Definitions of and Instruments for Disease Activity, Remission, and Relapse in Polymyalgia Rheumatica: A Systematic Literature Review.

OBJECTIVE: To perform a systematic literature review on definitions and instruments used to measure remission, relapse, and disease activity in polymyalgia rheumatica (PMR), to inform an OMERACT project to endorse instruments for these outcomes. METHODS: A search of Pubmed/MEDLINE, EMBASE, CINAHL, Cochrane, and Epistemonikos was performed May 2021 and updated August 2023. Qualitative and quantitative studies published in English were included if they recruited people with isolated PMR regardless of treatment. Study selection and data extraction was performed independently by two investigators and disagreement was resolved through discussion. Data extracted encompassed definitions of disease activity, remission and relapse, and details regarding the instruments used to measure these outcomes. RESULTS: From the 5,718 records, we included 26 articles on disease activity, 36 on remission, and 53 on relapse; 64 studies were observational and 15interventional, and none used qualitative methods. Some heterogeneity was found regarding definitions and instruments encompassing the domains pain, stiffness, fatigue, laboratory markers (mainly acute phase reactants), and patient and physician global assessment of disease activity. However, instruments for clinical signs were often poorly described. Whilst measurement properties of the polymyalgia rheumatica activity score (PMR-AS) have been assessed, data to support its use for measurement of remission and relapse is limited. CONCLUSION: Remission, relapse, and disease activity have been defined heterogeneously in clinical studies. Instruments to measure these disease states still need to be validated. Qualitative research is needed to better understand the concepts of remission and relapse in PMR. REVIEW REGISTRATION: PROSPERO identification: CRD42021255925.

The spectrum of giant cell arteritis through a rheumatology lens.

Treatment of giant cell arteritis (GCA) aims initially to prevent acute visual loss, and subsequently to optimise long-term quality of life. Initial prevention of acute visual loss in GCA is well-standardised with high-dose glucocorticoid therapy but in the longer term optimising quality of life requires tailoring of treatment to the individual. The licensing of the IL-6 receptor inhibitor tocilizumab combined with advances in vascular imaging have resulted in many changes to diagnostic and therapeutic practice. Firstly, GCA is a systemic disease that may involve multiple vascular territories and present in diverse ways. Broadening of the "spectrum" of what is called GCA has been crystallised in the 2022 GCA classification criteria. Secondly, the vascular inflammation of GCA frequently co-exists with the extracapsular musculoskeletal inflammation of the related disease, polymyalgia rheumatica (PMR). Thirdly, GCA care must often be delivered across multiple specialities and healthcare organisations requiring effective interprofessional communication. Fourthly, both GCA and PMR may follow a chronic or multiphasic disease course; long-term management must be tailored to the individual patient's needs. In this article we focus on some areas of current rheumatology practice that ophthalmologists need to be aware of, including comprehensive assessment of extra-ocular symptoms, physical signs and laboratory markers; advanced imaging techniques; and implications for multi-speciality collaboration.

Risk loci involved in giant cell arteritis susceptibility: a genome-wide association study.

BACKGROUND: Giant cell arteritis is an age-related vasculitis that mainly affects the aorta and its branches in individuals aged 50 years and older. Current options for diagnosis and treatment are scarce, highlighting the need to better understand its underlying pathogenesis. Genome-wide association studies (GWAS) have emerged as a powerful tool for unravelling the pathogenic mechanisms involved in complex diseases. We aimed to characterise the genetic basis of giant cell arteritis by performing the largest GWAS of this vasculitis to date and to assess the functional consequences and clinical implications of identified risk loci. METHODS: We collected and meta-analysed genomic data from patients with giant cell arteritis and healthy controls of European ancestry from ten cohorts across Europe and North America. Eligible patients required confirmation of giant cell arteritis diagnosis by positive temporal artery biopsy, positive temporal artery doppler ultrasonography, or imaging techniques confirming large-vessel vasculitis. We assessed the functional consequences of loci associated with giant cell arteritis using cell enrichment analysis, fine-mapping, and causal gene prioritisation. We also performed a drug repurposing analysis and developed a polygenic risk score to explore the clinical implications of our findings. FINDINGS: We included a total of 3498 patients with giant cell arteritis and 15 550 controls. We identified three novel loci associated with risk of giant cell arteritis. Two loci, MFGE8 (rs8029053; p=4·96 × 10-8; OR 1·19 [95% CI 1·12-1·26]) and VTN (rs704; p=2·75 × 10-9; OR 0·84 [0·79-0·89]), were related to angiogenesis pathways and the third locus, CCDC25 (rs11782624; p=1·28 × 10-8; OR 1·18 [1·12-1·25]), was related to neutrophil extracellular traps (NETs). We also found an association between this vasculitis and HLA region and PLG. Variants associated with giant cell arteritis seemed to fulfil a specific regulatory role in crucial immune cell types. Furthermore, we identified several drugs that could represent promising candidates for treatment of this disease. The polygenic risk score model was able to identify individuals at increased risk of developing giant cell arteritis (90th percentile OR 2·87 [95% CI 2·15-3·82]; p=1·73 × 10-13). INTERPRETATION: We have found several additional loci associated with giant cell arteritis, highlighting the crucial role of angiogenesis in disease susceptibility. Our study represents a step forward in the translation of genomic findings to clinical practice in giant cell arteritis, proposing new treatments and a method to measure genetic predisposition to this vasculitis. FUNDING: Institute of Health Carlos III, Spanish Ministry of Science and Innovation, UK Medical Research Council, and National Institute for Health and Care Research.

