Katsuno Takayuki, Kato Masashi, Fujita Takashi, Tsuboi Naotake, Hattori Ryohei, Ito Yasuhiko, Maruyama Shoichi
Department of Nephrology and Rheumatology, Aichi Medical University, 1-1 Karimata, Yazako, Nagakute, 480-1195, Japan.
Department of Nephrology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
CEN Case Rep. 2019 Aug;8(3):151-158. doi: 10.1007/s13730-019-00384-6. Epub 2019 Feb 25.
Proliferative glomerulonephritis with monoclonal immunoglobulin G (IgG) deposits (PGNMID) is a rare disease that recently became recognized. Its pathological findings are characterized by the deposition of a single heavy chain subclass and a single light chain isotype. PGNMID has been proven to recur in renal allografts. Herein, the authors describe the case of a 46-year-old man who presented with nephrotic syndrome and progressive kidney injury following kidney transplantation. One month after transplantation, his clinical condition stabilized; however, the protocol biopsy showed depositions of IgG and complement on the glomeruli by immunofluorescence staining. Electron microscopy (EM) revealed granular electron-dense deposits (EDD) in the mesangium. Thereafter, renal biopsy was repeated because his proteinuria level increased. Proliferative glomerulonephritis, mainly in the mesangium, with IgG and complement deposits and mesangial and subendothelial EDD were observed; however, the pathological diagnosis was difficult. Renal dysfunction then became apparent, and renal biopsy was performed again 4 years and 10 months after kidney transplantation. Glomerular deposits on a single IgG subclass and a single light chain isotype (IgG3 kappa) with membranoproliferative features were observed. Abundant subendothelial EDD were detected on EM. Finally, the patient was diagnosed with PGNMID. Since it seemed that PGNMID had already developed at 1 month after transplantation, we considered recurrent PGNMID case in the allograft. The treatment for PGNMID has not been established yet, and even in this case, the graft function was eventually lost. For improving renal prognosis, early diagnosis and further investigation on the treatment are necessary.
伴有单克隆免疫球蛋白G(IgG)沉积的增殖性肾小球肾炎(PGNMID)是一种最近才被认识的罕见疾病。其病理表现特征为单一重链亚类和单一轻链同种型的沉积。PGNMID已被证实在肾移植中会复发。在此,作者描述了一例46岁男性病例,该患者在肾移植后出现肾病综合征和进行性肾损伤。移植后1个月,他的临床状况稳定;然而,方案活检通过免疫荧光染色显示肾小球有IgG和补体沉积。电子显微镜(EM)显示系膜中有颗粒状电子致密沉积物(EDD)。此后,由于他的蛋白尿水平升高,再次进行了肾活检。观察到主要在系膜的增殖性肾小球肾炎,伴有IgG和补体沉积以及系膜和内皮下EDD;然而,病理诊断困难。随后肾功能障碍变得明显,在肾移植后4年10个月再次进行了肾活检。观察到单一IgG亚类和单一轻链同种型(IgG3 κ)的肾小球沉积,具有膜增生性特征。EM检测到大量内皮下EDD。最终,该患者被诊断为PGNMID。由于似乎在移植后1个月PGNMID就已经发生,我们认为这是同种异体移植中复发性PGNMID病例。PGNMID的治疗方法尚未确立,即使在该病例中,移植肾功能最终还是丧失了。为改善肾脏预后,早期诊断和对治疗的进一步研究是必要的。