Department of Laboratory Medicine, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
Department of Laboratory Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
Medicine (Baltimore). 2022 Sep 9;101(36):e30387. doi: 10.1097/MD.0000000000030387.
Immunoglobulin G4-related disease (IgG4-RD) is an immune-mediated fibroinflammatory condition with unique histopathological features that can affect most organs, making diagnosis challenging. This study characterized detailed laboratory characteristics of IgG4-RD. Baseline clinical and laboratory features of 33 patients with IgG4-RD were reviewed, including serum IgG4 concentrations, serum free light chains (sFLCs), IgGĸ- and IgGλ-heavy/light chains (HLCs), capillary serum protein electrophoresis (SPE), and immunofixation electrophoresis (IFE) of IgG4 subclass. The cohort of 33 patients showed male predominance (94%), with 8 (24%) exhibiting multiple organ involvement. Most patients (88%) had an elevated IgG4 concentration, and 67% had elevated erythrocyte sedimentation rate and IgE levels. Median IgG4 concentration at baseline was significantly higher in patients with >2 organs involved than those with ≤2. Furthermore, erythrocyte sedimentation rate was significantly correlated with serum IgG4 concentrations at baseline. SPE results demonstrated polyclonal gammopathy in most patients. Half of the patients had an increased κ/λ sFLC ratio, 42% had an increased IgGκ/IgGλ HLC ratio. Most patients exhibited hypergammaglobulinemia in the anodal end of the ɤ region on SPE. This study describes detailed laboratory features of IgG4-RD. Although none of these tests are considered diagnostically sufficient by itself, the provided laboratory characteristics can increase awareness of this disorder and help distinguish it from other IgG4-RD mimics.
免疫球蛋白 G4 相关疾病（IgG4-RD）是一种免疫介导的纤维炎症性疾病，具有独特的组织病理学特征，可影响大多数器官，因此诊断具有挑战性。本研究对 IgG4-RD 的详细实验室特征进行了描述。回顾了 33 例 IgG4-RD 患者的基线临床和实验室特征，包括血清 IgG4 浓度、血清游离轻链（sFLC）、IgGκ-和 IgGλ-重/轻链（HLC）、毛细管血清蛋白电泳（SPE）和 IgG4 亚类的免疫固定电泳（IFE）。该队列的 33 例患者表现为男性为主（94%），8 例（24%）存在多器官受累。大多数患者（88%）的 IgG4 浓度升高，67%的患者红细胞沉降率和 IgE 水平升高。基线时受累>2 个器官的患者 IgG4 浓度显著高于受累≤2 个器官的患者。此外，红细胞沉降率与基线时血清 IgG4 浓度显著相关。SPE 结果显示大多数患者存在多克隆丙种球蛋白血症。一半的患者κ/λ sFLC 比值升高，42%的患者 IgGκ/IgGλ HLC 比值升高。大多数患者在 SPE 的阳极末端表现为高丙种球蛋白血症。本研究描述了 IgG4-RD 的详细实验室特征。虽然这些检测都不能单独作为诊断充分的依据，但提供的实验室特征可以提高对这种疾病的认识，并有助于将其与其他 IgG4-RD 类似疾病区分开来。
