| Objectives:The serum concentrations of Procalcitonin(PCT)and high sensitivity C-Reactive Protein(hs-CRP)and mRNA expression of High Affinity Immunoglobulin Gamma Fc Receptor(FCGR1A)gene were determined with specimens from patients with respiratory tract infectious diseases.The detection results were then analyzed to evaluate the clinical potential for differential diagnosis of viral and bacterial infections,as well as to identify bacterial infection types.It could also be helpful for rational usage of antibiotics in infection treatment.Methods:360 cases of respiratory tract infection in our hospital from May of 2017-January of 2018 were screened out as research objects.According to results from bacterial culture and common respiratory viruses detection,patients were divided into bacterial infection group and viral infection group.The former group was further divided into Gram-negative(G~-)bacterial infection group and Gram-positive(G~+)bacterial infection group.144 healthy volunteers were selected as control group.Serum samples were collected and used for PCT and hs-CRP level detection.Whole blood samples from 110 chose patients were used for mRNA expression detection of FCGR1A gene.Detection results from various groups were statistically analyzed.Serum levels of PCT and hs-CRP,mRNA expression levels of FCGR1A gene and combined detection result of the three makers were chosen as variation to set up the Receiver Operating Characteristic(ROC)of those subjects and determine the best cut-off value for identifying infection type.Results:1.Average levels of serum PCT were 0.05(0.05,0.05)ng/ml in control group,0.05(0.05,0.07)ng/ml in viral infection group and 0.39(0.07,2.02)ng/ml in bacterial infection group.The statistical difference between any two groups was significant(P<0.01).Comparison of bacterial infection group with control group showed that Youden index was largest(0.717)when PCT level at 0.115 ng/ml,while sensitivity was 71.7%and specificity was 100.0%.Comparison of viral infection group with control group showed that Youden index was the largest(0.189)when PCT level at0.065 ng/ml,while sensitivity was27.2%and specificity was91.7%.Comparison of bacterial infection group with viral infection group showed that Youden index was largest(0.550)when PCT level at 0.115 ng/ml,while sensitivity was71.7%and specificity was83.3%.2.Average levels of serum hs-CRP were 2.00(1.00,4.00)mg/L in control group,21.50(10.00,47.25)mg/L in viral infection group and 78.00(31.50,145.25)mg/L in bacterial infection group.The statistical difference between any two groups was significant(P<0.01).Comparison of bacterial infection group with control group showed that Youden index was largest(0.803)when hs-CRP level at 11.95mg/L,while sensitivity was 85.9%and specificity was 94.4%.Comparison of viral infection group with control group showed that Youden index was largest(0.718)when hs-CRP level at6.10mg/L,while sensitivity was 86.4%and specificity was 85.4%.Comparison of bacterial infection group with viral infection group showed that Youden index was largest(0.439)when hs-CRP level at 38.50 mg/L,while sensitivity was 71.7%and specificity was 72.7%.3.Within bacterial infection group,PCT and hs-CRP serum levels and relative levels of FCGR1A m RNA in control group were 0.05(0.05,0.05)ng/ml,2.00(1.00,4.00)mg/L and(2.27±0.77),those in Gram-negative bacterial infection group were0.39(0.06,1.70)ng/ml,85.25(27.50,169.70)mg/L and(7.43±3.37)and those in Gram-positive bacterial infection group were 0.37(0.09,2.34)ng/ml,72.00(32.25,131.25)mg/L and(10.13±9.70).The levels of PCT,hs-CRP and FCGR1A mRNA in Gram-negative bacterial infection group and in Gram-positive bacterial infection group were significantly different from those in control group(P<0.01),and no significant difference was found between Gram-negative and Gram-positive groups(P>0.05).4.Relative expression levels of FCGR1A mRNA were 2.27±0.77 in control group,5.41±4.71 in viral infection group and 8.07±5.23 in bacterial infection group.The statistical difference between any two groups was significant(P<0.01).Comparison of bacterial infection group with control group showed that Youden index was largest(0.881)when FCGR1A mRNA level at 3.935,while sensitivity was 88.1%and specificity was 100.0%.Comparison of viral infection group with control group showed that Youden index was largest(0.546)when FCGR1A mRNA level at 3.378,while sensitivity was 57.9%and specificity was 96.7%.Comparison of bacterial infection group with viral infection group showed that Youden index was largest(0.355)when FCGR1A mRNA level at 3.817,while sensitivity was 88.1%and specificity was 47.4%.5.Comparison of bacterial infection group with control group showed that Youden index was largest(0.929)when prediction probability of combined detection results at 0.580,while sensitivity was 92.9%and specificity was 100.0%.Comparison of viral infection group with control group showed that Youden index was largest(0.775)when prediction probability of combined detection results at 0.592,while sensitivity was 84.2%and specificity was 93.3%.Comparison of bacterial infection group with viral infection group showed that Youden index was largest(0.532)when prediction probability of combined detection results at 0.525,while sensitivity was69.0%and specificity was 84.2%.Conclusions:1.The serum levels of PCT and hs-CRP and mRNA expression levels of FCGR1A gene elevated significantly in both bacterial and viral infection groups,especially in former group.Thus PCT,hs-CRP and FCGR1A could be used to differentially diagnose bacterial and viral infections.Combined detection of the three makers could increase the sensitivity and specificity which used to differential diagnosis bacterial and viral infection.2.The serum levels of PCT and hs-CRP and mRNA expression levels of FCGR1A geneshowed no significant statistical difference between Gram-negative bacterial infection group and Gram-positive bacterial infection group.Thus PCT,hs-CRP and FCGR1Acould not be used to identify Gram-negative bacterial infection from Gram-positive bacterial infection. |
PDF Full Text Request