Rarity of synovitis in polymyalgia rheumatica

Diagnostic value of 18F-fluorodeoxyglucose positron emission tomography and computed tomography for differentiating polymyalgia rheumatica and rheumatoid arthritis: Using classification and regression tree analysis

OBJECTIVES

Determining which sites were important to differentiate polymyalgia rheumatica (PMR) from rheumatoid arthritis (RA) using 18F-fluorodeoxyglucose (FDG) positron emission tomography and computed tomography (PET-CT) is challenging.

METHODS

Patients with PMR or RA who were undergoing PET-CT were recruited at two mutual-aid hospitals in Japan between 2009 and 2018. Classification and regression tree (CART) analyses were performed to identify FDG uptake patterns that differentiated PMR from RA.

RESULTS

We enrolled 35 patients with PMR and 46 patients with RA. Univariate CART analysis showed that FDG uptake in the shoulder joints, spinous processes of the lumbar vertebrae, pubic symphysis, sternoclavicular joints, ischial tuberosities, greater trochanters, and hip joints differentiated PMR from RA. Multivariate CART analysis revealed that FDG uptake by at least one of the ischial tuberosities had the highest diagnostic value for distinguishing PMR from RA (sensitivity, 77.1%; specificity, 82.6%). We performed the same CART analysis to patients who had not undergone treatment (PMR, n = 28; RA, n = 9). Similar results were obtained, and sensitivity and specificity were increased (sensitivity, 89.3%; specificity, 88.8%).

CONCLUSIONS

In PET-CT, FDG uptake by at least one of the ischial tuberosities best discriminates between PMR and RA.

Imaging methods in polymyalgia rheumatica: a systematic review

Polymyalgia rheumatica (PMR) is an inflammatory joint disease in patients over 50 years of age with pain and prolonged morning stiffness in the shoulder and hip girdles and neck. The lack of specific clinical findings, laboratory signs, biomarker and established imaging methods makes it difficult to diagnose patients with this disease. The aim of the systematic review is to present the literature data on the use of imaging methods for early diagnosis, assessment of disease activity and therapeutic response in PMR. At the same time, the advantages, disadvantages and contraindications of each method are considered. A literature search was carried out in PubMed and Scopus up to June 2022. Studies were selected that met the following criteria: (1) English language publications in peer-reviewed journals, (2) cohort or case-control studies and a series of more than five clinical cases, (3) studies of newly diagnosed or suspected PMR patients according to classification criteria or expert opinion, (4) imaging evaluation of articular, extraarticular and vascular impairment in PMR. Out of a total of 1431 publications, 61 articles were selected, which differed in the imaging techniques used: radiography (5), scintigraphy (4), magnetic resonance imaging (14), PET/CT (14) and ultrasound (24). Prevalence of extraarticular involvement (tendons, entheses and bursae) was identified in patients with PMR. In a significant number of cases, subclinical vasculitis of the large vessels was found, confirming the common pathogenetic pathways of the two diseases. The diagnostic, therapeutic and prognostic potential of imaging methods in PMR has been relatively poorly studied and remains to be clarified.

Polymyalgia rheumatica: 125 years of epidemiological progress?

OBJECTIVES

On the 125th anniversary of the first recognised publication on polymyalgia rheumatica, a review of the literature was undertaken to assess what progress has been made from the point of view of the epidemiology of this disease and whether such studies have advanced our knowledge of its aetiopathogenesis and management.

METHODS

The authors searched Medline and PubMed using the search terms 'polymyalgia rheumatica', 'giant cell arteritis' and 'temporal arteritis'. As much as possible, efforts were made to focus on studies where polymyalgia and giant cell arteritis were treated as separate entities. The selection of articles was influenced by the authors' bias that polymyalgia rheumatica is a separate clinical condition from giant cell arteritis and that, as yet, the diagnosis is a clinical one.

RESULTS

This review has shown that, following the recognition of polymyalgia as a distinct clinical problem of the elderly, the results of a considerable amount of research efforts investigating the populations susceptible, the geographic distribution of these affected populations and the associated sociological and genetic elements that might contribute to its occurrence, polymyalgia rheumatica remains a difficult problem for the public health services of the developed world.

CONCLUSIONS

Polymyalgia rheumatica remains a clinical enigma and its relationship to giant cell arteritis is no clearer now than it has been for the past 125 years. Diagnosing this disease is still almost exclusively dependent on the clinical acumen of a patient's medical attendant. Until an objective method of identifying it clearly in the clinical setting is available, uncovering the aetiology is still unlikely. Until then, clear guidelines on the future incidence and prevalence of polymyalgia rheumatica and the public health problems of the disease and its management, especially in relation to the use of long term corticosteroids, will be difficult to provide.

Polymyalgia rheumatica: 125 years of progress?

OBJECTIVES

On the 125th anniversary of the first recognised publication on polymyalgia rheumatica, a review of the literature was undertaken to assess what progress has been made from the point of view of the clinical care of affected patients.

METHODS

The authors searched Medline and PubMed using the search terms 'polymyalgia rheumatica', 'giant cell arteritis' and 'temporal arteritis'. As much as possible, efforts were made to focus on studies where polymyalgia rheumatica and giant cell arteritis were treated as separate entities. The selection of articles was influenced by the authors' bias that polymyalgia rheumatica is a separate clinical condition from giant cell arteritis and that, as yet, the diagnosis is a clinical one. Apart from the elevation of circulating acute phase proteins, which has been recognised as a feature of polymyalgia rheumatica for over 60 years, the diagnosis receives no significant help from the laboratory or from diagnostic imaging.

