THE ROLE OF AMNIOTIC-FLUID L-SELECTIN, GRO-ALPHA, AND INTERLEUKIN-8 IN THE PATHOGENESIS OF INTRAAMNIOTIC INFECTION

OBJECTIVE: Our purpose was to compare and correlate amniotic fluid GRO -alpha, interleukin-8, and L-selectin in patients with and without int raamniotic infection. STUDY DESIGN: Amniocentesis was performed on 45 pregnant women with preterm contractions, labor, or rupture of membran es. Fourteen patients had intraamniotic infection, and 31 did not. Int raamniotic infection was defined as the presence of a positive amnioti c fluid culture. Amniotic fluid tests for Gram stain, glucose, neutrop hil counts, creatinine, pH, and specific gravity were performed. Amnio tic fluid levels of soluble L-selectin, interleukin-8, and GRO-alpha w ere measured by an enzyme-linked immunoassay and normalized by amnioti c fluid creatinine levels. The Mann-Whitney U test and Spearman's rank correlation test were used for statistical analyses. RESULTS: Amnioti c fluid median levels of soluble L-selectin, interleukin-8, and GRO-al pha were significantly higher in pregnant women with intraamniotic inf ection than in those without intraamniotic infection (soluble L-select in: median 3334.6 ng/mg creatinine, range 408.4 to 15,956.8 vs 717.2 n g/mg creatinine, range 129.4 to 4601.9, p = 0.009; GRO-alpha: median 8 41.6 ng/mg creatinine, range 28.1 to 8591.7 vs 56.8 ng/mg creatinine, range 0.0 to 440.2, p < 0.0001; interleukin-8: median 4932.7 ng/mg cre atinine, range 0.0 to 55,058.7 vs 28.3 ng/mg creatinine, range 0.0 to 1161.6, p = 0.0004). Patients with intraamniotic infection had signifi cantly higher amniotic fluid leukocyte counts and leukocyte esterase a ctivities and significantly lower amniotic fluid glucose concentration s compared with those without intraamniotic infection. Amniotic fluid GRO-a, interleukin-8, and soluble L-selectin were positively correlate d, and each was positively correlated with amniotic fluid leukocytes a nd negatively correlated with amniotic fluid levels of glucose. CONCLU SIONS: Our data indicate amniotic fluid GRO-alpha and interleukin-8 ma y be two potent leukocyte chemoattractants and activators, and L-selec tin is rapidly shed from leukocytes in the amniotic fluid in patients with intraamniotic infection.