Background: Women with hormone-responsive breast cancer who receive adjuvant endocrine treatment with aromatase inhibitors (AI) are known to be at higher fracture risk due to a marked increase in bone resorption. In 2017, several interdisciplinary cancer and bone societies involved in the management of women with AI-associated bone loss (AIBL) published a joint position statement comprising evidence-based recommendations and a practical management algorithm for the assessment of fracture risk and optimal treatment of this patient population. Patients and methods: In order to provide updated recommendations that reflect recent advances in the assessment and management of AIBL since publication of the 2017 joint position statement, a systematic literature review was undertaken to identify relevant studies for analysis, including systematic reviews and meta-analyses. Individual trials identified were assessed for their level of evidence based on design, size, follow-up, and evaluation of safety, as well as the impact of bone directed treatments on breast cancer outcomes. Results: New evidence was combined with the existing recommendations to provide an updated joint position statement regarding fracture risk assessment and implementation of bone-directed therapy. Conclusion: Current published literature, including recent clinical trial reports, systematic reviews and meta-analyses, continue to affirm the high risk of fractures in women with breast cancer who are receiving adjuvant AI treatment, a risk which has been observed to increase with the commonly used approach of extended duration AI therapy (>5 years). Risk factors for fracture and risk assessment in this patient population as well as the most suitable treatment modalities have been updated. Finally, the influence of bone protective treatments on breast cancer outcomes such as incidence of bone metastasis and breast cancer related overall survival have been included.

Osteoporosis is a chronic disease that requires long-term management, particularly in high-risk patients who have a substantial increase in fracture risk. Antiresorptive medications remain the most widely used treatment for osteoporosis. This review aims to evaluate the available evidence on the long-term effects of bisphosphonates and denosumab, in order to help physicians determine the most suitable long-term management regimen for their patients, while balancing efficacy, safety, and fracture risk. Both bisphosphonates and denosumab have demonstrated efficacy in reducing fracture risk and increasing bone mineral density for up to 10 years. However, evidence to support their safety and efficacy beyond this period remains scarce. Given the increasing number of patients being treated with bisphosphonates or denosumab in the long term, we strongly advocate conducting observational follow-up studies in these patients. Currently, treatment decisions are based on personal experience and expert opinions, as well as discussions with the patient within a shared decision-making framework. We hope that this manuscript will give important background information for these discussions and facilitate final decisions.

INTRODUCTION:The discovery of romosozumab, a monoclonal antibody to sclerostin and treatment option for severe osteoporosis, resulted from convergent genetic research of persons with rare hyperostotic bone diseases and the discovery of the Wnt-signaling pathway, a vital pathway in bone metabolism. AREAS COVERED:The authors provide an overview of the discovery of the SOST gene in humans and of Wnt signaling in animals, leading to the identification of sclerostin, a major regulator of bone formation and resorption. The authors further provide an overview of the studies that led to the development of romosozumab, a unique dual action monoclonal antibody that increases bone formation while decreasing bone resorption. EXPERT OPINION:In postmenopausal women, the administration of romosozumab over one year decreased the risk of vertebral and clinical fractures versus placebo and versus alendronate. Furthermore, sequential treatment, switching romosozumab over to denosumab, reduced the risk of vertebral fractures compared to switching the placebo to denosumab. Meanwhile, switching romosozumab to alendronate reduced the risk of vertebral, clinical, nonvertebral, and hip fractures compared to continuous alendronate. An imbalance in cardiovascular events was found when using romosozumab in comparison to alendronate but not versus placebo. Romosozumab was eventually approved by EMA and FDA in 2019 for the treatment of patients with very high risk of fractures while considering their cardiovascular risk and is available and reimbursed in many countries.

