Pegat Antoine, Svahn Juliette, Gerfaud-Valentin Mathieu, Durel Cecile-Audrey, Durupt Stéphane, Bernard Emilien
Service d'ENMG et de Pathologies Neuromusculaires, Centre de Référence des Maladies Neuromusculaires PACA-Réunion-Rhône-Alpes, Hôpital Neurologique Pierre, Wertheimer, Hospices Civils de Lyon, Groupement Est, Bron, France.
Service de médecine Interne, Hôpital Saint Joseph Saint Luc, Lyon, France.
Eur J Neurol. 2025 Jul;32(7):e70293. doi: 10.1111/ene.70293.
IgG4-related disease (IgG4-RD) is a rare disease considered an acquired systemic autoimmune condition. Myotonic dystrophy type 2 (DM2) is a rare dominantly inherited multisystem disorder, with a high prevalence of associated autoimmune diseases, but IgG4-RD has not been described in this context.
A case series of three patients with concurrent IgG4-RD and DM2.
All three patients, from a cohort of 47 patients with DM2 (prevalence = 6%), were male, aged 61-80 years and exhibited at least pancreatic involvement. Elevated IgG4 levels were observed in blood, and two patients had lymphoplasmacytic infiltrates rich in IgG4+ plasma cells and CD4+ T cells, with fibrosis present in biopsies. In two cases, DM2 was diagnosed after IgG4-RD. All patients presented with a myopathic phenotype in the lower limbs, with myotonic discharges at myography.
The prevalence of IgG4-RD in the cohort of DM2 herein is more than 1000 times higher than expected. As both diseases display common organ involvement, especially the pancreas, IgG4-RD screening should be considered in DM2 patients with diabetes or/and atypical associated phenotypes. Additionally, genetic testing for DM2 should be considered in IgG4-RD patients with elevated creatine kinase levels, myopathic phenotype, cardiac disorders and/or cataracts. The present report also suggests that IgG4-RD may have a genetic predisposition, potentially elucidating an aspect of the disease's pathophysiology.
IgG4相关性疾病（IgG4-RD）是一种罕见疾病，被认为是一种获得性全身性自身免疫性疾病。2型强直性肌营养不良症（DM2）是一种罕见的常染色体显性遗传多系统疾病，伴有自身免疫性疾病的高患病率，但尚未见IgG4-RD与之相关的报道。
报告3例同时患有IgG4-RD和DM2的病例系列。
在47例DM2患者队列中（患病率=6%）的这3例患者均为男性，年龄61-80岁，均至少有胰腺受累。血液中IgG4水平升高，2例患者有富含IgG4+浆细胞和CD4+T细胞的淋巴浆细胞浸润，活检显示有纤维化。2例患者在诊断IgG4-RD后被诊断为DM2。所有患者均表现为下肢肌病表型，肌电图显示有强直放电。
本文中DM2患者队列中IgG4-RD的患病率比预期高1000倍以上。由于两种疾病均有常见的器官受累，尤其是胰腺，对于患有糖尿病或/和非典型相关表型的确DM2患者，应考虑进行IgG4-RD筛查。此外，对于肌酸激酶水平升高、肌病表型、心脏疾病和/或白内障的IgG4-RD患者，应考虑进行DM2的基因检测。本报告还提示IgG4-RD可能存在遗传易感性，这可能有助于阐明该疾病病理生理学的一个方面。
