Changes in polymorphonuclear leukocytes in the vagina of patients with preterm labor

To evaluate changes in vaginal polymorphonuclear leukocytes (vPMNL) in patients with preterm labor, we obtained vPMNL-rich suspensions from vaginal fluids of 77 women (21 with preterm labor and 56 control women with uncomplicated pregnancy). Total counts of vPMNL and % viability of vPMNL (viable vPMNL:total vPMNL) were significantly higher in patients with preterm labor (37 +/- 92 x 10(5), 23 +/- 29%) vs. controls (11 +/- 15 x 10(5), 6.9 +/- 8.3%). The concentration of granulocyte elastase in vaginal fluid diluted to 20 ml was also higher in patients with preterm labor than in controls (4,806 +/- 3,818 vs. 2,739 +/- 2,556 ng/ml). We conclude that PMNL and granulocyte elastase are abundant in the vagina in patients with preterm labor, which suggests that the PMNL may be involved in the pathogenesis of preterm labor.