[The use of maternal serum cytokines in the predicting of the efficacy of tocolytic therapy in case of the threat of preterm labor].

OBJECTIVES

The purpose of our study was to evaluate the use of maternal serum IL-8, IL-6, IFN-gamma levels in the predicting of the efficacy of tocolytic therapy in preterm labor.

MATERIALS AND METHODS

We investigated prospectively the group of 47 women in singleton pregnancies with threatened preterm labor in less than 36 weeks gestation and administered tocolytic therapy.

RESULTS

In 19 of them tocolysis failed (group II and they delivered premature newborns (the group I--successful tocolysis consisted of remaining 28 women). The incidence of clinical chorioamnionitis, histologic chorioamnionitis and inherited infection of newborns was significantly higher among women refractory to tocolytic therapy (10.2%, 36.8%, 26.3% versus 0%, 3.6%, 0%, respectively, p < 0.05). Maternal serum IL-8, IL-6, IFN-gamma (by means of ELISA technique) and CRP, WBC, ESR levels were measured at the admission to the study. The mean WBC, ESR and the median (range) IFN-gamma (0 (0-7.1) and 0.9 (0-10.4) pg/ml, respectively) didn't differ in both groups. The concentrations of serum IL-8, IL-6, CRP were significantly higher in the group of failed tocolysis (median (range): IL-8: 22.7 (6.3-83.2) vs 3.0 (0-26.0) pg/ml; IL-6: 7.4 (0-21.0) vs 0 (0-11.3) pg/ml; CRP: 1.8 (0.6-7.0) vs 0.6 (0.6-3.9) mg/dl; p < 0.05). Serum IL-8 determinations (definition of abnormal test: > 8 pg/ml) were found the most reliable in the prediction of tocolysis failure with a sensitivity 87.5%, specificity 81.8%, positive predictive value 77.8%, negative predictive value 90% and accuracy 84.2%. Also reliable were IL-6 determinations (IL-6 > 6 pg/ml had a sensitivity 75%, specificity 90.9%, positive predictive value 85.7%, negative predictive value 83.3% and accuracy 84.2%) and CRP determinations (CRP > 1.2 mg/dl had a sensitivity 75%, specificity 81.8%, positive predictive value 75%, negative predictive value 81.8% and accuracy 78.9%). The efficacy of IFN-gamma, WBC and ESR was significantly lower.

CONCLUSIONS

Our data revealed that the maternal serum IL-8, IL-6 and CRP determinations are very useful in the predicting of the efficacy of tocolytic therapy in women with threatened preterm labor. The use of IFN-gamma, WBC, ESR was significantly lower.