Polymyalgia rheumatica: an autoinflammatory disorder?

Polymyalgia Rheumatica Following Influenza B Infection: A Case Report

We describe a case of polymyalgia rheumatica (PMR) following an influenza B infection. The patient was a 71-year-old woman who developed a fever above 38.0°C and was diagnosed with influenza B, confirmed by a rapid antigen test. Although the fever resolved after three days, she continued to experience neck pain, back pain, and joint pain, particularly in both shoulders and hips. She also reported morning joint stiffness lasting for more than an hour and occasional low-grade fever. She presented to our hospital 25 days after the onset of symptoms. Blood tests revealed elevated C-reactive protein and erythrocyte sedimentation rate, but levels of creatine phosphokinase, rheumatoid factor, and anti-cyclic citrullinated peptide were not elevated. She was diagnosed with PMR and treated with prednisolone (PSL) 15 mg/day. The response to steroids was remarkably good, and PSL was tapered over six months. PMR is believed to result from an immune-mediated process and may be associated with certain human leukocyte antigen haplotypes. Additionally, PMR is sometimes preceded by an infection. To date, there have been very few reports suggesting a connection between influenza B and PMR, underscoring the need for further case accumulation.

MRI of shoulder girdle in polymyalgia rheumatica: inflammatory findings and their diagnostic value

BACKGROUND

Non-synovial inflammation as detected by MRI is characteristic in polymyalgia rheumatica (PMR) with potentially high diagnostic value.

OBJECTIVE

The objective is to describe inflammatory MRI findings in the shoulder girdle of patients with PMR and discriminate from other causes of shoulder girdle pain.

METHODS

Retrospective study of 496 contrast-enhanced MRI scans of the shoulder girdle from 122 PMR patients and 374 non-PMR cases. Two radiologists blinded to clinical and demographic information evaluated inflammation at six non-synovial plus three synovial sites for the presence or absence of inflammation. The prevalence of synovial and non-synovial inflammation, both alone and together with clinical information, was tested for its ability to differentiate PMR from non-PMR.

RESULTS

A high prevalence of non-synovial inflammation was identified as striking imaging finding in PMR, in average 3.4±1.7, mean (M)±SD, out of the six predefined sites were inflamed compared with 1.1±1.4 (M±SD) in non-PMR group, p<0.001, with excellent discriminatory effect between PMR patients and non-PMR cases. The prevalence of synovitis also differed significantly between PMR patients and non-PMR cases, 2.5±0.8 (M±SD) vs 1.9±1.1 (M±SD) out of three predefined synovial sites, but with an inferior discriminatory effect. The detection of inflammation at three out of six predefined non-synovial sites differentiated PMR patients from controls with a sensitivity/specificity of 73.8%/85.8% and overall better performance than detection of synovitis alone (sensitivity/specificity of 86.1%/36.1%, respectively).

CONCLUSION

Contrast-enhanced MRI of the shoulder girdle is a reliable imaging tool with significant diagnostic value in the assessment of patients suffering from PMR and differentiation to other conditions for shoulder girdle pain.

The contributions of deleterious rare alleles in NLRP12 and inflammasome-related genes to polymyalgia rheumatica

Polymyalgia rheumatica (PMR) is a chronic inflammatory disease characterized by arthralgia and myalgia of the shoulder and hip girdles, and fever. PMR is linked to autoimmune diseases and autoinflammatory disorders. Exome sequencing has revealed the roles of rare variants in some diseases. Causative genes for monogenic autoinflammatory disorders might be candidate genes for the selective exome analysis of PMR. We investigated rare variants in the coding and boundary regions of candidate genes for PMR. Exome sequencing was performed to analyze deleterious rare variants in candidate genes, and the frequencies of the deleterious rare alleles in PMR were compared with those of Japanese population controls. Deleterious rare alleles in the NLRL12 gene were associated with PMR (P = 0.0069, Pc = 0.0415, odds ratio [OR] 4.49, 95% confidence interval [CI] 1.79-11.27). A multigene analysis demonstrated the deleterious rare allele frequency of the candidate genes for autoinflammatory disorders was also increased in PMR (P = 0.0016, OR 3.69, 95%CI 1.81-7.54). The deleterious rare allele frequencies of the candidate genes including NLRP12 were increased in PMR patients, showing links to autoinflammatory disorders in the pathogenesis of PMR.

