Yang Yue, Guo Binbin, Li Xianqiao, Duan Shuhua
Department of Nephrology, Shengli Oilfield Central Hospital, Dongying, Shandong, China.
Department of Chinese and Western Medicine Combined, Shengli Oilfield Central Hospital, Dongying, Shandong, China.
BMC Nephrol. 2025 Jul 28;26(1):421. doi: 10.1186/s12882-025-04366-y.
IgG4-related kidney disease (IgG4-RKD) overlapping with diabetic nephropathy (DND) poses diagnostic challenges in terms of histopathological mimicry. This report highlights the first case of concurrent IgG4-related membranous nephropathy (IgG4-MN) and proliferative diabetic kidney disease (DKD) in a patient with diabetes, emphasizing the use of multidisciplinary diagnostic approaches. A 74-year-old male with a 24-year history of diabetes presented with nephrotic syndrome (proteinuria: 6.9 g/24 h), hypoalbuminemia (26.6 g/L), and lymphadenopathy. The patient's serum IgG4 levels were markedly elevated (2774.7 mg/L). Renal biopsy revealed IgG4-dominant subepithelial deposits (PLA2R-negative) with diabetic glomerulosclerosis, whereas lymph node histopathology confirmed the diagnosis of IgG4-related disease (IgG4-RD). Despite the absence of classic IgG4 + tubulointerstitial nephritis (TIN), integrative serological (hypergammaglobulinemia, IgE elevation), radiological (lymphadenopathy), and histological evidence confirmed the diagnosis of IgG4-MN. Low-dose prednisone and mycophenolate mofetil achieved partial remission (50% proteinuria reduction) without compromising glycemic control.
This case highlights the diagnostic complexity of dual renal pathologies in individuals with diabetes and underscores the necessity of multidisciplinary evaluation to differentiate IgG4-MN from DND or primary membranous nephropathy. Early recognition of IgG4-RKD in patients with diabetes and disproportionate proteinuria or systemic inflammation is critical to guide targeted immunosuppression while mitigating metabolic risk. The favorable outcome in this case emphasizes the efficacy of tailored, low-intensity regimens in comorbid populations.
与糖尿病肾病（DND）重叠的IgG4相关性肾病（IgG4-RKD）在组织病理学模拟方面带来了诊断挑战。本报告重点介绍了首例糖尿病患者并发IgG4相关性膜性肾病（IgG4-MN）和增殖性糖尿病肾病（DKD）的病例，强调了多学科诊断方法的应用。一名有24年糖尿病病史的74岁男性，出现肾病综合征（蛋白尿：6.9 g/24小时）、低白蛋白血症（26.6 g/L）和淋巴结病。患者血清IgG4水平显著升高（2774.7 mg/L）。肾活检显示IgG4为主的上皮下沉积物（PLA2R阴性）伴糖尿病肾小球硬化，而淋巴结组织病理学确诊为IgG4相关性疾病（IgG4-RD）。尽管没有典型的IgG4+肾小管间质性肾炎（TIN），但综合血清学（高球蛋白血症、IgE升高）、影像学（淋巴结病）和组织学证据确诊为IgG4-MN。低剂量泼尼松和霉酚酸酯实现了部分缓解（蛋白尿减少50%），且未影响血糖控制。
该病例突出了糖尿病患者双肾病理的诊断复杂性，并强调了多学科评估以区分IgG4-MN与DND或原发性膜性肾病的必要性。对于糖尿病且蛋白尿或全身炎症不成比例的患者，早期识别IgG4-RKD对于指导靶向免疫抑制同时降低代谢风险至关重要。该病例的良好结局强调了针对合并症人群的个体化、低强度治疗方案的有效性。
