Vasculitis: What Have We Learned in the Last 50 Years?

Realizing in the fall of 2021 that I had started medical school exactly 50 years ago, on September 7, 1971, I thought that it would be interesting for the 2022 Dunlop-Dottridge Lecture to briefly review what we knew about vasculitis prior to 1971 and then reflect on what we have learned since.

Advances in the Treatment of Giant Cell Arteritis

Giant cell arteritis (GCA) is the most common vasculitis among elderly people. The clinical spectrum of the disease is heterogeneous, with a classic/cranial phenotype, and another extracranial or large vessel phenotype as the two more characteristic patterns. Permanent visual loss is the main short-term complication. Glucocorticoids (GC) remain the cornerstone of treatment. However, the percentage of relapses with GC alone is high, and the rate of adverse events affects more than 80% of patients, so it is necessary to have alternative therapeutic options, especially in patients with worse prognostic factors or high comorbidity. MTX is the only DMARD that has shown to reduce the cumulative dose of GC, while tocilizumab is the first biologic agent approved due to its ability to decrease the relapse rate and lower the cumulative GC doses. However, apart from the IL-6 pathway, there are other pro-inflammatory cytokines and growth factors involved in the typical intima hyperplasia and vascular remodeling of GCA. Among them, the more promising targets in GCA treatment are the IL12/IL23 axis antagonists, IL17 inhibitors, modulators of T lymphocytes, and inhibitors of either the JAK/STAT pathway, the granulocyte-macrophage colony-stimulating factor, or the endothelin, all of which are updated in this review.

Giant cell arteritis: A case report and review of literature

Giant cell arteritis, the most common form of vasculitis in the elderly, is characterized by granulomatous inflammation of arteries, which can lead to serious, life-threatening conditions including aortic aneurysms, ruptures, and dissections as well as blindness. Since GCA can be treated by immunosuppressant therapy, such as corticosteroids, early diagnosis and treatment may reduce the risk of serious disability and morbidity. While temporal artery biopsy is considered the gold standard to diagnosis giant cell arteritis, it is intrusive with inherent risks as well as unreliable due to tissue sampling. Imaging studies, such as computerized tomography, are nonintrusive and have been shown to identify vasculitis including giant cell arteritis. We present a case of a 72-year-old male patient who was diagnosed with giant cell arteritis by temporal artery biopsy during surgery for aortic aneurysm and coronary artery bypass graft. Computerized tomography imaging studies, prior to the surgery and biopsy, were suggestive of vasculitis. This case serves to emphasize the beneficial role of imaging studies to assess vasculitis, including giant cell arteritis, that can be done prior to the progressive development of more serious debilitating and potentially fatal pathology.

Giant cell arteritis: what is new in the preclinical and early clinical development pipeline?

Introduction: Giant Cell Arteritis (GCA) is the most common systemic vasculitis worldwide. For decades, glucocorticoids have represented the mainstay of treatment, at the expense of toxic systemic effects owing to prolonged courses of high-dose treatment regimens. The search for effective drugs permitting lower glucocorticoid treatment regimens in GCA has been afrustrating one. The recent successful therapeutic application of tocilizumab, an interleukin-6 receptor inhibitor, has transformed the treatment of GCA and catalyzed research exploring other promising therapeutic targets.Areas covered: This review explores emerging drugs in preclinical and clinical development for the management of GCA, in addition to synthesizing data on the current standard of care therapeutic agents. Drug therapies were identified by search of MEDLINE and PubMed in addition to trials from registries (clinicaltrials.gov, clinicaltrialsregister.eu, pubmed.gov) from theyear 2010.Expert opinion: Tocilizumab has revolutionized the treatment of GCA. However, much remains to be learned about its optimal usage in GCA and asubstantial minority of pa tients do not achieve sustained glucocorticoid-free remission. Numerous exciting new agents are under investigation to fill this treatment gap in GCA, with the GM-CSF inhibitor mavrilimumab, and IL-12/23 blockade with ustekinumab providing promise through targeting the GCA pathogenic pathway in its proximal portion.

Contribution of Janus-Kinase/Signal Transduction Activator of Transcription Pathway in the Pathogenesis of Vasculitis: A Possible Treatment Target in the Upcoming Future

Janus-kinase (JAK) and signal transduction activator of transcription (STAT) signal transduction pathway is involved in a wide range of physiological and pathological processes, including in the pathogenesis of several autoimmune diseases. Data supporting the role of JAK/STAT in the development of vasculitis are limited and mostly focused on large vessel vasculitis and Behçet's disease. In this review, we provide a thorough picture of currently available evidence on the topic, gathered from in vitro experiments, animal models and human real-life data, analyzing the rationale for the use of JAK inhibitors for the management of vasculitis. Overall, despite a very strong biological and pathogenic basis, data are too few to recommend this therapeutic approach, beyond very severe and refractory forms of vasculitis. However, for the same reasons, a strong scientific effort in this direction is indeed worthwhile.

The Immunopathology of Giant Cell Arteritis Across Disease Spectra

Giant cell arteritis (GCA) is a granulomatous systemic vasculitis of large- and medium-sized arteries that affects the elderly. In recent years, advances in diagnostic imaging have revealed a greater degree of large vessel involvement than previously recognized, distinguishing classical cranial- from large vessel (LV)- GCA. GCA often co-occurs with the poorly understood inflammatory arthritis/bursitis condition polymyalgia rheumatica (PMR) and has overlapping features with other non-infectious granulomatous vasculitides that affect the aorta, namely Takayasu Arteritis (TAK) and the more recently described clinically isolated aortitis (CIA). Here, we review the literature focused on the immunopathology of GCA on the background of the three settings in which comparisons are informative: LV and cranial variants of GCA; PMR and GCA; the three granulomatous vasculitides (GCA, TAK, and CIA). We discuss overlapping and unique features between these conditions across clinical presentation, epidemiology, imaging, and conventional histology. We propose a model of GCA where abnormally activated circulating cells, especially monocytes and CD4⁺ T cells, enter arteries after an unknown stimulus and cooperate to destroy it and review the evidence for how this mechanistically occurs in active disease and improves with treatment.