HLA-DRB1 alleles associated with polymyalgia rheumatica in northern Italy: correlation with disease severity

Subclinical giant cell arteritis in polymyalgia rheumatica: Concurrent conditions or a common spectrum of inflammatory diseases?

Giant cell arteritis (GCA) and polymyalgia rheumatica (PMR) are common conditions in older adults. Their clinical connection has been recognized over time, with many patients experiencing both conditions separately, simultaneously or in temporal sequence to each other. Early GCA detection is essential to prevent vascular damage, but identifying subclinical GCA in PMR patients remains a challenge and routine screening is not standard practice. Subclinical GCA prevalence in newly diagnosed PMR patients ranges from 23 to 29%, depending on the screening method. Vessel wall imaging and temporal artery biopsy can detect subclinical GCA. Epidemiology and trigger factors show similarities between the two conditions, but PMR is more common than GCA. Genetic and pathogenesis studies reveal shared inflammatory mechanisms involving dendritic cells, pro-inflammatory macrophages, and an IL-6 signature. However, the inflammatory infiltrates differ, with extensive T cell infiltrates seen in GCA while PMR shows an incomplete profile of T cell and macrophage-derived cytokines. Glucocorticoid treatment is effective for both conditions, but the steroid requirements vary. PMR overall mortality might be similar to the general population, while GCA patients with aortic inflammatory aneurysms face increased mortality risk. The GCA-PMR association warrants further research. Considering their kinship, recently the term GCA-PMR Spectrum Disease (GPSD) has been proposed.

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.

Polymyalgia rheumatica

Polymyalgia rheumatica is an inflammatory disease producing pain and stiffness, mainly in the shoulders and pelvic girdle, in people older than 50 years. Elevation of acute phase reactants is common due to the inflammatory nature of the disease. Since there are no specific diagnostic tests, diagnosis requires the exclusion of other diseases with similar presentations. Imaging has helped to identify the pathological substrate of polymyalgia rheumatica and it is increasingly used to support clinical diagnosis or to detect coexistent giant cell arteritis. Although polymyalgia rheumatica does not clearly impair survival or organ function, it can have a detrimental effect on quality of life. Glucocorticoids at 12·5-25·0 mg prednisone per day are effective in inducing remission in most individuals but, when tapered, relapses occur in 40-60% of those affected and side-effects are common. Assessment of disease activity can be difficult because pain related to common comorbidities such as osteoarthritis and tendinopathies, can return when glucocorticoids are reduced, and acute phase reactants are increased less during flares in individuals undergoing treatment or might increase for other reasons. The role of imaging in assessing disease activity is not yet completely defined. In the search for more efficient and safer therapies, tocilizumab and sarilumab have shown efficacy in randomised controlled trials and additional targeted therapies are emerging. However, judicious risk-benefit balance is essential in applying therapeutic innovations to people with polymyalgia rheumatica.

(Dis)agreement of polymyalgia rheumatica relapse criteria, and prediction of relapse in a retrospective cohort

Background

To develop and assess a prediction model for polymyalgia rheumatica (PMR) relapse within the first year of glucocorticoid (GC) treatment.

Methods

A retrospective PMR cohort (clinical diagnosis) from a rheumatology department was used. All visits > 30 days after starting GC treatment and with > 2.5 mg/day oral prednisolone were used as potential relapse visits. Often used relapse criteria (1) rheumatologist judgement, (2) treatment intensification-based relapse) were assessed for agreement in this cohort. The proportion of patients with treatment-based relapse within 1 and 2 years of treatment and the relapse incidence rate were used to assess unadjusted associations with candidate predictors using logistic and Poisson regression respectively. After using a multiple imputation method, a multivariable model was developed and assessed to predict the occurrence (yes/no) of relapse within the first year of treatment.

