Association of complement C3 with urine protein level and proteinuria remission status in patients with primary membranous nephropathy
10.3760/cma.j.cn441217-20231204-01206
- VernacularTitle:补体C3与原发性膜性肾病患者尿蛋白水平及蛋白尿缓解情况的相关性
- Author:
Si CHEN
1
;
Ying PAN
;
Yifei LU
;
Li QIAN
;
Qing LI
;
Yili XU
;
Suyan DUAN
;
Lin WU
;
Bo ZHANG
;
Changying XING
;
Huijuan MAO
;
Yanggang YUAN
Author Information
1. 江苏省人民医院（南京医科大学第一附属医院）肾内科，南京 210000
- Keywords:
Glomerulonephritis, membranous;
Complement C3;
Proteinuria
- From:
Chinese Journal of Nephrology
2024;40(9):705-715
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the correlation between complement C3 and urine protein level and proteinuria remission status in patients with primary membranous nephropathy (PMN), and better guide individualized clinical treatment.Methods:It was a single-center retrospective study. The clinical data of PMN patients who underwent renal biopsy in the First Affiliated Hospital of Nanjing Medical University from January 2017 to June 2022 were collected. Patients with 24 h urinary protein ≥ 3.5 g were followed up after receiving standard treatment, and the last outpatient or inpatient review was used as the end point of follow-up. 24 h urine protein was collected to evaluate the remission status of proteinuria. Kaplan-Meier method was used to analyze the correlation between serum and renal complements and proteinuria remission. Cox regression analysis method was used to analyze the correlation between serum C3 level and renal tissue C3 deposition and proteinuria remission.Results:This study included 507 PMN patients with 312 (61.54%) males, aged 54 (43, 64) years old. Compared with 24 h urinary protein < 3.5 g group, proportion of males ( χ2=22.479, P<0.001), age ( Z=-2.521, P=0.012), systolic blood pressure ( Z=-4.148, P<0.001), diastolic blood pressure ( Z=-4.084, P<0.001), serum anti-phospholipase A2 receptor (PLA2R) antibody titer ( Z=-7.019, P<0.001), total cholesterol ( Z=-8.796, P<0.001), triglyceride ( Z=-6.158, P<0.001), low density lipoprotein cholesterol ( Z=-8.716, P<0.001), serum creatinine ( Z=-7.368, P<0.001), serum C3 ( Z=-3.663, P<0.001), serum C4 ( Z=-6.560, P<0.001), proportion of glucocorticoid use ( χ2=116.417, P<0.001) and proportion of immunosuppressant use ( χ2=53.839, P<0.001) were all higher, while serum albumin ( Z=12.518, P<0.001), estimated glomerular filtration rate ( Z=6.345, P<0.001) and serum IgG ( Z=7.321, P<0.001) were all lower in 24 h urinary protein ≥3.5 g group. There were 268 patients included in the follow-up cohort with baseline 24 h urinary protein of 7.15 (5.14, 10.24) g, serum anti-PLA2R antibody titer of 61.44 (14.35, 193.24) RU/ml, serum C3 of 1.005 (0.864, 1.150) g/L, and serum C4 of 0.260 (0.214, 0.317) g/L. Kaplan-Meier survival curve showed that the incomplete remission rate of proteinuria in serum C3 > 1.005 g/L group was lower than that in serum C3 ≤ 1.005 g/L group (log-rank χ2=4.757, P=0.029). There was no significant difference in the incomplete remission rate of proteinuria between serum C4 ≤ 0.260 g/L group and serum C4 > 0.260 g/L group (log-rank χ2=3.543, P=0.060). Renal C1q (log-rank χ2=0.167, P=0.683) and C4 (log-rank χ2=1.927, P=0.165) deposition had no significant effects on proteinuria remission in PMN patients. The incomplete remission rate of proteinuria in patients with renal C3 deposition was higher than that in patients without renal C3 deposition (log-rank χ2=7.018, P=0.008). Univariate Cox regression analysis showed that serum C3 level and C3 deposition in renal tissues were influencing factors of incomplete remission of proteinuria (both P<0.05), while adjusting for gender, age, mean arterial pressure, serum anti-PLA2R antibody, serum albumin and 24 h urinary protein, serum C3 ≤ 1.005 g/L ( HR=1.374, 95% CI 1.021-1.849, P=0.036), C3 deposition in renal tissues ( HR=1.949, 95% CI 1.098-3.460, P=0.023), and serum C3 ≤ 1.005 g/L combined with C3 deposition in renal tissues ( HR=1.472, 95% CI 1.093-1.983, P=0.011) were independent influencing factors of incomplete remission of proteinuria. Conclusions:The serum C3 level and C3 deposition in renal tissues are closely related to urinary protein level and proteinuria remission status in PMN patients. The patients with higher urinary protein have higher serum C3. For patients with massive proteinuria, serum C3 ≤ 1.005 g/L, C3 deposition in renal tissues, serum C3 ≤ 1.005 g/L combined with C3 deposition in renal tissues are independent risk factors of incomplete remission of proteinuria.
