IgG4-related disease (IgG4-RD) is an immune-mediated disorder often showing elevated serum IgG4 concentrations, dense T and B lymphocyte infiltration, and IgG4-positive plasma cells and storiform fibrosis. We prospectively evaluated for 4 years 5 patients with histologically proven IgG4-RD of whom 3 had tubulointerstitial nephritis (TIN) and 2 had retroperitoneal fibrosis (RPF). They received an intensive B depletion therapy with rituximab. The estimated glomerular filtration rate of TIN patients after 1 year increased from 9 to 24 ml/min per 1.73 m2. IgG/IgG4 dropped from 3236/665 to 706/51 mg/dl, C3/C4 went up from 49/6 to 99/27 mg/dl, and the IgG4-RD responder index fell from 10 to 1. CD20⁺ B cells decreased from 8.7 to 0.5%. A striking drop in interstitial plasma cell infiltrate as well as normalization of IgG4/IgG-positive plasma cells was observed at repeat biopsy. Both clinical and immunological improvement persisted over a 4-year follow-up. Treating these patients who were affected by aggressive IgG4-RD with renal involvement in an effort to induce a prolonged B cells depletion with IgG4 and cytokine production decrease resulted in a considerable rise in eGFR, with IgG4-RD RI normalization and a noteworthy improvement in clinical and histological features. Furthermore, the TIN subgroup was shown not to need for any maintenance therapy.

IgG4 相关疾病 (IgG4-RD) 是一种免疫介导的疾病，通常表现为血清 IgG4 浓度升高、密集的 T 和 B 淋巴细胞浸润以及 IgG4 阳性浆细胞和纹状纤维化。我们前瞻性地评估了 4 年 5 名经组织学证实为 IgG4-RD 的患者，其中 3 名患有小管间质性肾炎 (TI​​N)，2 名患有腹膜后纤维化 (RPF)。他们接受了利妥昔单抗的强化 B 耗竭疗法。TIN 患者的估计肾小球滤过率在 1 年后从每 1.73 m2 9 增加到 24 ml/min。IgG/IgG4 从 3236/665 下降到 706/51 mg/dl，C3/C4 从 49/6 上升到 99/27 mg/dl，IgG4-RD 反应指数从 10 下降到 1。 CD20 ⁺B 细胞从 8.7% 减少到 0.5%。在重复活检时观察到间质浆细胞浸润的显着下降以及 IgG4/IgG 阳性浆细胞的正常化。临床和免疫学改善持续了 4 年的随访。对这些受侵袭性 IgG4-RD 影响且肾脏受累的患者进行治疗，以努力诱导长期的 B 细胞耗竭和 IgG4 和细胞因子产生的减少，导致 eGFR 显着升高，IgG4-RD RI 正常化和临床显着改善和组织学特征。此外，TIN 亚组显示不需要任何维持治疗。