Association of serum complement C3, C4 with renal pathological lesion degree in IgA nephropathy patients / 中华肾脏病杂志

ABSTRACT

Objective:To explore the relationship between the levels of serum complement C3 and C4 and the degree of renal pathological injury in patients with IgA nephropathy (IgAN).Methods:It was a retrospective study. The clinical and pathological data of patients with primary IgAN diagnosed by renal biopsy in the Department of Nephrology of the Second People's Hospital of Qujing City, Yunnan Province from December 1, 2019 to December 31, 2022 were collected. According to the IgAN Oxford classification criteria, the patients were divided into mild renal pathological injury group (mild group, <3 pathologic types) and severe renal pathological injury group (severe group, ≥3 pathological types). The levels of serum C3 and C4 and other clinical data were compared between the two groups. Spearman correlation method was used to analyze the correlation between serum C3, C4 levels and estimated glomerular filtration rate (eGFR) during renal biopsy.Multivariate logistic regression model was used to analyze the influencing factors of the pathological injury degree in IgAN patients and the forest map depicted the effect of risk factors.Results:A total of 164 IgAN patients were included in the study, including 77 males (47.0%), aged (35.5±12.9) years old. There were 60 patients in the mild group and 104 patients in the severe group. Compared with the mild group, the patients in the severe group were older, had higher levels of serum C4, serum uric acid, low density lipoprotein cholesterol and 24 h urinary protein, higher proportions of hypertension, glucocorticoids/immunosuppressant therapy, C3 deposition in renal tissues and microscopic hematuria, and had lower hemoglobin and serum C3 level (all P<0.05). The results of Spearman correlation analysis showed that the level of serum C3 was positively correlated with eGFR ( r=0.303, P<0.001), and the level of serum C4 was negatively correlated with eGFR ( r=-0.238, P=0.002). Multivariate logistic regression analysis results showed that serum C3 (every 0.01 g/L increase, OR=0.976, 95% CI 0.957-0.996, P=0.018), serum C4 (every 0.01 g/L increase, OR=1.091, 95% CI 1.020-1.166, P=0.011), hemoglobin ( OR=0.969, 95% CI 0.950-0.988, P=0.002), and serum uric acid ( OR=1.005, 95% CI 1.001-1.009, P=0.012) were independent related factors of renal pathological damage (severe injury /mild injury) in IgAN patients. Conclusions:Serum C3 and C4 are independent related factors of the severity of renal pathological injury in IgAN patients.