Maternal serum interleukin-6 concentrations in patients with preterm premature rupture of membranes and evidence of infection.
OBJECTIVE
Our purpose was to determine whether maternal serum interleukin-6 concentrations are elevated in patients with preterm premature rupture of membranes and intrauterine infection.


METHODS
By use of a sensitive enzyme-linked immunosorbent assay maternal serum interleukin-6 concentrations were measured in 110 samples from patients at 22 to 34 weeks gestation with the following conditions: nonlaboring, uninfected controls (n = 46), preterm premature rupture of membranes > 48 hours before delivery without infection (n = 27), preterm premature rupture of membranes 24 to 48 hours before delivery with subsequent clinical or histologic infection (n = 11), and preterm premature rupture of membranes < 24 hours before delivery with infection present by clinical or histologic criteria (n = 26). The Mann-Whitney U test was used for statistical analysis.


RESULTS
Compared with that of nonlaboring controls, serum interleukin-6 was significantly higher in patients with preterm premature rupture of membranes < 24 hours before delivery with evidence of infection (17.2 vs 1.6 pg/ml, p < 0.0001). Patients with preterm premature rupture of membranes 24 to 48 hours before delivery who had infection had significantly higher interleukin-6 concentrations than did nonlaboring controls (3.6 vs 1.6 pg/ml, p = 0.006). There was no significant difference in interleukin-6 concentrations in nonlaboring controls compared with patients with preterm premature rupture of membranes when serum was obtained > 48 hours before delivery (1.6 vs 1.6 pg/ml, p = 0.90). A serum interleukin-6 level > or = 8 pg/ml yielded a sensitivity of 81%, a specificity of 99%, a positive predictive value of 96%, and a negative predictive value of 95% for identifying intrauterine infection in patients with preterm premature rupture of membranes on the day of delivery.


CONCLUSIONS
Maternal serum interleukin-6 concentrations are elevated in patients with preterm premature rupture of membranes with clinical or histologic chorioamnionitis.
Murtha
A P
AP
Department of Obstetrics and Gynecology, Duke University Medical Center, Durham, NC 27710, USA.
Greig
P C
PC
Jimmerson
C E
CE
Roitman-Johnson
B
B
Allen
J
J
Herbert
W N
WN
D036861:Delivery, Obstetric; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000097:blood*; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D009994:Osmolar Concentration; D011237:Predictive Value of Tests; D011247:Pregnancy / Q000097:blood*; D011251:Pregnancy Complications, Infectious / Q000097:blood*; D012016:Reference Values; D012680:Sensitivity and Specificity; D013997:Time Factors; D014591:Uterine Diseases / Q000097:blood*
D015850:Interleukin-6