Correlation Between The Level Of Lipoprotein-related Phospholipase A2(LP-PLA2)and The Severity Of Lower Extremity Atherosclerosis Obliterans

The research backgroundLower extremity atherosclerosis obliterans(ASO)is the most common type of peripheral vascular disease(PAD),which is a vascular degenerative disease based on atherosclerosis(AS).With the change of people’s dietary structure and the development of aging society,the diagnosis rate and incidence of ASO have been increasing year by year.Lipoprotein-associated phospholipase A2(LP-PLA2)is a serinase expressed in activated monocytes and macrophages.As a relatively new inflammatory marker,there is growing evidence that high levels of LP-PLA2 are associated with an increased risk of atherosclerosis and can reflect the status of atherosclerotic plaques.ObjectiveBy comparing the level of LP-PLA2 in peripheral blood of the ASO group and the experimental group,the correlation between LP-PLA2 and ASO was analyzed,and the difference of LP-PLA2 level between ASO patients with different severity was discussed,and the predictive value of LP-PLA2 level in predicting the occurrence of ASO was evaluated.Materials and MethodThe 76 patients who were diagnosed with ASO in the Department of Vascular Surgery of the Second Affiliated Hospital of Zhengzhou University from November2018 to January 2019 were selected as the research objects.and 41 healthy control patients of similar age who were seen in the physical examination center of our hospital during the same period were collected.The baseline data and laboratory data of the two groups was collected before treatment.All the selected patients need to fast for 8-12 hours.After that,10 ml of morning venous blood is drawn and sent to the the clinical laboratory tests.The two groups of data are statistically analyzed.Further the ASO group underwent Fontaine staging according to the severity of clinical symptoms,and at the same time,the results of the CTA examination of the ASO group were classified according to the Trans-Atlantic Inter-Society Consensus(TASC)second edition standard guideline classifies the severity,and analyzes the correlation between the plasma LP-PLA2 level and the severity of lower extremity occlusion in the experimental group.The level of LP-PLA2 is detected by time-resolved fluorescence immunochromatography.Result1.There is no significant difference between the ASO group and the control group in terms of gender,prevalence of hypertension,prevalence of hyperlipidemia,TC,TG,HDL-C,Fg,WBC,LDL-C(P> 0.05),indicating no comparability.The ASO group has significant differences in smoking history,age,LP-PLA2,Hcy compared with the control group(P<0.05),which is comparable,and level of Lp-PLA2 and Hcy concentrations in the ASO group were higher than those of the control group.2.According to the clinical severity of Fontaine,76 patients in the ASO group were divided into stages I,II,III,and IV according to the gradual aggravation of clinical symptoms.The LP-PLA2 level among the groups increased with the increase of the stage,and they were all higher than those in the control group,the difference is significant(all P values <0.05).At the same time,according to the TASCII classification,76 patients in the ASO group were divided into A,B,C,D grades according to the aggravation of the lower extremity arterial vascular disease,the level of LP-PLA2 among the groups increased with the increase in classification,and also was higher than that of the control group,the difference was statistically significant(all P values <0.05).3.Multivariate logistic regression analysis showed high levels of LP-PLA2(OR=1.027,P<0.0,1,95%CI=1.013～1.041)is a risk factor for ASO.4.Correlation analysis showed that Lp-PLA2 level was positively correlated with ASO severity in the ASO group(P<0.05),but had no correlation with other indexes(P>0.05).5.The receiver operating characteristic(ROC)curve was drawn using the LP-PLA2 levels in the severity of different clinical symptoms of ASO disease,showing:(1)When comparing the Fontaine stage I with II,III,and IV,the cut-off point is: 164.1ug /m L,that is,when LP-PLA2 is greater than 164.1ug/m L,it can be judged as intermittent claudication or more severe clinical symptoms.At this time,the sensitivity is 94%,the specificity is 90%,and the area under the ROC curve is0.964;(2)When comparing the I and II with the III and IV stages,the cut-off point is 196.4ug/m L.When LP-PLA2 is greater than 196.4ug/m L,it can be judged that there are clinical symptoms such as resting pain or tissue ulceration in the lower limbs.At this time,the sensitivity is 91%,the specificity is 93%,and the area under the ROC curve is 0.970;(3)When the stage I,II,and III are compared with the IV stage,the cut-off point is 241.2ug/m L,and when LP-PLA2 is greater than this value,It is judged that there are serious symptoms such as tissue ulceration.At this time,the sensitivity is 90%,the specificity is 99%,and the area under the ROC curve is 0.977.ConclusionLp-PLA2 is a risk factor affecting the occurrence of ASO and an effective indicator to reflect the risk degree of ASO.As its plasma concentration increases,the severity of ASO increases.The severity of ASO can be effectively assessed by detecting the level of Lp-PLA2 in the subjects,and Lp-PLA2 can be used as a serological indicator to predict the risk of ASO.