Clinical profile and outcome of large-vessel giant cell arteritis in Japanese patients: A single-centre retrospective cohort study

Identification of the VLDLR locus associated with giant cell arteritis and the possible causal role of low-density lipoprotein cholesterol in its pathogenesis

OBJECTIVES

To elucidate the association between genetic variants and the risk of GCA via large-scale genome-wide association studies (GWAS). In addition, to assess the causal effect of a specific molecule by employing the obtained GWAS results as genetic epidemiological tools.

METHODS

We applied additional variant quality control to the publicly available GWAS results from the biobanks of the UK (UKBB) and Finland (FinnGen), which comprised 532 cases vs 408 565 controls and 884 cases vs 332 115 controls, respectively. We further meta-analysed these two sets of results. We performed two-sample Mendelian randomization (MR) to test the causal effect of low-density lipoprotein (LDL) cholesterol on the risk of GCA.

RESULTS

The MHC class II region showed significant associations in UKBB, FinnGen and the meta-analysis. The VLDLR region was associated with GCA risk in the meta-analysis. The T allele of rs7044155 increased the expression of VLDLR, decreased the LDL cholesterol level and decreased the disease risk. The subsequent MR results indicated that a 1 s.d. increase in LDL cholesterol was associated with an increased risk of GCA (odds ratio 1.21, 95% CI 1.01-1.45; P = 0.04).

CONCLUSIONS

Our study identified associations between GCA risk and the MHC class II and VLDLR regions. Moreover, LDL cholesterol was suggested to have a causal effect on the risk of developing GCA.

Clinical characteristics and courses of Korean patients with giant cell arteritis: a multi-center retrospective study

Objective

Giant cell arteritis (GCA) is a large-vessel vasculitis that primarily affects elderly individuals. However, data regarding Korean patients with GCA are scarce owing to its extremely low prevalence in East Asia. This study aimed to investigate the clinical characteristics of Korean patients with GCA and their outcomes, focusing on relapse.

Methods

The medical records of 27 patients with GCA treated at three tertiary hospitals between 2007 and 2022 were retrospectively reviewed.

Results

Seventeen (63.0%) patients were females, and the median age at diagnosis was 75 years. Large vessel involvement (LVI) was detected in 12 (44.4%) patients, and polymyalgia rheumatica (PMR) was present in 14 (51.9%) patients. Twelve (44.4%) patients had fever at onset. The presence of LVI or concurrent PMR at diagnosis was associated with a longer time to normalization of the C-reactive protein level (p=0.039) or erythrocyte sedimentation rate (p=0.034). During follow-up (median 33.8 months), four (14.8%) patients experienced relapse. Kaplan-Meier analyses showed that relapse was associated with visual loss (p=0.008) and the absence of fever (p=0.004) at onset, but not with LVI or concurrent PMR.

Conclusion

Concurrent PMR and LVI were observed in approximately half of Korean patients with GCA, and the elapsed time to normalization of inflammatory markers in these patients was longer. The relapse rate in Korean GCA is lower than that in Western countries, and afebrile patients or patients with vision loss at onset have a higher risk of relapse, suggesting that physicians should carefully monitor patients with these characteristics.

Giant cell arteritis: incidence and phenotypic distribution in Western Norway 2013-2020

Objectives

There is an increasing awareness of the spectrum of phenotypes in giant cell arteritis (GCA). However, there is sparse evidence concerning the phenotypic distribution which may be influenced by both genetic background and the environment. We established a cohort of all GCA-patients in the Bergen Health Area (Western Norway), to describe the phenotypic distribution and whether phenotypes differ with regards to incidence and clinical features.

Methods

This is a retrospective cohort study including all GCA-patients in the Bergen Health Area from 2013-2020. Data were collected by reviewing patient records, and patients considered clinically likely GCA were included if they fulfilled at least one set of classification criteria. Temporal artery biopsy (TAB) and imaging results were used to classify the patients according to phenotype. The phenotype "cranial GCA" was used for patients with a positive TAB or halo sign on temporal artery ultrasound. "Non-cranial GCA" was used for patients with positive findings on FDG-PET/CT, MRI-, or CT angiography, or wall thickening indicative of vasculitis on ultrasound of axillary arteries. Patients with features of both these phenotypes were labeled "mixed." Patients that could not be classified due to negative or absent examination results were labeled "unclassifiable".

