Mechanisms of leukocyte accumulation and activation in chorioamnionitis: interleukin 1 beta and tumor necrosis factor alpha enhance colony stimulating factor 2 expression in term decidua.

Chorioamnionitis is a major cause of prematurity as well as perinatal morbidity and mortality. The present study observed a marked increase in immunohistochemical staining for Colony Stimulating Factor 2 (CSF2; also known as granulocyte macrophage-colony stimulating factor), a potent neutrophil and macrophage chemoattractant and activator, in the decidua of patients with CAM compared with controls (n = 8; P = .001). To examine the regulation of this CSF2, cultured decidual cells primed with estradiol (E2) or E2 plus medroxyprogesterone acetate, were exposed to tumor necrosis factor-alpha or interleukin-1beta and secreted CSF2 measured by ELISA. Levels of CSF2 in E2 plus MPA-treated cultures increased 18- and 245-fold following treatment with TNF or IL1B (n = 7, P < .05). Quantitative RT-PCR demonstrated parallel changes in mRNA levels. This study reveals that CSF2 is strongly expressed in decidua from patients with CAM and indicates TNF or IL1B as important regulators of CAM-related decidual leukocyte infiltration and activation.