Results

Data from 417 patients was used. Relapse occurred at 399 and 321 (of 2422) visits based on the rheumatologist judgement- and treatment-based criteria respectively, with low to moderate agreement between the two (87% (95% CI 0.86–0.88), with κ = 0.49 (95% CI 0.44–0.54)). Treatment-based relapse within the first two years was significantly associated with CRP, ESR, and pre-treatment symptom duration, and incidence rate with only CRP and ESR. A model to predict treatment intensification within the first year of treatment was developed using sex, medical history of cardiovascular disease and malignancies, pre-treatment symptom duration, ESR, and Hb, with an AUC of 0.60–0.65.

Conclusion

PMR relapse occurs frequently, although commonly used criteria only show moderate agreement, underlining the importance of a uniform definition and criteria of a PMR specific relapse. A model to predict treatment intensification was developed using practical predictors, although its performance was modest.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41927-022-00274-y.

A seasonal pattern in the onset of polymyalgia rheumatica and giant cell arteritis? A systematic review and meta-analysis

OBJECTIVES

Studies on the seasonality of onset of polymyalgia rheumatica (PMR) and giant cell arteritis (GCA) have shown conflicting results. The aim of this systematic literature review and meta-analysis is to determine from aggregated data whether there is a seasonal distribution for these diseases.

METHODS

A literature search was performed using Pubmed Central and Embase scientific databases. The incidences per 6-month periods, season or month of onset, that were reported in the studies were summarised in tables considering the two diseases as separate conditions or together. The Incidence Rate Ratio (IRR) for the cold period versus the warm period was pooled across studies by random effects meta-analysis weighed by inverse variance. Funnel plots and Egger test were used to explore possible publication biases. A sensitivity analysis was performed to weigh articles with a disproportionate number of patients compared to the rest.

RESULTS

In the scientific literature 22 suitable papers were found: 6 on PMR with 803 patients, 11 on GCA with 2,807 patients, and 5 studies considering both diseases with 19,613 patients. There was considerable heterogeneity amongst studies regarding their quality, the classification criteria used, and the definition of onset of symptoms. No seasonal aggregation was found for GCA and PMR. The pooled IRR estimate of the meta-analysis (1.13[0.89,1.36]) showed a non-significant, higher frequency of diseases onset in the warm season.

CONCLUSIONS

Our meta-analysis did not confirm a seasonal onset for PMR and GCA.

Pathogenesis, Diagnosis and Management of Polymyalgia Rheumatica

Polymyalgia rheumatica is an inflammatory rheumatic disease of the elderly characterised by pain and stiffness in the neck and pelvic girdle, and is the second most common inflammatory rheumatic condition in this age group, after rheumatoid arthritis. Polymyalgia rheumatica can occur independently or in association with giant cell arteritis, which is the most common form of primary vasculitis. The diagnosis of polymyalgia rheumatica is usually based on clinical presentation and increase of inflammatory markers. There are no pathognomonic findings that can confirm the diagnosis. However, different imaging techniques, especially ultrasonography, can assist in the identification of polymyalgia rheumatica. Glucocorticoids are the cornerstone of the treatment of polymyalgia rheumatica, but they might be associated with different adverse events. A subgroup of patients presents with a refractory disease course and, in these cases, adding methotrexate as a steroid-sparing agent could be useful. In this review, we summarise the latest findings regarding the pathogenesis, diagnosis and management of polymyalgia rheumatica and try to highlight the possible pitfalls, especially in elderly patients.

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.

Application of 2012 EULAR/ACR criteria for polymyalgia rheumatica to Korean patients previously classified by Chuang and Hunder criteria or Healey criteria

AIM

To apply 2012 European League Against Rheumatism/American College of Rheumatology (EULAR/ACR) criteria to Korean patients previously classified as polymyalgia rheumatica (PMR) by Chuang and Hunder criteria or Healey criteria and investigated whether they might be still reclassified as PMR or not.

METHODS

We retrospectively reviewed the medical records of 113 previously classified PMR patients. We applied 2012 EULAR/ACR criteria without ultrasonography to PMR patients, and fulfilment required at least 4 points. We evaluated odds ratios (OR) using logistic regression analyses.