Results

257 patients were included. The overall incidence of GCA was 20.7 per 100,000 persons aged 50 years or older. Overall, the cranial phenotype was dominant, although more than half of the patients under 60 years of age had the non-cranial phenotype. The diagnostic delay was twice as long for patients of non-cranial and mixed phenotype compared to those of cranial phenotype. Headache was the most common clinical feature (78% of patients). Characteristic clinic features occurred less frequently in patients of non-cranial phenotype compared to cranial phenotype.

Conclusion

The overall incidence for GCA was comparable to earlier reports from this region. The cranial phenotype dominated although the non-cranial phenotype was more common in patients under 60 years of age. The diagnostic delay was longer in patients with the non-cranial versus cranial phenotype, indicating a need for examination of non-cranial arteries when suspecting GCA.

Measuring treatment outcomes and change in disease activity in giant cell arteritis: a systematic literature review informing the development of the EULAR-ACR response criteria on behalf of the EULAR-ACR response criteria in giant cell arteritis task force

OBJECTIVES

To identify criteria and descriptors used to measure response to treatment and change in disease activity in giant cell arteritis (GCA).

METHODS

A systematic literature review (SLR) to retrieve randomised controlled trials (RCTs) and longitudinal observational studies (LOS). Criteria and descriptors of active disease, remission, response, improvement, worsening and relapse were extracted. RCTs, LOS with >20 subjects, and qualitative research studies were included.

RESULTS

10 593 studies were retrieved, of which 116 were included (11 RCTs, 104 LOS, 1 qualitative study). No unified definition of response to therapy was found. Most RCTs used composite endpoints to assess treatment outcomes. Active disease was described in all RCTs and 19% of LOS; and was largely defined by a combination of clinical and laboratory components. Remission was reported in 73% of RCTs and 42% of LOS; It was predominantly defined as the combination of clinical and laboratory components. One LOS reported response with a definition resembling the definition of remission from other studies. Improvement was rarely used as an endpoint and it was mostly a surrogate of remission. No study specifically defined worsening. Relapse was reported in all RCTs and 86% of LOS. It was predominantly defined as the combination of clinical, laboratory and treatment components.

CONCLUSIONS

The results of this SLR demonstrate that definitions of response used in clinical studies of GCA are scant and heterogeneous. RCTs and LOS mainly used remission and relapse as treatment outcomes. The descriptors identified will inform the development of the future European Alliance of Associations for Rheumatology-American College of Rheumatology response criteria for GCA.

Aging-Related Vascular Inflammation: Giant Cell Arteritis and Neurological Disorders

Aging is characterized by the functional decline of the immune system and constitutes the primary risk factor for infectious diseases, cardiovascular disorders, cancer, and neurodegenerative disorders. Blood vessels are immune-privileged sites and consist of endothelial cells, vascular smooth muscle cells, macrophages, dendritic cells, fibroblasts, and pericytes, among others. Aging also termed senescence inevitably affects blood vessels, making them vulnerable to inflammation. Atherosclerosis causes low-grade inflammation from the endothelial side; whereas giant cell arteritis (GCA) causes intense inflammation from the adventitial side. GCA is the most common autoimmune vasculitis in the elderly characterized by the formation of granulomas composed of T cells and macrophages in medium- and large-sized vessels. Recent studies explored the pathophysiology of GCA at unprecedented resolutions, and shed new light on cellular signaling pathways and metabolic fitness in wall-destructive T cells and macrophages. Moreover, recent reports have revealed that not only can cerebrovascular disorders, such as stroke and ischemic optic neuropathy, be initial or coexistent manifestations of GCA, but the same is true for dementia and neurodegenerative disorders. In this review, we first outline how aging affects vascular homeostasis. Subsequently, we review the updated pathophysiology of GCA and explain the similarities and differences between vascular aging and GCA. Then, we introduce the possible link between T cell aging, neurological aging, and GCA. Finally, we discuss therapeutic strategies targeting both senescence and vascular inflammation.