Polymyalgia rheumatica: An update (Review)

Polymyalgia rheumatica (PMR) is a chronic inflammatory disease which affects the connective vascular tissue, characterized by pain accompanied by morning stiffness, predominantly of the neck muscles, hip and shoulder girdle. Usually, patients with this disease are >50 years of age and biological inflammatory syndrome is present with an increase in both the erythrocyte sedimentation rate and C-reactive protein levels, aspects similar to giant cell arteritis. The aim of the present review was to depict the current pathogenic hypothesis, diagnostic and treatment approach for patients with PMR, and novelties since the development of the currently used 2012 European League Against Rheumatism and American College of Rheumatology provisional classification criteria. PMR is a prevalent disease that can occasionally prove difficult to diagnose and treat. Possibly, the most abundant type of evidence and data revealed over the past decade have been acquired through musculoskeletal imaging, with implications in diagnosis, disease monitoring and relapse, prognosis and changes with treatment. Further research on pathophysiology is required to gain a deeper understanding of the underlying processes, which will serve as the foundation for future personalized treatments. In addition, there is an increasing demand for improved diagnostic techniques, which should include a further development of various imaging modalities, in order to provide accurate diagnosis and appropriate therapy.

A Case Series on the COVID-19 Vaccines and Possible Immune-Related Adverse Events: A New Challenge for the Rheumatologists

The COVID-19 pandemic has been a prime health issue since December 2019. Consequently, there has been an urgent need to prevent severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) infection and its associated morbidity and mortality. The currently available vaccines are designed to prevent infection. Their efficacy and safety have been demonstrated in clinical trials. Yet, given the short duration of the trials and the urgency to start vaccination, adverse events have been reported worldwide in real-life data format. Immune-mediated disease flares or new-onset inflammatory diseases following vaccine administration have recently been reported worldwide. Here, we present three cases of inflammatory arthritis (IA) caused by the BNT162b2 COVID vaccination, including two new-onset cases and one case of a flare of existing disease. The first case is new-onset IA, the second case is new-onset rheumatoid arthritis, and the third case is a flare of existing rheumatoid arthritis. Given the timeline of when our patients developed either a flare of their existing rheumatoid arthritis or new-onset IA or polymyalgia rheumatica (PMR) (a few days after receiving the COVID-19 vaccine), in addition to the currently available evidence of documented similar cases post administration of mRNA vaccines, as well as the link between their mechanism of action and the pathogenesis of those diseases, we can speculate a causal relationship between the vaccine and the triggering of these disease entities. In the future, it is important to consider that autoimmune diseases might be triggered or flared by the administration of vaccines, which appears to be associated with the COVID vaccine as well. Further evaluation of its incidence will provide additional clarity, though the rarity of this occurrence in the setting of more than half of the US population becoming vaccinated indicates that the benefit of the vaccine in terms of protection from COVID morbidity and mortality far outweighs this risk.

RSЗPE Syndrome: Autoinflammatory Features of a Rare Disorder

Remitting seronegative symmetrical synovitis with pitting edema (RSЗPE) syndrome was first described by McCarty in 1985 and is characterized by pitting edema and an acute symmetrical synovitis of small joints. Self-directed inflammation in autoimmune disorders is caused by an abnormal activation of the adaptive immune system, while in autoinflammatory disorders is due to aberrant activation of the innate immune system without autoantibodies or autoreactive T cells. The role of autoimmunity in the pathogenesis of RSЗPE syndrome is suggested by possible associations with some autoimmune diseases and HLA haplotypes. However, several other features point to a possible role of autoinflammation in RSЗPE syndrome. In this review, the relative contributions of both innate and adaptive immune systems to the pathogenesis of RSЗPE syndrome are discussed.

Immune system activation in polymyalgia rheumatica: Which balance between autoinflammation and autoimmunity? A systematic review

BACKGROUND AND AIM

Polymyalgia rheumatica (PMR) is an inflammatory rheumatic disease that is common in elderly people. Its classification in the spectrum of autoinflammatory and autoimmune diseases is difficult because of its only partially understood immune-mediated mechanisms. The literature concerning the innate and adaptive immune system activation in PMR was systematically reviewed highlighting the relative weight of autoinflammation and autoimmunity in its pathogenesis and disease progression.

