Detection of interleukin-6 in vaginal secretions of women with preterm premature rupture of membranes and its association with neonatal infection: a rapid immunochromatographic test

OBJECTIVE: The purpose of this study was to evaluate the diagnostic value of an interleukin-6 (IL-6) bedside test of vaginal secretions for neonatal infection in cases of preterm premature rupture of membranes. STUDY DESIGN: This prospective clinical study included 73 patients. Interleukin-6 protein in vaginal secretions was determined with an immunochromatographic bedside test in <20 minutes. RESULTS: Elevated C-reactive protein level (>20 mg/dL; odds ratio, 5.1; 95% CI, 0.9-28.6) and positive interleukin-6 level (odds ratio, 4.6; 95% CI, 1.2-18.4) were both associated with neonatal infection. After adjustment, only interleukin-6 remained associated with neonatal infection (odds ratio, 4.5; 95% CI, 1.1-18.5). The sensitivity of interleukin-6 for the prediction of neonatal infection was 79% (95% CI, 65-92); its specificity was 56% (95% CI, 42-70); its positive predictive value was 30% (95% CI, 12-47), and its negative predictive value was 92% (95% CI, 84-99). CONCLUSION: Interleukin-6 protein determination by this new immunochromatographic test is a noninvasive prenatal vaginal marker of neonatal infection.