Systematic Review and Meta-Analysis for JCS 2026 Guideline on Management of Large-Vessel Vasculitis.

To provide evidence from randomized controlled trials (RCTs) for large-vessel vasculitis (LVV), including Takayasu arteritis (TAK) and giant cell arteritis (GCA), to inform the forthcoming 2026 Japanese Circulation Society (JCS) clinical practice guideline. We drafted 4 and 7 clinical questions for TAK and GCA, respectively. A systematic review (SR) of RCTs was conducted using PubMed, CENTRAL, EMBASE, and the Japan Medical Abstracts Society through March 2024. Assessed with the GRADE approach, the certainty of evidence was very low for the most critical outcomes, low for some outcomes, and moderate for only 1 outcome. Evidence for TAK was limited. Tocilizumab (TCZ) resulted in a numerically lower relapse rate vs. placebo (risk ratio (RR) 0.73, 95% confidence interval (CI) 0.39-1.37) and was similar to adalimumab. No clear difference between mycophenolate mofetil (MMF) and methotrexate (MTX), or between abatacept (ABA) and placebo was observed. In GCA, TCZ reduced relapse (RR 0.29, 95% CI 0.09-0.98) and increased remission (RR 3.56, 95% CI 2.29-5.54) over placebo at 52 weeks. Tumor necrosis factor inhibitor, ABA, and MTX showed no benefit in cranial GCA. Serious adverse events were comparable between treatment groups. Geographic variation and differences in entry criteria were noted. This SR was comprehensive synthesis of evidence from RCTs for LVV therapies to support the 2026 JCS guideline.