Objectives To assess whether prednisone use and/or disease activity score (DAS) are associated with the development of hyperglycaemia and diabetes in rheumatoid arthritis (RA).Methods We included 504 non-diabetic early RA patients from the BeSt study (Dutch acronym for treatment strategies). Patients were randomised to four DAS-steered treatment arms and followed for 10 years. The associations between DAS and prednisone use with glucose levels and the occurrence of hyperglycaemia over time were assessed with linear and logistic mixed effects regression models. Development of diabetes was analysed with Cox regression. Sensitivity analyses were performed in patients who had a first episode of hyperglycaemia.Results 31 of 504 patients (6.2%) with a mean age of 54 years developed diabetes during follow-up; 11 of these (35%) had received prior treatment with prednisone. Prednisone use was not associated with development of hyperglycaemia or diabetes after correction for multiple testing in main or sensitivity analyses. In the main analyses, DAS was significantly associated with development of diabetes (HR 1.802 per 1 point DAS increase, 95% CI 1.284 to 2.529) but not with glucose levels nor hyperglycaemia. In patients with previous hyperglycaemia, DAS was associated with glucose levels, recurrence of hyperglycaemia and diabetes.Conclusions In non-diabetic early RA patients, the use of prednisone was not associated with developing hyperglycaemia or diabetes. However, high DAS increased the risk of diabetes. Potential risks associated with prednisone use may have been mitigated by its effect on DAS.

Morales Torres, Jorge Luis Alberto MD; Vidal Neira, Luis Fernando MD; Messina, Osvaldo Daniel MD; Lems, Willem MD; Zerbini, Cristiano Author Information

BACKGROUND:There is considerable practice variation in labelling, diagnosis and treatment of adults with sterile bone inflammation. We developed a expert consensus recommendations on the disease definition, diagnosis and treatment of this rare condition. METHODS:Systematic literature review and Grading of Recommendations, Assessment, Development and Evaluations-based appraisal of evidence, two Delphi surveys and three digital and in-person consensus meetings with a multidisciplinary expert panel and patient representatives. RESULTS:A consensus disease definition was developed and the term 'chronic non-bacterial osteitis' (CNO) is proposed to describe adults with sterile bone inflammation. For initial imaging evaluation of adults with suspected CNO, the panel recommends MRI or otherwise CT combined with nuclear imaging. Whole-body imaging at initial evaluation can be considered for diagnostic and prognostic purposes. Suggested first-line treatment in adults with active CNO includes non-steroidal anti-inflammatory drugs/cyclooxygenase 2-inhibitors. Second-line treatment preferably consists of intravenous bisphosphonates, and otherwise tumour necrosis factor-α inhibitors. Choice between them should be individualised, considering the presence of additional inflammatory features. The panel further discusses outcome measures, follow-up and management of adverse events and complications. CONCLUSIONS AND FUTURE PERSPECTIVES:These expert consensus recommendations are intended to support healthcare professionals worldwide in their care for adults with CNO. They also lay the groundwork for establishing international patient registries, translational research lines and multicentre trials, all of which are urgently required.

OBJECTIVES:To study long-term (up to 20-year) mortality of two treat-to-target trial cohorts in undifferentiated arthritis (UA) and early rheumatoid arthritis (RA). METHODS:The BeSt (BehandelStrategieën) study (n=508, early RA) was performed between 2000 and 2012. For 10 years, patients were treated-to-target disease activity score (DAS)≤2.4.The Induction therapy with Methotrexate and Prednisone in Rheumatoid Or Very Early arthritic Disease (IMPROVED) study (n=610, early RA/UA) was performed between 2007 and 2015. For 5 years, patients were treated-to-target DAS<1.6.Vital status of BeSt/IMPROVED participants was assessed up to and including 31 December 2021. Standardised mortality ratios (SMRs) were calculated. Stratified analyses for anticitrullinated protein antibody (ACPA) and smoking status were performed. Death causes and the potential effect of disease activity during the trial period on late mortality were assessed. RESULTS:Excess mortality was found in both BeSt (SMR 1.32, 95% CI 1.14 to 1.53) and IMPROVED (SMR 1.33, 95% CI 1.10 to 1.63) and became manifest after 10 years. Excess mortality was statistically significant in ACPA+ patients who smoked (BeSt: SMR 2.80, 95% CI 2.16 to 3.64; IMPROVED: 2.14, 95% CI 1.33 to 3.45). Mean survival time was 10 (95% CI 5 to 16) months shorter than expected in BeSt and 13 (95% CI 11 to 16) months in IMPROVED. The HR for mortality was 1.34 (95% CI 0.96 to 1.86; BeSt)/1.13 (95% CI 0.67 to 1.91; IMPROVED) per 1 point increase in mean DAS during the trial. The main cause of death was malignancy. CONCLUSIONS:After long-term treatment-to-target, excess mortality occurred in patients with RA after>10 years since treatment start, with smoking as an important risk factor.

