PDF(Pubmed)
Abstract：
Proliferative glomerulonephritis with monoclonal immunoglobulin (mIg) deposits (PGNMID) is a rare glomerular disease characterized by glomerular deposits of mIg. The pathogenesis of PGNMID without circulating mIg is poorly understood but a role for aberrant immune response to infection or another exogenous stimulus has been proposed. We describe a unique case of PGNMID that presented with multiple episodes of acute kidney injury, nephritic syndrome, and hypocomplementemia, associated with self-limited febrile illnesses or COVID-19 vaccination. Monoclonal IgG lambda was detected in the serum and urine, consistent with monoclonal gammopathy of renal significance (MGRS). Consecutive kidney biopsies demonstrated evolving morphologic and immunohistologic features, with monotypic IgG lambda deposits identified only in the third biopsy. Despite the need for dialysis, renal dysfunction and hypocomplementemia resolved after each episode with corticosteroid therapy. This case illustrates infections or COVID vaccination maybe \"second hits\" that promote mIg deposition in PGNMID, possibly due to cytokine release by innate immune cells that promote endothelial cell injury.
摘要：
具有单克隆免疫球蛋白（mIg）沉积（PGNMID）的增殖性肾小球肾炎是一种罕见的肾小球疾病，其特征是肾小球mIg沉积。对不含循环mIg的PGNMID的发病机理了解甚少,但已经提出了对感染或另一种外源性刺激的异常免疫应答的作用。我们描述了一个独特的PGNMID病例，表现为多次急性肾损伤发作，肾病综合征,和低补体血症，与自限性发热疾病或COVID-19疫苗接种有关。在血清和尿液中检测到单克隆IgGλ，符合肾意义的单克隆丙种球蛋白病（MGRS）。连续的肾脏活检显示不断发展的形态学和免疫组织学特征，仅在第三次活检中鉴定出单型IgGλ沉积物。尽管需要透析,每次使用皮质类固醇治疗后,肾功能障碍和低补体血症均得到缓解.这种情况说明感染或COVID疫苗接种可能是“二次命中”，会促进PGNMID中的mIg沉积，可能是由于先天免疫细胞释放的细胞因子促进内皮细胞损伤。