METHODS

A literature search on PubMed Central and Embase scientific databases was performed by two independent reviewers. To be eligible, the studies needed to fully satisfy our initial PICO framework: a primary diagnosis of PMR as a population, the search for immune/inflammatory cells, cytokines and autoantibodies as an intervention, a control group consisting in healthy controls, patients with other inflammatory rheumatic diseases or PMR patients in remission after treatment and as outcomes the results of the investigations in the analyzed tissue samples. The most relevant data of the included papers were extracted by using a standardized template.

RESULTS

Of the 933 screened abstracts, 52 papers were included in the systematic review and categorized depending on their primary research objectives. The hyper-activity of neutrophils and monocytes, expressing toll-like receptor 7 in active disease, an impaired phagocytosis and endothelial dysfunction, as well as an increased count of innate T cells in patients with remission emerged among the major derangements of the innate immune response in PMR. Among the cytokines profile, interleukin-6 plays a key role but other pro-inflammatory mediators and angiogenesis markers such as chemokines, B-cell activating factor, vascular endothelial growth factor and angiopoietins seem to be involved in refractory or glucocorticoid-resistant PMR. The aberrant adaptive immune response was documented by tissue and serum findings of polarized T cells towards T helper 1 and 17 phenotypes, an increased expression of immunosenescent surface markers and a downregulated immunoregulatory response. The altered distribution of peripheral B cells, detected during active disease, suggested their peripheral migration towards unidentified sites. The interaction between innate and adaptive immune response was documented by a synovial infiltrate of macrophages and T cells. Despite multiple autoantibodies have been detected in PMR patients, none proved to correlate with disease activity seeming to be reactive to the marked inflammation or antigenic determinants provided by environmental triggers or tissue/cell damage.

CONCLUSIONS

The complex network between innate and adaptive immune system in PMR is supported by findings at molecular and cellular levels. By considering both the ends of the pathophysiological spectrum of immune-mediated rheumatic diseases, PMR may be regarded as an inflammatory immune-mediated disease with mixed mechanisms in a background of genetic and epigenetic factors together with immunological and endocrine senescence.

Long-term glucocorticoid treatment and high relapse rate remain unresolved issues in the real-life management of polymyalgia rheumatica: a systematic literature review and meta-analysis

A systematic review and meta-analysis were conducted, according to the PRISMA methodology, to summarize current evidence on the prevalence and predictors of long-term glucocorticoid (GC) treatment and disease relapses in the real-life management of polymyalgia rheumatica (PMR).

Out of 5442 retrieved studies, 21 were eligible for meta-analysis and 24 for qualitative analysis. The pooled proportions of patients still taking GCs at 1, 2, and 5 years were respectively 77% (95%CI 71–83%), 51% (95%CI 41–61%), and 25% (95CI% 15–36%). No significant difference was recorded by distinguishing study cohorts recruited before and after the issue of the international recommendations in 2010. The pooled proportion of patients experiencing at least one relapse at 1 year from treatment initiation was 43% (95%CI 29–56%). Female gender, acute-phase reactants levels, peripheral arthritis, starting GCs dosage, and tapering speed were the most frequently investigated potential predictors of prolonged GC treatment and relapse, but with inconsistent results. Only a few studies and with conflicting results evaluated the potential role of early treatment with methotrexate in reducing the GC exposure and the risk of relapse in PMR.

This study showed that a high rate of prolonged GC treatment is still recorded in the management of PMR. The relapse rate, even remarkable, can only partially explain the long-term GC treatment, suggesting that other and not yet identified factors may be involved. Additional research is needed to profile patients with a higher risk of long-term GC treatment and relapse and identify more effective steroid-sparing strategies.

Key Points: • High rate of long-term glucocorticoid (GC) treatment is recorded in polymyalgia rheumatica (PMR), being 77%, 51%, and 25% of patients still on GCs after respectively 1, 2, and 5 years. • A pooled relapse rate of 43% at 1 year, even remarkable, can only partially explain the long-term GC treatment in PMR. • Several studies have attempted to identify potential predictors of prolonged treatment with GCs and relapse, but with inconsistent results. • Additional research is needed to profile patients with a higher risk of long-term GC treatment and relapse and identify more effective steroid-sparing strategies.