RESULTS

The mean age was 61.7 years. Seventy-one patients (62.8%) fulfilled Chuang and Hunder criteria, and 113 patients (100%) met Healey criteria. When we applied 2012 EULAR/ACR criteria, 98 patients fulfilled essential items (≥50 years, bilateral shoulder aching and abnormal C-reactive protein or erythrocyte sedimentation rate), and only 80 patients achieved points ≥4. Eight patients fulfilling the criteria exhibited higher frequencies of all the detailed items than those who did not. In multivariate logistic regression analysis, absence of rheumatoid factor or anti-citrullinated peptide antibodies was the only independent contributing item to the fulfilment of 2012 EULAR/ACR criteria (OR 23.571, 95% CI 6.357-87.407, P < .001). When we reclassified 33 excluded patients, the most common newly classified disease was generalized osteoarthritis (24.2%), followed by osteoporosis with compression fracture (15.2%).

CONCLUSION

Eighty of 113 patients (81.6%) previously classified by Chuang and Hunder criteria or Healey criteria fulfilled 2012 EULAR/ACR criteria for PMR.

Baseline Shoulder Ultrasonography Is Not a Predictive Marker of Response to Glucocorticoids in Patients with Polymyalgia Rheumatica: A 12-month Followup Study

Objective.

In this study, we evaluated whether ultrasound (US) subdeltoid bursitis (SB) and/or biceps tenosynovitis (BT) presence at baseline could represent a predictive marker of response to standard therapy after 12 months of followup, and whether a positive US examination could highlight the need of higher maintenance dosage of glucocorticoids (GC) at 6 and 12 months in patients with polymyalgia rheumatica (PMR).

Methods.

Sixty-six consecutive patients with PMR underwent bilateral shoulder US evaluations before starting therapy and after 12 months of followup. Absence of girdle pain and morning stiffness (clinical remission) and laboratory variables were evaluated. After diagnosis, all patients were treated with prednisone.

Results.

At baseline, SB and/or BT were present in 46 patients (70%), of whom 33 (72%) became negative while 13 (28%) remained positive at the 12-month US evaluation. All patients rapidly achieved a clinical remission, and at 6 months 26 (39%) also achieved a laboratory variable normalization. According to US positivity at baseline, no difference was found in remission or relapse rate after 12 months. Thirty patients (46%) at 6 months and 7 (11%) at 12 months were still taking more than 5 mg/day of prednisone. According to the US pattern at baseline, no difference was found in the mean GC dose at 6 and 12 months.

Conclusion.

In patients with PMR, the presence of SB and/or BT on US at diagnosis is not a predictive marker of GC response or of a higher GC dosage to maintain remission in a 12-month prospective followup study.

2015 recommendations for the management of polymyalgia rheumatica: a European League Against Rheumatism/American College of Rheumatology collaborative initiative

Therapy for polymyalgia rheumatica (PMR) varies widely in clinical practice as international recommendations for PMR treatment are not currently available. In this paper, we report the 2015 European League Against Rheumatism (EULAR)/American College of Rheumatology (ACR) recommendations for the management of PMR. We used the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology as a framework for the project. Accordingly, the direction and strength of the recommendations are based on the quality of evidence, the balance between desirable and undesirable effects, patients' and clinicians' values and preferences, and resource use. Eight overarching principles and nine specific recommendations were developed covering several aspects of PMR, including basic and follow-up investigations of patients under treatment, risk factor assessment, medical access for patients and specialist referral, treatment strategies such as initial glucocorticoid (GC) doses and subsequent tapering regimens, use of intramuscular GCs and disease modifying anti-rheumatic drugs (DMARDs), as well as the roles of non-steroidal anti-rheumatic drugs and non-pharmacological interventions. These recommendations will inform primary, secondary and tertiary care physicians about an international consensus on the management of PMR. These recommendations should serve to inform clinicians about best practices in the care of patients with PMR.

