Systemic activation and vascular infiltration of neutrophils with term labor.
OBJECTIVE
The purpose of the current study was to determine if neutrophils infiltrate maternal systemic vascular tissue at the time of term labor.


METHODS
Subcutaneous fat biopsies were obtained at cesarean delivery or abdominal surgery from laboring women (n = 5), non-laboring women (n = 5), and normal non-pregnant women (n = 5). Immunohistochemical staining was performed for CD66b, a neutrophil antigen, and intercellular adhesion molecule-1 (ICAM-1; CD54), an endothelial cell adhesion molecule for neutrophils. Vessels (10 to 200 microm) were analyzed for intensity of staining and percentage of vessels with staining.


RESULTS
CD66b staining intensity was significantly greater for laboring women at term than for non-laboring women at term or for normal non-pregnant women (1.3 +/- 0.3 versus 0.2 +/- 0.1 versus 0.2 +/- 0.1, respectively, P < .01). Laboring women had significantly more vessels with staining for CD66b (79 +/- 4 versus 24 +/- 8 versus 19 +/- 6%, P < .001), more vessels with neutrophils adhered and flattened to endothelium (67 +/- 3 versus 16 +/- 7 versus 12 +/- 4%, P < .001), more vessels with neutrophils in the intima (30 +/- 6 versus 5 +/- 2 versus 2 +/- 1%, P < .05), and a greater number of neutrophils per vessel (5.4 +/- 1.1 versus 1.7 +/- 0.5 versus 1.2 +/- 0.3, P < .01) as compared to non-laboring or normal non-pregnant women. ICAM-1 staining was present in the endothelium of all groups, with no difference in staining intensity or percent of vessels stained. Between 86% to 96% of vessels stained for ICAM-1. Laboring patients had numerous leukocytes stained for ICAM-1 in their vessels.


CONCLUSIONS
This study demonstrates that neutrophils infiltrate maternal systemic vascular tissue at the time of term labor. Neutrophils were flattened and adhered to endothelium and infiltrated into the intimal space.
Leik
Courtney E
CE
Departments of Obstetrics and Gynecology and Physiology, Virginia Commonwealth University Medical Center, Richmond, Virginia 23298-0034, USA.
Walsh
Scott W
SW
D000328:Adult; D015703:Antigens, CD / Q000032:analysis; D001808:Blood Vessels / Q000737:chemistry / Q000166:cytology*; D015815:Cell Adhesion Molecules / Q000032:analysis; D002585:Cesarean Section; D004730:Endothelium, Vascular / Q000737:chemistry; D005260:Female; D058851:GPI-Linked Proteins; D006801:Humans; D007150:Immunohistochemistry; D018799:Intercellular Adhesion Molecule-1 / Q000032:analysis; D007743:Labor, Obstetric / Q000502:physiology*; D018375:Neutrophil Activation / Q000502:physiology*; D009504:Neutrophils / Q000502:physiology*; D011247:Pregnancy
D015703:Antigens, CD; C504120:CEACAM8 protein, human; D015815:Cell Adhesion Molecules; D058851:GPI-Linked Proteins; D018799:Intercellular Adhesion Molecule-1