Clinical and prognostic significance of PMN in children with glomerular C1q deposition

Abstract Background Currently, studies to data in MN are consistent with complement activation has an essential role in mediating renal injury, and the LP is considered to be the principal pathway in PMN. CP activation initiated by C1q which deposits are suggestive of SMN. However, C1q deposition together with IgG and C3 granular deposit is found in many cases of PMN. Currently, the clinical and prognostic significance of C1q deposition in PMN is unclear. Therefore, we conduct this single-center research to explore the clinical and prognostic significance of C1q deposition in children with PMN. Method: 73 patients with C1q deposition were enrolled in this study. According to the “Case-control matching principle”, 73 patients without C1q deposition during the same period of the renal biopsy were selected as a control group. The clinical and pathological characteristics, treatment response, and long-term renal prognosis were compared between patients with and without C1q deposition. Result A total of 146 pediatric patients with PMN included with 86 men(58.9%) and 60 women (41.1%). The median age at onset was 15.0 (14.0—16.0) years. During an average follow-up of 52.4 ± 35.6 months, 8 patients (5.5%) progressed ESKD, 12 (8.2%) patients developed ESRD or renal dysfunction. The frequency of glomerular C4 deposits in the C1q deposits group was significantly higher than no C1q deposits group (34.2% vs 5.5%, p = 0.000). There were no other distinct differences in clinical and pathological characteristics between the two groups. Glomerular IgG subclasses were available in 79 patients, there was no difference in the glomerular IgG subclass distribution between the two groups (p IgG1=0.468,p IgG2=1.000༌p IgG3=0.988༌p IgG4=0.216). The Kaplan-Meier survival analysis found that there was no difference in the renal survival of ESRD (p = 0.415) and a combined event of ESRD and/or renal dysfunction (p = 0.214) between the two groups. The logistic regression analysis (p = 0.553) and Cox regression analysis (p = 0.618) revealed that C1q deposition failed to associate with renal dysfunction. Conclusion The CP does occur in some patients of PMN. However, it may be unrelated to the progression of the disease.