 24 weeks, abatacept treatment showed a better response than ACT in the RF and/or ACPA-positive subgroups, but this effect was not significantly different from the negative subgroups. By 48 weeks, abatacept treatment showed better response regardless of RF/ACPA status. No differences were found across RF, ACPA, SE allele, valine at amino acid position 11 or valine-arginine-alanine haplotype subgroups for any biological treatment at 48 weeks. CONCLUSIONS: Based on this randomised controlled trial, abatacept treatment was associated with a better response than ACT in the RF and/or ACPA-positive subgroup at 24 weeks, but this was no longer seen at 48 weeks; adding SE allele-related genetic markers did not strengthen the association. Moreover, ACPA, RF and SE allele-related genotypes were not, alone or in combination, associated with clinical responses of importance sufficiently strongly to warrant implementation in clinical practice. TRIAL REGISTRATION NUMBER: EudraCT 2011-004720-35; ClinicalTrials.gov NCT01491815.

Certolizumab pegol, abatacept, tocilizumab or active conventional treatment in early rheumatoid arthritis: 48-week clinical and radiographic results of the investigator-initiated randomised controlled NORD-STAR trial.

BACKGROUND: The optimal first-line treatment in early rheumatoid arthritis (RA) is debated. We compared clinical and radiographic outcomes of active conventional therapy with each of three biological treatments with different modes of action. METHODS: Investigator-initiated, randomised, blinded-assessor study. Patients with treatment-naïve early RA with moderate-severe disease activity were randomised 1:1:1:1 to methotrexate combined with (1) active conventional therapy: oral prednisolone (tapered quickly, discontinued at week 36) or sulfasalazine, hydroxychloroquine and intra-articular glucocorticoid injections in swollen joints; (2) certolizumab pegol; (3) abatacept or (4) tocilizumab. Coprimary endpoints were week 48 Clinical Disease Activity Index (CDAI) remission (CDAI ≤2.8) and change in radiographic van der Heijde-modified Sharp Score, estimated using logistic regression and analysis of covariance, adjusted for sex, anticitrullinated protein antibody status and country. Bonferroni's and Dunnet's procedures adjusted for multiple testing (significance level: 0.025). RESULTS: Eight hundred and twelve patients were randomised. Adjusted CDAI remission rates at week 48 were: 59.3% (abatacept), 52.3% (certolizumab), 51.9% (tocilizumab) and 39.2% (active conventional therapy). Compared with active conventional therapy, CDAI remission rates were significantly higher for abatacept (adjusted difference +20.1%, p<0.001) and certolizumab (+13.1%, p=0.021), but not for tocilizumab (+12.7%, p=0.030). Key secondary clinical outcomes were consistently better in biological groups. Radiographic progression was low, without group differences.The proportions of patients with serious adverse events were abatacept, 8.3%; certolizumab, 12.4%; tocilizumab, 9.2%; and active conventional therapy, 10.7%. CONCLUSIONS: Compared with active conventional therapy, clinical remission rates were superior for abatacept and certolizumab pegol, but not for tocilizumab. Radiographic progression was low and similar between treatments. TRIAL REGISTRATION NUMBER: NCT01491815.

Blood chemokine levels are markers of disease activity but not predictors of remission in early rheumatoid arthritis.

OBJECTIVES: In early rheumatoid arthritis (eRA) plasma levels of specific chemokines have been shown to correlate with disease activity. However, it is unclear whether pre-treatment chemokine levels can predict disease remission at week 24, and it is not known how biological treatments with different modes of action affect plasma chemokine levels in patients with untreated eRA. METHODS: This study included 347 Swedish patients with untreated eRA from the larger NORD-STAR randomised treatment trial. Here, eRA patients were treated with methotrexate combined with either prednisolone, anti-TNF (certolizumab-pegol), CTLA-4Ig (abatacept) or anti-IL6 receptor (tocilizumab). The primary clinical outcome was remission by clinical disease activity index (CDAI) defined as CDAI ≤ 2.8. Disease activity was assessed by CDAI, DAS28-ESR, DAS28-CRP, swollen joint counts, tender joint counts, ESR and CRP. The plasma concentrations of 14 chemokines were measured at baseline and after 24 weeks of treatment by bead-based immunoassay or ELISA. RESULTS: Baseline plasma concentrations of CXCL10, CXCL8, CXCL9, CXCL11, CXCL5 and CCL2 correlated with baseline disease activity measures. After 24 weeks of treatment, plasma levels of CXCL10, CXCL8, CXCL9, CXCL11 and CXCL13 decreased in all treatment groups except in patients treated with anti-IL6 receptor. In multivariate factor analysis, plasma chemokine levels at baseline could not differentiate patients who attained remission by week 24 from those who did not in any of the treatment groups. CONCLUSIONS: In patients with untreated eRA, plasma levels of several chemokines correlate with disease activity at baseline but cannot predict remission after 24 weeks of treatment with methotrexate combined with prednisolone, anti­TNF, CTLA­4Ig or anti­IL6R.