Task Force on ‘Clinical Algorithms for Fracture Risk’ commissioned by the American Society for Bone and Mineral Research (ASBMR) Professional Practice Committee has recommended that FRAX® models in the US do not include adjustment for race and ethnicity. This position paper finds that an agnostic model would unfairly discriminate against the Black, Asian and Hispanic communities and recommends the retention of ethnic and race-specific FRAX models for the US, preferably with updated data on fracture and death hazards. In contrast, the use of intervention thresholds based on a fixed bone mineral density unfairly discriminates against the Black, Asian and Hispanic communities in the US. This position of the Working Group on Epidemiology and Quality of Life of the International Osteoporosis Foundation (IOF) is endorsed both by the IOF and the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases (ESCEO).

IntroductionRomosozumab is a monoclonal antibody that binds to sclerostin (an inhibitor of the Wingless-related integration site (Wnt) signaling pathway). It is a new osteoanabolic drug that simultaneously increases bone formation and decreases bone resorption. It has recently been approved by the US and EU authorities in postmenopausal women with at high risk of fractures.Areas coveredThe literature on romosozumab in preclinical and in phase II and III clinical studies has been reviewed about the effect on bone, bone markers, and fracture reduction and its safety.Expert opinionCompared to antiresorptive agents, its unique mechanism of action results in a quicker and greater increase in bone mineral density, it repairs and restores trabecular and cortical bone microarchitecture, and reduces fracture risk more rapidly and more effectively than alendronate, with persisting effects for at least two years after transition to antiresorptive agents. This finding has introduced the concept that, in patients at very high risk of fractures, the optimal sequence of treatment is to start with an osteoanabolic agent, followed by a potent AR drug. Recent national and international guidelines recommend the use of romosozumab as an initial treatment in patients at very high fracture risk without a history of stroke or myocardial infarction.

OBJECTIVES:To investigate cartilage tissue turnover in response to a supervised 12-week exercise-related joint loading training program followed by a 6-month period of unsupervised training in patients with knee osteoarthritis (OA). To study the difference in cartilage tissue turnover between high- and low-resistance training.METHOD:Patients with knee OA were randomized into either high-intensity or low-intensity resistance supervised training (two sessions per week) for 3 months and unsupervised training for 6 months. Blood samples were collected before and after the supervised training period and after the follow-up period. Biomarkers huARGS, C2M, and PRO-C2, quantifying cartilage tissue turnover, were measured by ELISA. Changes in biomarker levels over time within and between groups were analyzed using linear mixed models with baseline values as covariates.RESULTS:huARGS and C2M levels increased after training and at follow-up in both low- and high-intensity exercise groups. No changes were found in PRO-C2. The huARGS level in the high-intensity resistance training group increased significantly compared to the low-intensity resistance training group after resistance training (p = 0.029) and at follow-up (p = 0.003).CONCLUSION:Cartilage tissue turnover and cartilage degradation appear to increase in response to a 3-month exercise-related joint loading training program and at 6-month follow-up, with no evident difference in type II collagen formation. Aggrecan remodeling increased more with high-intensity resistance training than with low-intensity exercise. These exploratory biomarker results, indicating more cartilage degeneration in the high-intensity group, in combination with no clinical outcome differences of the VIDEX study, may argue against high-intensity training.

ObjectiveThe randomised placebo-controlled GLORIA (Glucocorticoid LOw-dose in RheumatoId Arthritis) trial evaluated the benefits and harms of prednisolone 5 mg/day added to standard care for 2 years in patients aged 65+ years with rheumatoid arthritis (RA). Here, we studied disease activity, flares and possible adrenal insufficiency after blinded withdrawal of study medication.MethodsPer protocol, patients successfully completing the 2-year trial period linearly tapered and stopped blinded study medication in 3 months. We compared changes in disease activity after taper between treatment groups (one-sided testing). Secondary outcomes (two-sided tests) comprised disease flares (DAS28 (Disease Activity Score 28 joints) increase >0.6, open-label glucocorticoids or disease-modifying antirheumatic drug (DMARD) increase/switch after week 4 of tapering) and symptoms/signs of adrenal insufficiency. In a subset of patients from 3 Dutch centres, cortisol and ACTH were measured in spot serum samples after tapering.Results191 patients were eligible; 36 met treatment-related flare criteria and were only included in the flare analysis. Mean (SD) DAS28 change at follow-up: 0.2 (1.0) in the prednisolone group (n=76) vs 0.0 (1.2) in placebo (n=79). Adjusted for baseline, the between-group difference in DAS28 increase was 0.16 (95% confidence limit –0.06, p=0.12). Flares occurred in 45% of prednisolone patients compared with 33% in placebo, relative risk (RR) 1.37 (95% CI 0.95 to 1.98; p=0.12). We found no evidence for adrenal insufficiency.ConclusionsTapering prednisolone moderately increases disease activity to the levels of the placebo group (mean still at low disease activity levels) and numerically increases the risk of flare without evidence for adrenal insufficiency. This suggests that withdrawal of low-dose prednisolone is feasible and safe after 2 years of administration.

