Polymyalgia rheumatica: 125 years of epidemiological progress?

[Polymyalgia rheumatica in 18-fluorodeoxyglucose-positron-emission-tomography/computed tomography : Improvement in diagnostic accuracy and differentiation from rheumatoid arthritis]

BACKGROUND

The diagnosis of patients with polymyalgia rheumatica (PMR) has relied upon the clinical examination of symptoms and laboratory parameters of inflammation until now. Currently, the use of different imaging modalities is being explored, including ultrasound, MRI and PET.

OBJECTIVES

The aim was to evaluate the diagnostic value of 18-fluorodeoxyglucose-positron-emission-tomography/computed tomography (18F-FDG-PET/CT) for PMR, in order to improve the sensitivity and specificity of diagnosing PMR and to improve the differential diagnosis of rheumatoid arthritis (RA).

MATERIALS AND METHODS

Examinations using 18F-FDG-PET/CT of 284 rheumatological patients, including 97 patients with PMR, were retrospectively evaluated over a 44-month period. Furthermore, 13 regions changed by inflammation were analysed via a three-dimensional region of interest (ROI) measurement with determination of maximum standardized uptake values (SUVmax), followed by statistical analyses.

RESULTS AND DISCUSSION

Patients with PMR presented significantly elevated uptake in all regions examined (p < 0.001), compared with a control group treated for rheumatological diseases. The method with the highest diagnostic relevance was represented by the combination of four SUVmax values of both anterolateral hip capsules and both ischial tuberosities, reaching a sensitivity of 91.3% and a specificity of 97.6% with a cut-off of 11.0 SUV at the initial diagnosis of PMR patients who had not yet received any immunosuppressive therapy. Patients with RA could be significantly distinguished from those with PMR at initial diagnosis in the same anatomical regions (p < 0.001).

The Role of Tumor Necrosis Factor Alpha Antagonists (Anti TNF-α) in Personalized Treatment of Patients with Isolated Polymyalgia Rheumatica (PMR): Past and Possible Future Scenarios

Background: Glucocorticoids (GCs) are the cornerstone of polymyalgia rheumatica (PMR) therapy, but their long-term use (as is usually necessary in PMR patients) can induce many adverse events. Alternatives have long been sought. The primary aim of our narrative review is to provide an overview about the use of anti-tumor necrosis factor alpha (TNF-α) drugs in patients with PMR, and discuss advantages and disadvantages. Materials and methods: we performed a non-systematic literature search (PRISMA protocol not followed) on PubMed and Medline (OVID interface). Results and Conclusions: only two anti TNF-α drugs have been prescribed to PMR patients: infliximab in 62 patients and etanercept in 28 patients. These drugs were normally used in addition to GCs when significant comorbidities and/or relapsing PMR were present; less commonly, they were used as first-line therapy. In general, they have been scarcely successful in patients with PMR. Indeed, randomized controlled trials did not confirm the positive results reported in case reports and/or case series. However, an administration schedule and study design different from those proposed in the past could favour new scenarios in the interest of PMR patients.

Antimitochondrial Antibodies and Primary Biliary Cholangitis in Patients with Polymyalgia Rheumatica/Giant Cell Arteritis

Background and Objectives: Laboratory liver abnormalities can be observed in patients affected with polymyalgia rheumatica (PMR) and/or giant cell arteritis (GCA), especially with a cholestatic pattern. The first objective of our review article is to discuss the potential link between antimitochondrial antibodies (AMA) and/or primary biliary cholangitis (PBC) and PMR/GCA, according to the evidences of literature. The second objective is to discuss the association of PMR/GCA with the other rheumatic diseases having PBC as a common manifestation. Materials and Methods: A literature search was performed on PubMed and Medline (OVID interface) using these terms: polymyalgia rheumatica, giant cell arteritis, antimitochondrial antibodies, primary biliary cholangitis, primary Sjogren’s syndrome, systemic sclerosis, and systemic lupus erythematosus. The search was restricted to all studies and case reports published in any language. Reviews, conference abstracts, comments, and non-original articles were excluded; however, each review’s reference list was scanned for additional publications meeting this study’s aim. When papers reported data partially presented in previous articles, we referred to the most recent published data. Results and Conclusions: Our literature search highlighted that cases reporting an association between AMA, PBC and PMR/GCA were very uncommon; AMA antigenic specificity had never been detected and biopsy-proven PBC was reported only in one patient with PMR/GCA. Finally, the association of PMR/GCA with autoimmune rheumatic diseases in which PBC is relatively common was anecdotal.

Incidence and Prevalence of Polymyalgia Rheumatica (PMR): The Importance of the Epidemiological Context. The Italian Case

OBJECTIVES

to evaluate incidence and prevalence rates of polymyalgia rheumatica (PMR) in Italy, depending on the epidemiological methodology used from time to time.

