Marahrens Lennart, Thomas Rhys, Malley Tamir
Rheumatology, Royal Free London NHS Foundation Trust, London, GBR.
Cureus. 2024 Oct 7;16(10):e70972. doi: 10.7759/cureus.70972. eCollection 2024 Oct.
Immunoglobulin G4 (IgG4)-related disease is a rare multi-system immune-mediated inflammatory condition. Pathologically, it is associated with an increase in plasma IgG4 levels and tissue infiltration of IgG4-secreting plasma cells of any organ. Clinical features vary, but it usually presents with the diffuse enlargement and dysfunction of the affected organ. IgG4-related disease leading to hyperviscosity syndrome from polyclonal hypergammaglobulinaemia has only been described in two case reports, and no consensus regarding the treatment of this organ- and life-threatening complication exists. We report the case of a 50-year-old man who was admitted with symptoms of hyperviscosity and an extremely elevated IgG4 level. A presumptive diagnosis of IgG4-related disease causing hyperviscosity syndrome was made. He underwent a therapeutic plasma exchange with a resolution of his symptoms. In view of the likely diagnosis of IgG4-related disease and only refractory improvements in IgG4 levels, immunosuppression with steroids and rituximab was commenced. This led to a sustained fall in IgG4 levels and remission. Hyperviscosity syndrome should be recognised as a complication of IgG4-related disease, and therapeutic plasma exchange can be employed in the emergency treatment of this life-threatening condition.
免疫球蛋白G4（IgG4）相关疾病是一种罕见的多系统免疫介导的炎症性疾病。在病理上，它与血浆IgG4水平升高以及任何器官中分泌IgG4的浆细胞的组织浸润有关。临床特征各不相同，但通常表现为受累器官的弥漫性肿大和功能障碍。仅在两篇病例报告中描述了IgG4相关疾病因多克隆高球蛋白血症导致高粘滞综合征，对于这种危及器官和生命的并发症的治疗尚无共识。我们报告了一名50岁男性的病例，他因高粘滞症状和IgG4水平极度升高入院。初步诊断为IgG4相关疾病导致高粘滞综合征。他接受了治疗性血浆置换，症状得到缓解。鉴于可能诊断为IgG4相关疾病且IgG4水平仅难治性改善，开始使用类固醇和利妥昔单抗进行免疫抑制治疗。这导致IgG4水平持续下降并缓解。高粘滞综合征应被视为IgG4相关疾病的一种并发症，治疗性血浆置换可用于这种危及生命状况的紧急治疗。
