Current and emerging diagnosis tools and therapeutics for giant cell arteritis

Giant Cell Arteritis: Focusing on Current Aspects From the Clinic to Diagnosis and Treatment

Giant cell arteritis (GCA) is a granulomatous arteritis involving large arteries, particularly the aorta and its major proximal branches, including the carotid and temporal arteries. GCA involves individuals over 50 years old. The etiopathogenesis of GCA may involve a genetic background triggered by unknown environmental factors (eg infections), the activation of dendritic cells as well as inflammatory and vascular remodeling. However, its pathogenetic mechanism still remains unclear, although progress has been made in recent years. In the past, inflammatory markers and arterial biopsy were considered as gold standard for the diagnosis of GCA. However, emerging imaging methods have been made more sensitive and specific for the diagnosis of GCA. Treatment includes biological and other modalities including interleukin-6 (IL-6) inhibitors.

Giant cell arteritis complicated by tongue necrosis and bilateral cerebellar ischaemic stroke

Giant cell arteritis (GCA) typically presents with headache, scalp tenderness or visual disturbance. Other symptoms include orofacial pain, constitutional symptoms and ischaemic stroke. An 81-year-old woman with a background of type-2 diabetes and hypertension presented with headache, oral pain and right visual loss. Examination showed hypertension, nodular temporal arteries, reduced visual acuity and suspected oral candida. Inflammatory markers were raised and she was diagnosed with GCA and commenced on corticosteroids. During treatment she developed tongue ulceration, then acute vertigo and incoordination with nystagmus and ataxia. Neuroimaging confirmed bilateral, cerebellar ischaemic strokes and temporal artery biopsy was consistent with GCA. With corticosteroids and secondary prevention of stroke measures she is now functionally independent. Oral pain is an uncommon symptom of GCA and delays in recognition may lead to catastrophic consequences. Clinicians should be aware of uncommon presentations and to optimise additional ischaemic stroke risk-factors.

[Giant Cell Arteritis. Recommendations in Primary Care]

Giant cell arteritis is a systemic vasculitis with significant intra and extracranial involvement that, with early diagnosis and treatment in primary care, can improve its prognosis as it is a medical emergency. Our working group on vascular diseases of the Spanish Society of Primary Care Physicians (SEMERGEN) proposes a series of recommendations based on current scientific evidence for a multidisciplinary approach and follow-up in primary care.

A Review of the Dermatological Complications of Giant Cell Arteritis

Giant cell arteritis (GCA) is characterized by granulomatous inflammation of large and medium-sized vessels. It is the most common vasculitis among elderly people in Europe and North America. GCA usually presents with ischemic cranial manifestations such as headache, scalp tenderness, visual manifestations, and claudication of the tongue and jaw. Thickness and tenderness of temporal arteries are the most recognizable signs of GCA on physical examination. Laboratory tests usually show raised acute phase reactants. Skin manifestations are uncommon in GCA and are rarely found as a presenting symptom of GCA. Necrosis of the scalp and tongue is the most common ischemic cutaneous manifestation of GCA. Although infrequent, when present it reflects severe affection and poor prognosis of GCA. Panniculitis-like lesions have been reported in the setting of GCA, with nodules being the most common finding. Other entities, such as generalized granuloma annulare or basal cell carcinoma have been occasionally described in GCA patients. Prompt recognition and initiation of therapy are crucial to prevent serious complications of GCA. When high suspicion of GCA exists, immediate administration of glucocorticoids is recommended. It is advisable to refer the patient to a specialist GCA team for further multidisciplinary assessment.

Tocilizumab in refractory giant cell arteritis. Monotherapy versus combined therapy with conventional immunosuppressive drugs. Observational multicenter study of 134 patients

OBJECTIVE

To compare the efficacy and safety of TCZ in monotherapy (TCZ_MONO) vs. combined with conventional immunosuppressive drugs (TCZ_COMBO) in Giant Cell Arteritis (GCA) in a clinical practice scenario.

