The Relationship Between The Deposition Intensity Of Complement C1q And The Clinical Pathological Features Of Patients With Membranous Nephropathy

Objective: To explore the clinical significance of different C1 q deposition intensity in patients with membranous nephropathy ruling out all those with definite secondary factors.Methods: We included patients hospitalized in the Department of Nephrology,Union Hospital,Tongji Medical College,Huazhong University of Science and Technology from January 2016 to December 2019,who were biopsy-proven MN,ruling out those with definite secondary factors and had used steroids or immunosuppressants before renal biopsy,as the research objects.We then divided the patients into three groups according to the deposition intensity of C1 q,group A(C1q negative group),group B(C1q weak positive group),and group C(C1q strong positive group),retrospectively analyzed and compared the clinical data,laboratory examinations,pathological findings and follow-up results in 1 year.Results:1.One hundred twenty-five cases were enrolled,and 52.8% of the patients had glomerular C1 q deposition with different intensities.There were 49 cases in the weak positive group and 17 cases in the strong positive group.The average age of the patients was 48.14±11.93 years old,males accounted for 61.6%,and the median duration of the disease was 1.0(0.5,3.0)months.Patients with clinical manifestations of edema accounted for 84.0%,and patients with nephrotic syndrome accounted for68.0%.There were 36.0% of patients with a history of hypertension.The three groups of patients showed no statistically significant differences in age,gender,duration of the disease,clinical symptoms,and hypertension comorbidities.2.After further comparison between each two groups,it was found that compared with group A,the serum anti-PLA2 R antibody titer of group C was lower(P<0.05).In addition,the PLA2 R antibody positive rates of group B and group C were significantly lower than that of group A,and that of group C was lower than group B(P<0.05).Among the three groups,there were no statistical differences in urine blood cell,24 h urine protein,serum albumin,creatinine level,uric acid,total cholesterol,triglyceride,immunoglobulin levels(Ig G,Ig M,Ig A),complement C3 and C4 levels,and the positive rate of ANA antibody.3.In terms of the pathological findings of light microscopy,the comparison between groups showed that the incidences of segmental sclerosis in group B and C were lower than that in group A,and group B was even lower than group C(all P<0.05).The proportion of glomeruli with segmental sclerosis in group C was lower than that in group A(P<0.05),but higher than that in group B(P<0.05).There was no significant difference between group A and group B.In terms of other pathological parameters,such as the incidence of spherical sclerosis,the proportion of glomeruli with spherical sclerosis,the presence of intraglomerular cell proliferation,the degree of renal interstitial fibrosis,the degree of renal tubular atrophy,and vascular lesions,there were no differences among the three groups with statistical significance.4.The comparison between each two groups showed that the strong positive rate of Ig M in group C was significantly higher than that in group A and B(P<0.05),but there was no significant difference in the positive rate of Ig M between group B and A(P>0.05).The positive rates of complement C4 in group B and C were significantly higher than that in group A,and group C was higher than group B(P<0.05).With the increase of Clq deposition intensity,the strong positive rate of Ig A and Ig G2 increased,and the strong positive rate of PLA2 R decreased,but there were no statistical differences.The differences in the strong positive rates of other Ig G subtypes and complement C3 among the three groups of patients were not statistically significant.5.In terms of pathological staging,the three groups of patients were all mainly in stage II,accounting for 67.8%,67.4%,and 41.2% respectively.There was no statistically significant difference in the distribution of pathological stages among the three groups of patients(P>0.05).In terms of the location of electron dense deposits,there was no statistically significant difference in the rates of finding electron density deposition in the subendothelial and mesangial areas among the three groups(P>0.05)).6.In the choice of treatment options,the difference was not statistically significant among the three groups(P>0.05).By the end of the 12-month follow-up,statistical analysis showed that there was no statistical difference in the effective rates of the three groups(P>0.05).7.Among anti-PLA2 R antibody negative and anti-PLA2 R antibody positive patients respectively,the three groups had no statistical significant differences in general characteristics,serum albumin,urine protein quantification,renal function,serum anti-PLA2 R antibody titers,treatment,and remission rates(P>0.05).Conclusion: The intensity of glomerular C1 q deposition is related to the level of serum anti-PLA2 R antibody,glomerular segmental sclerosis,and the deposition of Ig M and complement C4 in renal tissue.In patients with strong C1 q positive,the serum anti-PLA2 R antibody levels are lower,glomerular segmental sclerosis changes are mild,and renal Ig M and complement C4 deposition are more significant.Weak C1 q positive deposition is of limited value in MN patients without definite secondary factors to further distinguishing IMN and SMN,while the role of strong C1 q positive deposition needs to be further explored.