Effects of age, BMI and sex on the glial cell marker TSPO - a multicentre [11C]PBR28 HRRT PET study.

PURPOSE: The purpose of this study was to investigate the effects of ageing, sex and body mass index (BMI) on translocator protein (TSPO) availability in healthy subjects using positron emission tomography (PET) and the radioligand [11C]PBR28. METHODS: [11C]PBR28 data from 140 healthy volunteers (72 males and 68 females; N = 78 with HAB and N = 62 MAB genotype; age range 19-80 years; BMI range 17.6-36.9) were acquired with High Resolution Research Tomograph at three centres: Karolinska Institutet (N = 53), Turku PET centre (N = 62) and Yale University PET Center (N = 25). The total volume of distribution (VT) was estimated in global grey matter, frontal, temporal, occipital and parietal cortices, hippocampus and thalamus using multilinear analysis 1. The effects of age, BMI and sex on TSPO availability were investigated using linear mixed effects model, with TSPO genotype and PET centre specified as random intercepts. RESULTS: There were significant positive correlations between age and VT in the frontal and temporal cortex. BMI showed a significant negative correlation with VT in all regions. Additionally, significant differences between males and females were observed in all regions, with females showing higher VT. A subgroup analysis revealed a positive correlation between VT and age in all regions in male subjects, whereas age showed no effect on TSPO levels in female subjects. CONCLUSION: These findings provide evidence that individual biological properties may contribute significantly to the high variation shown in TSPO binding estimates, and suggest that age, BMI and sex can be confounding factors in clinical studies.

Brain glial activation in fibromyalgia - A multi-site positron emission tomography investigation.

Fibromyalgia (FM) is a poorly understood chronic condition characterized by widespread musculoskeletal pain, fatigue, and cognitive difficulties. While mounting evidence suggests a role for neuroinflammation, no study has directly provided evidence of brain glial activation in FM. In this study, we conducted a Positron Emission Tomography (PET) study using [11C]PBR28, which binds to the translocator protein (TSPO), a protein upregulated in activated microglia and astrocytes. To enhance statistical power and generalizability, we combined datasets collected independently at two separate institutions (Massachusetts General Hospital [MGH] and Karolinska Institutet [KI]). In an attempt to disentangle the contributions of different glial cell types to FM, a smaller sample was scanned at KI with [11C]-L-deprenyl-D2 PET, thought to primarily reflect astrocytic (but not microglial) signal. Thirty-one FM patients and 27 healthy controls (HC) were examined using [11C]PBR28 PET. 11 FM patients and 11 HC were scanned using [11C]-L-deprenyl-D2 PET. Standardized uptake values normalized by occipital cortex signal (SUVR) and distribution volume (VT) were computed from the [11C]PBR28 data. [11C]-L-deprenyl-D2 was quantified using λ k3. PET imaging metrics were compared across groups, and when differing across groups, against clinical variables. Compared to HC, FM patients demonstrated widespread cortical elevations, and no decreases, in [11C]PBR28 VT and SUVR, most pronounced in the medial and lateral walls of the frontal and parietal lobes. No regions showed significant group differences in [11C]-L-deprenyl-D2 signal, including those demonstrating elevated [11C]PBR28 signal in patients (p's ≥ 0.53, uncorrected). The elevations in [11C]PBR28 VT and SUVR were correlated both spatially (i.e., were observed in overlapping regions) and, in several areas, also in terms of magnitude. In exploratory, uncorrected analyses, higher subjective ratings of fatigue in FM patients were associated with higher [11C]PBR28 SUVR in the anterior and posterior middle cingulate cortices (p's < 0.03). SUVR was not significantly associated with any other clinical variable. Our work provides the first in vivo evidence supporting a role for glial activation in FM pathophysiology. Given that the elevations in [11C]PBR28 signal were not also accompanied by increased [11C]-L-deprenyl-D2 signal, our data suggests that microglia, but not astrocytes, may be driving the TSPO elevation in these regions. Although [11C]-L-deprenyl-D2 signal was not found to be increased in FM patients, larger studies are needed to further assess the role of possible astrocytic contributions in FM. Overall, our data support glial modulation as a potential therapeutic strategy for FM.

