An update on polymyalgia rheumatica

Broadening the clinical spectrum of giant cell arteritis: from the classic cranial to the predominantly extracranial pattern of the disease

INTRODUCTION

Giant cell arteritis (GCA) is a large vessel (LV) vasculitis that affects people aged 50 years and older. Classically, GCA was considered a disease that involved branches of the carotid artery. However, the advent of new imaging techniques has allowed us to reconsider the clinical spectrum of this vasculitis.

AREASCOVERED

This review describes clinical differences between patients with the cranial GCA and those with a predominantly extracranial LV-GCA disease pattern. It highlights differences in the frequency of positive temporal artery biopsy depending on the predominant disease pattern and emphasizes the relevance of imaging techniques to identify patients with LV-GCA without cranial ischemic manifestations. The review shows that so far there are no well-established differences in genetic predisposition to GCA regardless of the predominant phenotype.

EXPERT COMMENTARY

The large branches of the extracranial arteries are frequently affected in GCA. Imaging techniques are useful to identify the presence of 'silent' GCA in people presenting with polymyalgia rheumatica or with nonspecific manifestations. Whether these two different clinical presentations of GCA constitute a continuum in the clinical spectrum of the disease or whether they may be related but are definitely different conditions needs to be further investigated.

Naïve Inflammatory Proteome Profiles of Glucocorticoid Responsive Polymyalgia Rheumatica and Rheumatic Arthritis Patients-Links to Triggers and Proteomic Manifestations

Polymyalgia rheumatica (PMR) is an inflammatory disorder of unknown etiology, sharing symptoms with giant cell arthritis (GCA) and rheumatoid arthritis (RA). The pathogenic inflammatory roots are still not well understood, and there is a lack of extensive biomarker studies to explain the disease debut and post-acute phase. This study aimed to deeply analyze the serum proteome and inflammatory response of PMR patients before and after glucocorticoid treatment. We included treatment-naïve PMR patients, collecting samples before and after 3 months of treatment. For comparison, disease-modifying antirheumatic drug (DMARD)-naïve RA patients were included and matched to healthy controls (CTL). The serum proteome was examined using label-free quantitative mass spectrometry, while inflammation levels were assessed using multiplex inflammatory cytokine and cell-free DNA assays. The serum proteomes of the four groups comprised acute phase reactants, coagulation factors, complement proteins, immunoglobulins, and apolipoproteins. Serum amyloid A (SAA1) was significantly reduced by active PMR treatment. Cell-free DNA levels in PMR and RA groups were significantly higher than in healthy controls due to acute inflammation. Complement factors had minimal changes post-treatment. The individual serum proteome in PMR patients showed over 100 abundantly variable proteins, emphasizing the systemic impact of PMR disease debut and the effect of treatment. Interleukin (IL)-6 and interferon-gamma (IFN-γ) were significantly impacted by glucocorticoid treatment. Our study defines the PMR serum proteome during glucocorticoid treatment and highlights the role of SAA1, IL-6, and IFN-γ in treatment responses. An involvement of PGLYRP2 in acute PMR could indicate a response to bacterial infection, highlighting its role in the acute phase of the immune response. The results suggest that PMR may be an aberrant response to a bacterial infection with an exacerbated IL-6 and acute phase inflammatory response and molecular attempts to limit the inflammation.

Why is polymyalgia rheumatica a disease of older adults? Explanations through etiology and pathogenesis: a narrative review

Polymyalgia rheumatica is one of the most common inflammatory rheumatic conditions in older adults. The disease is characterized by pain and stiffness in the shoulder and pelvic girdle. Polymyalgia rheumatica is almost always observed in adults over the age of 50. The current article aimed to provide explanations for the age preference of polymyalgia rheumatica by reviewing the literature regarding disease etiology and pathogenesis. Potential factors related to the association between polymyalgia rheumatica and aging include immunosenescence/inflammaging, increased risk of infections by aging, endocrinosenescence, and age-related changes in gut microbiota. These factors and their potential contributions to immune-mediated inflammation will be discussed.

