The Role Of Toll-like Receptor4and9in Severe Sepsis-induced Acute Kidney Injury

Objective: Acute kidney injury (AKI) is one of the most commonclinical critical ill diseases,and even more a common complication of severesepsis patients. Severe sepsis is the leading cause of AKI,from10%to50%ofpatients with sepsis could occurred AKI,AKI to become an independent riskfactor for rhe poor prognosis of patients with sepsis.Although an importantorgan support and recovery means has made some progress,but the mortalityof sepsis patients with AKI still from20%to50%!The main reason is that thepathogenesis of AKI not very clear.The pathophysiological mechanisms ofAKI may be showed by some animal experiments:renal cell apopto-sis,inflammatory response;the pathophysiological mechanisms may be thesignaling pathways TLRs-mediated.TLRs are the identify receptors for pathogen associated molecularpatterns(PAMPs),can recognize exogenous or endogenous PAMPs.TLRs-mediated signal transduction pathway is a bridge to connect the Innateimmunity and acquired immunity,TLRS stand in the hub for regulating theInflammation and immune response of the body. At present,TLR4and TLR9is one focus of research. The experimental model of sepsis showed that:whenbacterial infections,TLR4and TLR9identified them,Activated TLR signalingpathway,triggered the function of innate immunity,released inflammatorycytokines and Modulated the immune response and inflammation throughregulated signal transduction pathways to affect the development of sepsis.TLR4,mainly expressed on immune cells,can also be found in the tissues andorgans,such as lung,joints,liver,heart, kidney.There are Seldom research aboutthe expression levels of TLR4,in Peripheral blood and kidney tissue forclinical patients with sepsis.Through detecting the expression levels of TLR4and TLR9in PBMC used the flow cytometry and detecting the levels of IL-6and IL-10in serumused ELISA for AKI group and non-AKI group,the topics to study and explorethe role of TLR4and TLR9in severe sepsis induced-AKI,to look for newtherapeutic approaches and targets for early prevention and treatment of clini-cal sepsis-induced AKI,to provide new ideas and theoretical foundation,evenmore to provide a theoretical basis for may improving the prognosis of sepsis-induced AKI.Method: Select November2011to February2012from stay in ICU ofthe Fourth Hospital of Hebei Medical University,in accordance with thediagnostic criteria of AKI the AKIN revised at September2005, patients wereare divided into the AKI group and non-AKI group. Patients into the ICU wereobserved and recorded the vital signs (temperature,pulse,respiration,bloodpressure, blood oxygen saturation) in0h (T0),24h (T1),48h (T2), and leavingICU time (T3), detected SCr,BUN,blood routine,CRP in serum,and Collectingthe patient's peripheral blood,for detecting the expression levels of TLR4andTLR9in PBMC used the flow cytometry and detecting the levels of IL-6andIL-10in serum used ELISA,And recording the change of renal function,thelength of ICU stay,ICU mortality and the APACHE II T0.All datas wasperformed using SPSS13.0statistical package for analysis of measure-ment.Data are expressed as mean±standard deviation (x±s),of two groupswere compared using two independent sample t-test, several LSD single factoranalysis of variance,The relationship between TLRs and inflammatory factorswere analyzed using multiple linear regression analysis,P<0.05was consider-ed statistically significant.Results:1The clinical characteristics of selected patients25cases of patients with severe sepsis were enrolled, including21malesand4females, The age of patients between52-89years, the mean of age was66.16±8.44years old, the APACHE II of patients between14-29points, themean of APACHE II was22.16±4.08points.In accordance with the diagnosticcriteria of AKI the AKIN revised at September2005, patients were are divided into the AKI group and non-AKI group. There were2females and8males InAKI group, the mean of age was68.30±9.63years old, the mean of APACHEII was23.00±4.81points. There were2females and13males In non-AKIgroup, the mean of age was64.73±7.55years old, the mean of APACHE IIwas21.60±3.58points.The primary disease:6cases of patients with infectiousperitonitis,11cases of patients with severe pneumonia,8cases of patientswith esophageal