BackgroundResearch on the disease severity of COVID-19 in patients with rheumatic immune-mediated inflammatory diseases (IMIDs) has been inconclusive, and long-term prospective data on the development of SARS-CoV-2 antibodies in these patients are lacking.MethodsAdult patients with rheumatic IMIDs from the Amsterdam Rheumatology and Immunology Center, Amsterdam were invited to participate. All patients were asked to recruit their own sex-matched and age-matched control subject. Clinical data were collected via online questionnaires (at baseline, and after 1–4 and 5–9 months of follow-up). Serum samples were collected twice and analysed for the presence of SARS-CoV-2-specific antibodies. Subsequently, IgG titres were quantified in samples with a positive test result.FindingsIn total, 3080 consecutive patients and 1102 controls with comparable age and sex distribution were included for analyses. Patients were more frequently hospitalised compared with controls when infected with SARS-CoV-2; 7% vs 0.7% (adjusted OR: 7.33, 95% CI: 0.96 to 55.77). Only treatment with B-cell targeting therapy was independently associated with an increased risk of COVID-19-related hospitalisation (adjusted OR: 14.62, 95% CI: 2.31 to 92.39). IgG antibody titres were higher in hospitalised compared with non-hospitalised patients, and slowly declined with time in similar patterns for patients in all treatment subgroups and controls.InterpretationWe observed that patients with rheumatic IMIDs, especially those treated with B-cell targeting therapy, were more likely to be hospitalised when infected with SARS-CoV-2. Treatment with conventional synthetic disease-modifying antirheumatic drugs (DMARDs) and biological DMARDs other than B-cell targeting agents is unlikely to have negative effects on the development of long-lasting humoral immunity against SARS-CoV-2.

ObjectiveTo investigate the pharmacokinetics of methotrexate polyglutamate (MTX-PG) accumulation in red blood cells (RBCs) and peripheral blood mononuclear cells (PBMCs) in patients with early rheumatoid arthritis (RA) after oral and subcutaneous MTX treatment.MethodsIn a clinical prospective cohort study (Methotrexate Monitoring study), newly diagnosed patients with RA were randomised for oral or subcutaneous MTX. At 1, 2, 3 and 6 months after therapy initiation, blood was collected and RBCs and PBMCs were isolated. MTX-PG1-6concentrations were determined by mass spectrometry methods using stable isotopes of MTX-PG1-6as internal standards.Results43 patients (mean age: 58.5 years, 77% female) were included. PBMCs and RBCs revealed disparate pharmacokinetic profiles in both absolute MTX-PG accumulation levels and distribution profiles. Intracellular MTX-PG accumulation in PBMCs was significantly (p<0.001) 10-fold to 20-fold higher than RBCs at all time points, regardless of the administration route. MTX-PG distribution in PBMCs was composed of mostly MTX-PG1(PG1>PG2>PG3). Remarkably, the distribution profile in PBMCs remained constant over 6 months. RBCs accumulated mainly MTX-PG1and lower levels of MTX-PG2-5at t=1 month. After 3 months, MTX-PG3was the main PG-moiety in RBCs, a profile retained after 6 months of MTX therapy. Subcutaneous MTX administration results in higher RBC drug levels than after oral administration, especially shortly after treatment initiation.ConclusionsThis is the first study reporting disparate MTX-PG accumulation profiles in RBCs versus PBMCs in newly diagnosed patients with RA during 6 months oral or subcutaneous MTX administration. This analysis can contribute to improved MTX therapeutic drug monitoring for patients with RA.Trial registration numberNTR 7149.