Review of phase 2/3 trials in polymyalgia rheumatica and giant cell arteritis

INTRODUCTION

GCA (giant cell arteritis) and PMR (polymyalgia rheumatica) are two overlapping inflammatory rheumatic conditions that are seen exclusively in older adults, sharing some common features. GCA is a clinical syndrome characterized by inflammation of the medium and large arteries, with both cranial and extracranial symptoms. PMR is a clinical syndrome characterized by stiffness in the neck, shoulder, and pelvic girdle muscles. Both are associated with constitutional symptoms.

AREAS COVERED

In this review, we assess the established and upcoming treatments for GCA and PMR. We review the current treatment landscape, completed trials, and upcoming trials in these conditions, to identify new and promising therapies.

EXPERT OPINION

Early use of glucocorticoids (GC) remains integral to the immediate management of PMR and GCA but being aware of patient co-morbidities that may influence treatment toxicity is paramount. As such GC sparing agents are required in the treatment of PMR. Currently there are limited treatment options available for PMR and GCA, and significant unmet needs remain. Newer mechanisms of action, and hence therapeutic options being studied include CD4 T cell co-stimulation blockade, IL-17 inhibition, IL-12/23 inhibition, GM-CSF inhibition, IL-1β inhibition, TNF-α antagonist and Jak inhibition, among others, which will be discussed in this review.

Evidence on treat to target strategies in polymyalgia rheumatica and giant cell arteritis: a systematic literature review

OBJECTIVES

To inform an international task force about current evidence on Treat to Target (T2T) strategies in PMR and GCA.

METHODS

A systematic literature research (SLR) was conducted in Medline, EMBASE, Cochrane Library, clinicaltrials.gov from their inception date to May 2022, and in the EULAR/ACR abstract database (2019-2021). Randomised clinical trials (RCTs) and non-randomised interventional studies published in English and answering at least one of the eleven PICO questions on T2T strategies, treatment targets and outcomes, framed by the taskforce, were identified. Study selection process, data extraction and risk of bias assessment were conducted independently by two investigators.

RESULTS

Of 7809 screened abstracts, 397 were selected for detailed review and 76 manuscripts were finally included (31 RCTs, eight subgroup/exploratory analyses of RCTs and 37 non-randomised interventional studies). No study comparing a T2T strategy against standard of care was identified. In PMR RCTs, the most frequently applied outcomes concerned treatment (90.9% of RCTs), particularly the cumulative glucocorticoids (GC) dose and GC tapering, followed by clinical, laboratory and safety outcomes (63.3% each). Conversely, the most commonly reported outcomes in RCTs in GCA were prevention of relapses (72.2%), remission as well as treatment-related and safety outcomes (67.0% each).

CONCLUSIONS

This SLR provides evidence and highlights the knowledge gaps on T2T strategies in PMR and GCA, informing the task force developing T2T recommendations for these diseases.

Human leucocyte antigens and Japanese patients with polymyalgia rheumatica: the protective effect of DRB1*09:01

OBJECTIVE

The hallmarks of the chronic inflammatory disease polymyalgia rheumatica (PMR) include pain, and morning stiffness in areas of the neck, shoulder and pelvic girdle. The human leucocyte antigen (HLA) gene was reported to be an important risk factor for PMR, but it has not been analysed precisely, especially in populations other than Europeans.

METHODS

Genotyping of DRB1 and DQB1 was performed in Japanese PMR patients (n=270) and controls (n=413). Associations between allele carrier and genotype frequencies were determined for PMR.

