背景：IgG4相關疾病（IgG4-RD）是一種全身性、免疫系統引起的纖維炎症性疾病，可能影響多重器官系統。IgG4-RD的臨床表現通常不具特異性，可能與惡性腫瘤的表現相似。誤診可能導致不必要的手術。血清IgG4是該疾病的血清生物標記。然而，血清IgG4的診斷應用仍有擴展的空間。本研究的目的是重新評估血清IgG4在檢測IgG4-RD方面的效能。方法：透過PubMed、Embase及 Cochrane文獻庫進行文獻檢索，以篩選符合資格的論文。納入研究須包含疑似或確診的IgG4-RD患者，採用組織病理診斷作為黃金標準進行確認。此外，納入的文獻須提供足夠數據以進行統合分析。本統合分析採用bivariate ran-dom-effects model。結果：本研究共納入20篇論文，涵蓋11,650名患者。統合分析顯示，血清IgG4在診斷IgG4-RD方面的敏感度為88.2%，特異度為80.5%。針對疑似IgG4相關硬化性膽管炎（IgG4-SC）患者的分析顯示，其敏感度為76.2%，特異度為97.4%。以135 mg/dL作為閾值，敏感度為87.9%。結論：本研究指出，血清IgG4可作為疑似IgG4相關疾病患者初期評估的工具。IgG4的另一項潛在優勢在於其對IgG4相關硬化性膽管炎的高特異性。

Background: Immunoglobulin G4-related disease (IgG4-RD) is a systemic, immune-mediated fibro-inflammatory condition with the potential to affect multiple organ systems. The clinical presentation of IgG4-RD is frequently nonspecific and can resemble that of malignancies. A misdiagnosis could lead to unnecessary surgery. Serum IgG4 serves as a serological biomarker for the disease. The clinical applica-bility of serum IgG4, however, remains a subject of ongoing investigation. The ob-jective of the meta-analysis is to re-evaluate the efficacy of serum IgG4 for the de-tection of IgG4-RD. Materials and methods: A literature search was conducted in the PubMed, Embase, and Cochrane Library databases to identify eligible articles. Studies that included patients with suspected or confirmed IgG4-RD were included. A reference standard, in the form of histopathology, was utilized for confirmation. Furthermore, studies that provided sufficient data for conducting a meta-analysis were assessed. The meta-analysis was performed using a bivariate random-effects model. Results: A total of 20 papers comprising 11,650 patients were included in the study. The meta-analysis yielded a pooled sensitivity of 88.2% and a pooled speci-ficity of 80.5% of serum IgG4 for identifying IgG4-RD. A subgroup analysis of par-ticipants with suspected IgG4-related Sclerosing Cholangitis (IgG4-SC) demon-strated a sensitivity of 76.2% and a specificity of 97.4%. The utilization of a 135 mg/dL cut-off in manuscripts yielded a pooled sensitivity of 87.9%. Conclusion: This meta-analysis validated that serum IgG4 serves as an accuracy tool for the ini-tial evaluation of patients with suspected IgG4-RD. Another potential benefit of this biomarker is its specificity to IgG4-SC.