Evidence of fatigue, disordered sleep and peripheral inflammation, but not increased brain TSPO expression, in seasonal allergy: A [11C]PBR28 PET study.

Allergy is associated with non-specific symptoms such as fatigue, sleep problems and impaired cognition. One explanation could be that the allergic inflammatory state includes activation of immune cells in the brain, but this hypothesis has not been tested in humans. The aim of the present study was therefore to investigate seasonal changes in the glial cell marker translocator protein (TSPO), and to relate this to peripheral inflammation, fatigue and sleep, in allergy. We examined 18 patients with severe seasonal allergy, and 13 healthy subjects in and out-of pollen season using positron emission tomography (n = 15/13) and the TSPO radioligand [11C]PBR28. In addition, TNF-α, IL-5, IL-6, IL-8 and IFN-γ were measured in peripheral blood, and subjective ratings of fatigue and sleepiness as well as objective and subjective sleep were investigated. No difference in levels of TSPO was seen between patients and healthy subjects, nor in relation to pollen season. However, allergic subjects displayed both increased fatigue, sleepiness and increased percentage of deep sleep, as well as increased levels of IL-5 and TNF-α during pollen season, compared to healthy subjects. Allergic subjects also had shorter total sleep time, regardless of season. In conclusion, allergic subjects are indicated to respond to allergen exposure during pollen season with a clear pattern of behavioral disruption and peripheral inflammatory activation, but not with changes in brain TSPO levels. This underscores a need for development and use of more specific markers to understand brain consequences of peripheral inflammation that will be applicable in human subjects.

Immunomodulatory effects of nicotine on interleukin 1ß activated human astrocytes and the role of cyclooxygenase 2 in the underlying mechanism.

BACKGROUND: The cholinergic anti-inflammatory pathway (CAP) primarily functions through acetylcholine (ACh)-alpha7 nicotinic acetylcholine receptor (α7nAChR) interaction on macrophages to control peripheral inflammation. Interestingly, ACh can also bind α7nAChRs on microglia resulting in neuroprotective effects. However, ACh effects on astrocytes remain elusive. Here, we investigated the effects of nicotine, an ACh receptor agonist, on the cytokine and cholinesterase production of immunocompetent human astrocytes stimulated with interleukin 1ß (IL-1ß) in vitro. In addition, the potential involvement of prostaglandins as mediators of nicotine was studied using cyclooxygenase 2 (COX-2) inhibition. METHODS: Cultured human fetal astrocytes were stimulated with human recombinant IL-1ß and treated simultaneously with nicotine at different concentrations (1, 10, and 100 µM). Cell supernatants were collected for cytokine and cholinesterase profiling using ELISA and MesoScale multiplex assay. α7nAChR expression on activated human astrocytes was studied using immunofluorescence. For the COX-2 inhibition studies, enzyme activity was inhibited using NS-398. One-way ANOVA was used to perform statistical analyses. RESULTS: Nicotine treatment dose dependently limits the production of critical proinflammatory cytokines such as IL-6 (60.5 ± 3.3, %inhibition), IL-1ß (42.4 ± 1.7, %inhibition), and TNF-α (68.9 ± 7.7, %inhibition) by activated human astrocytes. Interestingly, it also inhibits IL-8 chemokine (31.4 ± 8.5, %inhibition), IL-13 (34.243 ± 4.9, %inhibition), and butyrylcholinesterase (20.8 ± 2.8, %inhibition) production at 100 µM. Expression of α7nAChR was detected on the activated human astrocytes. Importantly, nicotine's inhibitory effect on IL-6 production was reversed with the specific COX-2 inhibitor NS-398. CONCLUSIONS: Activation of the cholinergic system through α7nAChR agonists has been known to suppress inflammation both in the CNS and periphery. In the CNS, earlier experimental data shows that cholinergic activation through nicotine inhibits microglial activation and proinflammatory cytokine release. Here, we report similar anti-inflammatory effects of cholinergic activation on human astrocytes, at least partly mediated through the COX-2 pathway. These results confirm the potential for cholinergic neuroprotection, which is looked upon as a promising therapy for neuroinflammation as well as neurodegenerative diseases and stroke. Our data implicates an important role for the prostaglandin system in cholinergic regulatory effects.