Objectives To investigate whether patients with rheumatoid arthritis (RA) can discontinue glucocorticoids (GC) after GC ‘bridging’ in the initial treatment step and to identify factors that may affect this. Methods Data from 7 clinical trial arms (with 1653 patients) that included a GC bridging schedule, previously identified in a systematic literature search, were combined in an individual patient data meta-analysis. Outcomes were GC use (yes/no) at predefined time points (1/3/6/12/18 months after bridging had ended), cumulative GC dose and continuous (≥3 months) GC use after bridging had ended. Age, sex, ACPA status, initial GC dose, duration of bridging schedule, oral versus parenteral GC administration and initial co-treatment were univariably tested with each outcome. Results The probability of using GC 1 month after bridging therapy had ended was 0.18, decreasing to 0.07 from 6 until 18 months after bridging had ended. The probability of continuous GC use after bridging had ended was 0.18 at 1 year and 0.30 at 2 years of follow-up. In oral GC bridging studies only, the probabilities of later and continuous GC use and the cumulative GC doses were higher compared to the combined analyses with also parenteral GC bridging studies included. A higher initial dose and a longer GC bridging schedule were associated with higher cumulative GC doses and more patients on GC at 18 months after bridging had ended. Conclusions Based on these RA clinical trial arms with an initial GC bridging schedule, the probability of subsequent ongoing GC use following bridging is low.

The filamentous bacteriophage cf infects the bacterium Xanthomonas campestris pv. citri. Northern blot analysis with probes derived from various restriction fragments of cf replicative form (RF) DNA has revealed the presence of five major phage-specific transcripts in infected cells. Four of these transcripts were shown to be derived from the region of the cf genome extending from gene II to gene VIII and are consistent with the cascade model of transcription proposed for Ff coliphages. These transcripts overlap with each other and terminate upstream of an efficient Rho-independent transcription terminator. Unlike the well-characterized Ff phages, in which only the minus strand of viral DNA serves as a transcription template, both strands of the RF DNA of phage cf appeared to be transcribed. Thus one of the five major cf transcripts was shown to be derived from a region of the viral minus strand that contains an open reading frame encoding a putative polypeptide of 165 amino acids. Primer extension analysis mapped the transcriptional initiation site of this RNA to a cytosine residue at position 870. A partial transcription map of phage cf revealed two independent regions of transcriptional activity. The region with the highest activity coincides with that encoding the polypeptides required in the largest amounts during the cf infection cycle.

