| Objective: Primary nephrotic syndrome (PNS) is the common renaldisease whose complications including infection, thrombus and embolism,acute renal injury (AKI), hyperglycemia, water and electrolytedisturbances and so on. AKI is a common and critical complication withpoor prognosis. In clinical practice, acute tubular necrosis (ATN) is theprimary pathological feature in the patients of PNS complicated withAKI. So renal biopsy puncture is considered as gold standard for AKI.However this method is invasive and perilous and the operator must beproficient in renal puncture. Besides, it will be a long time before we getthe pathology result. So, this method is diffcult in early diagnosis of AKI.So it is highly significant that trying to find more convenient, specific andsensitive biomarker to help the early diagnosis of PNS complicated withATN. According to the studies, neutrophil gelatinase associatedlipocalin(NGAL) is a new biomarker reflecting the kidney damage. Ourstudy is to investigate the urinary level of NGAL (by enzyme linkedimmunosorbent assay) and the expression of NGAL in kidney tissue (byimmunohistochemistry) in the patients of PNS, and to observe therelationship between the new trial index and commonly used in clinicalindex (such as24h urine protein, serum creatinine), so as to discuss thepossible effect of NGAL in the PNS complicated with AKI.Methods: Step1:72patients were selected as the cases(45male,27female), who conformed to the criterion of primary nephroticsyndrome(24h urine protein>3.5g, plasma albumin<30g/L).They weredivided into different groups depend on pathology:1.PNS without ATN57cases(30male and27female), including minimal change disease (MCD)(16male and8female); membranous nephropathy (MN)(15male and8female); mesangial proliferative glomerulonephritis (MsPGN)(6male and4female);2. PNS with ATN15cases(9male and6female),including MCD10cases, MsPGN5cases respectively. Step2:15cases (8male and7female) were collected from the patients who were performednormal urine analysis in the health examination. Moreover, the kidneytissue were obtained from5patients (3male and2female) who hadnephrectomy because of renal duplication, kidney tumor and so on. Step3:Enzyme linked immunosorbent assay (ELISA) was applied to detect theurinary level of NGAL in PNS patients and the control group. Alsocomparations were made between those groups and the control group.Immunohistochemistry was used to detect kidney tissue level of NGAL inpatients complicated with ATN and other groups. Step4: Determine theclinical index (such as serum creatinine, β2MG,24h urine protein),correlation analysis was processed between ELISA andimmunohistochemical result and clinical index. Step5: Differences amonggroups were evaluated by one-way analysis of variance test ornonparametric test. To determine the significance between group meansin the analysis of variance, the nearest significant difference test (SNK-qtest) or nonparametric test was used as the multiple comparison test.Step6:SPSS13.0statistical software is used to analyze the above mentioneddata, p <0.05was considered as significant.Results:1. Compared with normal controls, the urinary level of NGAL weresignificantly increased in patients with PNS. The urinary level of NGALin the MCD group, MN group, MsPGN group and control group was(46.81±15.75,22.09±7.69,15.31±3.74,8.03±0.35)ng/ml. The urinarylevel of NGAL in MCD group was higher than that in the other groups.2. It was shown that the positive staining for NGAL was observed inthe proximal tubule epithelium in the PNS and control groups. The levelof PNS group was visible than that in the control group. The EI values were observed by the specific software. The EI values in the MCD group,MN group, MsPGN group and control group was (5.69±0.54)%,(5.47±0.66)%,(5.66±0.31)%,(3.16±0.69)%.The EI values in threegroup were significantly higher compared with control group (p <0.05).3. The urinary level of NGAL in patients that MCD with ATN was(85.16±20.51)ng/ml, which was significantly increased, compared withMCD without ATN groups (p <0.05). Similarly, the result was alsotenable between MsPGN without ATN and MsPGN with ATN.4. Compared with the MCD and MsPGN groups that without ATN,the tissue level of NGAL in patients with ATN were significantlyincreased,which had statistical significance (p <0.05).5. The urinary level of NGAL was positively correlated with serumcreatinine, serum blood urea nitrogen, serum β2MG and24-hour urineprotein and negatively correlated with plasma albumin. Moreoverexpression of NGAL in kidney was positively correlated the urinary levelof NGAL.Conclusion:1. The urinary and tissue level of NGAL was significantly increasedin patients of PNS.2. The expression of NGAL both in urine and in kidney tissue wasincreased in patients of PNS complicated with ATN. The expression ofNGAL in kidney tissue was highly correlated with the urinary level ofNGAL. Furthermoer, the urinary and tissue level of may reflect thetubulointerstitial damage of PNS patients.3. The urinary level of NGAL in some patients increased prior toserum creatinine and blood urea nitrogen. The urinary level of NGAL wasspecific and sensitive biologic factors in the diagnosis of ATN. |
PDF Full Text Request