6 Association between proinflammatory cytokines and deficient vitamin D levels in early-onset preeclampsia

Abstract

Introduction Preeclampsia (PE) is a pregnancy specific syndrome characterized by intense systemic inflammatory response and abnormally activated phenotype of immune cells. The imbalance between pro- and anti-inflammatory cytokines seems to be dependent on the deficiency of regulatory factors capable of modulating this inflammatory response. Vitamin D plays an important role in the modulation of immune/inflammation system by regulating the production of inflammatory cytokines and generating an immune tolerogenic status. Objectives Since vitamin D deficiency has been reported in pregnant women with PE the present study assessed whether there is an association between plasma levels of vitamin D and pro-inflammatory and anti-inflammatory cytokines in this gestational pathology. Methods Plasma concentrations of 25-hydroxyvitamin D [25(OH)D] was evaluated by chemiluminescence, and the levels of Interleukin-1beta (IL-1b), IL-10 and tumor necrosis factor (TNF- α \) were determined by enzyme-linked immunosorbent assay (ELISA) in the plasma of 40 normotensive pregnant women, 45 women with early-onset PE and 75 women with late-onset PE. Differences between groups were analyzed by non-parametric tests with significance level set at 5%. Results The plasma concentration of 25(OH)D was significantly lower in early-onset PE group compared with the late-onset PE and normotensive groups, while the levels of TNF- α and IL-1 β were significantly higher in the early-onset PE group. Moreover, IL-10 levels were significantly lower in the both groups of preeclamptic women than in the normotensive group. A negative correlation between the values of 25(OH)D and TNF- α ( r =−0.6454, p β ( r =−0.4330, p =0.0059) was detected in early-onset PE women. Positive correlation between IL-10 and 25(OH)D plasma levels was observed in the three groups studied: early PE ( r =0.3403, p =0.0340), late-onset PE ( r =0.3512, p =0.0023) and normotensive pregnant women ( r =0.5629, p =0.0127). Conclusion The inverse association between circulating levels of 25(OH)D and the inflammatory cytokines TNF- α and IL-1 β detected in early-onset PE women suggest a deficient immunomodulatory role of vitamin D in the systemic inflammatory response of this form of PE.