Value Of Serum IgA/C3 Ratio And Serum IgG In The Diagnosis Of Iganephropathy And Its Correlation With Clinicopathological Features

Part Ⅰ: Research the diagnostic value of serum Ig A/C3 ratio and Ig G for Ig ANObjective: To study the value of serum IgA/C3 ratio and IgG diagnosis and prediction in patients with IgA nephropathy.Method:1.Select 80 cases of IgA nephropathy,100 cases of other glomerulonephritis diagnosed by renal biopsy in Gansu People’s Hospital from November 2015 to August 2018,and 50 cases of health examination in Gansu People’s Hospital Physical Examination Center at the same time.2.Collected the medical records during hospitalization in the first renal biopsy,and calculateed IgA/C3 ratio and other related indicators(eGFR)according the collected data.3.The basic data of IgA nephropathy group,other glomerular diseases and healthy control group were analyzed.4.By drawing ROC curve and calculating the area under the curve,the best predictive cut-off point,sensitivity and specificity of IgA/C3 ratio and serum IgG for disease diagnosis were determined.5.According to the results of serum IgA/C3 2.64 as the cut-off point,the experimental groups were divided into two groups: IgA/C3 < 2.64 and IgA/C3 < 2.64.The laboratory indicators and renal pathological characteristics were analyzed.6.The results were analyzed using statistical software SPSS20.0.Result:1.Comparison the basic data:①The average ages of IgAN group,other glomerular diseases group and healthy control group were 32.17 years old,41.02 years old and 41.84 years old respectively(P < 0.05).②There was no significant difference between the sexes of each group(P > 0.05).2.Comparison clinical data:①Compared with other glomerular diseases,IgA nephropathy group had lower 24-hour urinary protein,cholesterol,low density lipoprotein and triglyceride levels,but higher albumin levels(P < 0.05).②At the same time,IgA nephropathy group was compared with other glomerulonephritis and healthy control group.It was found that the levels of age,hemoglobin,glomerular filtration rate,high density lipoprotein and complement C3 in IgA nephropathy group were lower than those in control group.③On the other hand,the levels of serum creatinine,serum IgG,serum IgA and IgA/C3 ratio were higher than those in other two groups,and the difference was significant(P < 0.05).3.The diagnostic value of serum IgA/C3 ratio and IgG for diseases:①The sensitivity and specificity of serum IgA/C3 ratio in distinguishing IgAN from non-IgAN were 75% and 69%,respectively.The area under the curve was 0.777,and the cut-off point was 2.64.②The sensitivity and specificity of serum IgG in distinguishing IgA nephropathy from non-IgA nephropathy were 67.5% and 87%,respectively.The area under curve was 0.802 and the cut-off point was 7.76.3.After grouping according to the obtained cut-off points,the analysis is carried out:①The serum IgA/C3 > 2.64 levels of age,24-hour urinary protein quantification,serum IgG and IgA were higher than those of serum IgA/C3 < 2.64.②Other indicators such as hemoglobin,cholesterol,low density lipoprotein and complement C3 were lower,and the difference was statistically significant(p < 0.05).Conclusion:1.Compared with other patients with glomerular nephropathy,IgA nephropathy has the characteristics of younger age.2.The immune response of IgAN group was active,and the serum IgG,IgA and IgA/C3 were higher than those of other two groups,and the complement level was significantly lower than that of other two groups.The higher serum creatinine level and lower glomerular filtration rate of IgA nephropathy may be considered that the renal function damage of IgA nephropathy patients was more serious;the level of proteinuria was significantly smaller than that of other glomerular diseases,and the disorder of lipid metabolism in vivo was relatively lower.Light.3.ROC curve analysis showed that the predicted cut-off point of serum lgA/C3 ratio was 2.64 and serum IgG cut-off point was 7.76.According to its sensitivity and specificity,the sensitivity of serum lgA/C3 ratio was high,and the specificity of serum IgG was higher.Combining the two methods,the disease prediction effect could be better.Part Ⅱ: The correlation between serum Ig A/C3 ratio and pathological indexes of Ig A nephropathyObjective: To further explore the relationship between serum IgA/C3 ratio and renal pathological classification.Method:1.The clinical data are the same as in part I.The renal tissue samples of the experimental group undergoing renal biopsy were examined by light microscopy,immunofluorescence and electron microscopy.2.According to light microscopic findings,Oxford classification and WHO classification of renal pathology were performed.The criteria for Oxford classification were: 1.Mesangial cell and Matrix Hyperplasia(M): M0 or M1;2.Capillary endothelial cell proliferation E0 or E1;3.Segmental sclerosis and adhesion S0 or S0;4.Renal tubular atrophy and/or interstitial fibrosis(T)T0: < 50%,T1: > 50%.5.Crescent formation(C)C1 and C 2,MEST-C score = M+E+S+T+C,ranging from 0-5,and then the data were divided into MEST-C<3 groups and MEST-C>3 groups for analysis.3.According to the intensity of immunofluorescence staining of IgA and C3 deposited in renal tissue,the patients in the experimental group were divided into strong positive group(IgA staining intensity(++),C3 staining intensity(++),weak positive group(IgA staining intensity(++),C3 staining intensity(++).The clinical data of the two groups were analyzed.4.The results were analyzed using statistical software SPSS20.0.Result:1.According to Oxford grading,IgA nephropathy group was divided into MEST-C > 3group and MEST-C < 3 group.The higher score,the higher the serum creatinine level,24-hour urinary protein level,and the lower the glomerular filtration rate and hemoglobin level.2.According to the four indexes of Oxford typing M,E,S,T,C and the ratio of WHO typing index to serum IgA/C3,no statistical difference(p>0.05).3.According to the expression of IgA and complement C3 in renal biopsy,the ratio of IgA/C3 in strong positive group was higher than that in weak positive group(P < 0.05).Conclusion:1.There is no significant correlation between serum IgA/C3 level and pathological changes of IgA nephropathy,so according to the results of this experiment,IgA/C3 ratio can not be used as an index to evaluate clinical prognosis.2.The higher the patient’s pathological score,the more serious the patient’s condition is according to the relevant clinical indicators such as higher serum creatinine,urinary protein quantification and lower glomerular filtration rate.3.The ratio of IgA/C3 in serum of patients with IgA nephropathy can reflect the degree of IgA and C3 deposition in mesangial area.The higher the level of IgA/C3 in serum,the heavier the level of IgA and C3 deposition in mesangial area of glomeruli.4.Serum lgA/C3 ratio and serum Ig G could not replace renal biopsy,but could be used as a simple auxiliary diagnostic index for IgA nephropathy.