Study On The Relationship Between Renal Deposition Of Complement C3,IgG,IgM And Pathology In IgA Nephropathy

Objective:To investigate the effect of complement C3,IgG and IgM renal deposition on renal pathological damage in patients with IgA nephropathy,and to evaluate whether complement C3 pathological deposition is an independent risk factor for the prognosis of IgA nephropathy.Methods:Retrospectively analysis was performed for the electronic medical records of 119 patients with primary IgA nephropathy diagnosed by renal biopsy in the department of nephrology of The first affiliated Hospital of Kunming Medical University(From August 1,2019 to January 30,2021).Including 68 males and 51 females.Collect general data of patients such as sex,age,body mass index(BMI),nationality,history of smoking and drinking,etc,and laboratory data such as hemoglobin(Hb),albumin(Alb),serum creatinine(SCr),uric acid(UA),retinol binding protein(RBP),cystatin C(Cys-C),24-hour urinary protein(24h-UP),estimated glomerular filtration rate(eGFR),serum total cholesterol(TC),triglyceride(TG),high density lipoprotein cholesterol(HDL-C),low density lipoprotein cholesterol(LDL-C),serum immunoglobulin and complement components,etc,and pathological data such as glomerular IgA,IgG,IgM,complement C3 deposition intensity,Lee grade and Oxford classification.The patients were divided into three groups according to Lee grading.The differences of general data,laboratory data and pathological data among the three groups were compared.The independent influencing factors of pathological Lee grading in patients with IgAN were analyzed by Logistic regression.Glomerular immunoglobulin and complement deposition were evaluated by Lee classification and Oxford pathological classification,and their effects on kidney damage were discussed.p<0.05 there were significant differences.Results:1.The MAP level in Lee Ⅳ+Ⅴ group was higher than that in Lee Ⅰ+Ⅱ group(p<0.05).2.The average levels of Hb and Alb in Lee Ⅰ+Ⅱ group were higher than those inⅢ group and Ⅳ+Ⅴ group(p<0.05).3.The levels of renal function indexes SCr,UA,Urea,RBP and Cys-C in LeeⅣ+Ⅴ grade group were higher than those in Ⅰ+Ⅱ grade group and Ⅲ grade group(p<0.05),while eGFR was lower than that in two groups(p<0.05).4.In terms of 24h-UP level,the level of 24h-UP in Lee Ⅳ+Ⅴ group was higher than that in Ⅲ group(p<0.05).The level in Lee Ⅲ group was also higher than that in Lee Ⅰ+Ⅱ group(p<0.05).There was a significant step change among the three groups.5.There was no correlation between the levels of serum IgA,C3,IgM,IgG and the intensity of pathological deposition in patients with IgAN(p>0.05);6.The positive rate of complement C3 deposition in Lee Ⅲ group and Ⅳ+Ⅴgroup was higher than that in Ⅰ+Ⅱ group(p<0.017).7.Multivariate Logistic regression analysis showed that Hb,Alb,SCr,Cys-C,RBP and complement C3 deposition were independent factors affecting the Lee grade of renal biopsy in patients with IgAN.8.According to Oxford classification,the deposition rate of complement C32+～3+in M1 and S1 groups was higher than that in M0 and S1 groups(p<0.05).9.The positive rate of IgG deposition in Oxford type El group was higher than that in E0 group(p<0.05).Conclusions:1.The decrease of Hb and Alb,the increase of SCr,Cys-C and RBP in IgAN patients and the positive deposition of complement C3 are the independent risk factors affecting the Lee’s grade of patients.2.There was no correlation between the levels of serum IgA,C3,IgM,IgG and the intensity of pathological deposition in patients with IgAN.3.High deposition of complement C3(2+～3+)in renal tissue of patients with IgAN may promote mesangial cell proliferation and glomerular segmental sclerosis or adhesion.