RESULTS

This review has shown that, following the recognition of polymyalgia as a distinct clinical problem of the elderly, the results of a considerable amount of research efforts including those using the advances in clinical imaging technology over the past 60 years, have done little to change the ability of clinicians to define the disease more accurately. Since the introduction of corticosteroids in the 1950s, there has been also very little change in the clinical management of the condition.

CONCLUSIONS

Polymyalgia rheumatica remains a clinical enigma, and its relationship to giant cell arteritis is no clearer now than it has been for the past 125 years. Diagnosing this disease is still almost exclusively dependent on the clinical acumen of a patient's medical attendant. Until an objective method of identifying it clearly in the clinical setting is available, uncovering the aetiology is still unlikely, and until then, preventing the pain and stiffness of the disease while avoiding the problems of prolonged exoposure to corticosteroids is likely to remain elusive or serendipitous.

Imaging of polymyalgia rheumatica: indications on its pathogenesis, diagnosis and prognosis

OBJECTIVES

Imaging is one of the most appealing techniques to explore PMR, a disease whose causes, development mechanisms and anatomical targets of inflammatory damage are still scarcely known. This review is concerned with an appraisal of PMR with different imaging modalities with a view to highlighting possible clues to its pathogenesis, diagnosis and prognosis.

METHODS

A systematic literature research was performed searching PubMed until July 2010. The Cochrane Library was searched for the relevant reviews, and the abstracts of the ACR and European League Against Rheumatism congresses of the period 2005-10 were reviewed.

RESULTS

A total of 1059 papers were retrieved, 46 of which were selected at the end of the review process; 6 of them were concerned with two different imaging techniques. Of these papers, 6 (11.5%) were concerned with conventional radiology; 8 (15.4%) with scintigraphy; 17 (32.7%) with ultrasonography (US); 15 (28.8%) with MRI; and 6 (11.5%) with PET. MRI, US and PET appeared to be the most promising imaging techniques. Bilateral subacromial bursitis, biceps long head tenosynovitis and trochanteric bursitis were particularly consistent findings. In addition, MRI and PET showed interspinous bursitis and PET frequently showed large-vessel vasculitis. Few papers have addressed the role of imaging for diagnosis, differential diagnosis and prognosis of PMR.

CONCLUSIONS

Imaging plays an important role in the comprehensive evaluation of PMR, including its pathogenesis, diagnosis and prognosis. Most of its potential is still unexplored, which fact should stimulate further research.

Large vessel vasculitis (giant cell arteritis, Takayasu arteritis)

Giant cell arteritis and Takayasu arteritis are separate but similar idiopathic diseases clinically characterized by constitutional symptoms, shared surrogate markers of systemic inflammation and indistinguishable granulomatous pan-arteritis of large vessels. This review emphasizes and analyses changing perceptions about the diseases. Recent series suggest that aortic involvement in giant cell arteritis may be more common than was previously appreciated. The case for and against inflammatory arthritis in giant cell arteritis is discussed. Ethnic new geographical variation in Takayasu arteritis-disease expression is reviewed. New philosophies of treatment are presented for both diseases. Prognosis in giant cell arteritis and its relationship to treatment is analysed. The utility of the laboratory for diagnosis and monitoring disease activity is appraised for each.

Elderly-onset rheumatoid arthritis

Elderly-onset rheumatoid arthritis (EORA), defined as rheumatoid arthritis (RA) with onset at age 60 years or over, differs slightly at presentation from younger-onset RA (YORA) by a more equal gender distribution, a higher frequency of acute onset with systemic features, more frequent involvement of the shoulder, and higher disease activity. Longitudinal studies have showed more disease activity, radiographic damage, and functional decline in patients with EORA than in those with YORA. These differences were only found in seropositive patients. Seropositive EORA was reported to be associated with HLA-DR4, in contrast to seronegative EORA. Possible heterogeneity in the pathogenesis of seronegative EORA is supported by the recognition of subsets that overlap with the clinical manifestations of other syndromes such as polymyalgia rheumatica and remitting seronegative symmetrical synovitis with pitting edema. In addition, crystal-induced arthritis and inflammatory osteoarthritis may be difficult to distinguish from EORA. The efficacy and toxicity of second-line drugs is similar in both age groups, but in the elderly caution is needed with the use of nonsteroidal antiinflammatory drugs and prednisone.

Laboratory investigations including liver in polymyalgia rheumatica/giant cell arteritis

The most useful investigation in supporting the clinical diagnosis of PMR/GCA is elevation of the ESR or viscosity. Acute phase proteins, particularly C-reactive protein, are also elevated but in most cases are not more helpful than the ESR in either diagnosis or follow-up. The definitive investigation is the demonstration of giant cell arteritis histologically, usually from temporal artery biopsy. The classical changes are internal elastic lamina fragmentation and destruction, with marked intimal thickening and an inflammatory infiltrate in the vessel wall with giant cells. Changes of healed arteritis can be distinguished from ageing changes and can therefore confirm the diagnosis. Positive biopsies are found in about 70% of patients with clinical GCA but are unlikely to be helpful in pure PMR. Elevation of alkaline phosphatase of liver origin is seen in one-third to half of patients with both PMR and GCA. Abnormal tracer uptake has been reported in radionuclide scans with a variety of non-specific abnormalities on liver biopsy. Promising developments include measurement of CD8+ lymphocytes and interleukins.