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.

Giant cell arteritis: a systematic review of the qualitative and semiquantitative methods to assess vasculitis with 18F-fluorodeoxyglucose positron emission tomography

Giant cell arteritis (GCA) is the most common vasculitis affecting medium and large vessels. It shows a close clinical association with polymyalgia rheumatica (PMR), a musculoskeletal inflammatory disorder, which is clinically characterized by girdles pain and stiffness. 18F-Fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) is an effective tool for the diagnosis, grading, and follow-up of patients affected by GCA involving the aorta and its proximal branches, but the lack of a standardized method for the assessment of vascular inflammation remains a critical issue, potentially leading to misclassification. In our systematic review, including 19 original articles for a total of 442 GCA patients (with or without PMR symptoms) and 535 healthy controls, we described the different qualitative, semiquantitative and combined methods that have been proposed throughout the literature for assessing the presence and grading the severity of GCA-related vascular inflammation on 18F-FDG PET scans, focusing on the diagnostic performance and examining their respective advantages and limitations. The majority of the included studies adopted qualitative methods of PET image analysis, which are less sensitive but more specific than semiquantitative ones. Among the semiquantitative approaches, the aortic-to-blood pool uptake ratio of the aortic arch seems to be the most accurate method.

Current understanding and management of giant cell arteritis and polymyalgia rheumatica

Giant cell arteritis (GCA) and polymyalgia rheumatica (PMR) are linked conditions that occur in the elderly. GCA is a vasculitis of large- and medium-sized vessels causing critical ischemia. It is a medical emergency owing to the high incidence of neuro-ophthalmic complications. PMR is an inflammatory disease characterized by abrupt-onset pain and stiffness of the shoulder and pelvic girdle muscles. Both conditions are associated with a systemic inflammatory response and constitutional symptoms. The pathogeneses are unclear. The initiating step may be the recognition of an infectious agent by activated dendritic cells. The key cell type involved is CD4(+) T cells and the key cytokines are IFN-γ (implicated in granuloma formation) and IL-6 (key to the systemic response). The pathogenesis of PMR may be similar to that of GCA, however, PMR exhibits less clinical vascular involvement. The mainstay of therapy is corticosteroids, and disease-modifying therapy is indicated in relapsing disease. This article reviews recent guidelines on early recognition, investigations and management of these diseases, as well as advances in imaging.

The rheumatoid arthritis-associated allele HLA-DR10 (DRB1*1001) shares part of its repertoire with HLA-DR1 (DRB1*0101) and HLA-DR4 (DRB*0401)

OBJECTIVE

To identify the peptide anchor motif for the rheumatoid arthritis (RA)-related HLA allele, DR10, and find shared natural ligands or sequence similarities with the other disease-associated alleles, DR1 and DR4.

METHODS

The HLA-DR10-associated peptides were purified, and a proportion of these natural ligands were de novo sequenced by mass spectrometry. Based on crystallographic structures, the complexes formed by peptide influenza virus hemagglutinin HA306-318 with DR1, DR4, and DR10 were modeled, and binding scores were obtained.

RESULTS

A total of 238 peptides were sequenced, and the anchor motif of the HLA-DR10 peptide repertoire was defined. A large proportion of the DR10-associated peptides had the structural features to bind DR1 and DR4 but were theoretical nonbinders to the negatively associated alleles DR15 and DR7. Among the sequenced ligands, 10 had been reported as ligands to other RA-associated alleles. Modeling data showed that peptide HA306-318 can bind DR1, DR4, and DR10 with similar affinities.

CONCLUSION

The data show the presence of common peptides in the repertoires of RA-associated HLA alleles. The combination of the shared epitope present in DR1, DR4, and DR10 together with common putative arthritogenic peptide(s) could influence disease onset or outcome.

