Service de Néphrologie, Hôpital Nord CHU Saint Etienne, Saint Etienne, France.
University of Medicine and Pharmacy "Carol Davila", Nephrology Department, Bucharest, Romania.
Nephrol Dial Transplant. 2023 Nov 8;38(Supplement_2):ii11-ii18. doi: 10.1093/ndt/gfad163.
Complement alternative pathway (AP) activation is linked to immunoglobulin A nephropathy (IgAN) prognosis severity, but Bb fragment's role is unclear. We examined the relationship between serum Bb fragment concentration at IgAN diagnosis and disease activity and outcomes.
This retrospective study included 125 biopsy-proven IgAN patients [age 39.9 years, 75% male, estimated glomerular filtration rate (eGFR) 82 ml/min, proteinuria 0.5 g/day] enrolled from 1984 to 2010 and followed for a minimum of 18 months. Monitoring continued until the last follow-up, end-stage kidney disease (ESKD) or death. Serum Bb fragment was measured using an enzyme-linked immunosorbent assay at diagnosis. Oxford classification and global optical score (GOS) were utilized for pathology assessment.
Patients were followed for a median of 16 years; 42% developed chronic kidney disease stage ≥3, 19% reached ESKD and 9% died. Serum Bb fragment concentration negatively correlated with eGFR values at the last follow-up and positively with vascular and tubular histopathological indices. In univariate Cox regression analyses, higher Bb fragment concentration was associated with ESKD alongside older age, increased body mass index, arterial hypertension, lower eGFR, higher proteinuria, E1, S1, T1-2, GOS and corticotherapy. Patients with Bb levels ≥14.3 μg/ml had shorter mean kidney survival time (19.5 versus 22.7 years, P = .07); after adjusting for progression risk factors, the association persisted [hazard ratio 4.76 (95% confidence interval 1.56-14.43)].
Serum Bb fragment concentration at diagnosis may predict long-term IgAN outcomes, potentially due to AP activation at the endothelial surface. Further research is needed to confirm these results and evaluate Bb fragment's role in IgAN management.
补体替代途径 (AP) 的激活与免疫球蛋白 A 肾病 (IgAN) 的预后严重程度有关，但 Bb 片段的作用尚不清楚。我们研究了 IgAN 诊断时血清 Bb 片段浓度与疾病活动度和结局之间的关系。
本回顾性研究纳入了 1984 年至 2010 年间经活检证实的 125 例 IgAN 患者（年龄 39.9 岁，75%为男性，估算肾小球滤过率[eGFR]为 82ml/min，蛋白尿 0.5g/天），并进行了至少 18 个月的随访。监测持续到最后一次随访、终末期肾病（ESKD）或死亡。在诊断时使用酶联免疫吸附试验测量血清 Bb 片段。采用牛津分类和全球光学评分（GOS）进行病理评估。
患者中位随访时间为 16 年；42%的患者发展为慢性肾脏病 3 期及以上，19%的患者进入 ESKD，9%的患者死亡。血清 Bb 片段浓度与最后一次随访时的 eGFR 值呈负相关，与血管和管状组织病理学指标呈正相关。在单因素 Cox 回归分析中，较高的 Bb 片段浓度与 ESKD 以及年龄较大、体重指数增加、动脉高血压、eGFR 降低、蛋白尿增加、E1、S1、T1-2、GOS 和皮质激素治疗相关。Bb 水平≥14.3μg/ml 的患者平均肾脏生存时间较短（19.5 年 vs. 22.7 年，P=0.07）；在调整进展风险因素后，这种相关性仍然存在[风险比 4.76（95%置信区间 1.56-14.43）]。
诊断时血清 Bb 片段浓度可能预测 IgAN 的长期结局，这可能是由于内皮表面的 AP 激活所致。需要进一步研究来证实这些结果，并评估 Bb 片段在 IgAN 管理中的作用。
