Relation Between Amniotic Fluid Neutrophil Elastase, Interleukin-6 And Chorioamnionitis

BACKGROUND: Premature rupture of membranes (PROM) is oneof the most common complications of pregnancy. The incidence ofpremature membrane rupture has been reported to range between 3.03%and 21.9%. In patients after PROM "expectant management" iswide-ranging accepted. Chorioamnionitis is one of important complicationsof premature membrane rupture. When patients after PROM coexist withchorioamnionitis, most of them have never experienced any symptoms.Early diagnosis of chorioamnionitis is difficult. If it developed to clinicalchorioamnionitis, it would take serious complications to pregnant womenand newborn. At present, early diagnosis and treatment of PROMasscociated with chorioamnionitis have been fundamental to declineperinatal morbidity and mortality. At one time, the diagnosis ofchorioamnionitis depended on culturing amniotic fluid or microscopicexamination of membrane. But culturing amniotic fluid costs long time,and positive incidence is low. Histological examination can only be madeafter delivery. C-reactive protein (CRP) is correlated with early amnioticinfection. However, its sensitivity and specificity is controversial. Studiessuggest that neutrophil elastase, IL-6 are correlated with chorioamnionitis. OBJECTIVES: To evaluate the role of amniotic fluid neutrophilelastase, IL-6 levels in prediction in chorioamnionitis in pregnant womenafter PROM. METHODS: Samples come from 93 pregnant women after PROMand 40 normal pregnant women. Amniotic fluid was collected duringdelivery . ELISA analysis was employed to detect levels of neutrophilelastase, IL-6 in amniotic fluid. Examine fetal membranes with microscopeafter delivery. RESULTS: 1. Patients with PROM had significantly higher levels of neutrophilelastase, IL-6 in amniotic fluid than patients without PROM. There wassignificant difference between two groups (p<0.05). 2. The more long time of rupture, the more high levels of neutrophilelastase, IL-6 in the amniotic fluid. From PROM to in labor ≥24 hours,levels of neutrophil elastase, IL-6 in the amniotic fluid were significantlyhigher (p<0.05). 3. Patients with histological chorioamnionitis had significantlyhigher levels of neutrophil elastase, IL-6 in the amniotic fluid than patientswithout histological chorioamnionitis (p<0.05). 4. With the aggrevation of inflammation of fetal membranes, levels ofneutrophil elastase, IL-6 in the amniotic fluid are gradually increased. 5. In the group of histological chorioamnionitis, incidence ofpostpartum hemorrhage, puerperal infection,fetal distress and neonatalinfection was obviously higher than that in the group withoutchorioamnionitis (p<0.05); No significant difference in the incidence ofneonatal asphyxia was found between two groups. 6. Using amniotic fluid cutoff levels of 320.44 ng/ml for neutrophilelastase and 3908.63 pg/ml for IL-6 as a clear marker for chorioamnionitis,the sensitiveity ,specificity, and positive and negative predictive valueswere 90.62% verse 71.88%, 96.03% verse 92.01%, 87.88% verse 74.19%,and 97.00% verse 91.18%, respectively. CONCLUSIONS: 1. Amniotic fluid neutrophil elastase, IL-6 levels are valuable clinicalindexes in identification of chorioamnionitis in patients with PROM. Andneutrophil elastase is better marker for diagnosing chorioamnionitis thanIL-6. 2. Neutrophil elastase, IL-6 determination in amniotic fluid aresensitive indicator of degree of chorioamnionitis. 3. The more long time of rupture, the more high levels of neutrophilelastase, IL-6 in amniotic fluid.