In vivo evidence of a functional association between immune cells in blood and brain in healthy human subjects.

Microglia, the resident macrophages in the central nervous system, are thought to be maintained by a local self-renewal mechanism. Although preclinical and in vitro studies have suggested that the brain may contain immune cells also from peripheral origin, the functional association between immune cells in the periphery and brain at physiological conditions is poorly understood. We examined 32 healthy individuals using positron emission tomography (PET) and [(11)C]PBR28, a radioligand for the 18-kDa translocator protein (TSPO) which is expressed both in brain microglia and blood immune cells. In 26 individuals, two measurements were performed with varying time intervals. In a subgroup of 19 individuals, of which 12 had repeat examinations, leukocyte numbers in blood was measured on each day of PET measurements. All individuals were genotyped for TSPO polymorphism and categorized as high, mixed, and low affinity binders. We assessed TSPO binding expressed as total distribution volume of [(11)C]PBR28 in brain and in blood cells. TSPO binding in brain was strongly and positively correlated to binding in blood cells both at baseline and when analyzing change between two PET examinations. Furthermore, there was a significant correlation between change of leukocyte numbers and change in TSPO binding in brain, and a trend-level correlation to change in TSPO binding in blood cells. These in vivo findings indicate an association between immunological cells in blood and brain via intact BBB, suggesting a functional interaction between these two compartments, such as interchange of peripherally derived cells or a common regulatory mechanism. Measurement of radioligand binding in blood cells may be a way to control for peripheral immune function in PET studies using TSPO as a marker of brain immune activation.

Impaired vagus-mediated immunosuppression in microsomal prostaglandin E synthase-1 deficient mice.

The cholinergic anti-inflammatory pathway controls innate immune responses and inflammation. The prostaglandin (PG) system is involved in several neuro-processes and associated with inflammatory activation of cells in vagal nuclei. Here we aimed to investigate the potential role of PG in cholinergic neuro-regulation. The effect of vagus nerve stimulation (VNS) has been evaluated in microsomal prostaglandin E synthase-1 (mPGES-1) knockout (-/-) and wild-type (+/+) mice regarding cytokine and PG levels after lipopolysaccharides (LPS) challenge. As expected, VNS decreased the release of pro-inflammatory cytokines both in serum and spleen extracts of mPGES-1 (+/+)animals. However, the immune suppressive effect of VNS was completely abolished in mPGES-1 (-/-) mice. The PG content was not affected by VNS in the spleen of mPGES-1 (+/+) and mPGES-1 (-/-) mice but interestingly, acetylcholine (ACh) release in spleen induced by VNS confirmed an intact cholinergic pathway in mPGES-1 (+/+) whereas no VNS-induced ACh release was found in mPGES-1 (-/-) animals. Our data show that mPGES-1 and consequently PGE2 are crucial in the cholinergic anti-inflammatory pathway. Moreover, the mechanisms involved do not affect PG content in the spleen, but lack of mPGES-1 was found to strongly affect cholinergic mechanisms in the inflamed spleen. These findings illustrate previously unrecognized associations between the cholinergic and prostaglandin systems, and may be of importance for further development of therapeutic strategies directed at modulation of the inflammatory reflex, and immunosuppression in chronic inflammatory diseases.

Peripheral inflammatory disease associated with centrally activated IL-1 system in humans and mice.

During peripheral immune activation caused by an infection or an inflammatory condition, the innate immune response signals to the brain and causes an up-regulation of central nervous system (CNS) cytokine production. Central actions of proinflammatory cytokines, in particular IL-1ß, are pivotal for the induction of fever and fatigue. In the present study, the influence of peripheral chronic joint inflammatory disease in rheumatoid arthritis (RA) on CNS inflammation was investigated. Intrathecal interleukin (IL)-1ß concentrations were markedly elevated in RA patients compared with controls or with patients with multiple sclerosis. Conversely, the anti-inflammatory IL-1 receptor antagonist and IL-4 were decreased in RA cerebrospinal fluid (CSF). Tumor necrosis factor and IL-6 levels in the CSF did not differ between patients and controls. Concerning IL-1ß, CSF concentrations in RA patients were higher than in serum, indicating local production in the CNS, and there was a positive correlation between CSF IL-1ß and fatigue assessments. Next, spinal inflammation in experimental arthritis was investigated. A marked increase of IL-1ß, IL-18, and tumor necrosis factor, but not IL-6 mRNA production, in the spinal cord was observed, coinciding with increased arthritis scores in the KBxN serum transfer model. These data provide evidence that peripheral inflammation such as arthritis is associated with an immunological activation in the CNS in both humans and mice, suggesting a possible therapeutic target for centrally affecting conditions as fatigue in chronic inflammatory diseases, for which to date there are no specific treatments.

