Correlation Analysis Of ApoM, IL-6 And Other Indexes Of Inflammation With Bacterial Infection And Combined Diagnosis Research

Objective:Through the observation of expression levels of plasma APOM, IL-6 and other traditional laboratory markers of inflammation in bacterial infections of the blood, discuss the correlation of apolipoprotein M (ApoM),interleukin-6(IL-6) with bacterial infections of the blood and the value of early diagnosis; study the expression of apolipoprotein M (ApoM), interleukin-6 (IL-6) and other markers of inflammation in the bacterial infections of the blood with different course, bacteria, drug and department sourses, the correlation with traditional inflammatory markers, in order to provide new ideas and reference to study the pathogenesis; Further discover the more optimized joint laboratory diagnostic mode for blood bacterial infection.Methods:Collect the 90 patients (48 males,42 females) in the Affiliated Hospital of Chengdu University of Traditional Chinese Medcine from Marth 2014 to September and clinical diagnosis of bacterial infections in blood;Select healthy 50 cases(25 males,25 females) for the control group,and further divide the bacterial blood infection into four subgroups by duration, bacteria,drug and department sources.Collect the patients with heparin plasma,determine the plasma concentration of apolipoprotein M(ApoM), interleukin-6(IL-6) and procalcitonin (PCT).While collecting patient intravenous EDTA-K2 anticoagulated whole blood to measure C-reactive protein(CRP), White blood cell count(WBC),Neutrophil cell percentage(Neu%), Neutropenia average volume(MNV), Neutrophil average conductivity(MNC) and Neutrophils average scattering value(MNS),record the patient’s age, sex, blood glucose, blood pressure and blood lipid levels and other clinical data. The all experimental groups and subgroups test data were statistically processed and analyzed by using the statistical software SPSS 19.0.Results:1.The IL-6, PCT, CRP, MNV, WBC and Neu% levels of blood bacterial infection group are significantly higher than those of control group, the ApoM, MNC and MCS levels are significantly lower than those of control group, the difference is statistically significant (P<0.05).2. Further grouping the blood bacterial infection group according to the course, bacteria, drug resistance and department sources, the expression of ApoM, IL-6 and other markers of inflammation in each subgroup compared with the control group, the difference is statistically significant (P<0.05). (1) Compare with the four sub-groups (different courses), the different expression of APOM, PCT and CRP is statistically significant (P<0.05), each group which developed to the sepsis, in addition to the expression of ApoM is lower than that of bacteremia group, the expression of PCT and CRP are higher than that of bacteremia group. (2) Compare with the two sub-groups (different bacteria), the expression of IL-6, PCT, CRP and Neu% in gram negative bacteria infection group (G-) are higher than those of gram positive bacteria infection group (G+), the difference is statistically significant (P<0.05). (3) Compare with the three sub-groups (different drug resistance), the expression of ApoM, IL-6 and other markers of inflammation is not statistically significant (P>0.05). (4) Compare with the three sub-groups (different department sources), the expression of ApoM, IL-6 and other markers of inflammation is not statistically significant (P>0.05).3.Using spearman correlation analysis revealed, the levels of PCT in bacterial infection show a linear positive correlation with the level of IL-6 in the group (r=0.231, P=0.048<0.05), a linear negative correlation with the level of ApoM (r=-0.431, P=0.038<0.05); the levels of IL-6 in sepsis group show a linear positive correlation with the level of ApoM (r=0.625, P=0.01<0.05), the ApoM level, PCT level and MNC are linearly correlated with the IL-6 level in the group (r=0.625, P=0.01<0.05; 1-0.538, P=0.039<0.05; r=0.581, P=0.0180.05); the level of PCT in severe sepsis show a linear positive correlation with the level of IL-6 in the group (r=0.685, P=0.010<0.05), a linear negative correlation with the level of ApoM (r=-0.651, P=0.022<0.05)。