Association Between Polycyclic Aromatic Hydrocarbons Exposure And Plasma Levels Of Albumin And Hemopexin

Polycyclic aromatic hydrocarbons (PAHs) are a class of carcinogens widely distribute in the environment. A lot of reactive oxygen species (ROS) generate during the metabolism of PAHs and lead to severe oxidative damages. While acute phase proteins (APPs) in plasma play an important role in oxidative stress, there are rare researches which have focused on the association between APPs and PAHs. Plasma proteomics study had found that two representative APPs, albumin and hemopexin, expressed in different levels between PAHs exposure group and control group. However, the relation between these two APPs levels and PAHs internal exposure extent has not been well documented yet.[Objects] To assess the association between PAHs internal exposure extent and the plasma levels of albumin and hemopexin and to explore promising biomarkers for occupational health monitoring.[Methods] 475 coke oven workers who occupationally exposed to PAHs for more than one year were recruited as subjects. Urine 1-OHP was detected with a modified alkaline hydrolysis-HPLC spectrometry analysis and used as evaluation indicator of PAHs exposure. All coke oven workers were divided into three groups named low exposure, intermediate exposure and high exposure according to urine 1-OHP concentration. Plasma albumin and hemopexin levels were determined by surface plasmon resonance technology (SPR). Expression differences of these two proteins among three groups were assessed with covariance analysis. The associations between PAHs internal exposure extent and these two proteins were analyzed separately. Biochemistry indexes related to liver function were also analyzed.[Results] Urine 1-OHP concentrations in three groups were 2.84±0.61μmol/mol Cr (low exposure, n=157), 4.14±0.26μmol/mol Cr (intermediate exposure, n=160) and 5.15±0.54μmol/mol Cr (high exposure, n=158) respectively, P<0.01. While the concentration of plasma albumin did not show any difference (53.67±12.79mg/mL, 54.55±12.83 mg/mL and 52.92±10.67 mg/mL for low, intermediate and high exposure group separately, P=0.473), the hemopexin level elevated significantly with the increase of internal exposure extent, from low to high successively are 1.48±0.57 mg/mL, 1.57±0.49 mg/mL and 1.65±0.55 mg/mL, P=0.024. All these results were adjusted with other possible influencing factors such as age and alcohol use. Result from multivariate logistic regression analysis suggested that 1-OHP is an affecting factor to hemopexin, OR=1.254 (95% CI 1.003-1.568, P=0.047). A further confirmation of the association between 1-OHP and hemopexin was carried out with Spearman analysis, r=0.161, P=0.001. Correlation between hemopexin and glutamic pyruvic transaminase (GPT) was also took into consideration (r=0.205, P=0.000). Furthermore, markers which are indicative to liver function were also found to be related to hemopexin, including triglyceride (TG, r=0.254, P=0.000), total cholesterol (TC, r=0.105, P=0.050), low density lipoprotein (LDL, r=0.094, P=0.078) and high density lipoprotein (HDL, r=-0.163, P=0.002).[Conclusions] From all above we can reach the conclusion that there was no significant difference in plasma albumin expression among three groups. However, hemopexin level elevated with the increment of urine 1-OHP, which suggests that PAHs induces the expression of hemopexin. However, hemopexin is sensitive to many factors, thus further study should be carried out to verify the results. Correlations between hemopexin and biomarkers indexes indicative for liver function, such as GPT, TG, TC, LDL and HDL were also observed.