Tocilizumab reduces hypercoagulation in COVID-19 - Perspectives from the coagulation and immunomodulation Covid assessment (Coag-ImmCovA) clinical trial.

BACKGROUND: Despite medical interventions, COVID-19 continues to persist at pandemic proportions. A hypercoagulation state was rapidly observed in the severely ill, and the incidence of thromboembolic events remains elevated. Interleukin inhibitors have demonstrated positive effects on the hyperactivation of the immune system in COVID-19, with the interleukin-6 inhibitor tocilizumab showing promising results in reducing mortality. Nevertheless, the impact of interleukin inhibitors on the coagulation system remains incompletely understood. METHODS: In this clinical trial conducted in Stockholm, Sweden, interleukin inhibitors, namely anakinra (ANA) or tocilizumab (TOCI), were randomly administered in addition to standard care (SC) to hospitalized patients with COVID-19. A control group received only SC. The primary outcome sought to measure effects on global hemostasis, as indicated by changes in functional coagulation tests, specifically Rotational Thromboelastometry (ROTEM) or Overall Hemostatic Potential (OHP), visualized through scanning electron microscopy images. Secondary outcomes included effects on conventional coagulation laboratory tests. RESULTS: The study enrolled 74 patients who were randomized to receive either ANA or TOCI in addition to SC, or SC alone. In the TOCI group, ROTEM variables exhibited less hypercoagulation after 29 days compared with ANA or SC treatment groups, characterized by prolonged clot formation time and decreased clot firmness. OHP decreased, but there were no significant differences among the three treatment groups. Plasma fibrinogen levels, initially elevated, decreased significantly in TOCI recipients over time. CONCLUSION: Tocilizumab treatment demonstrated a significant reduction of hypercoagulation in hospitalized COVID-19 patients, by improvements in both global coagulation tests and conventional laboratory tests, in comparison with anakinra or SC alone. This finding underscores the significance of tocilizumab as a viable treatment option in severe COVID-19 cases, with the potential to decrease thrombosis incidence.

Urinary prostanoids are elevated by anti-TNF and anti-IL6 receptor disease-modifying antirheumatic drugs but are not predictive of response to treatment in early rheumatoid arthritis.

BACKGROUND: Disease-modifying antirheumatic drugs (DMARDs) are widely used for treating rheumatoid arthritis (RA). However, there are no established biomarkers to predict a patient's response to these therapies. Prostanoids, encompassing prostaglandins, prostacyclins, and thromboxanes, are potent lipid mediators implicated in RA progression. Nevertheless, the influence of DMARDs on prostanoid biosynthesis in RA patients remains poorly understood. This study aims to assess the impact of various DMARDs on urinary prostanoids levels and to explore whether urinary prostanoid profiles correlate with disease activity or response to therapy. METHODS: This study included 152 Swedish female patients with early RA, all rheumatoid factor (RF) positive, enrolled in the NORD-STAR trial (registration number: NCT01491815). Participants were randomized into four therapeutic regimes: methotrexate (MTX) combined with (i) prednisolone (arm ACT), (ii) TNF-α blocker certolizumab pegol (arm CZP), (iii) CTLA-4Ig abatacept (arm ABA), or (iv) IL-6R blocker tocilizumab (arm TCZ). Urine samples, collected before start of treatment and at 24 weeks post-treatment, were analyzed for tetranor-prostaglandin E metabolite (tPGEM), tetranor-prostaglandin D metabolite (tPGDM), 2,3-dinor thromboxane B2 (TXBM), 2,3-dinor-6-keto prostaglandin F1a (PGIM), leukotriene E4 (LTE4) and 12-hydroxyeicosatetraenoic acid (12-HETE) using liquid chromatography-mass spectrometry (LC-MS). Generalized estimating equation (GEE) models were used to analyze the change in urinary eicosanoids and their correlations to clinical outcomes. RESULTS: Patients receiving MTX combined with CZP or TCZ exhibited significant elevations in urinary tPGEM and TXBM levels after 24 weeks of treatment. Other eicosanoids did not show significant alterations in response to any treatment. Baseline urinary eicosanoid levels did not correlate with baseline clinical disease activity index (CDAI) levels, nor with changes in CDAI from baseline to week 24. Their levels were also similar between patients who achieved CDAI remission and those with active disease at week 24. CONCLUSIONS: Treatment with anti-TNF or anti-IL6R agents in early RA patients leads to an increased systemic production of proinflammatory and prothrombotic prostanoids. However, urinary eicosanoid levels do not appear to be predictive of the response to DMARDs therapy.

