The Role of Ultrasound and FDG-PET/CT to Detect Extracranial Artery Involvement in Patients with Suspected Large Vessel Vasculitis

The utility of 18F-FDG-PET/CT in detecting extracranial large vessel vasculitis in rheumatic polymyalgia or giant cell arteritis. A systematic review and meta-analysis

OBJECTIVE

Systematic review of current evidence to analyze the prevalence of extracranial large vessel vasculitis (LVV) using 18F-FDG PET/CT in patients with polymyalgia rheumatica (PMR) or giant cell arteritis (GCA).

MATERIALS AND METHODS

PubMed and EMBASE were searched and the results were screened by two reviewers. Study quality was assessed using a modified version of the Newcastle-Ottawa scale. Heterogeneity between studies was assessed using the I2 statistic and the Q test. Further subgroup analyses were performed by disease type, study quality, and 18F-FDG PET/CT uptake criteria. Publication bias was assessed by funnel plot and Egger's test.

RESULTS

268 publications were identified, of which 17 met the selection criteria and were included in the meta-analysis. The overall pooled prevalence of extracranial LVV by 18F-FDG PET/CT was 54.5% [95% CI: 42.6%-66.1%]. In patients with GCA the prevalence was significantly higher than in patients with PMR (60.1% vs. 41.8%, P = 0.006). Likewise, studies with a lower risk of bias reported a higher prevalence of extracranial LVV (61.1% vs. 46.9%; P = 0.010). No publication bias was observed.

CONCLUSIONS

The 18F-FDG PET/CT test may be useful in the detection of extracranial LVV, both in patients with PMR or GCA. Such involvement is more frequent in patients with GCA, and may vary depending on the quality of the studies.

Incidence and clinical manifestations of giant cell arteritis in Spain: results of the ARTESER register

OBJECTIVE

This study aimed to estimate the incidence of giant cell arteritis (GCA) in Spain and to analyse its clinical manifestations, and distribution by age group, sex, geographical area and season.

METHODS

We included all patients diagnosed with GCA between 1 June 2013 and 29 March 2019 at 26 hospitals of the National Health System. They had to be aged ≥50 years and have at least one positive results in an objective diagnostic test (biopsy or imaging techniques), meet 3/5 of the 1990 American College of Rheumatology classification criteria or have a clinical diagnosis based on the expert opinion of the physician in charge. We calculated incidence rate using Poisson regression and assessed the influence of age, sex, geographical area and season.

RESULTS

We identified 1675 cases of GCA with a mean age at diagnosis of 76.9±8.3 years. The annual incidence was estimated at 7.42 (95% CI 6.57 to 8.27) cases of GCA per 100 000 people ≥50 years with a peak for patients aged 80-84 years (23.06 (95% CI 20.89 to 25.4)). The incidence was greater in women (10.06 (95% CI 8.7 to 11.5)) than in men (4.83 (95% CI 3.8 to 5.9)). No significant differences were found between geographical distribution and incidence throughout the year (p=0.125). The phenotypes at diagnosis were cranial in 1091 patients, extracranial in 337 patients and mixed in 170 patients.

CONCLUSIONS

This is the first study to estimate the incidence of GCA in Spain at a national level. We found a predominance among women and during the ninth decade of life with no clear variability according to geographical area or seasons of the year.

Osteoimmunology: The Crosstalk between T Cells, B Cells, and Osteoclasts in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an ongoing inflammatory condition that affects the joints and can lead to severe damage to cartilage and bones, resulting in significant disability. This condition occurs when the immune system becomes overactive, causing osteoclasts, cells responsible for breaking down bone, to become more active than necessary, leading to bone breakdown. RA disrupts the equilibrium between osteoclasts and osteoblasts, resulting in serious complications such as localized bone erosion, weakened bones surrounding the joints, and even widespread osteoporosis. Antibodies against the receptor activator of nuclear factor-κB ligand (RANKL), a crucial stimulator of osteoclast differentiation, have shown great effectiveness both in laboratory settings and actual patient cases. Researchers are increasingly focusing on osteoclasts as significant contributors to bone erosion in RA. Given that RA involves an overactive immune system, T cells and B cells play a pivotal role by intensifying the immune response. The imbalance between Th17 cells and Treg cells, premature aging of T cells, and excessive production of antibodies by B cells not only exacerbate inflammation but also accelerate bone destruction. Understanding the connection between the immune system and osteoclasts is crucial for comprehending the impact of RA on bone health. By delving into the immune mechanisms that lead to joint damage, exploring the interactions between the immune system and osteoclasts, and investigating new biomarkers for RA, we can significantly improve early diagnosis, treatment, and prognosis of this condition.

Prevalence and characteristics of subclinical giant cell arteritis in polymyalgia rheumatica

OBJECTIVE

The main objective of this study was to analyse the prevalence and characteristics of subclinical GCA in patients with PMR.

METHODS

This was a cross-sectional multicentre international study of consecutive patients with newly diagnosed PMR without symptoms or signs suggestive of GCA. All patients underwent US of the temporal superficial, common carotid, subclavian and axillary arteries. Patients with halo signs in at least one examined artery were considered to have subclinical GCA. The clinical, demographic and laboratory characteristics of the PMR group without subclinical vasculitis were compared with subclinical GCA, and the pattern of vessel involvement was compared with that of a classical single-centre GCA cohort.

