bacterial 
 infection in newborns , especially preterm ,   may rapidly evolve into generalized 
 sepsis .
this condition has a gradual and subtle onset , with nonspecific symptoms 
 that may severely compromise the infant s clinical state if untreated and lead 
 to life - threatening consequences .  
neonatal sepsis has a fairly low incidence at 
 birth ( 110/1000 live births ) but may affect up to 16% of infants in the 
 neonatal intensive care unit ( nicu ) with birth weight of 5011500 
clinical 
 manifestations are nonspecific and laboratory parameters such as white blood 
 cell ( wbc ) count or c - reactive protein ( crp ) are of limited value in identifying 
 infected newborns . as a consequence , appropriate diagnosis and therapy
could be 
 delayed , worsening the prognosis of the patient [ 26 ] . in 
 studies elsewhere ,
even the combination of total neutrophil count , immature - to - total 
 neutrophil ratio ( i / t ) , and platelet count failed to reach an appropriate sensitivity 
 and specifity in this pathology .
c - reactive protein has been thoroughly studied 
 as a diagnostic tool in neonatal sepsis and also as an indicator of response to 
 therapy [ 9 , 10 ] .
the underdeveloped immune system 
 predisposes preterm newborns to infection , which is a major cause of neonatal 
 morbidity and mortality .
sepsis and endotoxin activate monocytes , macrophages , 
 lymphocytes , fibroblasts , and endothelial cells that produce and secrete il-1 , tnf- , 
 -interferon , il-6 , il-8 , and other proinflammatory cytokines .
il-6 , 
 stimulated by tnf- , il-1 , and endotoxin of viral and bacterial infections , 
 acts as a t - cell activation indicator , induces antibody secretion by human 
 b - cells , causes differentiation of cytotoxic t - cells , and also has the ability 
 to inhibit tnf- production .
moreover , il-6 is the major stimulant in hepatic 
 protein synthesis , that is , crp and fibrinogen during acute phase responses . 

previous studies have shown that determinations of il-6 in neonatal blood are of 
 diagnostic value in sepsis .
elevated serum il-1 , il-6 , il-8 , and tnf- levels have been 
 found in both the neonatal and adult sepsis .
several studies have evaluated the 
 role of cytokine determinations as early diagnostic markers in neonatal sepsis 
 [ 1117 ] .
the 
 aim of this study is to determine serum il-1 , il-6 , il-8 , and tnf- levels in 
 neonatal sepsis at the time of diagnosis and after therapy and to show the 
 meaningful on the follow up .
this prospective study was performed on newborns who were hospitalized for neonatal 
 sepsis at nicu .
inclusion criteria were positive clinical signs of sepsis 
 and/or history of factors associated with increased risk for infection and 
 parental informed consent .
exclusion criteria were congenital malformations , 
 congenital infections associated with the torch complex , and refusal of 
 parental consent .
clinical signs of sepsis were defined as the presence of three 
 or more of the following categories of clinical signs : apnea , tachypnea 
 ( > 60/min ) , nasalflaring , retraction , cyanosis , respiratory distress - bradycardia 
 ( < 100/min ) , tachycardia ( > 180/min ) , hypotonia , seizures - poor skin colour , 
 capillary refilling time longer than two seconds , irritability , and lethargy .
historical 
 factors associated with increased risk for infection included premature rupture 
 of the membranes ( in term infants > 18 hours ) , maternal fever during labour , intraamniotic 
 infection , and chorioamnionitis . 

