Oral lactoferrin for the prevention of sepsis and necrotizing enterocolitis in preterm infants

Enteral lactoferrin supplementation for prevention of sepsis and necrotizing enterocolitis in preterm infants

BACKGROUND

Lactoferrin, a normal component of human colostrum and milk, can enhance host defenses and may be effective for prevention of sepsis and necrotizing enterocolitis (NEC) in preterm neonates.

OBJECTIVES

To assess the safety and effectiveness of lactoferrin supplementation to enteral feeds for prevention of sepsis and NEC in preterm neonates. Secondarily, we assessed the effects of lactoferrin supplementation to enteral feeds on the duration of positive-pressure ventilation, development of chronic lung disease (CLD) or periventricular leukomalacia (PVL), length of hospital stay to discharge among survivors, and adverse neurological outcomes at two years of age or later.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to update our search. We searched the Cochrane Central Register of Controlled Trials (CENTRAL 2019, Issue 9), MEDLINE via PubMed (1966 to 20 January 2020), PREMEDLINE (1996 to 20 January 2020), Embase (1980 to 20 January 2020), and CINAHL (1982 to 20 January 2020). We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomized controlled trials and quasi-randomized trials.

SELECTION CRITERIA

In our search, we included randomized controlled trials (RCTs) evaluating enteral lactoferrin supplementation at any dose or duration to prevent sepsis or NEC in preterm neonates.

DATA COLLECTION AND ANALYSIS

We used the standard methods of Cochrane Neonatal and the GRADE approach to assess the certainty of evidence.

MAIN RESULTS

Meta-analysis of data from twelve randomized controlled trials showed that lactoferrin supplementation to enteral feeds decreased late-onset sepsis (typical RR 0.82, 95% CI 0.74 to 0.91; typical RD -0.04, 95% CI, -0.06, -0.02; NNTB 25, 95% CI 17 to 50; 12 studies, 5425 participants, low-certainty evidence) and decreased length of hospital stay (MD -2.38, 95% CI, -4.67, -0.09; 3 studies, 1079 participants, low-certainty evidence). Sensitivity analysis including only good methodological certainty studies suggested a decrease in late-onset sepsis with enteral lactoferrin supplementation (typical RR 0.87, 95% CI, 0.78, 0.97; typical RD -0.03, 95% CI, -0.05, -0.0; 9 studies, 4702 participants, low-certainty evidence). There were no differences in NEC stage II or III (typical RR 1.10, 95% CI, 0.86, 1.41; typical RD -0.00, 95% CI, -0.02, 0.01; 7 studies, 4874 participants; low-certainty evidence) or 'all-cause mortality' (typical RR 0.90, 95% CI 0.69, 1.17; typical RD -0.00, 95% CI, -0.01, 0.01; 11 studies, 5510 participants; moderate-certainty evidence). One study reported no differences in neurodevelopmental testing by Mullen's or Bayley III at 24 months of age after enteral lactoferrin supplementation (one study, 292 participants, low-certainty evidence). Lactoferrin supplementation to enteral feeds with probiotics decreased late-onset sepsis (RR 0.25, 95% CI 0.14 to 0.46; RD -0.13, 95% CI -0.18 to -0.08; NNTB 8, 95% CI 6 to 13; 3 studies, 564 participants; low-certainty evidence) and NEC stage II or III (RR 0.04, 95% CI 0.00 to 0.62; RD -0.05, 95% CI -0.08 to -0.03; NNTB 20, 95% CI 12.5 to 33.3; 1 study, 496 participants; very low-certainty evidence), but not 'all-cause mortality' (very low-certainty evidence). Lactoferrin supplementation to enteral feeds with or without probiotics had no effect on CLD, duration of mechanical ventilation or threshold retinopathy of prematurity (low-certainty evidence). Investigators reported no adverse effects in the included studies.

AUTHORS' CONCLUSIONS

We found low-certainty evidence from studies of good methodological quality that lactoferrin supplementation of enteral feeds decreases late-onset sepsis but not NEC ≥ stage II or 'all cause mortality' or neurodevelopmental outcomes at 24 months of age in preterm infants without adverse effects. Low- to very low-certainty evidence suggests that lactoferrin supplementation of enteral feeds in combination with probiotics decreases late-onset sepsis and NEC ≥ stage II in preterm infants without adverse effects, however, there were few included studies of poor methodological quality. The presence of publication bias and small studies of poor methodology that may inflate the effect size make recommendations for clinical practice difficult.

