原发性肾病综合征并发急性肾损伤患者血清及肾组织中NGAL的表达及意义

 目的：检测原发性肾病综合征（PNS）患者血清及肾组织中中性粒细胞明胶酶相关脂质运载蛋白（NGAL）的水平，探讨PNS合并急性肾损伤（AKI）时患者血清及肾组织中NGAL浓度的变化。方法：72例PNS患者根据病理结果分为：(1) PNS合并急性肾小管坏死（ATN）组15例，其中微小病变（MCD）合并ATN 10例，系膜增生（MsPGN）合并ATN 5例；(2) PNS不合并ATN组57例，其中MCD组24例，膜性肾病（MN）组23例和MsPGN组10例。15例健康体检者的血液及5例正常肾组织作为正常对照组。采用ELISA检测血清NGAL的水平；采用免疫组化法检测肾组织中NGAL的表达。结果：(1) PNS患者血清NGAL水平及肾组织中NGAL表达明显高于正常对照组（P<0.05），其中MN组较MCD组和MsPGN组血清NGAL水平明显升高（P<0.05）。(2) MCD合并ATN组和MsPGN合并ATN组血清NGAL水平及肾组织中NGAL表达较不合并ATN组显著升高（P<0.05）。(3)血清中NGAL与24 h尿蛋白定量、血尿素氮和血肌酐呈正相关（P<0.05），与血清白蛋白和β2微球蛋白无明显相关性（P>0.05）；血清中NGAL与肾组织NGAL的表达呈正相关（P<0.01）。结论：血清NGAL可能作为判断原发性肾病综合征并发急性肾损伤的早期、无创、敏感指标。

Expression of NGAL in serum and renal tissues of patients with primary nephrotic syndrome and acute kidney injury

AIM: To observe the changes of neutrophil gelatinase-associated lipocalin (NGAL) level in serum and renal tissues of the patients with primary nephrotic syndrome (PNS) and acute kidney injury (AKI). METHODS: Seventy-two PNS patients were selected in the study and divided into 2 groups according to the pathological results of renal biopsy.The patients in PNS+AKI group included 15 cases of PNS with acute tubular necrosis (ATN), in which there were 10 cases of minimal change disease (MCD) with ATN and 5 cases of mesangial proliferative glomerulonephritis (MsPGN) with ATN. The patients in PNS alone group included 57 cases of PNS without ATN. According to the pathological types, they were divided into MCD group (24 cases), membranous nephropathy (MN) group (23 cases) and MsPGN group (10 cases). Serum samples from 15 healthy persons and 5 cases of normal renal tissues were used as controls. The serum levels of NGAL were detected by ELISA. The distribution and expression of NGAL in the renal tissues were observed by immunohistochemical method. RESULTS: (1) The serum level of NGAL in PNS alone group (including MCD group, MN group and MsPGN group) was significantly higher than that in normal control group. Compared with MCD group and MsPGN group, the serum level of NGAL in MN group increased significantly. The renal tissue positive expression index of NGAL in MCD group, MN group and MsPGN group was significantly higher than that in normal control group. (2) The serum level of NGAL and the renal tissue positive expression index of NGAL in MCD+ATN group and MsPGN+ATN group were significantly increased compared with PNS alone group. (3) The serum level of NGAL was positively correlated with 24 h urine protein, blood urea nitrogen and serum creatinine. No relation with serum albumin and β2 microglobulin was observed. The serum level of NGAL was positively correlated with the NGAL level in the renal tissue. CONCLUSION: The serum level of NGAL can be used as one of the sensitive indexes for early and non-invasive detection of PNS with AKI.