Selenium status in neonates with connatal infection

Abstract

Infectious diseases impair Se metabolism, and low Se status is associated with mortality risk in adults with critical disease. The Se status of neonates is poorly characterised, and a potential impact of connatal infection is unknown. We hypothesised that an infection negatively affects the Se status of neonates. We conducted an observational case-control study at three intensive care units at the Charité-Universitätsmedizin Berlin, Germany. Plasma samples were collected from forty-four neonates. On the basis of clinical signs for bacterial infection and concentrations of IL-6 or C-reactive protein, neonates were classified into control (n 23) and infected (n 21) groups. Plasma Se and selenoprotein P (SePP) concentrations were determined by X-ray fluorescence and ELISA, respectively, at day of birth (day 1) and 48 h later (day 3). Se and SePP showed a positive correlation in both groups of neonates. Se concentrations indicative of Se deficit in adults (<20 µg/l) were observed in four infected neonates and one control subject, and three infected neonates had very low SePP concentrations (<0·5 mg/l). The univariate analysis revealed a significant difference in Se and SePP concentrations between the groups. Both parameters correlated inversely to IL-6 in neonates with severe inflammation (IL-6 >500 ng/l). During antibiotic therapy, SePP increased significantly from day 1 (1·03 (SD 0·10) mg/l) to day 3 (1·34 (SD 0·10) mg/l), indicative of improved hepatic Se metabolism. We conclude that both Se and SePP are suitable biomarkers for assessing Se status in neonates and for identifying subjects at risk of deficiency.

Sex-specific and inter-individual differences in biomarkers of selenium status identified by a calibrated ELISA for selenoprotein P

“…This can be considered as translational relaxation or translational errors, which have been shown to be of relevance for the function of selenoenzymes, e.g. in response to pharmacological treatments with antibiotics of the aminoglycoside type [55], [56], [57], [58]. Here, we report that on average only 5.4±0.5 Sec residues per SELENOP molecule are present, and that a considerable inter-individual variation exists.…”

“…Alternatively, it has been shown before that the selenoprotein biosynthesis machinery is not always working very precisely and incorporation errors occur, e.g., in the presence of antibiotics [55], [56], [57], [58]. A more relaxed precision rate would also nicely explain the overall phenomenon that such an inefficient and slow process as Sec insertion still proceeds relatively fast despite the consecutive hurdles that are given by a total of successive 10 UGA codons in a single reading frame, as is the case in human SELENOP [61], [62].…”

Copper to Zinc Ratio as Disease Biomarker in Neonates with Early-Onset Congenital Infections

“…The design of this prospective observational case-control study has been described before in the context of the effects of congenital infections on the selenium (Se) status [24]. Briefly, this explorative study was conducted on the neonatology wards of the Charité-Universitätsmedizin Berlin from February 2013 until April 2014, after clearance with the local ethics committee (approval no.…”

“…Several infants had to be excluded because of birth before 30 weeks of gestation, birth weight below 1000 g, a diagnosed genetic disease, severe congenital malformation, parenteral supplementation with trace elements, or a missing written consent. Details on the neonates enrolled into this study have been published earlier in relation to analyzing their Se status [24] and are provided below (Table 1). Neonates with suspected early-onset infection are summarized as the “infection group” and are denoted as “infected neonates” in this scientific report.…”

“…Total plasma Cu and Zn concentrations were determined by total reflection X-ray fluorescence (TXRF) as described in [24]. The method was chosen because of the low sample volume requirements, which is necessary particularly for infants, and prospectively because of the short time needed for analysis, which is a prerequisite for considering the technique in routine clinical decision-making.…”