METHODS

Multicenter study of 134 patients with refractory GCA. Patients on TCZ_MONO (n = 82) were compared with those on TCZ_COMBO (n = 52). Drugs were methotrexate (MTX) (n = 48), azathioprine (n = 3), and leflunomide (n = 1). The main outcomes were: prolonged remission (normalization of clinical and laboratory parameters for at least 6 months) and the number of relapses.

RESULTS

Patients on TCZ_COMBO were younger (68.8 ± 8.0 vs 71.2 ± 9.0 years; p = 0.04), with a trend to a longer GCA duration (median [IQR],18.5 [6.25-34.0] vs. 13.0 [7.75-33.5] months; p = 0.333), higher C-reactive protein (CRP) levels (2.1[1-4.7] vs 1.2 [0.2-2.4] mg/dL; p = 0.003), and more prevalence of extra-cranial large-vessel vasculitis (LVV) (57% vs. 34.1%; p = 0.007). In both groups, rapid and sustained improvement was observed. Despite the longer GCA duration, and the higher CRP levels and prevalence of LVV in the TCZ_COMBO, the improvement was similar in both groups at 12 months. Moreover, in the TCZ_COMBO group, prolonged remission was significantly higher at 12-month. Relapses and serious adverse events were similar in both groups.

CONCLUSION

In clinical practice, TCZ in monotherapy or combined with conventional immunosuppressive agents is effective and safe in patients with GCA. Nevertheless, the addition of immunosuppressive drugs, usually MTX, seems to allow a higher rate of prolonged remission, even in patients with a longer GCA duration, more extra-cranial LVV involvement, and higher acute-phase reactants.

Biologic Therapies for Giant Cell Arteritis

Glucocorticoids have been the mainstay of treatment in giant cell arteritis (GCA) for the past 70 years. Conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs) have largely failed to show significant clinical efficacy or reduction of the glucocorticoid burden in GCA. Tocilizumab is the first biologic to make a substantial impact in GCA treatment. With the current understanding of GCA pathogenesis implicating multiple cytokines, notably interleukin (IL) 6, IL-12, IL-23, IL-1β, and the role of janus kinases (JAKs) and the signal transducer and activator of transcription (STAT) pathway in these cytokines, many biologics are currently being investigated in GCA. This review article looks at the existing evidence for biologic agents in GCA. In addition to tocilizumab, the potential role of ustekinumab, abatacept, JAK inhibitors and other promising biologics in GCA are discussed in detail. A treatment algorithm based on the best evidence to date is also presented.

New-onset cutaneous sarcoidosis under tocilizumab treatment for giant cell arteritis: a quasi-paradoxical adverse drug reaction. Case report and literature review

Background

New-onset sarcoidosis has been previously described in three case reports in patients affected by rheumatoid arthritis treated with tocilizumab (TCZ). The existence of a cause-effect mechanism between the biological treatment and the onset of the illness is still being debated.

Patient concerns

A 74-year-old woman was diagnosed with giant cell arteritis (GCA). The first-line treatment with glucocorticoids; and the second-line with methotrexate and low-dose glucocorticoids were stopped due to multiple pathological vertebral fractures and insufficient biological and clinical response. The cytotoxic agent, cyclophosphamide, was then introduced and in turn stopped, because of gastrointestinal side effects. Thereafter a treatment with TCZ was begun. The patient experienced good clinical response; however, 8 months later she developed painful hyper-pigmented reddish cutaneous micronodular lesions localized to the abdomen and thorax. A cutaneous biopsy was performed, and histological analysis showed noncaseating epithelioid granulomas in the hypodermis. The diagnosis of cutaneous sarcoidosis was made.

Interventions

Topical corticosteroids were administered and, as requested by the patient, TCZ was discontinued with slow but complete resolution of the skin lesions. After TCZ discontinuation however, the GCA flared and the patient's symptoms and biological abnormalities reappeared. Thus, after a 6-month suspension, TCZ was re-administered. At 2 months later the skin lesions compatible with cutaneous sarcoidosis reappeared. Topical corticosteroids were once again prescribed and as suggested by the patient the TCZ posology was reduced. The patient's symptoms disappeared, and the cutaneous lesions resolved.