Background Low-dose glucocorticoid (GC) therapy is widely used in RA but the true balance of benefit and harm is still unknown. Objectives We studied the effects of prednisolone (5 mg/day, 2 years) in RA patients aged 65+, requiring adjustment of antirheumatic therapy (DAS28≥2.60). Methods Pragmatic double-blind placebo-controlled randomized trial; all co-treatments and changes therein were allowed during the trial except long-term open label GC; Ca/D supplementation was advised in all patients. Minimal exclusion criteria were tailored to seniors. Harm outcome: the number of patients with ≥1 serious adverse event (SAE), or ≥1 ‘other adverse event of special interest’ (other AESI). Other AESI comprised any AE (except worsening of RA) causing study discontinuation, and GC-specific events (Table 1). Table 1. Adverse events of special interest (AESI).* prednisolone (n=224) placebo (n=225) Events by protocol-defined category SAE other AESI SAE other AESI Infection 26 124 16 91 Urinary tract 4 49 4 29 Pneumonia 2 17 2 13 Other 20 58 10 49 Cardiovascular 8 2 6 0 Symptomatic fracture 2 11 4 6 New onset Hypertension 1 4 0 7 Diabetes mellitus 0 2 0 1 Cataract 0 7 2 6 Glaucoma 0 1 0 3 Other † 43 43 35 26 Total 80 194 63 140 *AESI: Comprises serious adverse events (SAE) and other AESI, defined by protocol. †‘Other’ other AESI: non-serious AE outside of the above predefined categories, but associated with premature discontinuation. Benefit outcomes: improvement in disease activity (DAS28) and joint damage progression (Sharp/van der Heijde). Longitudinal mixed models analyzed the data. Given prior knowledge we report one-sided 95% confidence limit (95%CL) and statistical tests, performed only for the main outcomes. Results We randomized 451 RA patients in 7 EU countries, 449 received the intervention; of these 63% prednisolone vs 61% placebo patients completed 2 years of follow up. Discontinuations were similar in both groups: for AE (14%) and active disease (4%); the remainder mostly for ‘trial fatigue’ and covid-related access issues (20%). Mean time on study drug was 19 (SD 8) months. 70% of patients were female, mean age was 72 (max 88) years, RA duration 11 years; 67% were RF+, 56% ACPA+, 96% had joint damage on radiographs: mean score 20, median 8. Mean DAS28 was 4.5. Most patients (79%) were on current DMARD treatment, including 14% on biologics; 47% had previously used GC, 14% changed DMARD therapy at baseline. Patients had mean 2.1 active comorbidities, and used median 7 drugs. Benefit: Disease activity rapidly declined to stabilize after 1 year (Figure 1), and was lower on prednisolone (adjusted mean difference in DAS28 over 2 years: 0.37, 95%CL 0.23, p<0.0001). The contrast in early (3-month) response was larger in 331 patients adherent to protocol on stable treatment: mean difference in DAS28 0.62 (95%CL 0.44), more responders on prednisolone (Figure 1). Significant time-treatment interaction in secondary analyses suggested a decrease in contrast after the first year, most likely caused by significantly more changes in DMARD treatment on placebo. Joint damage progression over 2 years was significantly lower on prednisolone: mean 0.6 (SD 1.9) v 1.8 (6.4) score points on placebo, difference 1.2 (95%CL 0.2, p=0.02). Harm: 60% prednisolone vs 49% placebo patients experienced the harm outcome: adjusted RR 1.24, 95%CL 1.04, p=0.02; number needed to harm 9.5 (Table 1). During the study 1 vs 2 patients died, and 3 vs 0 died within 5 months of discontinuation. Per 100 patient-years, AE totaled 278 in prednisolone vs 206 in placebo patients, and the difference was most marked for infections (Table 1); these were mostly mild or moderately severe. Other GC-specific AESI were rare without relevant differences. Conclusion Add-on low dose prednisolone has beneficial long-term effects on disease activity and damage progression in senior RA patients on standard treatment. The tradeoff is a 24% increase in patients with mostly mild to moderate AE, suggesting a favorable balance of benefit and harm. Acknowledgements Trial registration: NCT02585258 (clinicaltrials.gov). The trial is part of a larger project funded by the European Union’s Horizon 2020 research and innovation program under grant agreement No. 634886. Apart from the listed authors and centers, the GLORIA Trial Consortium comprises: L.M. Middelink, Middelinc BV The Netherlands, Operational Lead; V. Dekker, Amsterdam UMC, Vrije Universiteit, Financial Lead; Partners: Trial operations: N. van den Bulk, CR2O BV, The Netherlands; Study Medication (Development, Manufacturing & Supply): R.M.A. Pinto, Bluepharma – Indústria Farmacêutica, S.A., Portugal; Data management: L. Doerwald, Linical Netherlands BV, The Netherlands; S. Manger, Department of Epidemiology & Data Science, Amsterdam UMC, Vrije Universiteit, The Netherlands. Adherence monitoring: J. Redol, BeyonDevices LDA, Portugal; Safety monitoring: K. Prinsen, Clinfidence BV, The Netherlands; Patient partner: M. Scholte-Voshaar, Stichting Tools (Tools2Use), The Netherlands. Investigators (other recruiting centers): T.L.T.A. Jansen, VieCuri – location Venlo, The Netherlands; C. Codreanu, Clinical Center for Rheumatic Diseases, Bucarest, Rumania; R.M.Zandhuis-Mooij, MSc, Gelre Ziekenhuis, Apeldoorn, The Netherlands; E. Molenaar, Groene Hart Ziekenhuis, Gouda, The Netherlands; J.M. van Laar, UMC Utrecht, The Netherlands; Y.P.M. Ruiterman, Haga Ziekenhuis, Den Haag, The Netherlands; A.E.R.C.H. Boonen, MUMC, Maastricht, The Netherlands; M. Micaelo, Instituto Português de Reumatologia, Lisboa, Portugal; J. Costa, Hospital de Ponte Lima, Portugal; M. Sieburg, Rheumatologische Facharztpraxis Magdeburg, Germany; J.P.L. Spoorenberg, UMC Groningen, The Netherlands; U. Prothmann, Knappschaftsklinikum Saar GbmH, Puettlingen, Germany; M.J. Saavedra, Hospital de Santa Maria, Lisboa, Portugal; I. Silva, Hospital de Egas Moniz, Lisboa, Portugal; M.T. Nurmohamed, Reade, Amsterdam, The Netherlands; J.W.G. Jacobs, UMC Utrecht, The Netherlands; and S.W. Tas, Amsterdam UMC, University of Amsterdam, The Netherlands. Scientific Advisory Committee: J.W.J. Bijlsma, UMC Utrecht, The Netherlands; R. Christensen, The Parker Institute, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark; Y.M. Smulders, Amsterdam UMC, VU University, The Netherlands; and S.H. Ralston, University of Edinburgh, Edinburgh, UK. Radiographic assessment: D.M.F.M. van der Heijde (Imaging Rheumatology BV, the Netherlands) coordinated the reading of the hand and foot x-rays. A.F. Marsman and W.F. Lems scored the spine X-rays. Patient panel: C. Rusthoven and M. Bakkers, The Netherlands E. Frazão Mateus, and G. Mendes, Portugal C. Elling-Audersch and D. Borucki, Germany A. Cardone, Italy P. Corduta and O. Constantinescu, Romania P. Richards, United Kingdom G. Aanerud, Norway Disclosure of Interests Maarten Boers Consultant of: Novartis, Linda Hartman: None declared, Daniela Opris-Belinski Consultant of: Abbvie, Pfizer, MSD, Novartis, Eli Lilly, Ewo Pharma, UCB, Reinhard Bos: None declared, Marc R Kok: None declared, José Antonio P. da Silva: None declared, Eduard N. Griep: None declared, Ruth Klaasen: None declared, Cornelia Allaart: None declared, Paul Baudoin: None declared, Hennie Raterman Consultant of: Abbvie, Pfizer, MSD, Novartis, Eli Lilly, Ewo Pharma, UCB, Zoltán Szekanecz: None declared, Frank Buttgereit Consultant of: Abbvie, AstraZeneca, Gruenenthal, Horizon Therapeutics, Mundipharma, Pfizer, Roche, Pavol MASARYK: None declared, Thomas Klausch: None declared, Sabrina Paolino: None declared, Annemarie M. Schilder Consultant of: Eli Lilly, Novartis, Genzyme, WIllem Lems Consultant of: Pfizer, Galapagos, Lilly, Amgen, UCB., Maurizio Cutolo: None declared

