Harvard Medical School, Boston, MA.
Harvard Medical School, Boston, MA; Department of Medicine, Brigham and Women's Hospital, Boston, MA; Department of Biostatistics, Harvard School of Public Health, Boston, MA.
Semin Arthritis Rheum. 2017 Oct;47(2):276-280. doi: 10.1016/j.semarthrit.2017.03.021. Epub 2017 Mar 30.
Immunoglobulin G4-related disease (IgG4-RD) is a relatively newly defined disease entity that refers to a group of immune-mediated disorders that have certain histopathologic, serologic, and clinical features in common. IgG4-RD is often associated with elevated serum IgG4. The discovery of IgG4-RD highlights the scarcity of literature examining elevations in other IgG subclasses and their potential associations to disease. In this retrospective chart review study, we aim to address that gap, by exploring disease associations in patients with isolated IgG subclass elevations.
We identified 552 patients with an isolated elevation of one of the IgG subclasses, and performed a systematic chart review to identify the diagnoses of those patients. We examined the distribution of diagnoses, using the Fisher's exact test to determine if a diagnosis was significantly associated with an isolated elevation in one of the subclasses.
Autoimmune pancreatitis, aspirin-exacerbated respiratory disease (AERD), nasal polyps, eosinophilia, and celiac disease were significantly associated with an isolated elevation in IgG4. Hepatitis C and monoclonal gammopathy were significantly associated with isolated elevations in IgG1. Rheumatoid arthritis (RA) was associated with both an isolated elevation in IgG1 and IgG3. Hypothyroidism and irritable bowel syndrome (IBS) were significantly associated with isolated elevations in IgG2.
These results confirmed some established associations between autoimmune pancreatitis, AERD, nasal polyps, and eosinophilia and elevated serum IgG4, and between monoclonal gammopathy and hepatitis C with elevated serum IgG1. It uncovered novel associations between RA and elevated IgG1 and IgG3, hypothyroidism and IBS and elevated IgG2, and between celiac disease and elevated IgG4.
免疫球蛋白 G4 相关疾病（IgG4-RD）是一种相对较新定义的疾病实体，它指的是一组具有某些组织病理学、血清学和临床特征的免疫介导性疾病。IgG4-RD 常伴有血清 IgG4 升高。IgG4-RD 的发现凸显了文献中对其他 IgG 亚类升高及其与疾病潜在关联的研究相对较少。在这项回顾性图表审查研究中，我们旨在通过探讨孤立性 IgG 亚类升高患者的疾病关联来填补这一空白。
我们确定了 552 例 IgG 亚类单一升高的患者，并进行了系统的图表审查，以确定这些患者的诊断。我们使用 Fisher 精确检验检查了诊断的分布，以确定诊断是否与 IgG 亚类之一的孤立性升高显著相关。
自身免疫性胰腺炎、阿司匹林加重的呼吸道疾病（AERD）、鼻息肉、嗜酸性粒细胞增多症和乳糜泻与 IgG4 的孤立性升高显著相关。丙型肝炎和单克隆丙种球蛋白病与 IgG1 的孤立性升高显著相关。类风湿关节炎（RA）与 IgG1 和 IgG3 的孤立性升高均相关。甲状腺功能减退症和肠易激综合征（IBS）与 IgG2 的孤立性升高显著相关。
这些结果证实了一些已确立的关联，即自身免疫性胰腺炎、AERD、鼻息肉和嗜酸性粒细胞增多症与血清 IgG4 升高之间，以及单克隆丙种球蛋白病与丙型肝炎与血清 IgG1 升高之间的关联。它揭示了 RA 与 IgG1 和 IgG3 升高、甲状腺功能减退症和 IBS 与 IgG2 升高以及乳糜泻与 IgG4 升高之间的新关联。