Enteral lactoferrin supplementation for prevention of sepsis and necrotizing enterocolitis in preterm infants

BACKGROUND

Lactoferrin, a normal component of human colostrum and milk, can enhance host defenses and may be effective for prevention of sepsis and necrotizing enterocolitis (NEC) in preterm neonates.

OBJECTIVES

Primary objective 1. To assess the safety and effectiveness of lactoferrin supplementation to enteral feeds for prevention of sepsis and NEC in preterm neonates Secondary objectives 1. To determine the effects of lactoferrin supplementation to enteral feeds to prevent neonatal sepsis and/or NEC on duration of positive-pressure ventilation, development of chronic lung disease (CLD) or periventricular leukomalacia (PVL), length of hospital stay to discharge among survivors, and adverse neurological outcomes at two years of age or later2. To determine the adverse effects of lactoferrin supplementation for prophylaxis of neonatal sepsis and/or NECWhen data were available, we analyzed the following subgroups.1. Gestational age < 32 weeks and 32 to 36 weeks2. Birth weight < 1000 g (extremely low birth weight (ELBW) infants) and birth weight < 1500 g (very low birth weight (VLBW) infants)3. Type of feeding: breast milk versus formula milk SEARCH METHODS: We used the search strategy of the Cochrane Neonatal Review Group (CNRG) to update our search in December 2016. We searched the databases Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, PREMEDLINE, Embase, and the Cumulative Index to Nursing and Allied Health Literature (CINAHL), as well as trial registries and conference proceedings.

SELECTION CRITERIA

Randomized controlled trials (RCTs) evaluating oral lactoferrin at any dose or duration to prevent sepsis or NEC in preterm neonates.

DATA COLLECTION AND ANALYSIS

Review authors used standard methods of the CNRG.

MAIN RESULTS

This review includes six RCTs. Trial results show that lactoferrin supplementation to enteral feeds decreased late-onset sepsis (typical risk ratio (RR) 0.59, 95% confidence interval (CI) 0.40 to 0.87; typical risk difference (RD) -0.06, 95% CI -0.10 to -0.02; number needed to treat for an additional beneficial outcome (NNTB) 17, 95% CI 10 to 50; six trials, 886 participants; low-quality evidence) and NEC stage II or III (typical RR 0.40, 95% CI 0.18 to 0.86; typical RD -0.04, 95% CI -0.06 to -0.01; NNTB 25, 95% CI 17 to 100; four studies, 750 participants; low-quality evidence). Lactoferrin supplementation did not have an effect on "all-cause mortality" (typical RR 0.65, 95% CI 0.37 to 1.11; typical RD -0.02, 95% CI -0.05 to 0; six studies, 1041 participants; low-quality evidence).Lactoferrin supplementation to enteral feeds with probiotics decreased late-onset sepsis (RR 0.27, 95% CI 0.12 to 0.60; RD -0.13, 95% CI -0.19 to -0.06; NNTB 8, 95% CI 5 to 17; one study, 321 participants; low-quality evidence) and NEC stage II or III (RR 0.04, 95% CI 0.00 to 0.62; RD -0.05, 95% CI -0.08 to -0.03; NNTB 20, 95% CI 12.5 to 33.3; one study, 496 participants; low-quality evidence), but not "all-cause mortality" (low-quality evidence).Lactoferrin supplementation to enteral feeds with or without probiotics decreased bacterial and fungal sepsis but not CLD or length of hospital stay (low-quality evidence). Investigators reported no adverse effects and did not evaluate long-term neurological outcomes and PVL.

AUTHORS' CONCLUSIONS

Evidence of low quality suggests that lactoferrin supplementation to enteral feeds with or without probiotics decreases late-onset sepsis and NEC stage II or III in preterm infants without adverse effects. Completed ongoing trials will provide data from more than 6000 preterm neonates, which may enhance the quality of the evidence. Clarification regarding optimal dosing regimens, types of lactoferrin (human or bovine), and long-term outcomes is needed.

