Copper and selenium status as biomarkers of neonatal infections.

Neonatal infections are a major risk factor for neonatal mortality. A reliable diagnosis of early-onset sepsis (EOS) is hampered by the variable clinical presentations of the children. We hypothesized that changes in the Se or Cu status, or the biomarkers selenoprotein P (SELENOP) or ceruloplasmin (CP) alone or in combination may be informative of EOS. We generated a new human CP-specific non-competitive immunoassay (ELISA) suitable of analysing small sample volumes and validated the method with a commercial CP source. Using this novel CP assay, we analysed a case-control study of EOS (n = 19 control newborns, n = 18 suspected cases). Concentrations of Se, Cu, SELENOP, CP, interleukin-6 (IL-6), and C-reactive protein (CRP) along with the Cu/Se and CP/SELENOP ratios were evaluated by correlation analyses as biomarkers for EOS. Diagnostic value was estimated by receiver operating characteristic (ROC) curve analyses. The new CP-ELISA displayed a wide working range (0.10-6.78 mg CP/L) and low sample requirement (2 µL of serum, EDTA-, heparin- or citrate-plasma). Plasma CP correlated positively with Cu concentrations in the set of all samples (Pearson r = 0.8355, p < 0.0001). Three of the infected neonates displayed particularly high ratios of Cu/Se and CP/SELENOP, i.e., 3.8- to 6.9-fold higher than controls. Both the Cu/Se and the CP/SELENOP ratios correlated poorly with the early infection marker IL-6, but strongly and positively with the acute-phase protein CRP (Cu/Se-CRP: Spearman ϱ = 0.583, p = 0.011; CP/SELENOP-CRP: ϱ = 0.571, p = 0.013). The ROC curve analyses indicate that a combination of biomarkers for the Se and Cu status do not improve the early identification of EOS considerably. This study established a robust, highly precise, partly validated and scalable novel CP sandwich ELISA suitable for basic and clinical research, requiring minute amounts of sample. The ratio of circulating CP/SELENOP constitutes a promising new composite biomarker for detection of EOS, at least in a subset of severely diseased children.

Selenium status in neonates with connatal infection.

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 (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.

Delta-He, Ret-He and a New Diagnostic Plot for Differential Diagnosis and Therapy Monitoring of Patients Suffering from Various Disease-Specific Types of Anemia.

BACKGROUND: The present study was aimed to prove the usefulness of a new diagnostic plot (Hema-Plot), illustrating the relationship between the hemoglobin content of reticulocytes (Ret-He) as a marker of functional iron deficiency and the difference between the reticulocyte and erythrocyte hemoglobin content (Delta-He) as a marker of an impaired hemoglobinization of newly formed reticulocytes occurring during inflammatory processes, to differentiate between various disease-specific types of anemia. METHODS: A complete blood and reticulocyte count was performed on routine EDTA blood samples from 345 patients with and without various disease-specific types of anemia using the Sysmex XN-9000 hematology analyzer: blood healthy newborns (n = 23), blood healthy adults (n = 31), patients suffering from anemia of chronic disease (ACD) due to diverse oncological, chronic inflammatory, or autoimmune diseases (total n = 138) with (n = 65) and without therapy (n = 73), patients with thalassemia and/or hemoglobinopathy (n = 18), patients with iron deficiency anemia (IDA) (n = 35), patients with a combination of ACD and IDA (n = 17), as well as patients suffering from sepsis (total n = 83) with (n = 32) and without therapy (n = 51). The results for Ret-He, Delta-He, and C-reactive protein (CRP) were statistically compared (Mann-Whitney U Test) between the particular patient groups and the diagnostic plots were drawn. RESULTS: Delta-Hemoglobin showed a statistically significant difference between blood healthy newborns and blood healthy adults (p ≤ 0.05), while Ret-He and C-reactive protein did not. In addition, of all three biomarkers only Delta-He showed a statistically significant difference (p ≤ 0.05) between the ACD/IDA and IDA cohort. Delta-He, Ret-He, and CRP showed a statistically significant difference between patient cohorts with and without therapy suffering from ACD, ACD/IDA, and sepsis before and after medical therapy (p ≤ 0.05). The Hema-Plot illustrated the dynamic character of Ret-He and Delta-He, notably in inflammation-based types of anemia like ACD or ACD/ IDA. CONCLUSIONS: Delta-He is a new biomarker clearly distinguishing between inflammation-based types of anemia before and after medical therapy, as well as between ACD/IDA and IDA. The new Hema-Plot is a helpful tool for differential diagnosis and disease-monitoring in various types of disease-specific anemia, especially in ACD and ACD/IDA. The Hema-Plot can be used to identify non-adherent patients or an insufficient therapy.