RESULTS

We included 346 PMR patients, 267 (77.2%) without subclinical GCA and 79 (22.8%) with subclinical GCA. The PMR patients with subclinical GCA were significantly older, had a longer duration of morning stiffness and more frequently reported hip pain than PMR without subclinical GCA. PMR with subclinical GCA showed a predominant extracranial large vessel pattern of vasculitic involvement compared with classical GCA, where the cranial phenotype predominated. The patients with PMR in the classical GCA group showed a pattern of vessel involvement similar to classical GCA without PMR but different from PMR with subclinical involvement.

CONCLUSION

More than a fifth of the pure PMR patients had US findings consistent with subclinical GCA. This specific subset of patients showed a predilection for extracranial artery involvement. The optimal screening strategy to assess the presence of vasculitis in PMR remains to be determined.

Takayasu's arteritis after a prolonged course of hypertrophic osteoarthropathy

A 71-year-old male with hypertrophic osteoarthropathy was referred to our hospital because of a nocturnal fever and tenderness stretching from the left parotid region to the left front neck, in which antibacterials were ineffective. He was diagnosed with Takayasu's arteritis following findings of contrast-enhanced computed tomography and neck ultrasound. This is the first report to describe the development of Takayasu's arteritis after a prolonged course of typical hypertrophic osteoarthropathy, and the proposed hypertrophic osteoarthropathy and Takayasu's arteritis have common underlying pathophysiological factors.

Impact of ultrasound limitation to assess aortitis in patients with giant cell arteritis: comparative study with FDG-PET/CT

OBJECTIVE

To determine the impact of ultrasound (US) intrinsic limitation to assess aortitis versus FDG-PET/CT in patients with US-proven giant cell arteritis (GCA) and to identify factors associated with aortic involvement.

METHODS

Retrospective observational study of patients referred to US fast-track clinics at two academic centres over a 4-year period. Only patients with GCA confirmed by US were included. Temporal arteries (TA) and extracranial arteries US were performed at baseline. FDG-PET/CT was performed according to clinician's criteria. An FDG artery uptake at the aorta higher than liver uptake was considered positive for aortitis.

RESULTS

Seventy-two of 186 patients with US-proven GCA underwent an FDG-PET/CT; 29 (40.3%) had a positive FDG-PET/CT and 24 (33.3%) presented aortitis. Only 6 (20.7%) patients with positive FDG-PET/CT had negative US findings of large vessel (LV)-GCA. Among patients with aortitis in FDG-PET/CT, only two (8.3%) had negative US findings of LV-GCA. Patients with aortitis were younger (68.9 vs 81;p<0.001), more frequently females (79.2% vs 39.6%;p=0.002) and had higher platelets count (413.4 vs 311.1;p=0014). Patients with aortitis presented positive TA US less frequently (41.7% vs 83.3%;p<0.001), but more LV US involvement (91.7% vs 41.7%; p<0.001) versus patients without aortitis. None of the patients with aortitis exhibited visual symptoms (0% vs 31.2%;p=0.001).

CONCLUSIONS

FDG-PET/CT can detect aortitis in one out of every three patients with US-proven GCA. However, a negative US examination for LV-GCA suggests a low risk of aortitis. Younger and female GCA patients with thrombocytosis, absence of visual manifestations and LV-GCA on US may more frequently present aortitis by FDG-PET/CT.

Performance of the 2022 ACR/EULAR giant cell arteritis classification criteria for diagnosis in patients with suspected giant cell arteritis in routine clinical care

OBJECTIVE

To examine the performance of the new 2022 American College of Rheumatology (ACR)/EULAR giant cell arteritis (GCA) classification criteria for diagnosis in routine clinical care.

METHODS

Multicentric retrospective observational study of patients referred to two ultrasound (US) fast track clinics. Patients with GCA were compared with unselected controls with suspected GCA. The gold standard for GCA diagnosis has been clinical confirmation after 6 months of follow-up. All patients underwent an US exam of temporal and extracranial arteries (carotid, subclavian and axillary) at baseline. Fluorodeoxyglucose-positron emission tomography/CT was performed according to standard clinician criteria. The performance of the new 2022 ACR/EULAR GCA classification criteria was evaluated in all patients with GCA across different subsets of the disease.

RESULTS

A total of 319 patients (188 cases, 131 controls) were included for analysis (mean age 76 years, 58.9% females). Overall, the 2022 EULAR/ACR GCA classification criteria had a sensitivity of 92.6% and a specificity of 71.8%, using GCA clinical diagnosis as external criterion and the area under the curve (AUC) was 0.928 (95% CI 0.899 to 0.957). Isolated large vessel-GCA showed a sensitivity of 62.2% and a specificity of 71.8% (AUC 0.691 (0.592 to 0.790)), while biopsy-proven GCA showed a sensitivity of 100% and a specificity of 71.8% (AUC 0.989 (0.976 to 1)). Overall sensitivity and specificity of the 1990 ACR criteria was 53.2% and 80.2%, respectively.

CONCLUSIONS

The new 2022 ACR/EULAR GCA classification criteria showed adequate diagnostic accuracy in patients with suspected GCA under routine care, and an improvement on the sensitivity and specificity of the 1990 ACR classification criteria in all patient subsets.