RESULTS

DRB1*04:05 was associated with a predisposition to PMR (p=0.0006, Pc=0.0193, OR 1.85, 95% CI 1.31 to 2.62). DRB1*09:01 was associated with protection against PMR (p=1.46×10-5, Pc=0.0004, OR 0.40, 95% CI 0.26 to 0.61). A shared epitope (SE) associated with PMR (p=3.07×10-6, OR 2.11, 95% CI 1.54 to 2.88). DQB1*03:03 (p=0.0010, Pc=0.0140, OR 0.52, 95% CI 0.35 to 0.77) was associated with protection against PMR and DQB1*04:01 (p=0.0009, Pc=0.0140, OR 1.82, 95% CI 1.28 to 2.58) was associated with predisposition to PMR. A gene dosage effect was observed for DRB1*09:01 and DQB1*03:03, but not for DRB1*04:05, SE or DQB1*04:01. Haplotype and logistic regression analyses suggested a protective effect for DRB1*09:01.

CONCLUSION

This study is the first to demonstrate predisposing associations of DRB1*04:05, SE, and DQB1*04:01, and protective associations of DRB1*09:01 and DQB1*03:03 with PMR in Japanese patients. Our data indicate HLA has predisposing and protective effects on the pathogenesis of PMR.

Decoding polymyalgia rheumatica, the role of Nuclear Medicine Imaging

Polymyalgia rheumatica (PMR) is an inflammatory joint disease that presents in patients older than 50 years with prolonged morning pain and stiffness in the shoulder and hip joints and neck. The lack of specific clinical findings, laboratory signs, biomarkers and established imaging methods makes it difficult to diagnose patients with this disease. 18F-FDG PET/CT is a functional imaging technique that is an established tool in oncology and has also proven useful in the field of inflammatory diseases. The aim of this paper is to present literature evidence on the use of molecular imaging methods such as PET/CT for early diagnosis, assessment of disease activity and therapeutic response in PMR. At the same time, the advantages, disadvantages and contraindications of other methods are considered.

Differential diagnostics of polymyalgia rheumatica in a university hospital in Finland

OBJECTIVES

Diagnosing polymyalgia rheumatica (PMR) can be difficult as many conditions present with similar symptoms and findings. This study aimed to analyse how often the diagnosis of PMR changes during follow-up in a university hospital setting and to determine the most common clinical conditions initially misdiagnosed as PMR.

METHOD

All patients with a new primary diagnosis of PMR on at least one visit during the years 2016-2019 were identified from the hospital discharge register of Turku University Hospital, Finland. A diagnosis of PMR was confirmed if the patient met at least one of the five classification criteria, complete clinical follow-up (median 34 months) was compatible with PMR, and no other diagnosis better explained their condition.

RESULTS

Of the patients initially diagnosed with PMR, 65.5% were considered to have PMR after further evaluation and clinical follow-up. The most common conditions initially diagnosed as PMR were inflammatory arthritides (34.9%), degenerative or stress-related musculoskeletal disorders (13.2%), infection (9.3%), malignancy (9.3%), giant cell vasculitis (6.2%) and other vasculitis (6.2%), and a wide range of other less common diseases. The diagnosis of PMR remained in 81.3% of patients who fulfilled the 2012 American College of Rheumatology/European League Against Rheumatism PMR classification criteria and in 45.5% of patients who did not.

CONCLUSIONS

Diagnosing PMR is challenging, even in a university hospital. One-third of the initial diagnoses of PMR changed during further evaluation and follow-up. There is a substantial risk of misdiagnosis, especially in patients with atypical presentation, and the differential diagnoses of PMR must be considered carefully.

Water vapor therapy and polymyalgia rheumatica: Coincidental?

Polymyalgia rheumatica (PMR) is an inflammatory rheumatic condition characterized by pain and stiffness around the shoulders and hip girdles, an elevated erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP) and a dramatic response to corticosteroids. It is usually seen in adults aged over 50 years; about 30% also have giant cell arteritis. Its etiology is unknown. A 72-year-old male received water vapor therapy, a novel, minimally invasive therapy for benign prostate hypertrophy (BPH). On postoperative day 1, he developed severe shoulder pain and weakness, with difficulty with lifting his arms above his head, and hip pain and weakness, with difficulty getting out of a bed or chair. Laboratory results showed elevated ESR and CRP, but a normal creatine kinase level. The patient received low-dose prednisone and had prompt symptom relief. This case illustrates that a diagnosis of PMR after water vapor therapy can be easily overlooked.

