The Detection And Value Of The Levels Of Urinary NGAL And Urinary CysC In Children With HSP

Background and ObjectiveHenoch-schonlein purpura (HSP) is one of the most common diseases in children, and is a systemic abnormal reactive vasculitis,and renal function failure induced by severe renal pathologic damage is the primary cause of the mortality in HSP Children. Glomerular pathological change in HSPN kidney pathological damage was given priority to previous, but recent studies found that tubulointerstitium damage plays an important role in the decision of HSPN prognosis. Interstitial inflammatory cells infiltrating, fibrosis and renal tubular atrophy is the important factors in affecting the prognosis of patients. The traditional renal tubular damage indexs including urinary retinol binding protein (RBP),β2- micro globulin (β2-MG), N-acetyl-β-D amine glycosidase enzymes (NAG), Etc,are mostly influenced by inflammation, gender, urine ph of influence.Therefore,it's necessary for us to looking for early renal tubular damage indexs.Neutrophil Gelatinase-Associated Lipoealin(NGAL) is a new lipocalin discovered by Kjeldsen in 1993. Plasmatic NGAL can pass glomerular filtration freedly, and most of them are reabsorbed in renal tubular through endocytosis. It appears in urine commonly rarely. The concentration of urinary NGAL increased mainly because of renal tubular reuptake dysfunction. CysC (CystatinC) is a non glycosyl of alkaline protein product,and it's formation rate is stable. The concentration of urinary CysC increased when renal tubular damaged. Researches from home and abroad show that they are more sensitive and peculiar in detecting renal tubular damage. In this study, we investigated the levels of urinary NGAL,urinary CysC,urinaryβ2-MG and 24-h urinary proteinuria (UTP/24h) in children with HSP, and discussed the significance of urinary NGAL and urinary CysC in renal tubulointerstitial damage.Methods 1. Our study included 75 patients who had been diagnosed with HSP and 20 healthy children as the control. Based on UTP/24h, the HSP children were divided into four groups:the normal urine protein (group A,n=20, UTP/24h<0.15g), the micro urine protein (group B,n=20,0.15g<UTP/24h<1g), the macro urine protein (group C,n=20,UTP/24h>1g),the alleviated period (group D,n=15, UTP/24h<1g). 15 patients (5 patients in group B and 10 patients in group C) who received renal biopsy were scored on the pathologic change of renal tubulointerstitum.30 patients(10 patients in group B and 20 patients in group C) got urine protien electrophoresis analysis.2. Urinary NGAL and CysC excretion was determined by ELISA(enzyme-1inked immunosorbend assay). Urinaryβ2-MG excretion was determined by turbidimetry. 24-h urine tatol protien (UTP/24h) was determined by sulfosalicylic acid-sodium sulfate turbidimetry(SS-S) in automatic biochemical assay.3.Renal biopsy per cutem locating at B -type hyperacoustic was performed in the patients.The nephridial tissue were embedded in paraffin, and studied by light microscopy(HE,PAS,PASM,Masson),fluorescencemicroscopy(IgG,IgM,IgA,C3,Clq) and electron microscopy.Renal interstitum lesions were scored.4. Sodium dodecy sulfate-argarose gel electrophoresis(SDS-AGE)was used to analyze non-concentrated urine samples from patients.5. Statistical analysis:All the data were analyzed by SPSS17.0 statistical software package. Differences between groups were compared with one-way analysis of variance. The rates were assessed with chi-square statistics. Correlation analysis by Pearson's correlation or Spearman. Statistic test were two-sided test of probability (a=0.05). Probability of less than 0.05 were considered significant.Results1. Compared with the control,the urinay NGAL level was increased in group A,B and C(group A,P<0.05; group B,P<0.01; group C,P<0.01).The concentration of urinary CysC and urinaryβ2-MG were increased in group B and C(group B,P< 0.01; group C,P< 0.01).2. Compared with the control, the concentrationes of urinary CysC and urinary β2-MG in group A were not found statistical difference(P>0.05).3. Compared with the control, the urinay NGAL level in gtoup D was not found statistical difference(P> 0.05); howere, the urinay CysC level in gtoup D was increased (P<0.05)4. The Abnormity Rates of urinary NGAL, urinay CysC and urinaryβ2-MG in group A were not found statistical difference(P>0.05).The Abnormity Rate of urinary NGAL was larger than that of urinaryβ2-MG in group B; the Abnormity Rate of urinaryβ2-MG in group D was larger than that of urinary NGAL5. The levels of urinary NGAL and CysC were positively correlated with urinary 32-MG(r=0.615,0.725,P<0.01); the levels of urinary NGAL was positively correlated with urinary CysC(r=0.862,P<0.01); the levels of urinary NGAL, CysC andβ2-MG were positively correlated with the UTP/24h(r=0.638,0.607,0.349, P<0.01).6. The levels of urinary NGAL,CysC andβ2-MG were positively correlated with the pathologic score of renal tubulointerstitum and the result of urine protien electrophoresis analysis(r=0.638,0.471;0.661,0.436;0.526,0.441,P<0.05).7. The pathologic score of renal tubulointerstitum and the result of urine protien electrophoresis analysis in group C were larger than that of group B(P<0.05).Conclusions1. The levels of urinary NGAL is more sensitive in assessing the severity of changes of renal tubulointerstitum function.2. The level of urinary CysC was increased in the alleviated period (group D).It showed that the level of urinary CysC lasted longer than urinary NGAL in assessing the severity of changes of renal tubulointerstitum function.3. The levels of urinary NGAL and CysC were positively correlated with the pathologic score of renal tubulointerstitum and the result of urine protien electrophoresis analysis.They are of great value in assessing the severity of changes of renal tubulointerstitum function.4. It suggested that urinary NGAL and urinary CysC can be used as early index for renal tubulointerstitial damage in HSP patients, they are more sensitive and peculiar than tradition index.5. The levels of urinary NGAL,CysC will increase along with the UTP/24h; the levels of urinary NGAL and CysC were positively correlated with the pathologic score of renal tubulointerstitum and the UTP/24h.It show that The levels of urinary NGAL,CysC are of great value in assessing the severity of the illness of the HSPN children to a certain extent.