Department I of Nephrology, Beijing Children's Hospital, National Center for Children's Health, Capital Medical University, Beijing, 100045, China.
Department of Pathology, Beijing Children's Hospital, National Center for Children's Health, Capital Medical University, Beijing, 100045, China.
Pediatr Nephrol. 2023 Feb;38(2):431-438. doi: 10.1007/s00467-022-05585-3. Epub 2022 Jun 13.
Both IgA nephropathy (IgAN) and Henoch-Schönlein purpura nephropathy (HSPN) are characterized by glomerular mesangial IgA deposition. Several large studies on adults have suggested that glomerular C4d deposition has prognostic value in IgAN. However, there are few relevant studies on the clinical value of C4d deposition in children with IgAN or HSPN.
We performed a retrospective cohort study in pediatric patients with IgAN or HSPN. Clinicopathological data were collected at the time of kidney biopsy. Kidney C4d deposition was analyzed by immunohistochemistry. The end point was defined as a ≥ 20% decrease in estimated glomerular filtration from baseline.
We enrolled 75 children, including 36 children with IgAN and 39 with HSPN. The prevalence of C4d deposition was 36% (27/75). C4d deposition was more abundant in children with proteinuria ≥ 50 mg/kg/day (51.9% versus 20.8%, P = 0.006) or nephrotic syndrome (37.0% versus 10.4%, P = 0.006). Mesangial hypercellularity (hazard ratio [HR], 5.745, 95% confidence interval [CI], 1.670-19.761, P = 0.006) and IgM deposition (HR, 4.522, 95% CI, 1.321-15.478, P = 0.016) were associated with C4d deposition. After a median follow-up of 22 months, seven (19.4%) IgAN patients and one (2.6%) HSPN patient had decreased kidney function. In children with IgAN, positive C4d was associated with decreased kidney function (P = 0.047).
Glomerular C4d deposition was associated with mesangial hypercellularity and glomerular IgM deposition in IgAN and HSPN. Glomerular C4d deposition may be a risk factor for eGFR decline in children with IgAN. A higher resolution version of the Graphical abstract is available as Supplementary information.
IgA 肾病（IgAN）和过敏性紫癜性肾炎（HSPN）的特征均为肾小球系膜区 IgA 沉积。几项针对成人的大型研究表明，肾小球 C4d 沉积在 IgAN 中具有预后价值。然而，关于 IgAN 或 HSPN 患儿肾小球 C4d 沉积的临床价值的相关研究较少。
我们对 IgAN 或 HSPN 患儿进行了回顾性队列研究。在肾活检时收集临床病理数据。通过免疫组织化学分析肾脏 C4d 沉积。终点定义为肾小球滤过率从基线下降≥20%。
我们纳入了 75 名儿童，其中 36 名患有 IgAN，39 名患有 HSPN。C4d 沉积的患病率为 36%（27/75）。蛋白尿≥50mg/kg/天（51.9%比 20.8%，P=0.006）或肾病综合征（37.0%比 10.4%，P=0.006）患儿的 C4d 沉积更丰富。系膜细胞增生（危险比[HR]，5.745，95%置信区间[CI]，1.670-19.761，P=0.006）和 IgM 沉积（HR，4.522，95%CI，1.321-15.478，P=0.016）与 C4d 沉积相关。中位随访 22 个月后，7 名（19.4%）IgAN 患儿和 1 名（2.6%）HSPN 患儿出现肾功能下降。在 IgAN 患儿中，C4d 阳性与肾功能下降相关（P=0.047）。
IgAN 和 HSPN 中，肾小球 C4d 沉积与系膜细胞增生和肾小球 IgM 沉积相关。肾小球 C4d 沉积可能是 IgAN 患儿 eGFR 下降的一个危险因素。一个更高分辨率的图表摘要版本可以作为补充信息获得。