Polymyalgia rheumatica and giant-cell arteritis

Polymyalgia rheumatica and giant-cell arteritis are closely related disorders that affect people of middle age and older. They frequently occur together. Both are syndromes of unknown cause, but genetic and environmental factors might have a role in their pathogenesis. The symptoms of polymyalgia rheumatica seem to be related to synovitis of proximal joints and extra-articular synovial structures. Giant-cell arteritis primarily affects the aorta and its extracranial branches. The clinical findings in giant-cell arteritis are broad, but commonly include visual loss, headache, scalp tenderness, jaw claudication, cerebrovascular accidents, aortic arch syndrome, thoracic aorta aneurysm, and dissection. Glucocorticosteroids are the cornerstone of treatment of both polymyalgia rheumatica and giant-cell arteritis. Some patients have a chronic course and might need glucocorticosteroids for several years. Adverse events of glucocorticosteroids affect more than 50% of patients. Trials of steroid-sparing drugs have yielded conflicting results. A greater understanding of the molecular mechanisms involved in the pathogenesis should provide new targets for therapy.

Association of FCGR2A and FCGR2A-FCGR3A haplotypes with susceptibility to giant cell arteritis

The Fc gamma receptors have been shown to play important roles in the initiation and regulation of many immunological and inflammatory processes and to amplify and refine the immune response to an infection. We have investigated the hypothesis that polymorphism within the FCGR genetic locus is associated with giant cell arteritis (GCA). Biallelic polymorphisms in FCGR2A, FCGR3A, FCGR3B and FCGR2B were examined for association with biopsy-proven GCA (n = 85) and healthy ethnically matched controls (n = 132) in a well-characterised cohort from Lugo, Spain. Haplotype frequencies and linkage disequilibrium (D') were estimated across the FCGR locus and a model-free analysis performed to determine association with GCA. There was a significant association between FCGR2A-131RR homozygosity (odds ratio (OR) 2.10, 95% confidence interval (CI) 1.12 to 3.77, P = 0.02, compared with all others) and carriage of FCGR3A-158F (OR 3.09, 95% CI 1.10 to 8.64, P = 0.03, compared with non-carriers) with susceptibility to GCA. FCGR haplotypes were examined to refine the extent of the association. The haplotype showing the strongest association with GCA susceptibility was the FCGR2A-FCGR3A 131R-158F haplotype (OR 2.84, P = 0.01 for homozygotes compared with all others). There was evidence of a multiplicative joint effect between homozygosity for FCGR2A-131R and HLA-DRB1*04 positivity, consistent with both of these two genetic factors contributing to the risk of disease. The risk of GCA in HLA-DRB1*04 positive individuals homozygous for the FCGR2A-131R allele is increased almost six-fold compared with those with other FCGR2A genotypes who are HLA-DRB1*04 negative. We have demonstrated that FCGR2A may contribute to the 'susceptibility' of GCA in this Spanish population. The increased association observed with a FCGR2A-FCGR3A haplotype suggests the presence of additional genetic polymorphisms in linkage disequilibrium with this haplotype that may contribute to disease susceptibility. These findings may ultimately provide new insights into disease pathogenesis.

Polymyalgia rheumatica: diagnosis and treatment

Polymyalgia rheumatica (PMR) typically manifests as inflammatory pain in the shoulder and/or pelvic girdles in a patient over 50 years of age. This condition was long underrecognized and therefore underdiagnosed. Today, however, overdiagnosis may occur. Physicians must be aware that many conditions may simulate PMR, including diseases that carry a grim prognosis or require urgent treatment. PMR may be the first manifestation of giant cell arteritis, and a painstaking search for other signs is mandatory. PMR may inaugurate other rheumatologic diseases such as rheumatoid arthritis, RS3PE syndrome, spondyloarthropathy, systemic lupus erythematosus (SLE), myopathy, vasculitis, and chondrocalcinosis. Finally, PMR may be the first manifestation of an endocrine disorder, a malignancy, or an infection. Failure to respond to glucocorticoid therapy should suggest giant cell arteritis, malignant disease, or infection. Ultrasonography may assist in the diagnosis by showing bilateral subdeltoid bursitis. Glucocorticoids are the mainstay of the treatment of PMR. Although the optimal starting dosage and tapering schedule are not agreed on, a low starting dosage and slow tapering may decrease the relapse rate. Methotrexate is probably useful when glucocorticoid dependency develops. In contrast, TNF-alpha antagonists are probably ineffective.