Inflammatory Markers are Quickly Improved by Tocilizumab in Early Polymyalgia Rheumatica and Might Predict Early Response to Interleukin-6 Blockade

INTRODUCTION

It is unclear whether polymyalgia rheumatica (PMR) should be considered an inflammatory disease or an autoimmune disease.

METHODS

Eighteen untreated early PMR patients and 18 sex- and age-matched healthy controls (HCs) were included. PMR patients received tocilizumab from week 0 to week 12 and glucocorticoids from week 12 to week 24. Leukocytes, neutrophils, platelets, hemoglobin, γ-globulins, IgG, IgA, and IgM were compared between the PMR patients and HCs and before and after tocilizumab treatment in the PMR group.

RESULTS

The mean age was 68 ± 7 and 66 ± 11 years, and the mean serum C-reactive protein level was 82 ± 16 and 5 ± 2 mg/l for PMR patients and HCs, respectively. At inclusion, leukocytes (p < 0.0001), neutrophils (p < 0.0001), and platelets (p < 0.0001) were increased and hemoglobin (p < 0.0001) decreased in the PMR group compared to the HC group. After tocilizumab therapy, leukocytes, neutrophils, and platelets decreased, and hemoglobin increased. At inclusion, all four parameters were significantly associated with the serum IL-6 level, though it was not associated after tocilizumab therapy. Levels of γ-globulin were increased in the PMR patients compared to HCs (p = 0.0087), and PMR patients with γ-globulins levels over 11 g/l at inclusion responded more quickly to tocilizumab therapy. Autoantibody profiles did not differ between the PMR patients and HCs.

CONCLUSIONS

This study suggests that PMR is more an inflammatory disease than an autoimmune disease. Tocilizumab improves all markers of inflammation. Patients with elevated γ-globulins respond more quickly to tocilizumab.

Somatic Mutations and the Risk of Undifferentiated Autoinflammatory Disease in MDS: An Under-Recognized but Prognostically Important Complication

Objectives: We theorized that myelodysplastic syndrome (MDS) with somatic mutations and karyotype abnormalities are associated with autoinflammation, and that the presence of autoinflammatory disease affected prognosis in MDS. Methods: One hundred thirty-four MDS patients were assessed for the prevalence of autoinflammatory complications and its link with karyotypes and somatic mutation status. Autoinflammatory complications were described either as well-defined autoinflammatory diseases (AD) or undifferentiated "autoinflammatory disease" (UAD) (defined as CRP over 10.0 mg/L on five consecutive occasions, taken at separate times and not explained by infection). Several patient characteristics including demographic, clinical, laboratory, cytogenetics charts, and outcomes, were compared between different groups. Results: Sixty-two (46.3%) patients had an autoinflammatory complication manifesting as arthralgia (43.5% vs. 23.6%, p = 0.0146), arthritis (30.6% vs. 15.3%, p = 0.0340), skin rash (27.4% vs. 12.5%, p = 0.0301), pleuritis (14.5% vs. 4.2%, p = 0.0371) and unexplained fever (27.4% vs. 0%, p < 0.0001). AD were found in 7.4% of MDS patients (with polymyalgia rheumatic being the most frequently one). Classical autoimmune diseases were found only in 4 MDS patients (3.0%). Transcription factor pathway mutations (RUNX1, BCOR, WTI, TP53) (OR 2.20 [95%CI 1.02-4.75], p = 0.0451) and abnormal karyotypes (OR 2.76 [95%CI 1.22-6.26], p = 0.0153) were associated with autoinflammatory complications. Acute leukaemic transformation was more frequent in MDS patients with autoinflammatory features than those without (27.4% vs. 9.7%, p = 0.0080). Conclusions: Autoinflammatory complications are common in MDS. Somatic mutations of transcription factor pathways and abnormal karyotypes are associated with greater risk of autoinflammatory complications, which are themselves linked to malignant transformation and a worse prognosis.

Comorbidities in patients with polymyalgia rheumatica prior to and following diagnosis: A case control and cohort study

OBJECTIVES

To determine the burden of comorbidities, including glucocorticoid (GC) related adverse effects, in patients with polymyalgia rheumatica (PMR) before and after diagnosis.

