Persistency of high proinflammatory cytokine levels from colostrum to mature milk in preeclampsia

Objectives: Recent evidence suggests a role of an excessive maternal inflammatory response in the pathogenesis of preeclampsia. Whether this imbalance can be transferred from mother to breast milk remains to be established. Design and methods: 15 preeclamptic and 15 healthy pregnant women were recruited in this study. Colostrum and milk samples were collected postpartum in the first 48 h and at 30 days, respectively. Samples were analyzed for interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor (TNF)-α and soluble IL-2R (sIL-2R) levels with chemiluminescence enzyme immunometric assays. Results: Colostrum cytokine levels corrected for gestational age and type of delivery were not significantly different in the two groups. Cytokine levels significantly decreased in mature milk versus colostrum in the control group (P < 0.05), but did not significantly decrease in the preeclampsia group (P > 0.05), except for TNF-α (P < 0.05). Mature milk IL-8 and TNF-α levels were higher in the preeclampsia group versus controls (P < 0.05). Conclusion: Results of this study show that proinflammatory cytokines in breast milk exhibit biological variation at different periods of human lactation. In preeclampsia, high cytokine levels persist at least for 30 days. These results suggest that preeclampsia may affect milk cytokine balance and offer an immunological signal for the host defense in high-risk neonates.