Associations Of Urinary OH-PAHs,Oxidative Stress And Immune-related Factors With Idiopathic Membranous Nephropathy

Objectives: IMN(idiopathic membranous nephropathy),as a kind of chronic glomerulonephritis disease,is mediated by immune response and shows an increasing incidence rate by year.In recent years,the influence of environmental factors on the pathogenesis of IMN has been concerned,but the relevant researches are still scarce.In this study,we estimate the association between the exposure of polycyclic aromatic hydrocarbons(PAHs)and oxidative stress,mmune-related factors with IMN in adults,in order to provide the scientific basis for the effect of PAHs exposure on the onset of IMN.Methods: A total number of 101 patients diagnosed with IMN for the first time in nephrology department of a third-grade hospital in Nanning,Guangxi were selected from September 2016 to December 2018.Healthy volunteers were selected as control group from the same hospital and occupational health examination population.In this study,the 1:1 matched case-control study was designed according to the principle of the same sex and similar age(±4 years old),meaning 101 newly diagnosed IMN patients who were selected according to pathological diagnosis results of renal puncture and completed final information and 101 healthy volunteers consented to join in the research.Retrospective health questionnaire survey and physical examination were conducted on the subjects,and biological samples such as blood and urine were collected as well.The seven kinds of urinary OH-PAHs metabolites levels in subjects in this study were measured by UPLC-MS/MS,including1-hydroxynathalene(1-OHNAP),2-hydroxynathalene(2-OHNAP),2-hydroxyfluorene(2-OHFLU),3-hydroxyfluorene(3-OHFLU),9-hydroxyfluorene(9-OHFLU),9-hydroxyphenanthrene(9-OHPHE)and1-hydroxypyrene(1-OHPYR).Urinary creatinine concentrations were detected at the same time by the urine creatinine Kit,and then seven OH-PAHs levels were adjusted by creatinine.DNA oxidative damage marker8-hydroxyguanosine(8-oHdG)and lipid peroxidation marker8-isomeric-prostaglandin F2?(8-iso-PGF2?)and immune-related factors IL-4and IgG4 in serum were detected by ELISA.Blood creatinine was tested by automatic biochemical analyzer to estimate eGFR(glomerular filtration rate).One-sample Kolmogorov-Smirnov was used to test the normality of the above variables.T-test or Wilcoxon Symbolic Rank Sum test were used to compare the differences of urinary OH-PAHs levels,8-OHdG,8-iso-PGF2?,IL-4 and IgG4 between the IMN case group and the control group,and the Chi-Square test was used to analyze the differences in the distribution of the classified variables.Spearman correlation analysis was used to analyze the correlation between the variables.Conditional logistic regression model was used to adjust gender,age,ethnicity,education level,active smoking,passive smoking,BMI and drinking status,in order to analyze and discuss the impact of changes in 7 urinary OH-PAHs levels,oxidative stress and immune factors levels on the risk of IMN.Results:Part ?:(1)Among seven urinary OH-PAHs metabolites measured in the IMN case group and control group in this study,the highest proportion metabolite was found to be the total OHNAP(higher than ninety percent),and those with higher proportion of single OH-PAHs metabolite were 1-OHNAP and 2-OHNAP,both were greater than 40%.(2)The levels of urinary OH-PAHs(1-OHNAP,2-OHNAP,total OHNAP and total OH-PAHs)of IMN patients whether creatinine was corrected or not were all higher than those of the control group(except 1-OHNAP with uncorrected creatinine),and the difference was statistically significant(P <0.05).(3)The levels of 8-OHdG,8-iso-PGF2?,IL-4 and IgG4 in serum in the case group were significantly higher than those in the control group(P < 0.05).(4)Concentrations of 1-OHNAP,2-OHNAP,total OHNAP and total OH-PAHs were positively correlated with 8-oHdG levels before and after creatinine correction were found in this study.8-iso-PGF2? was positively correlated with increased IL-4 and IgG4 concentrations.IgG4 was negatively correlated with urinary OH-PAHs before and after creatinine correction.eGFR was negatively correlated with the levels of 8-iso-PGF2?,IL-4 and IgG4.Part ?:(1)Logistic regression analysis showed that after multi-factor adjustment,the risk of IMN in urinary 2-OHNAP and total OH-PAHs high concentration group was 3.16 and 2.95 times higher than that in low concentration group,respectively(P<0.05),OR values(95% confidence interval)were OR value of uncorrected 2-OHNAP=3.16,95%CI: 1.06-9.44;OR value of uncorrected OH-PAHs =2.95,95%CI: 1.03-8.74.(2)Logistic regression analysis showed that after multi-factor adjustment,the risk of IMN in urinary 1-OHNAP,2-OHNAP,total OHNAP and totalOH-PAHs after creatinine correction of high concentration group was 5.5,6.09,4.65 and 6.09 times higher than that in low concentration group,respectively(P<0.05),and the OR values(95% confidence interval)were 1-OHNAP=5.55,95%CI: 1.87-16.52;2-OHNAP=6.09,95%CI: 1.85-20.04;total OHNAP=4.65,95%CI: 1.66-13.06;total OH-PAHs =6.09,95%CI: 1.93-19.27.(3)Logistic regression analysis showed that the risk of IMN in the high concentration group of 8-OHdG,8-iso-PGF2?,IL-4 and IgG4 were 13.99,7.24,2.85 and 12.39 times higher than that of low concentration group(P<0.05),OR values(95% CI)were: 8-OHdG=13.99,95%CI : 3.52-55.60;8-iso-PGF2?=7.24,95%CI:2.25-23.33;IL-4=2.85,95%CI:1.10-7.40;IgG4=12.39,95%CI:2.62-58.62(P < 0.05).Conclusions:(1)PAHs exposure may be a risk factor for IMN.(2)The increased levels of 8-OHdG,8-isoPGF2?,IL-4 and IgG4 may associated with the increased risk of IMN.(3)The increase of PAHs level may be related to the increase of 8-OHdG level,and the increase of 8-iso-PGF2? level may be related to the increase of IL-4 and IgG4 level.