Human Milk Components Modulate Toll-Like Receptor-Mediated Inflammation

Toll-like receptor (TLR) signaling is central to innate immunity. Aberrant expression of TLRs is found in neonatal inflammatory diseases. Several bioactive components of human milk modulate TLR expression and signaling pathways, including soluble toll-like receptors (sTLRs), soluble cluster of differentiation (sCD) 14, glycoproteins, small peptides, and oligosaccharides. Some milk components, such as sialyl (α2,3) lactose and lacto-N-fucopentaose III, are reported to increase TLR signaling; under some circumstances this might contribute toward immunologic balance. Human milk on the whole is strongly anti-inflammatory, and contains abundant components that depress TLR signaling pathways: sTLR2 and sCD14 inhibit TLR2 signaling; sCD14, lactadherin, lactoferrin, and 2'-fucosyllactose attenuate TLR4 signaling; 3'-galactosyllactose inhibits TLR3 signaling, and β-defensin 2 inhibits TLR7 signaling. Feeding human milk to neonates decreases their risk of sepsis and necrotizing enterocolitis. Thus, the TLR regulatory components found in human milk hold promise as benign oral prophylactic and therapeutic treatments for the many gastrointestinal inflammatory disorders mediated by abnormal TLR signaling.

Oral lactoferrin for the prevention of sepsis and necrotizing enterocolitis in preterm infants

BACKGROUND

Lactoferrin, a normal component of human colostrum and milk, can enhance host defense and may be effective in the prevention of sepsis and necrotizing enterocolitis (NEC) in preterm neonates.

OBJECTIVES

Primary objective To assess the safety and effectiveness of oral lactoferrin in the prevention of sepsis and NEC in preterm neonates. Secondary objectives1. To determine the effects of oral lactoferrin used to prevent neonatal sepsis and/or NEC on duration of positive-pressure ventilation, development of chronic lung disease (CLD) or periventricular leukomalacia (PVL), length of hospital stay to discharge among survivors, and adverse neurological outcomes at two years of age or later.2. To determine the adverse effects of oral lactoferrin in the prophylaxis of neonatal sepsis and/or NEC.When data were available, we analyzed the following subgroups.1. Gestational age < 32 weeks and 32 to 36 weeks.2. Birth weight < 1000 g (extremely low birth weight (ELBW) infants) and birth weight < 1500 g (very low birth weight (VLBW) infants).3. Type of feeding: breast milk versus formula milk.

SEARCH METHODS

We used the search strategy of the Cochrane Neonatal Review Group (CNRG) and updated our search in July 2014. We searched the databases Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, PREMEDLINE, EMBASE, and the Cumulative Index to Nursing and Allied Health Literature (CINAHL), as well as trials registries and conference proceedings.

SELECTION CRITERIA

Randomized controlled trials (RCTs) evaluating oral lactoferrin at any dose or duration to prevent sepsis or NEC in preterm neonates.

DATA COLLECTION AND ANALYSIS

Review authors used standard methods of the CNRG.

MAIN RESULTS

Four RCTs are included in this review. Oral lactoferrin supplementation decreased late-onset sepsis (typical risk ratio (RR) 0.49, 95% confidence interval (CI) 0.32 to 0.73; typical risk difference (RD) -0.09, 95% CI -0.14 to -0.04; number needed to treat for an additional beneficial outcome (NNTB) 11, 95% CI 7 to 25; four trials, 678 participants, moderate-quality evidence), NEC stage II or greater (typical RR 0.30, 95% CI 0.12 to 0.76; typical RD -0.05, 95% CI -0.08 to -0.01; NNTB 20, 95% CI 12.5 to 100; two studies, 505 participants, low-quality evidence), and "all-cause mortality" (typical RR 0.30, 95% CI 0.12 to 0.75; typical RD -0.05, 95% CI -0.08 to -0.01; NNTB 20, 95% CI 12.5 to 100; two studies, 505 participants, low-quality evidence).Oral lactoferrin supplementation with a probiotic decreased late-onset sepsis (RR 0.27, 95% CI 0.12 to 0.60; RD -0.13, 95% CI -0.19 to -0.06; NNTB 8, 95% CI 5 to 17; one study, 321 participants, low-quality evidence) and NEC stage II or greater (RR 0.04, 95% CI 0.00 to 0.62; RD -0.05, 95% CI -0.08 to -0.03; NNTB 20, 95% CI 12.5 to 33.3; one study, 496 participants, low-quality evidence), but not "all-cause mortality."Oral lactoferrin with or without probiotics decreased fungal sepsis but not chronic lung disease or length of hospital stay (from one study, low-quality evidence). No adverse effects were reported. Long-term neurological outcomes or periventricular leukomalacia was not evaluated.