Modifiable risk factors and inflammation-related proteins in polymyalgia rheumatica: genome-wide meta-analysis and Mendelian randomisation.

OBJECTIVE: Polymyalgia rheumatica (PMR) is an age-related inflammatory disease of unknown cause. We aimed to identify potentially modifiable risk factors and therapeutic targets for preventing or treating PMR. METHODS: We meta-analysed genetic association data from 8,156 cases of PMR (defined using diagnostic codes and self-report) and 416,495 controls of European ancestry from the UK Biobank and FinnGen. We then performed Mendelian randomization analyses to estimate the association between eight modifiable risk factors (using data from up to 1.2 million individuals) and 65 inflammation-related circulating proteins (up to 55,792 individuals), using the inverse variance weighted and pleiotropy robust methods. RESULTS: We identified three novel genome-wide significant loci in the IL1R1, NEK6 and CCDC88B genes and confirmation of previously described associations with HLA-DRB1 and ANKRD55. Genetically predicted smoking intensity (OR 1.32; 95%CI 1.08-1.60; p = 0.006) and visceral adiposity (OR 1.22; 95%CI 1.10-1.37; p = 3.10x10-4) were associated with PMR susceptibility. Multiple circulating proteins related to IL-1 family signaling were associated with PMR. IL-1 receptor-like 2, also known as IL-36 receptor (OR 1.25; p = 1.89x10-32), serum amyloid A2 (OR 1.06, 9.91x10-10) and CXCL6 (OR 1.09, p = 4.85x10-7) retained significance after correction for multiple testing. CONCLUSION: Reducing smoking and visceral adiposity at a population level might reduce incidence of PMR. We identified proteins that may play causal roles in PMR, potentially suggesting new therapeutic opportunities. Further research is needed before these findings are applied to clinical practice.

Polymyalgia rheumatica shows metabolomic alterations that are further altered by glucocorticoid treatment: Identification of metabolic correlates of fatigue.

OBJECTIVE: In polymyalgia rheumatica (PMR), glucocorticoids (GCs) relieve pain and stiffness, but fatigue may persist. We aimed to explore the effect of disease, GCs and PMR symptoms in the metabolite signatures of peripheral blood from patients with PMR or the related disease, giant cell arteritis (GCA). METHODS: Nuclear magnetic resonance spectroscopy was performed on serum from 40 patients with untreated PMR, 84 with new-onset confirmed GCA, and 53 with suspected GCA who later were clinically confirmed non-GCA, and 39 age-matched controls. Further samples from PMR patients were taken one and six months into glucocorticoid therapy to explore relationship of metabolites to persistent fatigue. 100 metabolites were identified using Chenomx and statistical analysis performed in SIMCA-P to examine the relationship between metabolic profiles and, disease, GC treatment or symptoms. RESULTS: The metabolite signature of patients with PMR and GCA differed from that of age-matched non-inflammatory controls (R2 > 0.7). There was a smaller separation between patients with clinically confirmed GCA and those with suspected GCA who later were clinically confirmed non-GCA (R2 = 0.135). In PMR, metabolite signatures were further altered with glucocorticoid treatment (R2 = 0.42) but did not return to that seen in controls. Metabolites correlated with CRP, pain, stiffness, and fatigue (R2 ≥ 0.39). CRP, pain, and stiffness declined with treatment and were associated with 3-hydroxybutyrate and acetoacetate, but fatigue did not. Metabolites differentiated patients with high and low fatigue both before and after treatment (R2 > 0.9). Low serum glutamine was predictive of high fatigue at both time points (0.79-fold change). CONCLUSION: PMR and GCA alter the metabolite signature. In PMR, this is further altered by glucocorticoid therapy. Treatment-induced metabolite changes were linked to measures of inflammation (CRP, pain and stiffness), but not to fatigue. Furthermore, metabolite signatures distinguished patients with high or low fatigue.

Immune Checkpoint Inhibitor-induced Polymyalgia Rheumatica.