Assessing the feasibility of SUVindex (a metric derived from FDG PET/CT) for the diagnosis of polymyalgia rheumatica

AIM

To evaluate the feasibility of standard uptake value (SUV) index (ratio lesional maximum SUV [SUVmax] to liver mean SUV [SUVmean]) as a metabolic parameter for diagnosing polymyalgia rheumatica (PMR).

MATERIALS AND METHODS

A retrospective group of patients with PMR and controls with symptoms similar to PMR but diagnosed with other diseases. Semiquantitative and qualitative analysis of 2-[18F]-fluoro-2-deoxy-d-glucose (18F-FDG) uptake at 18 sites was undertaken for all patients. The diagnostic value of positron-emission tomography/computed tomography (PET/CT) for PMR was assessed by R software using logistic regression and a generalised additive model (GAM). All images were examined independently by two nuclear medicine physicians with extensive work experience.

RESULTS

The characteristic sites of PMR were the ischial tuberosity, interspinous bursa, periarticular hip, and symphysis pubis enthesis. The area under the curve (AUC) of the characteristic site SUV index was 0.930, and the best cut-off value was 1.685 with a sensitivity of 84.6% and a specificity of 92.6%. After adjusting for potential confounders, the probability of PMR diagnosis increased as the characteristic site SUV index increased and there was a nonlinear correlation between the two. When the characteristic site SUV index was ≥2.56, the probability of PMR gradually reached the threshold effect, which was as high as 90% or more.

CONCLUSION

The characteristic site SUV index is an independent factor for diagnosing PMR, and PMR should be highly suspected when it is ≥ 1.685. Nonetheless, it is important to note that these findings are based on an initial retrospective single-centre study and require external validation and further prospective evaluation before being translated into clinical practice.

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

Objectives

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

Methods

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

Results

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

Conclusion

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

New-Onset Polymyalgia Rheumatica Complicated by Giant Cell Arteritis Following COVID-19 Infection

A 68-year-old female with a past medical history significant for tophaceous gout presented with pain and stiffness in her bilateral shoulders and hip joints for about two weeks after testing positive for COVID-19. Her laboratory results showed an elevated erythrocyte sedimentation rate (ESR) of 74 mm/h and C-reactive protein (CRP) of 25 mg/L. She showed clinical improvement in her symptoms after steroid therapy and was diagnosed with polymyalgia rheumatica (PMR). Despite prompt treatment with steroids, she continued to have persistent joint pain. Also, she developed new bilateral temporal artery tenderness, headaches, blurry vision, and jaw claudication concerning giant cell arteritis (GCA). She was admitted to the hospital for high-dose pulsed IV methylprednisolone and discharged with a steroid taper along with tocilizumab injections. Her symptoms improved rapidly, and she continued to follow up with rheumatology while continuing low-maintenance doses of prednisone. Although the association between PMR and GCA is well-known, the time it takes to reach disease remission, the rate of relapse, and the length of steroid treatment are variable. There are a few COVID-19-associated cases of PMR and GCA; however, the timeline and pathophysiology of this association remain an area for further investigation.

Polymyalgia Rheumatica Originally Thought to Be Cervical Spinal Stenosis

Polymyalgia rheumatica (PMR) is an inflammatory condition that causes joint pain and stiffness. This case report describes an atypical presentation of PMR that was initially misdiagnosed as cervical spinal stenosis, leading to surgery before correctly being diagnosed with PMR. Because of an absence of specific diagnostic tests and a presentation of symptoms that often overlap with other conditions, PMR can be difficult to diagnose. This case highlights the importance of clinical evaluation and awareness of PMR's clinical features to prevent unnecessary interventions and ensure appropriate management.

JAK inhibitors and black box warnings: what is the future for JAK inhibitors?