OBJECTIVE:To determine whether macrophage positron emission tomography (PET)/computed tomography (CT) imaging using (R)-[11C]PK11195 at 0 and 2 weeks is associated with clinical response at 13 weeks in patients with early rheumatoid arthritis (RA).METHODS:Whole-body (R)-[11C]PK11195 PET/CT scans were performed at baseline and after 2 weeks of COBRA-light (combination therapy of methotrexate and prednisone) treatment in 35 patients with clinically active early RA. Clinical assessment (Disease Activity Score of 44 joints (DAS44)) was performed at 0, 2 and 13 weeks of treatment. PET/CT scans were assessed visually by two blinded, experienced readers, and by calculating standardised uptake values (SUVs) for shoulders, elbows, hips, knees, and hand and feet joints. Clinical and PET variables were compared using (multivariate) linear regression.RESULTS:18 males and 17 females were included (baseline DAS44=3.2 ± 1.0). 171 out of 1470 joints were visually PET positive at baseline, decreasing to 100 joints after 2 weeks. In general, small feet joints showed the highest uptake at baseline, and the largest decrease after 2 weeks (Δ0-2). Neither baseline nor Δ0-2 PET measures correlated with DAS44 at 13 weeks. However, at 2 weeks, average SUV of the feet significantly correlated with DAS44 at 13 weeks (R2=0.14, p=0.04). In a multivariable model, DAS44 and average SUV of the feet at 2 weeks showed substantial combined predictive value (combined R2=0.297, p<0.01).CONCLUSION:Quantitative macrophage PET assessment of feet joints, together with DAS44, after 2 weeks of COBRA light treatment in patients with early RA correlates with clinical response after 3 months of treatment.