Warrington, Kenneth J.

ObjectiveTo compare the efficacy of abatacept to that of placebo for the treatment of giant cell arteritis (GCA).MethodsIn this multicenter trial, patients with newly diagnosed or relapsing GCA were treated with abatacept 10 mg/kg intravenously on days 1, 15, and 29 and week 8, together with prednisone administered daily. At week 12, patients in remission underwent a double‐blinded randomization to continue to receive abatacept monthly or switch to placebo. Patients in both study arms received a standardized prednisone taper, with discontinuation of prednisone at week 28. All patients remained on their randomized assignment until meeting criteria for early termination or until 12 months after enrollment of the last patient. The primary end point was duration of remission (relapse‐free survival rate).ResultsForty‐nine eligible patients with GCA were enrolled and treated with prednisone and abatacept; of these, 41 reached the week 12 randomization and underwent a blinded randomization to receive abatacept or placebo. Prednisone was tapered using a standardized schedule, reaching a daily dosage of 20 mg at week 12 with discontinuation in all patients at week 28. The relapse‐free survival rate at 12 months was 48% for those receiving abatacept and 31% for those receiving placebo (P = 0.049). A longer median duration of remission was seen in those receiving abatacept compared to those receiving placebo (median duration 9.9 months versus 3.9 months; P = 0.023). There was no difference in the frequency or severity of adverse events, including infection, between the treatment arms.ConclusionIn patients with GCA, the addition of abatacept to a treatment regimen with prednisone reduced the risk of relapse and was not associated with a higher rate of toxicity compared to prednisone alone.

Objective To compare the efficacy of abatacept to that of placebo for the treatment of Takayasu arteritis (TAK). Methods In this multicenter trial, patients with newly diagnosed or relapsing TAK were treated with abatacept 10 mg/kg intravenously on days 1, 15, and 29 and week 8, together with prednisone administered daily. At week 12, patients in remission underwent a double‐blinded randomization to continue to receive abatacept monthly or switch to placebo. Patients in both study arms received a standardized prednisone taper, reaching a dosage of 20 mg daily at week 12, with discontinuation of prednisone at week 28. All patients remained on their randomized assignment until meeting criteria for early termination or until 12 months after enrollment of the last patient. The primary end point was duration of remission (relapse‐free survival). Results Thirty‐four eligible patients with TAK were enrolled and treated with prednisone and abatacept; of these, 26 reached the week 12 randomization and underwent a blinded randomization to receive either abatacept or placebo. The relapse‐free survival rate at 12 months was 22% for those receiving abatacept and 40% for those receiving placebo ( P = 0.853). Treatment with abatacept in patients with TAK enrolled in this study was not associated with a longer median duration of remission (median duration 5.5 months for abatacept versus 5.7 months for placebo). There was no difference in the frequency or severity of adverse events, including infection, between the treatment arms. Conclusion In patients with TAK, the addition of abatacept to a treatment regimen with prednisone did not reduce the risk of relapse.

Significance Antigen recognition by the immune system triggers rapid, specific, and protective responses, which are counterbalanced by inhibitory checkpoints to minimize potentially harmful immunity. The programmed death-1/ programmed death ligand-1 (PD-1/PD-L1) checkpoint is overreactive in cancer patients, curbing antitumor immunity. Whether a failing PD-1/PD-L1 checkpoint contributes to spontaneous autoimmune disease in humans is unknown. Here, we found that in patients with the autoimmune vasculitis giant cell arteritis, antigen-presenting cells provide insufficient negative signaling; unleashing highly activated T cells to infiltrate and damage the walls of large arteries. Thus, immunoinhibitory signals protect large arteries against inflammatory attack and checkpoint activation may be a suitable strategy to treat autoimmune vasculitis.

ObjectivePolyarteritis nodosa (PAN) is a systemic necrotizing vasculitis of medium‐sized visceral vessels. However, cutaneous arteritis (CA) and gastrointestinal (GI) vasculitis are forms of single‐organ vasculitis having indistinguishable histopathologic findings from PAN. The aim of this study was to evaluate and compare the clinical characteristics, treatment, and outcomes of patients with systemic PAN, CA, and GI vasculitis.MethodsRetrospective cohorts were assembled, consisting of patients with PAN, CA, and GI vasculitis between 1980 and 2014. The demographics, clinical characteristics, treatment, and outcomes of patients were abstracted from medical records.ResultsWe included 48 patients with PAN, 41 patients with CA, and 19 patients with GI vasculitis. The disease of 1 patient evolved from CA to systemic PAN during the disease course. At diagnosis, 94% of patients with PAN, 93% of patients with CA, and 67% of patients with GI vasculitis were treated with glucocorticoids. Additional immunosuppressive agents were used in 67% of PAN, 37% of GI vasculitis, and 32% of CA cases. The 5‐year cumulative relapse rate was 45.2% in CA, and only 9.6% in PAN during a followup of approximately 6 years. No deaths were observed in the CA group. The survival rate at 10 years was 66% in the PAN group and 61% in the GI vasculitis group.ConclusionSystemic PAN, CA, and GI vasculitis take different clinical courses and therefore may be different diseases, rather than existing on a spectrum of the same disease. Progression of CA to systemic PAN is very rare. Relapse risk is low during followup in PAN. Patients with CA have a higher relapse rate than those with systemic PAN, possibly due to less use of immunosuppressive therapy in CA.