Vanjarapu Jagan Mohan Rao, Iglesias Jose, Ahmed Rumana, Singh Pratiksha, Gerbino Gabrielle, Stokes Michael Barry
Internal Medicine, Community Medical Center, Toms River, USA.
Nephrology, Community Medical Center, Toms River, USA.
Cureus. 2022 Jun 15;14(6):e25949. doi: 10.7759/cureus.25949. eCollection 2022 Jun.
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.
伴单克隆免疫球蛋白（mIg）沉积的增殖性肾小球肾炎（PGNMID）是一种罕见的肾小球疾病，其特征为肾小球存在mIg沉积。对于无循环mIg的PGNMID的发病机制了解甚少，但有人提出，对感染或其他外源性刺激的异常免疫反应起了一定作用。我们描述了一例独特的PGNMID病例，该病例表现为多次急性肾损伤、肾病综合征和补体减少，与自限性发热性疾病或新冠病毒疫苗接种有关。在血清和尿液中检测到单克隆IgG λ，这与具有肾意义的单克隆丙种球蛋白病（MGRS）一致。连续的肾活检显示出不断演变的形态学和免疫组织学特征，仅在第三次活检中发现了单型IgG λ沉积。尽管需要透析，但每次发作后，通过皮质类固醇治疗，肾功能障碍和补体减少均得到缓解。该病例表明，感染或新冠病毒疫苗接种可能是促进PGNMID中mIg沉积的“二次打击”，可能是由于先天免疫细胞释放细胞因子促进了内皮细胞损伤。
