Analysis On The Histopathologic Classification, Clinical Characteristics And Outcome In Patients With ANCA-associated Glomerulonephritis

Backgrounds:Patients with ANCA-associated vasculitis（AAV）are often associated with renal involvement leading to ANCA-associated glomerulonephritis（AGN）.Considering the important diagnostic value of renal histology on AGN,Berden et al and an international working group of renal pathologists proposed four categories of glomerular lesions:Focal,Crescentic,Mixed and Sclerotic in 2010 and pointed out that this classification is related to the prognosis of patients^[1].There are many reports on the verification of this classification in foreign countries.Domestic reports are mostly concentrated in Beijing and Nanjing.There are few reports in our region.In order to further clarify the relationship between different classifications and prognosis of AGN in our region and the diagnosis and treatment of AGN in our center for the past 10 years,we used Berden histological classification to group patients and compare general information,clinical characteristics,and prognosis of different classifications.Objective:This article aims to analyze the renal pathological features of patients with AGN;compare the general data,clinical manifestations,laboratory indicators,treatment options and disease prognosis between the groups according to Berden classification,explore the correlation between renal pathology classification and renal prognosis,ascertain the treatment of patients with AGN in our center,and provide new ideas for future optimization of treatment plans.Methods:57 patients with ANCA-associated glomerulonephritis who met the screening criteria and underwent ultrasound-guided percutaneous renal biopsy at the Second Hospital of Jilin University from January 2009 to December 2018 were collected to do retrospective analysis.They were divided into focal type（17 patients）,crescent type（13 patients）,mixed type（16 patients）and sclerotic type（11patients）according to Berden classification.The general conditions,clinical manifestations,kidney related indexes,laboratory indexes,treatment plans and prognosis of the 4 groups were compared.The SPSS 25.0 statistical software was used to analyze the data by the corresponding statistical methods and the corresponding results were obtained.Results:1.A total of 57 patients with AGN were enrolled,including 29 males（51%）and28 females（49%）.The male to female ratio was 1.03:1.The average age was 57±13.15years old,men aged from 15 to 84 years old and women aged from 33 to 77 years old.Mean arterial pressure increased according to focal type,crescent type,mixed type and sclerosis type,but the difference between the four groups was not statistically significant.2.The median time interval from first clinical symptom to diagnosis was 2months,and the difference between the groups was not statistically significant.The affected organs besides kidney of the four groups were extensive.The difference of Birmingham vasculitis activity score（BVAS）which was used to evaluate disease activity between the 4 groups was statistically significant（P<0.05）.BVAS of focal type was lower than BVAS of crescent type（P<0.05）and mixed type（P<0.05）,and BVAS of mixed type was higher than BVAS of sclerotic type（P<0.05）.3.There was a statistically significant difference in glomerular filtration rate between 4 groups（P<0.001）.The glomerular filtration rate of focal type was higher than the other 3 groups（P<0.001）,and there was no statistically significant difference among crescent type,mixed type and sclerotic type（P>0.05）.4.The difference of renal tubular atrophy between the 4 groups was statistically significant（P<0.05）,the degree of focal type was lower than crescent type and sclerotic type（P<0.05）.The patient’s glomerular filtration rate was linearly related to the percentage of normal normal glomeruli and the degree of chronic tubular atrophy in renal pathology.5.At the end of follow-up,comparing the renal survival rate of patients treated with hormone shock treatment of 4 groups,the difference was statistically significant,however,only the survival rate of focal type was higher than that of mixed and crescent types when comparing between any two groups.93%of patients whose renal dysfunction at admission was required for renal replacement therapy died or needed long-term renal replacement therapy at the end of follow-up.6.At the end of follow-up,there was a statistically significant difference in renal survival between the 4 groups（P<0.05）.Kidney survival rate was the highest in focal type（P<0.001 compared with the other 3 groups）.There was no statistically significant difference in the kidney survival rate among the other three groups.7.Cox regression analysis showed that eGFR<15ml/min/1.73m² was an independent risk factor for death or long-term renal replacement therapy,but the independent predictiveness of Berden histological classification was poor in Cox regression analysis.Conclusion:1.The eGFR of focal type is highest in the 4 groups;the normal glomerular ratio and the degree of tubular atrophy are linearly correlated with eGFR.2.Comparing the degree of tubular atrophy among the 4 groups,the degree in patients with focal type is the lower than crescent and sclerotic types.3.In response to steroid pulse therapy,focal type is superior to the crescent and mixed types.4.The kidney survival rates in patients with focal type is highest in the 4 groups.eGFR<15 ml/min/1.73 m² is an independent risk factor for death or long-term renal replacement therapy in AGN patients.