METHODS

We extracted anonymised electronic medical records of patients over the age of 40 years from the Clinical Practice Research Datalink from 1990-2016. Patients with PMR were individually matched on age, sex and registered General Practice to between three and five controls. The prevalence, cumulative probability and likelihood of a range of comorbidities was estimated. Odds ratios (ORs) and hazard ratios (HRs) were calculated using conditional logistic regression and Cox proportional hazards regression respectively, adjusted for a wide range of covariates.

RESULTS

31,984 patients with PMR were matched to 149,436 controls. PMR was prospectively associated with vascular disease (adjusted HR 1.23 [95% confidence interval (CI) 1.19, 1.28]), as well as respiratory (HR 1.25 [1.18, 1.32]), renal (HR 1.34 [1.30, 1.39]), and autoimmune diseases (HR 4.68 [4.35, 5.03]). Conversely, before PMR diagnosis, the risk of cancer (adjusted OR [OR] 0.89 [0.86, 0.93]) and neurological disease (OR 0.36 [0.33, 0.40]) was significantly lower. Patients with PMR had an increased risk of comorbidities associated with glucocorticoid (GC) use.

CONCLUSIONS

Patients with PMR have a high comorbidity burden, both before and after diagnosis. Whilst further work is needed to more fully understand these associations, clinicians should be aware of the high prevalence of comorbid conditions in this group and the impact that treatment with glucocorticoids may have on comorbidity.

Comorbidities in polymyalgia rheumatica: a systematic review

BACKGROUND AND AIM

Comorbidities are known to exist in many rheumatological conditions. Polymyalgia rheumatica (PMR) is a common inflammatory rheumatological condition affecting older people which, prior to effective treatment, causes severe disability. Our understanding of associated comorbidities in PMR is based only on case reports or series and small cohort studies. The objective of this study is to review systematically the existing literature on the comorbidities associated with PMR.

METHODS

MEDLINE, EMBASE, PsycINFO and CINAHL databases were searched for original observational research from inception to November 2016. Papers containing the words 'Polymyalgia Rheumatica' OR 'Giant Cell Arteritis' OR the terms 'PMR' OR 'GCA' were included. Article titles were reviewed based on pre-defined criteria by two reviewers. Following selection for inclusion, studies were quality assessed using the Newcastle-Ottawa tool and data were extracted.

RESULTS

A total of 17,329 papers were reviewed and 41 were incorporated in this review, including three published after the search took place. Wide variations were found in study design, comorbidities reported and populations studied. Positive associations were found between PMR diagnosis and stroke, cardiovascular disease, peripheral arterial disease, diverticular disease and hypothyroidism. Two studies reported a positive association between PMR and overall malignancy rate. Seven studies reported an association between PMR and specific types of cancer, such as leukaemia, lymphoma, myeloproliferative disease and specified solid tumours, although nine studies found either no or negative association between cancer and PMR.

CONCLUSION

Quantification of the prevalence of comorbidities in PMR is important to accurately plan service provision and enable identification of cases of PMR which may be more difficult to treat. This review highlights that research into comorbidities in PMR is, overall, methodologically inadequate and does not comprehensively cover all comorbidities. Future studies should consider a range of comorbidities in patients with a validated diagnosis of PMR in representative populations.

Mechanistic immunological based classification of rheumatoid arthritis

The classical autoimmunity paradigm in rheumatoid arthritis (RA) is strongly supported by immunogenetics suggesting follicular helper T-cell responses driving high titre specific autoantibodies that pre-dates disease onset. Using the immunological disease continuum model of inflammation against self with "pure" adaptive and innate immune disease at opposite boundaries, we propose a novel immune mechanistic classification describing the heterogeneity within RA. Mutations or SNPs in autoinflammatory genes including MEFV and NOD2 are linked to seronegative RA phenotypes including some so called palindromic RA cases. However, just as innate and adaptive immunity are closely functionally integrated, some ACPA+ RA cases have superimposed "autoinflammatory" features including abrupt onset attacks, severe attacks, self-limiting attacks, relevant autoinflammatory mutations or SNPs and therapeutic responses to autoinflammatory pathway therapies including colchicine and IL-1 pathway blockade. An emergent feature from this classification that non-destructive RA phenotypes, both innate and adaptive, have disease epicentres situated in the extracapsular tissues. This mixed innate and adaptive immunopathogenesis may be the key to understanding severe disease flares, resistant disease subsets that are unresponsive to standard therapy and for therapies that target the autoinflammatory component of disease that are not currently considered by expert therapeutic recommendations.