Peritubular capillaries injury and its association with clinical characteristics and long term renal survival in primary malignant nephrosclerosis patients / 中华肾脏病杂志

ABSTRACT

Objective To analyze the clinic-pathological data and peritubular capillary (PTC) injuries of malignant nephrosclerosis (MN) patients and their correlations with the long term renal survival.Methods This was a retrospective cohort study of 52 MN patients in Peking Union Medical College Hospital from January 2003 to March 2012.Their clinical data and renal biopsy samples were carefully studied.CD34 staining was performed to evaluate the PTC area,using Benign nephrosclerosis (BN,n=17) patients and glomerular minimal lesions (GML,n=19) patients as controls.Multivariate Cox proportional hazard model was used to identify the potential independent risk factors for long term renal survival.Results Fifty-two MN patients were enrolled.The sex ratio of male to female was 12:1 and the average age was (34.0±8.2) years.The maximum blood pressure (SBP/DBP) was (230.4 ± 25.0)/(156.4 ± 20.6) mmHg,companied with significant loss of eGFR and proteinuria.Glomerular sclerosis index,tubular atrophy and interstitial fibrosis correlated with eGFR and proteinuria (P ＜ 0.05).After aggressive treatment,BP control rate improved significantly (76.9％ vs 3.7％,P ＜0.01),Scr [(376.4±263.8) μmol/L vs (486.8±375.7) μmol/L,Wilcoxon test,P＜ 0.01] and proteinuria [(1.10±0.70) g/24 h vs (2.04± 1.26) g/24 h,P ＜ 0.01,n=21] also improved.PTC area in MN patients was significantly lower than those in BN patients and GML patients,and it correlated well with Scr (r=-0.553,P=0.001) and eGFR (r=0.476,P=0.004).The median follow-up time was 74 months,the cumulative renal survival rate at 1 year,5 year and 10 year was 90％,64％ and 23％,respectively.Kaplan-Meier analysis showed that the patients with higher PTC area had longer renal survival time [(114.8± 12.4) months vs (63.0±8.3) months, x2=5.312,P ＜ 0.05].Univariate Cox proportional hazard model found that unsatisfied BP control,eGFR ＜ 30 ml · min-1 · (1.73 m2)-1 upon discharge,lower PTC area,severer tubular-interstitial damage and anemia were associated with poor renal outcome.Multivariate Cox model showed that unsatisfied BP control (RR=3.89,95％ CI 1.75-8.65,P=0.001),eGFR ＜ 30 ml · min-1 · (1.73 m2)-1 upon discharge (RR=4.27,95％ CI 1.40-13.09,P=0.011) were independent risk factors for long-term renal survival.Conclusions The correlation between PTC area and renal functions in MN patients are much better than that of classic vascular changes.Unsatisfied BP control and eGFR ＜ 30 ml · min-1 · (1.73 m2)-1 upon discharge are independent risk factors for long-term renal survival.