Correlative Analysis Of The Degree Of Primary IgA Nephropathy Tubulointerstitial Lesions With Clinical Indicators And Pathological Data

Objective: This study retrospectively analyzed the clinical and pathological data of patients with primary IgAN,and explored the correlation between the degree of tubulointerstitial lesions and clinical and pathological data.Methods: Clinical and pathological data of patients with primary IgAN diagnosed in the second Hospital of Jilin University from January 2013 to October 2020 were collected retrospectively,including sex,age,course of disease,body mass index,diastolic blood pressure,systolic blood pressure,hemoglobin,platelet,albumin,blood urea nitrogen,serum creatinine,estimated glomerular filtration rate,uric acid,cystatin C,high density lipoprotein,low density lipoprotein,triglyceride,total cholesterol,immunoglobulin A,immunoglobulin M,immunoglobulin G,the concentration of complement C₃,the concentration of complement C₄,24 hours urinary protein,Lee’s pathological type,the criteria of oxford classification（including Mesangial hypercellularity,endocapillary hypercellularity,segmental sclerosis or adhesion,tubular atrophy or interstitial fibrosis,crescent）.According to the criteria of oxford classification in 2016 years,the selected patients were divided into mild tubulointerstitial lesions（tubulointerstitial lesions 0%²5%）T0 group,moderate tubulointerstitial lesions（tubulointerstitial lesions 26%⁵0%）T1 group,and severe tubulointerstitial lesions（tubulointerstitial lesions>50%）T2 group.Clinical and pathological data of the 3 groups were compared to explore the correlation between the degree of tubulointerstitial lesions and clinical and pathological features.Single factor and multivariate logistic regression were used to explore the risk factors affecting tubulointerstitial lesions.Results:1.General data: A total of 538 patients with primary IgAN were enrolled,among them including 295（54.83%）males and 243（45.17%）females,The ratio of men to women is 1.21:1,with an average age of 37.04±12.62.299 cases in T0 group,accounted for 55.58%,154 cases in T1 group,accounted for 28.62%,85 cases in T2 group,The proportion is 15.80.Age mean,diastolic blood pressure and systolic blood pressure in three groups were statistically significant（P<0.05）,but there was no significant difference in sex,course（month）and BMI（P>0.05）.2.Laboratory indicators: Hb,Alb,BUN,Scr,eGFR,UA,Cys C,TC,IgM,IgG,the concentration of complement C₄,urine osmotic pressure and 24 h UP in three groups were statistically significant（P<0.05）,but there was no significant difference in PLT,blood glucose,TG,HDL,LDL,IgA,the concentration of complement C₃ and hematuria ratio（P>0.05）.3.The number and proportion of cases from the stages of CKD1 to 5 were 183（34.01%）、166（30.86%）、135（25.09%）、32（5.95%）、22（4.09%）.With the increase of CKD stage,the number and proportion of cases decreases gradually,that is,the number and proportion of cases in the stages of CKD1 is the largest and the number and proportion of cases in CKD5 stage is the least.The number and proportion of cases decreases gradually with the increase of TIL degree in the stages of CKD1-3 patients,the number and proportion of cases increases with the increase of TIL degree in the stages of CKD4-5 patients.More than half of the patients were in moderate degree of 24 h UP,There was a significant positive correlation between the stages of CKD and 24 h UP and the degree of tubulointerstitial lesions（P<0.001）.4.Pathological data: The results of renal biopsy in 538 patients were 15.43% for Lee’s pathological type I-II and 84.57% for Lee’s pathological type III-V.There was a significant positive correlation between Lee’s pathological type and the degree of tubulointerstitial lesions（P<0.001）.Mesangial hypercellularity,endocapillary hypercellularity,segmental sclerosis or adhesion in three groups were statistically significant,but there was no significant difference in criteria ratio.IgA +C₃ was the main form of immunoglobulin deposition in 538 patients with primary IgAN,accounting for 50.93%,and the proportion of IgA+IgG and IgA+ IgG +C₃ deposition were less,0.93% and 0.74% respectively.5.Single factor and multivariate logistic regression analysis: Univariate logistic regression analysis of tubulointerstitial damage showed that age,course of disease,diastolic blood pressure,systolic blood pressure,Hb,Alb,UA,BUN,Scr,Cys C,urine osmotic pressure,24 h UP,Mesangial hypercellularity,endocapillary hypercellularity,segmental sclerosis or adhesion and crescent ratio were the influencing factors of tubulointerstitial damage.The above statistically significant items were included in the multivariate ordered logistic regression analysis.The results showed that UA,BUN,Scr,urine osmotic pressure,24 h UP and Mesangial hypercellularity were still the influencing factors for the degree of tubulointerstitial lesions.Conclusion: 1.The proportion of tubulointerstitial lesions included in this study was T0 group> T1 group > T2 group.2.The higher the stage of CKD,the heavier the degree of 24 h UP,the higher the Lee’s pathological type,and the more serious the degree of renal tubulointerstitial lesions.3.UA,BUN,Scr,urine osmotic pressure,24 h UP,and Mesangial hypercellularity were the influencing factors of tubulointerstitial damage.