Expression Level Of ANPGTL8 In Patients With Primary Nephrotic Syndrome And Analysis Of Its Relationship With Serum Lipids And Proteinuria

Objectives:To analyze the expression characteristics of angiogenin-like protein 8(ANGPTL8)in patients with primary nephrotic syndrome(PNS),and to explore the relationship between ANGPTL8 and blood lipids and proteinuria in PNS patients,aim to provide new evidence for further research on the role of ANGPTL8 in the pathogenesis of PNS.Methods:A total of 133 PNS patients who were treated at Gansu Provincial People’s Hospital from November 2017 to November 2019 were collected as the experimental group,and 60 healthy controls were selected from the physical examination center of the hospital.Subjects were collected fasting venous blood and morning cleaning mid-stream urine,-20℃ frozen.The ANGPLT8 concentration of all specimens was measured by enzyme-linked immunosorbent assay,and the laboratory index(CHOL,TG,HDL-C,LDL-C,ALB,CREA,Ur,24 hUTP,UCr,urine protein)was detected from the Clinical Laboratory Center of Gansu Provincial People’s Hospital.Statistical analysis was performed using SPSS 26.0 software.Results:1.Compared with the control group,the age,sex composition,BMI,blood pressure and CREA level of the PNS group were not statistically different(P>0.05),the serum and urine ANGPTL8 levels in the PNS group were significantly increased(P<0.001),blood lipids(CHOL,TG,HDL-C,LDL-C),Ur and urine protein levels were significantly increased(P<0.001),ALB levels was significantly significantly decreased(P<0.001).In the PNS group,compared with aged ≥18 years’ patients,the level of ANGPTL8/UCr was significantly increased in aged <18 years’ patients(P<0.05).2.The relationship between urine ANGPTL8/UCr and pathological types in PNS patients: The expression of urine ANGPTL8/UCr in different pathological types was statistically different(P<0.05).A further pairwise comparison showed that the expression of urine ANGPTL8/UCrwas onlystatistically differentin two pathological types of MN and MsPGN(P<0.05),and the expression level of MsPGN was higher than that of MN.3.The relationship between urine ANGPTL8/UCr and proteinuria in PNS patients:The expression of urine ANGPTL8/UCr in different degrees of proteinuria was statistically different(P<0.05).A further pairwise comparison showed that the expression of urine ANGPTL8/UCrwas onlystatistically differentin moderate(24hUTP 1~3.5 g/d)and severe(24hUTP ≥ 3.5 g/d)proteinuria(P<0.05),and the expression level of moderate proteinuria was higher than that of severe proteinuria.4.Correlation between ANGPTL8 and serum lipid index and proteinuria in PNS patients: serum ANGPTL8 was positively correlated with CHOL(r = 0.209,P<0.05),TG(r = 0.412,P<0.001),and not correlated with 24hUTP(r = 0.087,P>0.05).Urine ANGPTL8 was positively correlated with HDL-C(r = 0.181,P<0.05),andnegatively correlated with 24hUTP(r =-0.182,P<0.05).Urine ANGPTL8/UCr was positively correlated with HDL-C(r = 0.201,P<0.05),and negatively correlated with 24hUTP(r =-0.268,P<0.05).5.Differences in the expression of major biochemical indexesof PNS group in the ANGPTL8 interquartile group: TG expression levels were statistically different only between the 1st and 2nd,3rd,4th quartiles of serum ANGPTL8(P<0.05).HDL-Cexpression levels were statistically different only between the 2nd and 4th quartile arrays of urine ANGPTL8(P<0.05).24 hUTP expression levels were statistically different only between the 1st and 4th quartile arrays ofurine ANGPTL8/UCr(P<0.05).6.Prediction value of ANGPTL8 ROC curve to PNS:The area under the curve of serum and urine ANGPTL8 was 0.722 and 0.765 respectively,which were statistically significant compared with the area under the curve = 0.5(P<0.001),the optimal critical concentrations were 26.00 ng/ml and 45.02ng/ml,respectively.The combined serum and urine ANGPTL8 levels had higher predictive value for PNS(area under the curve: 0.823,P<0.001).Conclusions:1.Serum and urine levels of ANGPTL8 in patients with PNS were significantly increased.The expression level of urine ANGPTL8/UCr are differentbetween MN and MsPGN pathological types,and may provide non-invasive diagnostic value for determining the pathological type of PNS.2.In patients with PNS,serum ANGPTL8 was only related to serum lipid level,which was positively correlated to the serum lipid level,and urine ANGPTL8 level was related to the degree of proteinuria,which was negatively correlated to the degree of proteinuria,suggesting that serum and urine ANGPTL8 may play different roles in PNS hyperlipidemia and proteinuria.ROC curve analysis also indicated that ANGPTL8 may be a new biomarker for PNS.