4.The multiple linear stepwise regression analysis is performed in blood bacterial infection group, different courses of various subgroups and different bacterial infection of various subgroups, in which ApoM and IL-6 levels as the dependent variable, with the correlation index in each experimental group as the independent variable, the IL-6, PCT and APOM, PCT of the bacterial infection group enter the regression equation, and obtain the regression equation:Y (IL-6)=8.824PCT+448.616 and Y (APOM)=-12.328PCT+48.65; the ApoM and IL-6, IL-6 and ApoM, MNC, PCT of sepsis group enter the regression equation, and obtain the regression equation:Y(APOM)=40.482-0.003IL-6 and Y(IL-6)=755.846PCT-13.772ApoM+19.142MNC-2922.592; the IL-6, PCT and APOM, PCT of severe sepsis group enter the regression equation, and obtain the regression equation:Y (IL-6)= 100.449PCT -56.852 and Y (APOM)=-5.219PCT+64.81; the indexes of bacteremia, septic shock group, gram positive bacteria(G+bacteria) and gram negative bacteria(G-bacteria) group are not enter into the regression equation.5.Application of ROC curve and the area under the curve (AUC) to analyse the inflammatory indexes of each experimental group, get the diagnostic efficacy of each index: the area under the curve (AUC) of APOM、IL-6、PCT、CRP、WBC、N%、MNV、MNC and MNS in blood bacterial infection group are 0.978,0.980.0.986.0.974,0.728.0.966.0.985. 0.785.0.908 respectively; the area under the curve (AUC) of APOM.PCT and CRP in general bacteremia and sepsis group are 0.964.0.967.0.946 and 0.981,0.982,0.969 respectively; the area under the curve (AUC) of IL-6、PCT、CRP and N%in gram positive bacteria(G+ bacteria) and gram negative bacteria(G-bacteria) group are 0.972、0.984、0.957.0.947 and 0.970.0.990,0.989.0.974 respectively.6. Application of ROC curve and the area under the curve (AUC) to analyse the differential diagnosis value of the inflammatory indexes in each experimental group,as the general bacteremia to non disease group, sepsis for the disease group, the area under the curve (AUC) of ApoM. PCT and CRP are 0.903,0.997.0.713 respectively; As the gram positive bacteria (G+bacteria) to the non disease group, the gram negative bacteria (G-bacteria) for the disease group, the area under the curve (AUC) of IL-6、PCT、CRP and N%are 0.641、 0.667.0.683,0.666 respectively.7. Application of ROC curve and the area under the curve (AUC) to analyse the combined diagnosis value of the inflammatory indexes in each experimental group:for bacterial infection, the AUC of united four (APOM+IL-6+CRP+PCT) at a maximun, is 0.991, the sensitivity and specificity are maximum too, respectively 97.6%and 97.5%; for the differential diagnosis of sepsis, the AUC of united three (APOM+CRP+PCT) at a maximun, is 0.989, the sensitivity and specificity are maximum too, respectively 98.6% and 97.9%; for the differential diagnosis of gram negative bacteria(G-bacteria) infection, the AUC, sensitivity and specificity are 0.712,70.3% and 71.0% respectively, to achieve the diagnosis value of medium.Conclusion:1.The level of ApoM in bacterial infections of the blood group and the subgroups are lower than that in the control group,but the level of IL-6 is higher (P<0.05), the AUC of which is 0.978 and 0.980 respectively, indicate that the level of ApoM and IL-6 have high diagnostic value for the early diagnosis of bacterial infections of the blood.2.The expression level of ApoM in bacterial infection is associated with the disease progress, along with the aggravating of the degree of infection, by bacteremia to sepsis, to the development of septic shock, the expression level of ApoM decreased gradually, the AUC of differential diagnosis is 0.903, suggest that ApoM not only closely related with lipid metabolism, possibly through certain metabolic pathways play a potent anti-inflammatory effects; The expression level of IL-6 in gram negative bacteria (G-) infection is higher, the AUC of differential diagnosis is 0.64 Vindicating that the cell wall lipopolysaccharide (LPS) stimulation factor is strong, induce the production of inflammatory cytokines in monocyte macrophages, endothelial cells and lymphoid cells.3.The ApoM, IL-6 and PCT inflammatory index of bacterial infection and sepsis has certain relevance, to provide the experimental basis for clarifing the approach and mechanism of ApoM and IL-6 involved in inflammation.4. The combined of APOM and IL-6, PCT, CRP and other inflammatory markers is better than that of single index in diagnosis and differential diagnosis, three or four, the diagnosis and differential diagnosis of united reached the highest. But the diagnostic value of single detection is still less than the combined diagnosis with multiple indexes, although the experiments show that the PCT has high early diagnosis value in the diagnosis of bacterial infection and identification of general bacteremia and sepsis, and have certain application value in the identification of different bacteria (G-/G+) infection.5. The APOM and IL-6 have certain value in the early diagnosis of blood bacterial infection. Although with the aggravating of the degree of infection, the diagnostic value of ApoM increase and in gram negative bacterial infection the expression of IL-6 is up regulated, but compared with the diagnostic value of the traditional inflammatory markers the clinical used, there are still some gaps, and to the further elaboration of the participating and developing mechanism of inflammation and the pathophysiological role of two.