AUTHORS' CONCLUSIONS

Evidence of moderate to low quality suggests that oral lactoferrin prophylaxis with or without probiotics decreases late-onset sepsis and NEC stage II or greater in preterm infants without adverse effects. Completion of ongoing trials will provide evidence from more than 6000 preterm neonates and may enhance the quality of the evidence. Clarifications regarding optimum dosing regimens, type of lactoferrin (human or bovine), and long-term outcomes are still needed.

Immunomodulatory effects of lactoferrin

Lactoferrin (Lf) is an iron-binding glycoprotein of the transferrin family, which is expressed in most biological fluids with particularly high levels in mammalian milk. Its multiple activities lie in its capacity to bind iron and to interact with the molecular and cellular components of hosts and pathogens. Lf can bind and sequester lipopolysaccharides, thus preventing pro-inflammatory pathway activation, sepsis and tissue damages. Lf is also considered a cell-secreted mediator that bridges the innate and adaptive immune responses. In the recent years much has been learned about the mechanisms by which Lf exerts its activities. This review summarizes the recent advances in understanding the mechanisms underlying the multifunctional roles of Lf, and provides a future perspective on its potential prophylactic and therapeutic applications.

Necrotising enterocolitis in preterm infants: epidemiology and antibiotic consumption in the Polish neonatology network neonatal intensive care units in 2009

The aim of this study was to describe the epidemiology of necrotising enterocolitis (NEC), antibiotic consumption and the usefulness of microbiological tests in very low birth weight (VLBW) Polish newborns.

METHODS

Prospective surveillance was performed in the year 2009 by local infection control teams. The study covered 910 infants hospitalized in six Polish neonatal intensive care units. Two kinds of indicators were used for the description of antibiotic usage: the duration of treatment (days of treatment, DOTs) and the defined daily dose (DDD).

RESULTS

NEC incidence was 8.7% and fatality rate was 19%. Chorioamnionitis, late gestational age and low birth weight were identified as risk factors for NEC. Catheterization, mechanical ventilation and other selected procedures were used considerably longer in newborns with NEC than in the remaining neonates. Total usage of antibiotics reached 2.9 DDDs or 1.437 days; the average use of drugs per case of NEC amounted to 0.47 DDD or 23.2 DOTs. The level of antibiotic usage was analysed with correlation to microbiological tests performed and it was non-significantly greater in the group of children with NEC in whom the tests were performed.

CONCLUSIONS

A high risk of developing NEC is closely associated with VLBW and with inflammation of the amnion during labour. We observed no relationship between the consumption of antibiotics in neonates with NEC and positive results of microbiological testing indicating sepsis accompanying NEC or gut colonization with pathogens.

Considerations in the pharmacologic treatment and prevention of neonatal sepsis

The management of neonatal sepsis is challenging owing to complex developmental and environmental factors that contribute to inter-individual variability in the pharmacokinetics and pharmacodynamics of many antimicrobial agents. In this review, we describe (i) the changing epidemiology of early- and late-onset neonatal sepsis; (ii) the pharmacologic considerations that influence the safety and efficacy of antibacterials, antifungals, and immunomodulatory adjuvants; and (iii) the recommended dosing regimens for pharmacologic agents commonly used in the treatment and prevention of neonatal sepsis. Neonatal sepsis is marked by high morbidity and mortality, such that prompt initiation of antimicrobial therapy is essential following culture collection. Before culture results are available, combination therapy with ampicillin and an aminoglycoside is recommended. When meningitis is suspected, ampicillin and cefotaxime may be considered. Following identification of the causative organism and in vitro susceptibility testing, antimicrobial therapy may be narrowed to provide targeted coverage. Therapeutic drug monitoring should be considered for neonates receiving vancomycin or aminoglycoside therapies. For neonates with invasive fungal infections, the development of new antifungal agents has significantly improved therapeutic outcomes in recent years. Liposomal amphotericin B has been found to be safe and efficacious in patients with renal impairment or toxicity caused by conventional amphotericin B. Antifungal prophylaxis with fluconazole has also been reported to dramatically reduce rates of neonatal invasive fungal infections and to improve long-term neurodevelopmental outcomes among treated children. Additionally, several large multicenter studies are currently investigating the safety and efficacy of oral lactoferrin as an immunoprophylactic agent for the prevention of neonatal sepsis.