Methotrexate Safety and Efficacy in Combination Therapies in Patients With Early Rheumatoid Arthritis: A Post Hoc Analysis of a Randomized Controlled Trial.

OBJECTIVE: We investigated methotrexate safety and the influence of dose on efficacy outcomes in combination with three different biologic treatments and with active conventional treatment (ACT) in early rheumatoid arthritis (RA). METHODS: This post hoc analysis included 812 treatment-naïve patients with early RA who were randomized (1:1:1:1) in the NORD-STAR trial to receive methotrexate in combination with ACT, certolizumab-pegol, abatacept, or tocilizumab. Methotrexate safety, doses, and dose effects on Clinical Disease Activity Index (CDAI) remission were assessed after 24 weeks of treatment. RESULTS: Compared with ACT, the prevalence of methotrexate-associated side effects was higher when methotrexate was combined with tocilizumab (hazard ratio [HR] 1.48, 95% confidence interval [CI] 1.20-1.84) but not with certolizumab-pegol (HR 0.99, 95% CI 0.79-1.23) or with abatacept (HR 0.93, 95% CI 0.75-1.16). With ACT as the reference, the methotrexate dose was significantly lower when used in combination with tocilizumab (ß -4.65, 95% CI -5.83 to -3.46; P < 0.001) or abatacept (ß -1.15, 95% CI -2.27 to -0.03; P = 0.04), and it was numerically lower in combination with certolizumab-pegol (ß -1.07, 95% CI -2.21 to 0.07; P = 0.07). Methotrexate dose reductions were not associated with decreased CDAI remission rates within any of the treatment combinations. CONCLUSION: Methotrexate was generally well tolerated in combination therapies, but adverse events were a limiting factor in receiving the target dose of 25 mg/wk, and these were more frequent in combination with tocilizumab versus ACT. On the other hand, methotrexate dose reductions were not associated with decreased CDAI remission rates within any of the four treatment combinations at 24 weeks.

CD163+ macrophages monitor enhanced permeability at the blood-dorsal root ganglion barrier.

In dorsal root ganglia (DRG), macrophages reside close to sensory neurons and have largely been explored in the context of pain, nerve injury, and repair. However, we discovered that most DRG macrophages interact with and monitor the vasculature by sampling macromolecules from the blood. Characterization of the DRG vasculature revealed a specialized endothelial bed that transformed in molecular, structural, and permeability properties along the arteriovenous axis and was covered by macrophage-interacting pericytes and fibroblasts. Macrophage phagocytosis spatially aligned with peak endothelial permeability, a process regulated by enhanced caveolar transcytosis in endothelial cells. Profiling the DRG immune landscape revealed two subsets of perivascular macrophages with distinct transcriptome, turnover, and function. CD163+ macrophages self-maintained locally, specifically participated in vasculature monitoring, displayed distinct responses during peripheral inflammation, and were conserved in mouse and man. Our work provides a molecular explanation for the permeability of the blood-DRG barrier and identifies an unappreciated role of macrophages as integral components of the DRG-neurovascular unit.

Circulating Baseline CXCR3+Th2 and Th17 Cell Proportions Correlate With Trabecular Bone Loss After 48 Weeks of Biological Treatment in Early Rheumatoid Arthritis.