Polymyalgia rheumatica and colon malignacy: case report

Polymyalgia rheumatica (PMR) is a relatively common disorder in the elderly. Whereas the relationship between polymyalgia rheumatica and giant cell arteritis (GCA) is well recognized, there is still controversy about PMR and malignancy. We are presenting a patient with PMR and adenocarcinoma of the sygmoid colon and hypothesize a paraneoplastic relationship.

HLA-DRB1 allele distribution in polymyalgia rheumatica and giant cell arteritis: Influence on clinical subgroups and prognosis

OBJECTIVE

To evaluate HLA-DRB1 associations in patients with polymyalgia rheumatica (PMR) and giant cell arteritis (GCA) in the Spanish population, especially those alleles that include the disease-linked sequence motif DRYF (positions 28 to 31 of the HVR2).

METHODS

We performed a PCR based HLA-DRB1 genotyping in 89 PMR patients, 44 GCA patients, and 99 unrelated healthy controls from the same geographic area.

RESULTS

We did not find any significant difference between the whole group of PMR/GCA patients (n = 133) compared with the healthy controls with the exception of a lower frequency of HLA-DRB1*0405 in the patient group (odds ratio [OR], 0.1 [CI0.02 to 1.2]; P =.04). The distribution of DRB1 alleles was very similar between PMR patients and controls. However, DRB1*0401 (OR, 3.1 [1.1 to 8.6]; P =.02) and DRB1*0404 (OR, 3.5 [0.97 to 12.9]; P =.04) were overrepresented in patients with GCA compared with the control group. DRB1*04 (OR, 1.9 [0.96 to 3.8]; P =.06), especially *0401 (OR, 2.8 [1 to 7.7]; P =.04), and DRB1*07 (OR, 2.3 [1.2 to 4.6]; P =.01) were more frequent in GCA than in PMR. Frequency of the DRYF 28-31 motif was similar among GCA (79.5%), PMR (89.9%), and controls (87.9%) and did not confer any significant risk of the development of systemic vasculitis. We also compared the DRB1 allele distribution in patients with classic PMR (n = 58) and those with an erythrocyte sedimentation rate (ESR) <40 mm/hour (n = 31). Patients with classic PMR expressed DRB1*07 less frequently (OR, 0.4 [0.1 to 1]; P =.04) and had a higher frequency of the DRYF 28-31 motif (94.8% vs 80.6%; P =.03) than patients with ESR < 40. Within the GCA group, DRB1 alleles were not predictive for the development of severe ischemic complications. However, the development of relapses in patients with PMR was associated with a higher frequency of DRB1*09 (5.6% vs 0%; P =.04).

CONCLUSIONS

Our data suggest that the HLA-DRB1 alleles associated with susceptibility for developing PMR and GCA are different. Whether PMR with low ESR represents a different clinical subset of the disease should be clarified in a larger sample of patients. HLA-DRB1 genes might predict the presence of relapses in PMR, but they do not seem to be indicators of severe disease in GCA patients.

Are polymyalgia rheumatica and giant cell arteritis the same disease?

OBJECTIVE

To summarize the evidence about the relationship between polymyalgia rheumatica (PMR) and giant cell arteritis (GCA).

METHODS

Review of relevant articles from the English-language literature.

