Antibiotherapy at birth in very low birth weight infants before and after the use of interleukin 6 as an infectious biomarker in a tertiary level unit.

BACKGROUND: Neonatal sepsis is a condition with high mortality and morbidity that contributes to high rates of antibiotic therapy at birth. In addition, very low birth weight newborns (VLBWN) are particularly vulnerable. Interleukin 6 (IL-6) seems to be an early and effective marker that could help a better selection of patients to be treated. This study aimed to evaluate the use of antibiotics in the first 72 hours of life in VLBW infants before and after using IL-6 as an infection marker. Also, we wanted to analyze the differences in morbidity and mortality during admission and other factors associated with the decision to start antibiotic treatment. METHODS: We conducted a cohort retrospective study. We included VLBWN born in our hospital or admitted before 72 hours of life in two two-year periods (2007-2008 and 2011-2012). RESULTS: Antibiotics use during the first 72 hours of life was analyzed as the primary variable, which was reduced by 20% on the second period (p = 0.002). Regarding the analysis of secondary variables, we found no significant differences in mortality during hospital admission and the incidence of nosocomial sepsis, enterocolitis, or invasive fungal infection. The multivariate analysis indicated extreme prematurity and the study group as the most strongly related factors to the start of antibiotic therapy. CONCLUSIONS: IL-6 was a useful marker of infection to reduce the use of antibiotic therapy in VLBW infants without increasing mortality.

In vivo study of the effect of lactoferrin on iron metabolism and bioavailability from different iron chemical species for formula milk fortification.

Iron fortification in infant formulas is a common practice for providing iron to newborns in order to avoid its deficiency (anemia). Depending on the physicochemical species used, its bioavailability might be insufficient to meet iron requirements. In this vein, the influence of Lactoferrin (Lf) presence on iron bioavailability in 2-week-old wistar rats fed with formula milk fortified with 57 Fe(III)2 -Lf or 57 Fe(II)SO4 (in presence of Lf) using quantitative speciation (by HPLC-ICP-MS) and Isotope Pattern Deconvolution (IPD) is studied here. Results obtained were compared among fortifiers and also with the maternal group. In RBCs, iron was mainly bound to hemoglobin in all the assayed groups in the same extent. Regarding serum samples, several iron-proteins were observed (such as transferrin and albumin). In both samples, iron content in the fractions studied was similar in all groups compared and exogenous 57 Fe incorporation of intaked iron was always above 50%, showing no significative differences between physicochemical forms but related to the dose administered. Regarding iron stores (liver) the group fed with formula milk fortified with the higher dose of 57 FeSO4 in presence of Lf presented the highest values of total iron even superior than those found in the maternal group, and also the highest exogenous (57 Fe) incorporation. In conclusion, it was proved that iron fortification is required to ensure proper iron levels in all body compartments. No significative differences were observed between different physicochemical species when iron is administered at low doses. However, higher iron doses lead to a greater incorporation in all the iron-proteins studied.

Iron bioavailability from supplemented formula milk: effect of lactoferrin addition.

PURPOSE: In this work, the absorption and/or bioavailability of iron from two chemical species, 57Fe-Lf (apo-lactoferrin) complex and 57FeSO4 at low and high dose, and in Lf excess were investigated in lactating wistar rats. METHODS: The methodology used is based on the use of stable isotopes in combination with the approach "isotope pattern deconvolution" and ICP-MS for detection. This approach provides quantitative information about exogenous (57Fe) and endogenous iron (natFe) distribution in fluids and tissues in the iron-supplemented rat groups. RESULTS: The observed results with supplemented rats were compared with those found in rats receiving maternal feeding. Interestingly, differences were found between groups in iron for transport and storage compartments, but not in the functional one, depending upon the dose of iron administered and the chemical species. CONCLUSION: Considering the results obtained, supplementation with iron salts in excess of Lf appears to be the best way of iron supplementation of formula milk.

FLIP-2 Study: risk factors linked to respiratory syncytial virus infection requiring hospitalization in premature infants born in Spain at a gestational age of 32 to 35 weeks.

BACKGROUND: Ex-premature infants are more predisposed to complicated primary respiratory syncytial virus (RSV) infection. The aim of the present study was to validate the risk factors found in a previous epidemiologic case-control study regarding hospitalization as a result of RSV infection in premature infants born at 32-35 weeks of gestational age (WGA) in Spain. METHODS: A prospective 2-cohort study was conducted during the 2005-2006 (October 2005 to April 2006) and 2006-2007 (October 2006 to April 2007) RSV seasons, respectively. Cases were premature infants hospitalized for RSV infection whereas controls were premature infants of the same age who did not require any hospitalization for respiratory causes. RESULTS: During the study period 5441 children from 37 Spanish hospitals were included in the risk factor analysis. Two hundred two (3.7%) were cases and the rest controls. Of the cases, 17.8% were admitted to the intensive care unit and 7.4% required mechanical ventilation. None of the patients died. Logistic regression analysis demonstrated that the risk of RSV-related respiratory infection requiring hospital admission in preterm infants (32-35 WGA) was associated with the following factors: absolute chronologic age of < or = 10 weeks at the onset of RSV season [odds ratio (OR): 2.99; 95% confidence interval (CI): 2.23-4.01]; presence of school-age siblings or day care attendance (OR: 2.04; 95% CI: 1.53-2.74); and smoking during pregnancy (OR: 1.61; 95% CI: 1.16-2.25). CONCLUSIONS: In premature infants (32-35 WGA), only 3 independent risk factors were found to significantly increase the risk of RSV-related respiratory infection and hospitalization.