MATERIALS AND METHODS

A comprehensive literature search in MEDLINE and EMBASE was carried out. The following search terms were used: polymyalgia rheumatica, incidence, prevalence, epidemiology, general practitioner, family medicine, Italy. A search was also carried out in Google scholar using the search phrase: epidemiology of polymyalgia rheumatica in Italy. The period considered was between 1970 and March 2019. All articles containing data on incidence and prevalence of PMR in Italy were read in full. Reviews and non-original manuscripts were excluded as well as all the studies containing incidence and prevalence rates of giant cell arteritis (GCA), unless clearly distinct from data related to patients with PMR alone (isolated and pure PMR).

RESULTS

Five articles corresponded to inclusion and exclusion criteria. Two articles were excluded as they were review articles, and three articles were excluded because there were not clear data on incidence and prevalence rates of isolated PMR. Three articles reported data on the annual incidence of PMR (two of them published by the same group of investigators); two articles reported prevalence data. In one article, both incidence and prevalence were calculated. The annual rate of incidence of PMR was between 0.12 and 2.3 cases/1000 inhabitants aged over 50 years. In the two studies publishing prevalence data, they varied from 0.37% to 0.62%. The differences in incidence and prevalence rates were related to several factors such as the different set of diagnostic criteria used for identifying patients or the diagnostic difficulty for patients with atypical presentations, specifically those without raised erythrocyte sedimentation rate (ESR). In the study with higher annual rate of incidence and higher prevalence of PMR, the collaboration between general practitioner (GP) and the out-of-hospital public rheumatologist resulted in significantly different data than in the other studies. All the five articles presented data from monocentric cohorts.

CONCLUSION

Very few Italian studies addressed the epidemiology of PMR. The contribution of a specific professional figure represented by the out-of-hospital public rheumatologist, present in the Italian National Health System and absent in other countries, can make the Italian experience unique in its kind.

Genetic Predispositions of Glucocorticoid Resistance and Therapeutic Outcomes in Polymyalgia Rheumatica and Giant Cell Arteritis

Polymyalgia rheumatica (PMR) and giant cell arteritis (GCA) are closely related chronic inflammatory diseases. Glucocorticoids (GCs) are first-choice drugs for PMR and GCA, although some patients show poor responsiveness to the initial GC regimen or experience flares after GC tapering. To date, no valid biomarkers have been found to predict which patients are at most risk for developing GC resistance. In this review, we summarize PMR- and GCA-related gene polymorphisms and we associate these gene variants with GC resistance and therapeutic outcomes. A limited number of GC resistance associated-polymorphisms have been published so far, mostly related to HLA-DRB1*04 allele. Other genes such ICAM-1, TLR4 and 9, VEGF, and INFG may play a role, although discrepancies are often found among different populations. We conclude that more studies are required to identify reliable biomarkers of GC resistance. Such biomarkers could help distinguish non-responders from responders to GC treatment, with concomitant consequences for therapeutic strategy.

Diagnosis of polymyalgia rheumatica in primary health care: favoring and confounding factors - a cohort study

Objectives

To evaluate in a primary care setting the favoring and confounding factors for the diagnosis of polymyalgia rheumatica (PMR).

Material and methods

Among 303 patients consecutively referred by their general practitioners (GPs) to our rheumatologic outpatient clinic, we identified three groups: group A – patients with confirmed diagnosis of PMR, group B – patients with unconfirmed diagnosis, group C – patients with unrecognized PMR. All the diagnostic confounding and favoring factors were discussed with GPs using an e-mail questionnaire. Participation in rheumatology training courses represented the final question. The collected data were statistically assessed in a blind way. In Fisher’s exact test and ANOVA test, a p-value was significant if < 0.05. The study was carried out in compliance with the Helsinki Declaration and approved by the Ethics Committee of Mariano Lauro Hospital. Every patient signed an informed consent form at the time of the first visit.

Results

All patients were Caucasian; 24.1% were male; mean age was 72.3 ±8.6 years (min. – 51, max. – 94). There were 41 patients in group A, 93 in group B and 169 in group C. The percentage of misdiagnoses was very high (87.1%): among 134 patients diagnosed with PMR by their GPs (group A + group B) confirmation was made in 41, and in 169 unrecognized PMR was found. Participation in training courses was very significant compared to the diagnostic accuracy (p < 0.0001 in χ² test) and to the diagnosis timing (24.3 days ±12.5 vs. 42.9 ±15.5 with p-value < 0.05 in the ANOVA test). When the percentages were assessed according to participation, an inadequate evaluation of some clinical manifestations favored over-diagnosis among the trained GPs.

Conclusions

The level of diagnostic accuracy for PMR must be improved in primary care. Participation in rheumatology training courses can be an important step.

