GRO-ALPHA IN THE FETOMATERNAL AND AMNIOTIC-FLUID COMPARTMENTS DURING PREGNANCY AND PARTURITION

PROBLEM: GRO alpha/MGSA is a new member of the chemokine superfamily C XC(alpha) and is produced by a variety of cells including macrophages, fibroblasts, epithelial, and endothelial cells, and keratinocytes. Th is chemokine has chemoattractant activity and may participate in neutr ophil recruitment and activation during the course of intrauterine inf ection. This study was conducted to investigate the effect of labor an d microbial invasion of the amniotic cavity (MIAC) on amniotic fluid, fetal, and maternal plasma GRO alpha concentrations. METHOD: A cross-s ectional study was designed using parameters that included gestational age, results of amniotic fluid (AF) cultures, and labor status at the time of amniocentesis. Fluid was retrieved by transabdominal amniocen tesis. MIAC was defined as a positive amniotic fluid culture for bacte ria. Umbilical cord blood was retrieved at the time of delivery. Amnio tic fluid, maternal and fetal plasma GRO alpha concentrations were mea sured with a sen- Human Development, Bethesda, Maryland sitive and spe cific ELISA (Quantikine, R&D Systems, Minneapolis, MN). RESULTS: 1) GR O alpha was detectable in amniotic fluid, umbilical cord, and maternal plasma ROMERO samples; 2) GRO alpha concentrations in amniotic fluid increased with advancing gestational age; 3) Both term and preterm ges tations with MIAC were associated with higher amniotic fluid GROa conc entrations than those with sterile amniotic fluid, independent of the labor status (term, MIAC, labor: median 2.7 ng/ml, range 1.4-12.7 vs. term, no MIAC, labor: median 2.1 ng/ml, range 0.7-3.4, vs term, no MIA C, no labor: median 1.9 ng/ml, range 1.8-4.2; P <0.005; preterm: MIAC median 5 ng/ml, range 0.6-47.9 vs. no MIAC: median 2.3 ng/ml, range 0. 5-10; P <0.008); 4) A strong correlation was found between umbilical c ord plasma GRO alpha concentrations and neonatal neutrophil count, and between GRO alpha concentrations and white blood cell count in the am niotic fluid (r = 0.67, P < 0.0005 and r = 0.38, P < 0.001, respective ly). CONCLUSION: GRO alpha is a physiologic constituent of amniotic fl uid and cord blood. Amniotic fluid GRO alpha concentrations increase w ith gestational age. Intrauterine infection both preterm and at term i s associated with an increase in GRO alpha concentrations of amniotic fluid, suggesting that GRO alpha may play an important role in recruit ment of neutrophils into the amniotic cavity. (C) Munksgaard, Copenhag en