Polymyalgia rheumatica (PMR) immune-related adverse events (ICI-PMRs) represent a novel, distinct entity, despite many clinical, laboratory, and imaging similarities to classical PMR. Important questions remain in differentiating ICI-PMR from classical PMR, as well as other immune-related adverse events and PMR mimics. Despite this, ICI-PMR currently takes treatment cues from classical PMR, albeit with considerations relevant to cancer immunotherapy. Comparisons between ICI-PMR and classical PMR may provide further bidirectional insights, especially given that important questions remain unanswered about both diseases. The cause of classical PMR remains poorly understood, and ICI-PMR may represent a model of induced PMR, with important therapeutic implications.

Treatment of polymyalgia rheumatica: British Society for Rheumatology guideline scope.

The last British Society for Rheumatology (BSR) guideline on PMR was published in 2009. The guideline needs to be updated to provide a summary of the current evidence for pharmacological and non-pharmacological management of adults with PMR. This guideline is aimed at healthcare professionals in the UK who directly care for people with PMR, including general practitioners, rheumatologists, nurses, physiotherapists, occupational therapists, pharmacists, psychologists and other health professionals. It will also be relevant to people living with PMR and organisations that support them in the public and third sector, including charities and informal patient support groups. This guideline will be developed using the methods and processes outlined in the BSR Guidelines Protocol. Here we provide a brief summary of the scope of the guideline update in development.

Consensus of the definitions of the OMERACT glucocorticoid impact core domain set for people with rheumatic and musculoskeletal diseases.

BACKGROUND: The Outcome Measures in Rheumatology (OMERACT) Glucocorticoid (GC) Impact Working Group has been working to develop a core domain set to measure the impact of GCs on patients living with rheumatic and musculoskeletal diseases. The mandatory domains previously identified for inclusion in all clinical trials measuring the GC effects include infection, bone fragility, mood disturbance, hypertension, diabetes, weight, fatigue, and mortality. Before progressing to instrument selection, the Working Group sought to establish precise definitions of all mandatory domains within the core domain set. METHODS: OMERACT methodology was applied with the use of evidence and consensus-based decision making of all stakeholder groups (patient research partners, health care professionals, clinician researchers, industry members and methodologists) to develop detailed definitions for the broad domain, target domain and domain components, taking into consideration sources of variability that could affect measurement of the domain.  The working group synthesized prior qualitative studies, quantitative work, and results from Delphi rounds, to develop a rich definition of 'what' is to be measured. RESULTS: Between 2021 and 2023, the OMERACT Working Group on GC Impact conducted virtual meetings to establish domain definitions. First, we mapped each domain onto an OMERACT Core Area. All domains were primarily represented within the Pathophysiological Manifestations Core Area, except from Fatigue which was primarily Life Impact and Weight which spanned both Core Areas. Sources of variability included cultural factors, age, gender, education level, socioeconomic status, personal experiences, emotional state, and language barriers. The domain definitions will form the foundation for instrument selection and the initial step of domain / concept match and content validity in the OMERACT pillar of 'truth' before moving on to feasibility and discrimination. CONCLUSION: The OMERACT GC Impact Working Group has developed and agreed upon detailed domain definitions for core domains. Future steps of the working group are to select instruments and develop the core outcome measurement set for clinical trials measuring the impact of GC on patients with rheumatic and musculoskeletal diseases.

Jaw claudication and jaw stiffness in giant cell arteritis: secondary analysis of a qualitative research dataset.

Objective: Jaw symptoms can be a vital clue to the diagnosis of GCA. Guidelines recommend more intensive treatment if jaw claudication is present. We sought to explore how patients with GCA described their jaw symptoms. Methods: We carried out a secondary, qualitative analysis of interview data from 36 participants from the UK (n = 25) and Australia (n = 11), originally collected in order to develop a patient-reported outcome measure for GCA. In all cases, GCA had been confirmed by biopsy/imaging. Interview transcripts were organized within QSR NVivo 12 software and analysed using template analysis. Themes were refined through discussion among the research team, including a patient partner. Results: Twenty of 36 participants reported jaw symptoms associated with GCA. The median age of these 20 participants was 76.5 years; 60% were female. Five themes were identified: physical sensations; impact on function; impact on diet; symptom response with CSs; and attribution to other causes. Physical sensations included ache, cramp, stiffness and 'lockjaw'. Functional impacts included difficulty in eating/chewing, cleaning teeth, speaking or opening the mouth. Dietary impacts included switching to softer food. Response to CSs was not always immediate. Jaw symptoms were initially mis-attributed by some participants to arthritis, age or viral illnesses; or by health-care professionals to a dental cavity, ear infection or teeth-grinding. Conclusion: Jaw symptoms in GCA are diverse and can lead to diagnostic confusion with primary temporomandibular joint disorder, potentially contributing to delay in GCA diagnosis. Further research is needed to determine the relationship of jaw stiffness to jaw claudication.