The Predictive Value Of Oxford Classification And ISKDC Classification In Adult Henoch-Sch(?)lein Purpura Nephritis

ObjectivePathological feature of Henoch-Sch(?)lein Purpura Nephritis(HSPN)is mainly evaluated by ISKDC classification(International Study of Kidney Disease in Children),which based on crescent formation、mesangial proliferation and glomerular sclerosis.The value of crescents in predicting long-term outcome of HSPN is still lack of consensus.Evaluation of pathological characteristics of IgA nephropathy have been redefined by Oxford classification in 2016,crescents formation was added to the classification,pointeing out that crescents can predict renal outcomes.This suggests the important predictive value of crescents in renal prognosis.IgA nephropathy shares many similarities with HSPN in clinical,immunological and histological features.In view of the similarity between HSPN and IgA nephropathy,it is important to evaluate the predictive value of the two pathological classifications(Oxford classification and ISKDC classification)in HSPN.However,in Oxford classification,crescents formation was mainly scored by percentages,and the type of crescent and its prognostic value was not discussed.And no studies have yet indicated the correlation between crescent type and renal prognosis in adult HSPN.Therefore,the aim of this study is to evaluate the predictive value of the two pathological classifications in adult HSPN and the value of of types of crescents in renal prognosis analysis.MethodsWe analyzed 275 cases diagnosed as HSPN in The First Affiliated Hospital of Zhejiang University between January 2005 and December 2015 retrospectively.All patients were divided into two groups according to ISKDC classification.The CA group included grade Ⅰ、Ⅱ and Ⅲ,the percentage of crescent was<50%;The CB group included grade Ⅳ、Ⅴ and Ⅵ,and the percentage of crescent was≥50%.The biopsy was re-read according to Oxford classification.They were divided into group M0、M1;group S0、S1;group E0、E1;group TO、T1/T2;and group CO、C1、C2.The clinical and pathological data at the time of renal biopsy were collected and follow-up duration was recorded.The clinical data include age、gender、extrarenal performance、mean arterial pressure(MAP)、24h urine protein quantitation、serum creatinine(Scr)、estimated glomerular filtration rate(eGFR,calculated according to the formula of EPI-Cr)5 and the use of immunosuppressants drugs.And according to the type and proportion of crescent,they were also divided into four groups:none crescent group(group 1),segmental crescent group(group 2),circumferential crescent<25%group(group 3),and circumferential crescen≥25%group(group 4).Follow-up time was more than 1 year.Renal poor prognostic events were defined as estimated glomerular filtration rate(eGFR)decreased by 30%over baseline within 2 years,doubling of serum creatinine or end-stage renal disease[defined as eGFR<15ml/(min·1.73 m2)or into maintaining dialysis,or kidney transplantation]during follow-up.Kaplan-Meier survival analysis was used to compare the renal survival rate of each group divided by type of crescent.Univariate and multivariate cox regression model was used to recognize the risk factor of poor renal outcome.Results1.According to Oxford classification,the E lesion was associated with 24h urine protein.The S lesion was associated with MAP,Scr and eGFR.The T lesion was associated with Scr and eGFR.The C lesion was associated with 24h urine protein s Scr and eGFR,and the 24h urine protein was significantly different between C1 and C2 group,while there was no significant difference between Scr and eGFR.According to ISKDC classification,there were significant difference in 24h urine protein、Scr and eGFR between CA and CB group(p<0.05).The patients were followed up for a median of 86(58,116)months.In the univariate COX analysis,the S、T and C lesions(whether grouped by ISKDC classification or Oxford classification)were associated with renal outcome.But in the multivanate COX regression analysis,only the S lesion was associated with renal events,and was an independent risk factor for renal prognosis.The T and C lesions were not associated with renal outcome.2.Grouped by crescent type,there were no significant differences in age,extra renal performance and mean arterial pressure among group 1、2、3、4,but the differences in serum creatinine(p=0.001),eGFR(p=0.003)and 24h urine protein(p<0.001)were significant.In the pathology,there were no significant differences in the proportion of glomerulosclerosis,mesangial hypercellularity and interstitial inflammation/fibrosis,but there was a significant difference in the presence of endothelial hypercellularity between the groups(p<0.001).The renal survival rates of group 1、group 2、group 3 and group 4 were 96%、100%、83.6%and 68.4%respectively.K-M survival analysis showed significant difference among the groups(Log Rank=23.24,p<0.001).Multivariate COX regression analysis indicated that the presence of circunferential crescent(HR=3.59,95%Cl:1.34-9.62,p=0.008)was an independent prognostic factor.ConclusionThe Oxford classification of IgA nephropathy can be used to analyze clinical prognosis in HSPN.The S lesion is associated with renal prognosis and is an independent risk factor for renal prognosis.As for crescent type,the presence of circumferential crescent is an independent risk factor for poor renal prognosis in adult HSPN patients.