OBJECTIVE: The high prevalence of osteoporosis in rheumatoid arthritis (RA) is due to inflammation that stimulates differentiation of osteoclasts, a process involving circulating monocytes and T cell-derived factors. The aim of this study was to evaluate relations between circulating monocytes, T cell subsets, and changes in bone characteristics before and after treatment with biological disease-modifying antirheumatic drugs (bDMARDs) in RA. METHODS: Thirty patients with untreated early RA who met the American College of Rheumatology/EULAR 2010 criteria were included. Data were collected before and 48 weeks after treatment with methotrexate (MTX) together with one of three bDMARDs (abatacept, tocilizumab, or certolizumab pegol). Disease activity was measured using the Clinical Disease Activity Index, swollen or tender joint counts, C-reactive protein levels, and erythrocyte sedimentation rates. Proportions of monocyte and CD4+ T cell subsets in blood samples were analyzed by flow cytometry. Bone densitometry was performed using high-resolution peripheral quantitative computed tomography (HR-pQCT). RESULTS: HR-pQCT revealed an overall decrease in cortical (P = 0.009) and trabecular (P = 0.034) bone mineral density, although a subset of patients showed no bone loss after 48 weeks of treatment. The overall bone loss was not associated with age, body mass index, sex, intraarticular glucocorticoid injections, or baseline disease activity. Loss of trabecular bone volume fraction correlated with high proportions of circulating CXCR3+Th2 cells (r = -0.38, P = 0.04) and CXCR3+Th17 cells (r = -0.36, P = 0.05) at baseline. Similarly, no loss of trabecular bone volume fraction correlated with high proportions of regulatory T cells (r = 0.4, P = 0.03) at baseline. However, the associations were not significant when corrected for confounders and multiple testing. CONCLUSION: MTX together with bDMARDs efficiently reduce disease activity but only prevent bone loss in a subset of patients with RA after 48 weeks of treatment. The correlations of circulating baseline T helper cell and regulatory T cell populations with trabecular bone changes suggest a potential novel role for these cells in systemic bone homeostasis during early RA.

Obesity is a risk factor for poor response to treatment in early rheumatoid arthritis: a NORD-STAR study.

OBJECTIVE: This report from the NORD-STAR (Nordic Rheumatic Diseases Strategy Trials and Registries) trial aimed to determine if obesity is associated with response to conventional and biological antirheumatic treatment in early rheumatoid arthritis (RA). METHODS: This report included 793 participants with untreated early RA from the randomised, longitudinal NORD-STAR trial, all of whom had their body mass index (BMI) assessed at baseline. Obesity was defined as BMI ≥30 kg/m2. All participants were randomised 1:1:1:1 to one of four treatment arms: active conventional treatment, certolizumab-pegol, abatacept and tocilizumab. Clinical and laboratory measurements were performed at baseline and at 8, 12, 24 and 48-week follow-up. The primary endpoint for this report was response to treatment based on Clinical Disease Activity Index (CDAI) and Simple Disease Activity Index (SDAI) remission and Disease Activity Score with 28 joints using C-reactive protein (DAS28-CRP) <2.6 stratified by BMI. RESULTS: Out of 793 people included in the present report, 161 (20%) had obesity at baseline. During follow-up, participants with baseline obesity had higher disease activity compared with those with lower BMI, despite having similar disease activity at baseline. In survival analyses, obesity was associated with a lower likelihood of achieving response to treatment during follow-up for up to 48 weeks (CDAI remission, HR 0.84, 95% CI 0.67 to 1.05; SDAI, HR 0.77, 95% CI 0.62 to 0.97; DAS28-CRP <2.6, HR 0.78, 95% CI 0.64 to 0.95). The effect of obesity on response to treatment was not influenced by the treatment arms. CONCLUSION: In people with untreated early RA followed up for up to 48 weeks, obesity was associated with a lower likelihood of good treatment response, irrespective of the type of randomised treatment received. TRIAL REGISTRATION NUMBER: NCT01491815.

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.

Cerebrospinal fluid immune cells appear similar across neuropathic and non-neuropathic pain conditions.

Background: Microglia have been implicated in the pathophysiology of neuropathic pain. Here, we sought to investigate whether cerebrospinal fluid (CSF) might be used as a proxy-measure of microglial activation in human participants. Methods: We preformed fluorescence-activated cell sorting (FACS) of CSF immune cell populations derived from individuals who experienced pain with neuropathic features. We sorted CD4+, CD8+ T cells and monocytes and analyzed their transcriptome using RNA sequencing. We also performed Cellular Indexing of Transcriptomes and Epitopes (CITE) sequencing to characterize the expression of all CSF immune cells in a patient with postherpetic neuralgia and in a patient with neuropathic pain after failed back surgery. Results: Immune cell numbers and phenotypes were not obviously different between individuals regardless of the etiology of their pain. This was true when examining our own dataset, as well as when comparing it to previously published single-cell RNA sequencing data of human CSF. In all instances, CSF monocytes showed expression of myeloid cell markers commonly associated with microglia ( P2RY12, TMEM119 and OLFML3), which will make it difficult to ascertain the origin of CSF proteins: do they derive directly from circulating CSF monocytes or could some originate in spinal cord microglia in the parenchyma? Conclusions: We conclude that it will not be straightforward to use CSF as a biomarker for microglial function in humans.