two or more abnormal values of the sepsis screen ( as white blood cell count 
 < 4000 or > 10.000  mm , immature - to - total neutrophil ratio 
 higher than 0.2 and crp positivity ) were considered as supportive for diagnosis 
 of infection .
newborns were classified as culture - proven sepsis ( positive 
 blood culture ) , as culture - negative sepsis ( negative blood culture , but 
 clinical signs of sepsis with positive sepsis screen and/or a history of risk 
 factors , and antibiotic treatment longer than 7 days ) , and as control groups ( healthy , 
 noninfectious newborns ) .
blood samples were obtained at time of diagnosis and seventh day after 
 antibiotic treatment , their serum extracted and il-1 , il-6 , il-8 , and tnf- were determined .
blood 
 analysis was done in firat medical center immunology laboratory ( elazig , turkey ) .
crp was determined by the behring 
 nephelometer 100 analyzer bn ii ( ny , usa ) .
mg / l and a 
 serum value of > 8  mg / l was defined as 
 abnormally elevated .
the serum samples 
 of the study and control groups were studied by elisa for il-1 , il-6 , il-8 , 
 and tnf- levels with human cytokine kits ( biosource , calif , usa ) .
detection 
 limit for serum il-1 level was 1  pg / ml , measure range was 0250  pg / ml .
detection limit for serum il-6 level was 2  pg / ml , 
 measure range was 0500  pg / ml .
detection limit for serum il-8 level was 5  pg / ml , 
 measure range was 01000  pg / ml .
detection limit for serum tnf- level was 1.7  pg / ml , measure range was 01000  pg / ml the collected blood samples were 
 centrifuged at 2500  g for 10 minutes at 4c .
the serum 
 layer was separated and frozen at 80c for 
 cytokine analysis , which was performed in less than 2 weeks .
kruskal wallis and post hoc test 
 scheffe procedures 
 were used ; the difference in three groups and p<.05 was considered 
 to be significant .
wilcoxon test was used for the interpretation of the 
 difference between at time of diagnosis and after therapy .
in 
 total , 50 newborns were included in the study : 12 culture - proven sepsis , 21 
 culture - negative sepsis , and 17 control .
table 1 shows the characteristics of 
 the study group . at 
 time of diagnosis ,
serum il-1 , il-6 , il-8 , and tnf- levels of culture - proven 
 sepsis were significantly higher than those of the control groups ( p<.05 ) ; 
 but only serum il-8 levels of culture - proven sepsis was significantly higher 
 than culture - negative sepsis ( p<.05 ) . at 
 time of diagnosis ,
serum il-1 , il-6 , il-8 , and tnf- levels of culture - proven 
 sepsis and culture - negative sepsis were significantly higher than levels at 
 seventh day after antibiotic treatment ( p<.05 ) .
serum 
 il-1 , il-6 , il-8 , and tnf- levels were showed in table 2 .
bacterial 
 infection continues to be the major cause of morbidity and mortality in the 
 newborn . because the prognosis for sepsis largely depends on early identification 
 and treatment ,
these newborns are subjected to extensive diagnostic evaluation 
 and empirical systemic antibiotic treatment , pending laboratory results .
the definitive 
 diagnosis of sepsis is made by a positive blood culture , which requires a 
 minimum of 4872 hours , yields a positive result in only 3070% of cases , and 
 may not always be available in peripheral health centers .
there is , 
 however , a lack of consensus on the essential tests that would identify 
 newborns with acute infection .
conducted a systematic review 
 to determine the value of diagnostic tests for bacterial infection in early 
 life ( from birth to 90 days old ) and reported that the accuracy of tests varies 
 enormously and the tests are of limited value in the diagnosis of infection .
the possible sources of 
 heterogeneity were population , age , whether the subjects were at term or 
 preterm , methodological quality , different leukocyte indices , different cutoff 
 values , and interpretation of test results by different laboratory observers . in 
 the past few decades
, it has been observed that several mediators of 
 inflammation tend to become elevated during sepsis .
the concentrations of some 
 proinflammatory cytokines , especially tnf- , il-6 , and il-8 , in systemic circulation 
 were reported to increase in severe infections and septic shock .
.   showed that serum il-6 , il-8 , and tnf- levels were all higher in 
 septic than in nonseptic newborns .
the study of il-1 and tnf- , cytokines that 
 are synthesized at the beginning of the inflammatory cascade has rendered 
 differing results . in our study , the serum tnf- and il-1 levels were significantly 
 increased in newborns with sepsis .
results of different published studies 
 relation to these cytokines are contradictory . concerning il-1 results , 
 similar to ours , they 
 have been reported by some researchers while not by others [ 2528 ] .
some studies found the diagnostic 
 utility of this cytokine [ 25 , 26 ] while others demonstrated similar or even 
 lower levels in infected newborns compared to healthy newborns [ 29 , 30 ] .
discrepancies 
 in results among different studies could be explained by the variations in 
 laboratory methods in performing the analysis , the time of the sample 
 collection , or the control population selected .
interleukin-6 
 has been reported as an early indicator of neonatal sepsis because of its rapid 
 increase after endotoxin challenge .
previous studies have shown il-6 to 
 be a useful marker of early infection in the newborn [ 3134 ] .
. 
 showed that septic preterm newborns had significantly elevated il-6 levels at 
 the onset of sepsis as compared to the recovery period and the controls . in our 
 study , it was observed that il-6 levels of newborn with culture - proven sepsis 
 and culture - negative sepsis were significantly higher than controls ( p<.05 ) .
interleukin-8 
 is a cytokine that has a role in the release , activation , and chemotaxis of 
 neutrophils .
serum il-8 level has been reported to increase in neonatal sepsis 
 and have a sensitivity of about 8090% and a specifity of about 76100% [ 35 , 36 ] . 
 in this study
, it was detected that il-8 levels of newborns with culture - proven 
 sepsis were significantly higher than culture - negative sepsis and controls ( p<.05 ) .
another 
 characteristic of the markers that are used in the diagnosis of neonatal sepsis 
 is that it gives information about the prognosis of the disease and helps in 
 coming to a decision as to whether to stop or continue antibiotic treatment . in 
 this study
, it is found that il-1 , il-6 , il-8 , and tnf- levels were 
 statistically decreased in newborns after seven - day therapy than in newborns at 
 the time of diagnosis ( p<.05 ) .
serum levels of il-1 , il-6 , il-8 , and tnf- 
 are mediators of inflammation and can be used at the diagnosis and at the 
 evaluation of the therapeutic efficiency in neonatal sepsis .
 
 aim . to determine serum   il-1 , il-6 , il-8 , and tnf- levels in neonatal sepsis at the time of diagnosis and after therapy , and to show the meaningful on the follow up 
 . methods . 
 this prospective study was performed on newborns who were hospitalized for neonatal sepsis and who were classified as culture - proven sepsis ( n=12 ) , as culture - negative sepsis ( n=21 ) , and as healthy newborns ( n=17 ) . 
 results . at the time of diagnosis , 
 serum il-1 , il-6 , il-8 , and tnf- levels of culture - proven sepsis were significantly higher than those of the control groups ( p<.05 ) . at the time of diagnosis , il-1 , il-6 , il-8 , and tnf- levels of culture - proven sepsis and culture - negative sepsis were significantly higher than levels at the seventh day after antibiotic treatment . 
 conclusion . 
 serum il-1 , il-6 , il-8 , and tnf- are mediators of inflammation and can be used at the diagnosis and at the evaluation of the therapeutic efficiency in neonatal sepsis . 
1. INTRODUCTION
2. MATERIAL AND METHODS
3. RESULTS
4. DISCUSSION
5. CONCLUSION