Relapse of polymyalgia rheumatica after a fall

Approximately half of PMR patients have a relapse with a necessity to increase GC dosages. The role of external factors in inducing PMR relapse have been poorly investigated. We present a case-series of five PMR patients in remission with low doses of glucocorticosteroids (GC), who presented with relapse immediately after a fall. The assessment of PMR relapse was made using PMR-AS by Leeb and Bird, and a score > 9.35 was consistent with diagnosis of relapse. Gender, age, and cumulative dose of GC at the time of the fall were compared between the group of these five patients and a group of 41 PMR patients who had no PMR relapse after a fall: using the Fischer's exact test a significant difference was pointed out when the p-value was < 0.05. In our five PMR patients, the sharp worsening of clinical manifestations was always accompanied by a significant rise of the inflammatory indices and the increase of GC dosage (almost always 10 mg/day of prednisone) prompted a fast return (seven days as average) to the previous clinical and laboratory features. All other potentially responsible factors were excluded. Several months (6-10 months on average) after the fall, none of these five patients had a new relapse. No significant differences were found when we compared age, sex, and the cumulative dose of GC at the time of the fall between the group of patients with PMR relapse and the group of patients without. The possibility of PMR relapse being realised immediately after a fall should be kept in mind in daily practice, especially when typical manifestations reappear immediately after a fall and other diagnostic hypotheses have been carefully excluded. The lack of important data (genetic factors, hormonal dosages, serum levels of IL-6 and/or serum soluble IL-6 receptor) in our case-series represented important limits for clarifying the nature of our observations and should be included in any subsequent study design on this argument. If our monocentric data are confirmed by multicentric data, the assessment of the risk of falls through specific scales should be an integral part of the visit of all PMR patients.

Diagnosis of polymyalgia rheumatica usually means a favourable outcome for your patient

Polymyalgia rheumatica (PMR) is a unique disease of elderly people, traditionally diagnosed based on a clinical picture. A typical case is a combination of severe musculoskeletal symptoms and systemic inflammatory response with spectacular response to corticosteroids treatment. The severity of symptoms may be surprising in older patients where immunosenescence is normally expected. However, PMR may be diagnosed in haste if there is a temptation to use this diagnosis as a shortcut to achieve rapid therapeutic success. Overdiagnosis of PMR may cause more problems compared to underdiagnosis. The 2012 PMR criteria proposed by European League against Rheumatism/American College of Rheumatology aim to minimize the role of clinical intuition and build on more objective features. However, questions arise if this is possible in PMR. This has been discussed in this review.

Polymyalgia rheumatica and cancer risk: the importance of the diagnostic set

In the last few years, the relationship between polymyalgia rheumatica (PMR) and cancer has been considered with very different conclusions. In particular, in 2010, Ji et al examined the overall and specific cancer risks among Swedish subjects following hospitalization for PMR and giant cell arteritis and noted that the risk of cancer was highest in the first year after hospitalization (of 3941 total cancer diagnoses, 783 [19.1%] were in the first year). In 2013, Muller et al, using data from General Practice Research Database, highlighted that elderly patients with a PMR diagnosis were significantly more likely to receive a cancer diagnosis in the year after PMR diagnosis (313/667 cancer cases [69%]). In a series of 200 patients with PMR consecutively observed in our geriatric rheumatologic outpatient clinic from 2004 to 2014, we have observed 51 cancer cases; five of these were observed in the first year after diagnosis of PMR (percentage equal to 9.8%). In our article, we point out the importance of the diagnostic set. PMR is a disease that can be managed in a rheumatologic outpatient clinic without patients’ hospitalization. On the other hand, hospitalization of the elderly with PMR is useful when there are grounds for suspicion for a paraneoplastic syndrome, and this represents per se an important inclusion bias. The studies from institutional databases such as those of Ji et al and Muller et al have a very large series but diagnoses of the various diseases are based on coding and not always confirmed by individual medical record review. On the other hand, studies based on cohorts followed by single rheumatologic outpatient clinics can have much smaller data but have a higher diagnostic accuracy, because all patients are visited by rheumatologists and data are usually more accurate. The specificity of geriatric rheumatologic outpatient clinics with respect to elderly patients and to disease with an outpatient management (such as PMR) is often underestimated. In the health care organization of the geographic area that belongs to the hospital “Mariano Lauro”, the majority of patients for whom the general practitioner suspects a PMR are visited by a rheumatologist, as a consequence of an active collaboration between the general practitioner and the rheumatologist and thanks to the very short (5–7 days on average) waiting lists. In our cohort, diagnosis of PMR must be confirmed at least by a second rheumatologist. No change in the initial diagnosis was observed in any of our patients with PMR over the years and even after being examined by other colleagues from different centers. The repercussions of cancer risk in the elderly with PMR on health policies are easily understandable, and therefore the detection of all potential bias is mandatory. Data from other rheumatologic outpatient clinics are necessary.