The relationship between complement 3 and IgAN in clinic and pathology / 中国医师杂志

ABSTRACT

Objectives By Oxford pathological classification and analysis of circulating complement complement 3 (C3),renal C3 deposition,and clinical laboratory tests,we discussed the correlation between complement C3 and immunoglobin A nephropathy (IgAN) in pathogenesis.Methods A retrospective study of 558 IgAN cases at Xinhua Hospital from January of 2000 through December of 2013 was performed.All 558 IgAN diagnoses were made and confirmed by renal needle biopsy.Results Compared to patients who had circulating C3 ＜ 0.9,patients with circulating C3 level ＞ 0.9 showed statistically significant decreases in serum creatinine [(100.92 ± 105.31) μmol/L vs (157.58 ± 208.39) μmol/L,t =-2.283,P =0.025],blood urea nitrogen [(5.69 ± 2.88) mmol/L vs (7.69 ± 5.90) mmoL/L,t =-2.81,P =0.006];besides,other parameters like IgA,body weight,body mass index (BMI),cholesterol,triglyceride,serum IgA/C3 ratio,albumin,and estimated glomeruli filtrate rate (eGFR) also presented statistically significant differences between two patient groups;no statistically significant differences were observed between two groups in glomerular mesangial cell proliferation,capillary endothelial proliferation,segmental glomerular sclerosis or adhesions,renal tubule atrophy,tubulointerstitial fibrosis,and formation of glomerular crescent;meanwhile,no statistically significant differences were observed between two groups in mesangial depositions of IgA,IgG,IgM,and complement C3;meanwhile the blood level of C3 between C3 deposition negative group,deposition 2 + and 3 + subgroup showed statistically significant differences (2.493 and 2.782;0.013 and 0.006),nevertheless,prognostic indices in Oxford classification,such as mesangial cell proliferation,capillary endothelial proliferation,segmental glomerular sclerosis or adhesions,renal tubule atrophy and tubulointerstitial fibrosis,were also statistically different between two patient groups (Pearson Square test result was 50.782,35.141,21.105,30.182,respectively;P ＜0.01).Conclusions Renal deposition of complement C3 or decrease in circulating C3 level may be associated with a poor prognosis of IgA nephropathy,and alteration in C3 dynamics may be implicated in the pathogenesis of IgAN through its involvement in humoral immunity.