Sama Srikar, Weickhardt Alexander, Subramanian Preethi, Reddy Pooja
Department of Internal Medicine, University of California San Francisco Fresno, Fresno, CA, USA.
Department of Anatomic and Clinical Pathology, University of California San Francisco, San Francisco, CA, USA.
SAGE Open Med Case Rep. 2024 Aug 31;12:2050313X241279696. doi: 10.1177/2050313X241279696. eCollection 2024.
IgG4-related disease is a fibroinflammatory condition characterized by dense lymphoplasmacytic infiltrates rich in IgG4-positive plasma cells affecting multiple organs. Though the most common renal manifestation of IgG4-related disease is tubulointerstitial nephritis, it can rarely present as secondary membranous nephropathy. We present a case of a 75-year-old male with phospholipase A2 receptor-negative membranous nephropathy as an atypical manifestation of IgG4-related disease. The patient presented with nephrotic syndrome and was found to have elevated serum IgG4 levels and IgG4-positive plasma cells in the kidney biopsy. He was successfully treated with corticosteroids and rituximab, resulting in significant improvement in proteinuria and normalization of IgG4 levels. This case highlights the importance of considering IgG4-related disease in patients with phospholipase A2 receptor-negative membranous nephropathy, especially in those with a history of other organ involvement. Early recognition and treatment of IgG4-related disease are crucial to prevent progressive kidney damage and improve patient outcomes.
IgG4相关性疾病是一种纤维炎性疾病，其特征为富含IgG4阳性浆细胞的致密淋巴浆细胞浸润，可累及多个器官。尽管IgG4相关性疾病最常见的肾脏表现是肾小管间质性肾炎，但它很少表现为继发性膜性肾病。我们报告一例75岁男性，其患有磷脂酶A2受体阴性的膜性肾病，这是IgG4相关性疾病的一种非典型表现。该患者表现为肾病综合征，肾活检发现血清IgG4水平升高及IgG4阳性浆细胞。他接受糖皮质激素和利妥昔单抗治疗后获得成功，蛋白尿显著改善，IgG4水平恢复正常。该病例强调了在磷脂酶A2受体阴性的膜性肾病患者中考虑IgG4相关性疾病的重要性，尤其是那些有其他器官受累病史的患者。早期识别和治疗IgG4相关性疾病对于预防进行性肾损害和改善患者预后至关重要。
