Assessment On MiR-15b,miR-210 And MiR-486 As Elderly Sepsis Diagnosis And Prognosis Biomarkers

ObjectiveWe aim to detect microRNAs levels in elderly septic patients and healthy controls.A correlation analysis was performed between differentially expressed serum miRNAs and various inflammatory factors or clinical indicators.The value of these selected miRNAs in the diagnosis and prognosis evaluation of sepsis was also investigated.Methods82 elderly sepsis patients(65 males and 17 females with a mean age of 77.71±14.40 years)admitted to Medical Intensive Care Unit(MICU)department at General Hospital of Guangzhou Military Command(Guangzhou,China)from March 2014 to June 2016 were enrolled in our study.They were divided into two groups according to the severity:42 patients with sepsis,40 with septic shock.Based on 28-day mortality,sepsis patients were also divided into survivors(n=47)and non-survivors(n=35).22 elderly people(14 males and 8 females,with an average age of 74.05±5.72 years)from the Health Screening Center of General Hospital of Guangzhou Military Command as control group were recruited.Clinical data and plasma samples were collected from the septic group and the control group.Five miRNAs(miR-15b,miR-145,miR-146a,miR-210 and miR-486)which is closely related to inflammatory and immune responses were selected and their plasma levels in sepsis patients and control group were detected by real-time quantitative reverse transcription-polymerase chain reaction(qRT-PCR).Target genes were predicted for differentially expressed miRNAs and the possible mechanism involved in the pathogenesis of sepsis using Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)were also explored.Serum inflammatory factors such as IL-6,IL-10,TNF-α levels were detected by Enzyme-linked Immunosorbent Assay(ELISA).Correlation between differentially expressed miRNA levels and common inflammatory factors and clinical indicators or scores has been further analyzed using the Spearman correlation test.The Receiver Operating Characteristic(ROC)curve was performed to compare their clinical value for the diagnosis and prognosis in elderly septic patients.Kaplan-Meier curves and log-rank test calculations were performed to display the impact of miR-210 on survival.Cox regressions were used to identify factors which were able to predict 28 days mortality,100 days mortality or all-cause mortality of patients.Results(1)We found that miR-15b and miR-486 levels in sepsis group were significantly decreased while miR-210 increased(P<0.05,respectively)compared to control group.No differences were observed in the expression of miR-145 and miR-146a between elderly sepsis patients and controls(P>0.05,respectively).(2)Target genes of miR-15b,miR-210 and miR-486 were predicted and 62 target genes closely related to inflammation and immunity were found.The further GO and KEGG analysis showed that these target genes might involved in relative pathways of sepsis such as Toll-like receptor signaling pathway,TNF signaling pathway,MAPK signaling pathway,NF-kappa B signaling pathway etc.(3)Spearman correlation analysis revealed that serum miR-15b concentration was signifcantly correlated with ALT and CKMB while inversely correlated with Cr;serum miR-486 levels were inversely correlated with IL-6,IL-10,CRP,procalcitonin(PCT),and Cr;serum miR-210 concentrations were signifcantly correlated with IL-6,IL-10,TNF-α,CRP,PCT,bilirubin,BUN,CKMB,lactic dehydrogenase,myoglobin alpha--hydroxybutyrate dehydrogenase,lactate levels and SOFA scores while inversely correlated with urine volume(UV)and survival time.(4)ROC curve analysis showed that miR-486 had the largest Area Under the Curve(AUC:0.887)which also had higher sensitivity(84.21%)and specificity(86.36%)to diagnose elderly sepsis,followed by miR-15b with an AUC of 0.671 and miR-210 with an AUC of 0.651.The three miRNAs combined together showed an AUC of 0.959.(5)Compared with septic group,miR-210 was significantly increased in septic shock group(P<0.05).ROC curve analysis demonstrated that the AUC of miR-210 was 0.685 with specificity and sensitivity of 82.05%and 57.5%.MiR-210 combined with SOFA,APACHE II score,IL-6 and IL-10 could improve its ability to distinguishing sepsis and sepsis shock,with an AUC of 0.873.(6)Serum miR-210 levels were significantly higher in non-survival group than survival group(P<0.05).ROC analyses utilized to compare the prognostic value of miR-210 levels with established prognosis scores revealed that the AUC of miR-210 was slightly higher than SOFA scores(AUC=0.77 vs.0.707).Kaplan-Meier survival analysis showed that the mortality rate was higher in patients with high miR-210 level than those with low miR-210 concentration at 28 days,100 days or long-term survival time.Univariate Cox regression analysis showed that miR-210 level was a risk factor for 28 days and 100 days of death,but not for long-term mortality.Conclusions1.Serum miR-15b,miR-210 and miR-486 may be used as biomarkers for diagnosis of sepsis,in which miR-486 showed a higher value.Combination of these three miRNAs can best diagnose sepsis.2.miR-210 level not only reflect the situation of inflammatory response and organ dysfunction,but also distinguish severity of sepsis in the elderly and act as an independent risk factor for evaluating short-term prognosis.