Cell-Associated Interleukin-8 in Cord Blood of Term and Preterm Infants

Abstract

To assess the effect of gestational age and labor on the interleukin-8 (IL-8) concentration in whole cord blood and serum, IL-8 levels were determined simultaneously in cord blood serum and lysate in 134 infants. Following the elimination of some of the samples due to exclusion criteria, the data for 99 uninfected infants (71 term and 28 preterm) and 9 infants with neonatal bacterial infection delivered either vaginally or by elective or emergency cesarean section were analyzed. The effects of labor and gestational age were tested by analysis of variance. IL-8 was not detectable in the serum of 25 infants, whereas IL-8 levels in whole blood were measurable in all of the samples. The median IL-8 conncentrations in whole cord blood lysate were 106 pg/ml (range, 20 to 415 pg/ml) in preterm infants and 176 pg/ml (range, 34 to 1,667 pg/ml) in term infants. In contrast to the IL-8 levels in serum, IL-8 levels in whole blood were reduced after ECS. Gestational age had no independent effect on the IL-8 concentrations in either serum or whole blood; these concentrations increased in infected infants after labor. We conclude that the neonatal proinflammatory response to labor stress was more evident in the concentrations of IL-8 in whole blood than in serum. The levels of IL-8 in whole-blood lysate reflect proinflammatory stimulation in neonates and may be a useful diagnostic tool for the early diagnosis of neonatal infection.Interleukin-8 (IL-8) belongs to the class of proinflammatory "CC" chemokines defined by the position of two cysteine groups and is synthesized predominantly by monocytes. Its active form effectively activates neutrophil granulocytes, advancing the chemotaxis and synthesis of myeloperoxidase, thus suggesting a critical role in host defense to infectious diseases (1, 2).The IL-8 concentration in serum has been studied as a diagnostic marker of neonatal bacterial infection (NBI) (10, 11) and has been shown to be an early marker of neonatal bacterial infection, whereas the concentration of C-reactive protein (CRP) increases after 12 to 24 h in the course of systemic infectious disease. A "diagnostic gap " exists between the decline of IL-8 after 4 to 6 h and the increase in C-reactive protein at 12 to 24 h, which is a well-established marker of confirmed bacterial infection. Due to the rapid serum clearing of IL-8, its value as a monitoring parameter of infectious disease may be limited. In vivo, a large proportion of IL-8 is associated with erythrocytes and leukocytes (polymorphonuclear leukocytes and peripheral blood mononuclear cells), and the concentration in serum represents only a small fraction of the total amount of IL-8. The measurement of cell-associated IL-8 reflects more quantitatively its production and adds information regarding the stage of the disease and the patient's inflammatory response (7,9,13,14). Total IL-8 can be measured in whole blood after cell lysis with a good analytical test (16). In healthy adults, we previously observed an IL-8 peak level of Ͻ12 pg/ml with a median of 83 p...

Influence of Gestational Age, Cesarean Section and Hematocrit on IL-8 Concentrations in Plasma and Detergent-Lysed Whole Blood of Noninfected Newborns

“…In agreement with observations of Dembinksi et al [28], plasma IL-8 was not influenced by gestational age, in contrast to DLWB IL-8; late preterm neonates had lower DLWB IL-8 concentrations ( fig. 1).…”

“…In our group of spontaneous births (table 2), we also registered the duration of labor and found no correlation between either DLWB or plasma IL-8 concentrations (not shown); however, we did not analyze or standardize labor pain. Dembinski et al [28] found more evident neonatal proinflammatory response to labor stress in concentrations of IL-8 in whole blood than in serum.…”

Rapid simultaneous measurement of multiple cytokines using 100 µl sample volumes − association with neonatal sepsis

“…No previous studies have identified increased IL‐12 levels in the plasma of newborns with infection. The present study shows that elevation of this cytokine and IL‐6, IFN‐ γ and IL‐1 β are associated with neonatal infection and may be more sensitive than IL‐8, a cytokine that has reportedly been increased in several studies [2,4]. However, much larger numbers are required to clarify any statistical significance between individual cytokine sensitivity for neonatal infection with other confounding conditions such as inflammatory diseases.…”

OX40 induces CCL20 expression in the context of antigen stimulation: An expanding role of co-stimulatory molecules in chemotaxis

“…It is well documented that certain chemokines such as CXCL1, CXCL8, and CCL2 mainly present as a cell-bound form in the circulation during various physiological and pathological conditions [34–36]. The cell-bound chemokines function as a reservoir to maintain and adjust their systemic and local level.…”