fistula.2Comparison of the levels of creatinine and blood urea nitrogen in serum2.1Between the two groupsCompared to non-AKI group, the levels of SCr and BUN of the AKIgroup at T0, T1, was significantly increased (P<0.01); there was no differenceat other time points,other groups at each time point between the two groups(P>0.05).2.2Comparison within groupThe levels of SCr of two groups compared to T0, T1, T3wassignificantly lower (P<0.05). The level of BUN was gradually decreased inAKI group, but there were no significant differences at each time point(P>0.05). The level of BUN was gradually increased in Non-AKI group,compared toT0, T3was significantly increased (P<0.05); The level of SCr wasgradually decreased, but there were no significant differences at each timepoint (P>0.05).3Comparison of the levels of both TLR4and TLR9in PBMC3.1Between the two groupsCompared to non-AKI group, the levels of TLR4and TLR9of the AKIgroup at T0, was significantly increased (P<0.05); the levels of TLR9of theAKI group at T3, was significantly increased (P<0.05); other groups at eachtime point between the two groups (P>0.05).3.2Comparison within groupThe level of TLR4was gradually decreased and the level of TLR9wasgradually increased in AKI group,but there were no significant differences ateach time point (P>0.05). The level of TLR4was gradually increased and the level of TLR9was gradually decreased in non-AKI group, but there were nosignificant differences at each time point (P>0.05).4Comparison of the level of both TLR4and TLR9in PBMC4.1Between the two groupsThe expression level of both TLR4and TLR9between the two groupscompared at each time point, there were no significant differences(P>0.05).4.2Comparison within groupThe expression level of both TLR4and TLR9within the two groups weregradually decreased, but there were no significant differences(P>0.05).5Comparison of the levels of IL-6å'ŒIL-10in serum5.1Between the two groupsCompared to non-AKI group, the levels of IL-6å'ŒIL-10of the AKIgroup at each time point, there were significantly increased (P<0.05).5.2Comparison within groupthe levels of IL-6å'ŒIL-10within the two groups showed a decreasingtrend, Compared to T0,there were significantly lower at T1, T2, T3time point(P<0.01). Compared among the three time points,there were no statisticallydifferent (P>0.05).6The correlation between the levels of TLR4and TLR9and the levels of IL-6and IL-10between the two groupsTake the expression levels of TLR4and TLR9in PMBC to correlate thelevels of IL-6, IL-10in serum at T0in two groups by multiple linearregression analysis,found that there was a linear correlation between the levelsof TLR9and the level of IL-10in AKI group(F=8.578,P=0.019).7Comparison of the level of CRP in serum7.1Between the two groupsThe level of CRP between the two groups compared at each time point,there were no significant differences(P>0.05).7.2Comparison within groupIn non-AKI group, Compared to T0,there was significantly lower at T3(P<0.05). there were no significant differences at other time points(P>0.05). The level of CRP within AKI group were gradually decreased, but there wereno significant differences(P>0.05).8clinical outcomesTo transfer out of ICU, the length of ICU stay of AKI group was10±6.49days, the improving rate of renal function was60%, there were4patients hasdead, the mortality was40%; the length of ICU stay of non-AKI group was5.93±3.39days, kidney function were normal, there were4patients has dead,the mortality was20%. Comparison of the length of ICU stay and mortalitybetween two groups,there were no significant difference (P=0.093, P=0.275).Conclusion:1severe sepsis patients with AKI group peripheral blood mononuclear cells ofTLR4and TLR9expression levels higher thanin severe sepsis non-AKI group,suggesting that TLR4and TLR9may play an important role in the occurrenceof severe sepsis AKI.2Of TLR4and TLR9may be involved in the occurrence of severe sepsis AKI,activation of TLRs signaling pathways, Activating transcription factor througha series of protein cascade reaction, caused by IL-6, IL-10and other cytokinescontinue to produce and release, and activate innate immune cells, leadingtoimmune and inflammatory response caused by the severe sepsisAKI.3inflammation plays an important role in theoccurrence of severe sepsis AKI.