INTRODUCTION

Janus kinase inhibitors (JAKi) have dramatically improved the treatment of various autoimmune and myeloproliferative disorders. Recently, concern has arisen regarding their safety in patients with rheumatoid arthritis.

AREAS COVERED

Here, we provide a comprehensive summary of the major current and emerging JAKi and their indications, address recent studies on comparative safety, and provide insight into their future and use. We emphasize that the application of the research findings on a case-by-case basis should consider a patient's age, comorbidities, disease for which JAKi is being considered, disease activity, the JAKi target(s), alternate treatment options available for the patient, and the planned duration of JAKi.

EXPERT OPINION

Rheumatologists are used to prescribing therapies in which a risk-to-benefit assessment is required as well as to screening and monitoring the safety of medications. Thus, rheumatologists are already practiced in applying specific criteria to effectively screen and monitor patients who are candidates for JAKi therapy. Ongoing research will help to clarify any mechanisms underlying differential safety signals between JAK and other therapies, what the balance between risk and efficacy is, who the susceptible subpopulations are, and whether safety signals are shared between different JAKis and across indications.

Effects of Whole-Body Cryostimulation on Pain Management and Disease Activity in Active Rheumatic Polymyalgia: A Case-Report

Polymyalgia rheumatica (PMR) is the most common inflammatory rheumatic disease among people over 50 and occurs with symptoms such as musculoskeletal pain and stiffness in the neck, shoulders, and hips. To date, corticosteroids represent the cornerstone of PMR treatment. However, it is well known that their prolonged use is associated with several adverse effects, making it crucial to find therapeutic alternatives. The purpose of this case report was to describe the effectiveness of 10 whole-body cryostimulation (WBC) sessions on a 74-year-old woman suffering from PMR. An improvement in disease impact, fatigue, pain, quality of sleep, and total physical activity was observed after WBC. Moreover, the patient reduced her daily drug intake by 67% following WBC treatments. Given the increasing prevalence of PMR and considering the side effects that drug treatments can lead to, WBC could represent a valuable adjuvant and well-tolerated alternative for treating PMR.

[Methods for assessment of disease activity of polymyalgia rheumatica]

Polymyalgia rheumatica (PMR) is the second most frequent inflammatory rheumatic disease in old age. Remission and recurrence are frequently used as endpoints in clinical trials; however, there is as yet no international consensus on the definition of these states, which limits the comparability of published studies. The PMR activity score (PMR-AS) is the only composite score specifically developed for PMR, which together with remission is used to define low, middle and high disease activity. In recent studies the PMR-AS was often used and low disease activity was established as endpoint. The most important limitation of the PMR-AS is the potential influence of the individual variables by comorbidities. The value of C‑reactive protein (CRP) and the erythrocyte sedimentation rate (ESR) are of restricted value in studies using drugs that influence the interleukin 6 (IL-6) axis. In these cases, calprotectin and osteopontin are promising alternative biomarkers, as they have already been shown to reflect disease activity independently of CRP in rheumatoid arthritis. Furthermore, imaging modalities including sonography, magnetic resonance imaging and fluorodeoxyglucose (FDG) positron emission tomography could also be helpful in monitoring disease activity; however, these techniques must first be validated in further studies. The PMR impact scale (PMR-IS) is a composite score to assess the impact of PMR on the patients; however, it has not yet been used in clinical studies. The development of additional patient reported outcomes (PRO) for PMR and the definition of standardized criteria for documentation of remission and recurrence are important questions in the future research agenda for PMR.