Anakinra or tocilizumab in patients admitted to hospital with severe covid-19 at high risk of deterioration (IMMCoVA): A randomized, controlled, open-label trial.

BACKGROUND: Anakinra and tocilizumab are used for severe Covid-19, but only one previous randomized controlled trial (RCT) has studied both. We performed a multi-center RCT comparing anakinra or tocilizumab versus usual care (UC) for adults at high risk of deterioration. METHODS: The study was conducted June 2020 to March 2021. Eligibility required ≥ 5 liters/minute of Oxygen to maintain peripheral oxygen saturation at ≥ 93%, CRP > 70 mg/L, ferritin > 500 µg/L and at least two points where one point was awarded for lymphocytes < 1x 109/L; D-dimer ≥ 0.5 mg/L and; lactate dehydrogenase ≥ 8 microkatal/L. Patients were randomly assigned 1:1:1 to receive either a single dose of tocilizumab (8 mg/kg) or anakinra 100 mg IV QID for seven days or UC alone. The primary outcome was time to recovery. RESULTS: Recruitment was ended prematurely when tocilizumab became part of usual care. Out of a planned 195 patients, 77 had been randomized, 27 to UC, 28 to anakinra and 22 to tocilizumab. Median time to recovery was 15, 15 and 11 days. Rate ratio for recovery for UC vs anakinra was 0.91, 0.47 to 1.78, 95% [CI], p = 0.8 and for UC vs tocilizumab 1.13, 0.55 to 2.30; p = 0.7. There were non-significant trends favoring tocilizumab (and to limited degree anakinra) vs UC for some secondary outcomes. Safety profiles did not differ significantly. CONCLUSION: Premature closure of trial precludes firm conclusions. Anakinra or tocilizumab did not significantly shorten time to clinical recovery compared to usual care. (IMMCoVA, NCT04412291, EudraCT: 2020-00174824).

Unmet Needs in Rheumatoid Arthritis: A Subgroup of Patients With High Levels of Pain, Fatigue, and Psychosocial Distress 3 Years After Diagnosis.

OBJECTIVE: The study objective was to identify subgroups of patients with rheumatoid arthritis (RA) based on their health status 3 years after diagnosis and to assess potential associations to clinical presentation at diagnosis. METHODS: This observational study included patients with RA with 3-year follow-up data from the Swedish Epidemiological Investigation of RA study, collected from 2011 to 2018. Hierarchical agglomerative cluster analysis, based on symptoms of pain, fatigue, sleep quality, mood disturbances, and overall health-related quality of life (HRQoL), was used to identify subgroups 3 years after diagnosis. Modified Poisson regression was used to estimate risk ratios (RRs) and 95% confidence intervals (CIs) for the associations between the subgroups and patient characteristics at diagnosis. RESULTS: A total of 1055 individuals constituted the study population, of whom 1011 had complete data on the clustering variables and were therefore eligible for analysis (73% women, median age 58 years). The following three clusters were identified: cluster 1 (466 patients with good health status), cluster 2 (398 patients in an intermediate group), and cluster 3 (147 patients with high levels of pain and fatigue together with markedly impaired HRQoL). Cluster 3 was associated to higher baseline pain (RR: 3.71 [95% CI: 2.14-6.41]), global health (RR: 6.60 [95% CI: 3.53-12.33]), and the Stanford Health Assessment Questionnaire (RR: 4.40 [95% CI: 2.46-7.87]), compared with cluster 1 (highest compared with lowest quartiles). An inverse association was seen for baseline swollen joint count (RR: 0.51 [95% CI: 0.34-0.85]). CONCLUSION: A subgroup of patients with RA experience high levels of pain, fatigue, and psychosocial distress 3 years after diagnosis. This subgroup already displayed pronounced pain and functional disabilities at diagnosis.