Lessons

The time elapsed from TCZ treatment start and the onset of cutaneous sarcoidosis, as well as its recurrence after TCZ suspension and rechallenge supported the diagnosis of a drug-induced reaction. To the best of our knowledge, this case report represents the first instance of cutaneous sarcoidosis most likely induced by TCZ in patients affected by GCA. In addition, our case emphasizes that although TCZ in monotherapy confirms to be an effective treatment for GCA, further immunological disorders could be unmasked, and the discussed side effect of the drug could be dose-dependent.

Tocilizumab in giant cell arteritis. Observational, open-label multicenter study of 134 patients in clinical practice

OBJECTIVE

Tocilizumab (TCZ) has shown efficacy in clinical trials on giant cell arteritis (GCA). Real-world data are scarce. Our objective was to assess efficacy and safety of TCZ in unselected patients with GCA in clinical practice Methods: Observational, open-label multicenter study from 40 national referral centers of GCA patients treated with TCZ due to inefficacy or adverse events of previous therapy. Outcomes variables were improvement of clinical features, acute phase reactants, glucocorticoid-sparing effect, prolonged remission and relapses. A comparative study was performed: (a) TCZ route (SC vs. IV); (b) GCA duration (≤6 vs. >6 months); (c) serious infections (with or without); (d) ≤15 vs. >15 mg/day at TCZ onset.

RESULTS

134 patients; mean age, 73.0 ± 8.8 years. TCZ was started after a median [IQR] time from GCA diagnosis of 13.5 [5.0-33.5] months. Ninety-eight (73.1%) patients had received immunosuppressive agents. After 1 month of TCZ 93.9% experienced clinical improvement. Reduction of CRP from 1.7 [0.4-3.2] to 0.11 [0.05-0.5] mg/dL (p < 0.0001), ESR from 33 [14.5-61] to 6 [2-12] mm/1st hour (p < 0.0001) and decrease in patients with anemia from 16.4% to 3.8% (p < 0.0001) were observed. Regardless of administration route or disease duration, clinical improvement leading to remission at 6, 12, 18, 24 months was observed in 55.5%, 70.4%, 69.2% and 90% of patients. Most relevant adverse side-effect was serious infections (10.6/100 patients-year), associated with higher doses of prednisone during the first three months of therapy.

CONCLUSION

In clinical practice, TCZ yields a rapid and maintained improvement of refractory GCA. Serious infections appear to be higher than in clinical trials.

Utility of serological biomarkers for giant cell arteritis in a large cohort of treatment-naïve patients

Early diagnosis and treatment of giant cell arteritis (GCA) is crucial for preventing ischemic complications. Multiple serological markers have been identified; however, there is a distinct lack of predicting markers for GCA relapse and complications. Our main objective was to identify serological parameters in a large cohort of treatment-naïve GCA patients, which could support clinicians in evaluating the course of the disease. Clinical data was gathered, along with analyte detection using Luminex technology, ELISA, and nephelometry, among others. Unsupervised hierarchical clustering and principal component analysis of analyte profiles were performed to determine delineation of GCA patients and healthy blood donors (HBDs). Highest, significantly elevated analytes in GCA patients were SAA (83-fold > HBDs median values), IL-23 (58-fold), and IL-6 (11-fold). Importantly, we show for the first time significantly changed levels of MARCO, alpha-fetoprotein, protein C, resistin, TNC, TNF RI, M-CSF, IL-18, and IL-31 in GCA versus HBDs. Changes in levels of SAA, CRP, haptoglobin, ESR, MMP-1 and MMP-2, and TNF-alpha were found associated with relapse and visual disturbances. aCL IgG was associated with limb artery involvement, even following adjustment for multiple testing. Principal component analysis revealed clear delineation between HBDs and GCA patients. Our study reveals biomarker clusters in a large cohort of patients with GCA and emphasizes the importance of using groups of serological biomarkers, such as acute phase proteins, MMPs, and cytokines (e.g. TNF-alpha) that could provide crucial insight into GCA complications and progression, leading to a more personalized disease management.