Rheumatic Immune-Related Adverse Events due to Immune Checkpoint Inhibitors—A 2023 Update

With the aging of the population, malignancies are becoming common complications in patients with rheumatoid arthritis (RA), particularly in elderly patients. Such malignancies often interfere with RA treatment. Among several therapeutic agents, immune checkpoint inhibitors (ICIs) which antagonize immunological brakes on T lymphocytes have emerged as a promising treatment option for a variety of malignancies. In parallel, evidence has accumulated that ICIs are associated with numerous immune-related adverse events (irAEs), such as hypophysitis, myocarditis, pneumonitis, and colitis. Moreover, ICIs not only exacerbate pre-existing autoimmune diseases, but also cause de novo rheumatic disease–like symptoms, such as arthritis, myositis, and vasculitis, which are currently termed rheumatic irAEs. Rheumatic irAEs differ from classical rheumatic diseases in multiple aspects, and treatment should be individualized based on the severity. Close collaboration with oncologists is critical for preventing irreversible organ damage. This review summarizes the current evidence regarding the mechanisms and management of rheumatic irAEs with focus on arthritis, myositis, and vasculitis. Based on these findings, potential therapeutic strategies against rheumatic irAEs are discussed.

Challenges in the diagnosis of polymyalgia rheumatica and related giant cell arteritis

INTRODUCTION

Polymyalgia rheumatica (PMR) has emerged as a relatively common condition in Western countries. Although the diagnosis is relatively straightforward in people over 50 years of age who complain of sudden onset of pain and stiffness in the shoulder and hip girdles along with elevation of biomarkers of inflammation, manifestations of polymyalgia can also occur in the context of different conditions. For this reason, a complete history and examination is required, including looking for symptoms and signs suggestive of giant cell arteritis (GCA).

AREAS COVERED

The review describes when and how to identify PMR, as well as when to suspect the presence of associated GCA or multiple conditions mimicking PMR.

EXPERT OPINION

PMR does not have a specific diagnostic test. For this reason, a thorough clinical history searching for clinical data of GCA is needed. Moreover, the possibility of other diseases mimicking PMR should be considered, particularly when atypical presentation or unusual clinical data are present.

Elderly-onset rheumatoid arthritis vs. polymyalgia rheumatica: Differences in pathogenesis

Rheumatoid arthritis is a chronic autoimmune disease that mainly affects the facet joints. Elderly-onset rheumatoid arthritis appears to exhibit symptoms similar to those of polymyalgia rheumatica, characterized by morning stiffness and pain in the shoulder and hip joints. Both diseases develop in the elderly, and it is sometimes challenging to distinguish them. Here, we identify the differences in pathogenesis between elderly-onset rheumatoid arthritis and polymyalgia rheumatica to assist with a clear differential diagnosis and effective early intervention.

Concurrent baseline diagnosis of giant cell arteritis and polymyalgia rheumatica - A systematic review and meta-analysis

INTRODUCTION

Giant cell arteritis (GCA) and polymyalgia rheumatica (PMR) can be concurrent diseases. We aimed to estimate the point-prevalence of concurrent GCA and PMR. Additionally, an incidence rate (IR) of GCA presenting after PMR diagnosis in patients was estimated.

METHODS

Two authors performed a systematic literature search, data extraction and risk of bias assessment independently. Studies assessing cohorts of patients presenting with both GCA and PMR were included. The outcomes were point-prevalence of concurrent GCA and PMR and IR for development of GCA after PMR diagnosis. A meta-analysis was performed to calculate a pooled prevalence of concurrent PMR and GCA.

RESULTS

We identified 29 studies investigating concurrent GCA and PMR. Only two studies applied imaging systematically to diagnose GCA and none to diagnose PMR. GCA presenting after PMR diagnosis was assessed in 12 studies but imaging was not applied systematically. The point-prevalence of concurrent GCA present at PMR diagnosis ranged from 6%-66%. The pooled estimate of the point-prevalence from the meta-analysis was 22%. The point-prevalence of PMR present at GCA diagnosis ranged from 16%-65%. The pooled estimate of the point-prevalence from the meta-analysis was 42%. The IR ranged between 2-78 cases of GCA presenting after PMR per 1000 person-years.

CONCLUSION

This review and meta-analysis support that concurrent GCA and PMR is frequently present at the time of diagnosis. Additionally, we present the current evidence of GCA presenting in patients after PMR diagnosis. These results emphasize the need for studies applying imaging modalities to diagnose GCA.