Comparison of methotrexate and azathioprine as the first-line steroid-sparing immunosuppressive agents in patients with Takayasu's arteritis.

BACKGROUND: Immunosuppressive (IS) agents are recommended for the first-line treatment of patients with active Takayasu's arteritis (TAK) together with glucocorticoids (GCs). However, there is limited data comparing the efficacy and outcomes of different IS agents for this purpose. OBJECTIVES: In this study, we aimed to compare the outcomes of two most frequently used first-line IS agents, namely methotrexate (MTX) and azathioprine (AZA) in TAK patients. METHODS: TAK patients who received any IS agent in addition to GCs as the initial therapy were included in this multicentre, retrospective cohort study. Clinical, laboratory and imaging data of the patients were assessed. In addition, a matched analysis (cc match) using variables 'age', 'gender' and 'diffuse aortic involvement' was performed between patients who received MTX or AZA as the first-line IS treatment. RESULTS: We recruited 301 patients (F/M: 260/41, mean age: 42.2 ± 13.3 years) from 10 tertiary centres. As the first-line IS agent, 204 (67.8 %) patients received MTX, and 77 (25.6 %) received AZA. Less frequently used IS agents included cyclophosphamide in 17 (5.6 %), leflunomide in 2 (0.5 %) and mycophenolate mofetil in one patient. The remission, relapse, radiographic progression and adverse effect rates were similar between patients who received MTX and AZA as the first-line IS agent. Vascular surgery rate was significantly higher in the AZA group (23% vs. 9 %, p = 0.001), whereas the frequency of patients receiving ≤5 mg/day GCs at the end of the follow-up was significantly higher in the MTX group (76% vs 62 %, p = 0.034). Similarly, the rate of vascular surgery was higher in AZA group in matched analysis. Drug survival was similar between MTX and AZA groups (median 48 months, MTX vs AZA: 32% vs 42 %, p = 0.34). IS therapy was discontinued in 18 (12 MTX, 6 AZA) patients during the follow-up period due to remission. Among those patients, two patients had a relapse at 2 and 6 months, while 16 patients were still on remission at the end of a mean 69.4 (±50.9) months of follow-up. CONCLUSIONS: Remission, relapse, radiographic progression and drug survival rates of AZA and MTX were similar for patients with TAK receiving an IS agent as the first-line f therapy. The rate of vascular surgery was higher and the rate of GC dose reduction was lower with AZA compared to MTX at the end of the follow-up.

Utility of positron emission tomography as a new tool for muscle involvement in patients with idiopathic inflammatory myositis: a controlled study.

OBJECTIVES: Idiopathic inflammatory myositis (IIM) represents a rare group of disease that can affect multiple organs in addition to the muscles. 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is an emerging scanning method that is widely used in diagnosing, staging and response to treatment in patients with cancer. In this study, we aimed to evaluate the muscle involvement in PET/CT which was performed for malignancy screening and its correlation with myositis-specific antibodies (MSA) and/or myositis-associated antibodies (MAA) in patients with IIM. METHODS: IIM patients who fulfilled 2017 EULAR/ACR classification criteria and had PET-CT scans during the active phase of myositis (within two weeks of starting steroids) were included into the study. Age and sex matched participants with history of malignancy (non-IIM patients) were defined as control group. RESULTS: Data of 160 IIM patients were evaluated and 34 patients (of 64.7% female) whose PET/CT results were available, included into the study. Fourteen patients with diagnosis of malignancy without IIM (non-IIM patients) defined as the control group. Sensitivity and specificity of a positive FDG muscle uptake were 37.1% and 100%, 65.7% and 92.9%, 91.4% and 7.1% compared to liver, mediastinum and LTM uptakes, respectively. In multivariate analysis, higher baseline CRP (p=0.017, confidence interval [CI] 95%: 1.03-1.36, OR:1.18) and LDH (p=0.029, CI 95%:1.001-1.017, OR:1.01) levels were associated with muscle PET/CT positivity. CONCLUSIONS: In patients with active IIM, median muscle FDG uptake with PET/CT was higher compared to non-IIM. PET/CT may be used for the evaluation of extent and activity in patients with IIM.