ObjectiveTo analyze the significance of complement C3 deposition in the mesangial region of glomeruli in IgA nephropathy pathogenesis and progression, so as to provide the basis for disease diagnosis, condition monitoring and prognosis judgment.

MethodsThe clinical and pathological examination indexes in patients with IgA nephropathy were retrospectively analyzed.According to the intensity of C3 deposition in the mesangial area, the patients were divided into the negative group(-), weak positive group(±to +) and strong positive group(2+ to 3+), and the corresponding indicators were statistically analyzed.

ResultsAccording to the classification of complement C3 deposition intensity, 10 cases(23.3%) in the negative group, 13 cases(30.2%) in weak positive group and 20 cases(46.5%) in strong positive group were identified.With the aggravation of tissue C3 deposition, the blood creatinine and urea nitrogen increased, the eGFR decreased, and the difference of which was statistically significant(P < 0.05 to P < 0.01).However, the differences of the uric acid, 24 h urine protein quantification and microscopic haematuria, blood lipid, blood pressure and blood glucose were not statistically significant(P>0.05).The results of Pearson correlation analysis showed that the intensity of complement C3 was opposite to the value of serum C3, but there was no statistical significance between them(P>0.05).The intensity of C3 immunofluorescence deposition in renal tissue was correlated with the pathological damage, but the difference of pathological grading(Lee grading) was not statistically significant(P>0.05), and the differences of intensity of C3 immunofluorescence deposition in renal tissue among the different mesangial cell proliferation, capillary endothelial cell proliferation, globular sclerosis, and renal tubular interstitial lesions(including interstitial inflammatory cell infiltration, interstitial fibrosis and renal tubular atrophy) were statistically significant(P < 0.05).

ConclusionsThe intensity of C3 deposition in the mesangial region of glomeruli in patients with IgA nephropathy is related to the serum creatinine, urea nitrogen, eGFR and pathological damage, and which may be used as an indicator to monitor and predict the prognosis of IgA nephropathy.