Long Jun, Shi Yuchen, Wang Xianyao, Zi Ying, Shi Rongjie
The Clinical Medical College of Dali University, Dali, Yunnan, China.
First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China.
Immun Inflamm Dis. 2025 Aug;13(8):e70244. doi: 10.1002/iid3.70244.
Multiple myeloma (MM) is a common malignant tumor of the hematological system caused by the malignant proliferation of plasma cells, characterized by the production of M proteins and CRAB symptoms. Among them, the Immunoglobulin G MM is the most common, while the IgG4-MM is extremely rare. Smoldering multiple myeloma refers to a state where there are no clinical symptoms. However, bone marrow plasma cell infiltration reaches 10%-59%, and previously, there were no reports of Immunoglobulin G4 smoldering multiple myeloma (IgG4 SMM) internationally.
An over-50-year-old woman visited the hospital due to abnormal liver function. Laboratory tests showed a significant increase in serum IgG4 (24.95 g/L), and serum protein electrophoresis detected IgG-κ M protein (16.05 g/L). A liver biopsy showed IgG4 + plasma cell infiltration (11/HPF) and interface hepatitis. Bone marrow biopsy confirmed IgG4 monoclonal plasma cell proliferation. The diagnosis was IgG4-κ SMM combined with Immunoglobulin G4-related autoimmune hepatitis (IgG4-AIH) and primary biliary cholangitis (PBC). The patient had no typical CRAB symptoms, and no osteolytic destruction was found in imaging. So we formulated a chemotherapy regimen using Bortezomib and dexamethasone, combined with azathioprine for immunomodulation. Unfortunately, after one session of chemotherapy, the patient did not return to the hospital for further evaluation.
This article explores the clinical features and diagnostic challenges of IgG4 SMM coexisting with IgG4-AIH. IgG4 type SMM needs to be identified with IgG4-RD. Clinicians should pay attention to IgG subtype detection and clonal plasma cell analysis.
多发性骨髓瘤（MM）是一种常见的血液系统恶性肿瘤，由浆细胞恶性增殖引起，其特征为产生M蛋白和CRAB症状。其中，免疫球蛋白G型MM最为常见，而IgG4-MM极为罕见。冒烟型多发性骨髓瘤是指没有临床症状，但骨髓浆细胞浸润达10%-59%的状态。此前，国际上尚无免疫球蛋白G4冒烟型多发性骨髓瘤（IgG4 SMM）的报道。
一名50多岁女性因肝功能异常就诊。实验室检查显示血清IgG4显著升高（24.95 g/L），血清蛋白电泳检测到IgG-κ M蛋白（16.05 g/L）。肝脏活检显示IgG4 +浆细胞浸润（11/HPF）及界面性肝炎。骨髓活检证实IgG4单克隆浆细胞增殖。诊断为IgG4-κ SMM合并免疫球蛋白G4相关自身免疫性肝炎（IgG4-AIH）和原发性胆汁性胆管炎（PBC）。患者无典型CRAB症状，影像学检查未发现溶骨性破坏。因此，我们制定了使用硼替佐米和地塞米松的化疗方案，并联合硫唑嘌呤进行免疫调节。遗憾的是，化疗一个疗程后，患者未回院进一步评估。
本文探讨了IgG4 SMM合并IgG4-AIH的临床特征及诊断挑战。IgG4型SMM需要与IgG4相关疾病（IgG4-RD）相鉴别。临床医生应重视IgG亚型检测及克隆性浆细胞分析。