RESULTS

Epidemiologic studies suggest that PMR and GCA are closely related conditions affecting people over 50 years and frequently occurring in the same patient. PMR symptoms have been observed in 40 to 60 percent of GCA clinical series. Also, temporal artery biopsy may yield positive results for GCA in patients with isolated PMR. Conflicting HLA-DRB1 genotype results have been reported, and recent studies have shown that PMR and GCA have different expression of RANTES, TNFalpha microsatellite, and IL-6 promoter genetic polymorphisms. Search for a possible common infectious agent have yielded disappointing results. Although parvovirus B19 DNA is present in the artery wall of patients with GCA, this virus may be only an innocent bystander. Cytokine studies on a limited number of temporal artery biopsy specimens have shown that interferon-gamma is produced in GCA and not in PMR, suggesting that this cytokine may be crucial to the development of overt vasculitis.

CONCLUSIONS

PMR and GCA frequently occur together but no definitive conclusions can be drawn about the nature of this association.

[Rhizomelic pseudopolyarthritis: update]

PURPOSE

Update of recent works on polymyalgia rheumatica (PMR). CURRENT KNOWLEDGE ANS KEY POINTS: In polymyalgia rheumatica (PMR) unassociated with giant cell arteritis (GCA) (twice as frequent as GCA without PMR) several recent works demonstrated by MRI or echography that synovitis and/or subacromial bursitis accounted for most of the painful shoulders and could be relieved by steroid injections. Peripheral synovitis can also occur in 10-20% of PMR, and lead to consideration of other diagnoses, mostly RA or the RS3PE syndromes for those cases of PMR with peripheral edema. PMR with asymmetrical onset are often difficult to diagnose early, and the classification criteria for PMR are not widely accepted. When clinical signs suggestive of GCA are lacking, temporal biopsy is positive in only 1 to 5% of PMR cases. Several studies on PMR with so-called 'normal' ESR (below 30 mm, first hour) have cast doubts on the value of this biological sign (although 'normal ESR' should only stand for values below 11 mm). Hence it would be worthwhile to study whether CRP and even SAA deserve to be added to future sets of criteria for PMR. A defect in hypothalamic axis response is often noticed and could play a part in PMR pathogenesis, thus explaining why PMR is quite exclusively noticed after ages 50 or 60. Two-thirds of patients can stop prednisone within 2 years after the onset of treatment. The lack of a prompt response within the first days should suggest differential diagnoses, including some myelodysplastic disorders.

FUTURE PROSPECTS AND PROJECTS

The search for genetic factors common or specific to PMR and GCA could enhance our understanding of these overlapping syndromes. Studies of the transcriptosomes of lymphocytes infiltrating the target tissues (arterial wall in GCA, synovium in PMR) might also prove informative. Controlled studies of new biological treatments like cytokine inhibitors (anti-TNF-alpha, anti-interferon gamma) could demonstrate a clear sparing effect in steroids, a goal not yet achieved by the use of current DMARDs, including MTX.

DRB1 alleles in polymyalgia rheumatica and rheumatoid arthritis in southern France

To investigate the association of HLA-DRB1 alleles with polymyalgia rheumatica (PMR) and rheumatoid arthritis (RA), 55 patients with PMR without giant cell arteritis, 203 patients with RA and 230 controls, all from the European population of Marseille, were HLA-DRB1 genotyped by PCR-SSO. HLA-DRB1*01 was significantly increased in both the PMR and RA groups compared to controls (35% versus 17%, P(c) < 0.05, and 41% versus 17%, P(c) < 0.001, respectively). HLA-DRB1*04 was significantly increased in the RA group compared to controls (48% versus 23%, P(c) < 0.001) but not in the PMR group. HLA-DRB1*04 subtype frequencies were significantly different between PMR patients and RA patients. Shared epitope-positive HLA-DRB1*04 alleles (DRB1*0401, 0404, 0405, 0408) were significantly overrepresented in RA patients compared to PMR patients and shared epitope-negative HLA-DRB1*04 alleles were overrepresented in PMR patients compared to RA patients. In conclusion, in the Mediterranean population studied, HLA-DRB1*01 is associated with RA and PMR whereas HLA-DRB1*04 is associated with RA only.