TGF-β2, a protective intestinal cytokine, is abundant in maternal human milk and human-derived fortifiers but not in donor human milk

OBJECTIVE

This study compared cytokines (in particular transforming growth factor [TGF]-β2) and lactoferrin in maternal human milk (MHM), human-derived milk fortifier (HDMF), and donor human milk (DHM).

MATERIALS AND METHODS

MHM was randomly collected from breastfeeding mothers who had no infectious illness at the time of milk expression. HDMF and DHM were products derived from human milk processed by Holder pasteurization. MHM samples were collected at different times (early/late) and gestations (preterm/term). Lactoferrin was analyzed by western blotting, and cytokines were quantified using commercial enzyme-linked immunosorbent assays. Significance was determined using analysis of variance.

RESULTS

In the 164 samples analyzed, TGF-β2 concentrations in HDMF and preterm MHM (at all collection times) were fivefold higher than in DHM (p<0.05). Early preterm MHM had levels of interleukin (IL)-10 and IL-18, 11-fold higher than DHM (p<0.05). IL-6 in DHM was 0.3% of the content found in MHM. IL-18 was fourfold higher in early MHM versus late MHM regardless of gestational age (p<0.05). Lactoferrin concentration in DHM was 6% of that found in MHM.

CONCLUSIONS

Pasteurization decreases concentrations of most cytokines and lactoferrin in DHM. TGF-β2, a protective intestinal cytokine, has comparable concentrations in HDMF to MHM despite pasteurization.

Neonatal immune adaptation of the gut and its role during infections

The intestinal tract is engaged in a relationship with a dense and complex microbial ecosystem, the microbiota. The establishment of this symbiosis is essential for host physiology, metabolism, and immune homeostasis. Because newborns are essentially sterile, the first exposure to microorganisms and environmental endotoxins during the neonatal period is followed by a crucial sequence of active events leading to immune tolerance and homeostasis. Contact with potent immunostimulatory molecules starts immediately at birth, and the discrimination between commensal bacteria and invading pathogens is essential to avoid an inappropriate immune stimulation and/or host infection. The dysregulation of these tight interactions between host and microbiota can be responsible for important health disorders, including inflammation and sepsis. This review summarizes the molecular events leading to the establishment of postnatal immune tolerance and how pathogens can avoid host immunity and induce neonatal infections and sepsis.

Role of innate immunity in neonatal infection

Newborns are at increased risk of infection due to genetic, epigenetic, and environmental factors. Herein we examine the roles of the neonatal innate immune system in host defense against bacterial and viral infections. Full-term newborns express a distinct innate immune system biased toward T(H)2-/T(H)17-polarizing and anti-inflammatory cytokine production with relative impairment in T(H)1-polarizing cytokine production that leaves them particularly vulnerable to infection with intracellular pathogens. In addition to these distinct features, preterm newborns also have fragile skin, impaired T(H)17-polarizing cytokine production, and deficient expression of complement and of antimicrobial proteins and peptides (APPs) that likely contribute to susceptibility to pyogenic bacteria. Ongoing research is identifying APPs, including bacterial/permeability-increasing protein and lactoferrin, as well as pattern recognition receptor agonists that may serve to enhance protective newborn and infant immune responses as stand-alone immune response modifiers or vaccine adjuvants.

P-glycoprotein induction by breast milk attenuates intestinal inflammation in experimental necrotizing enterocolitis

P-glycoprotein (Pgp), a product of the multi-drug resistance gene MDR1a, is a broad specificity efflux ATP cassette transmembrane transporter that is predominantly expressed in epithelial tissues. Because mdr1a(-/-) mice tend to develop spontaneous colitis in bacteria-dependent manner, Pgp is believed to have a role in protection of the intestinal epithelium from luminal bacteria. Here we demonstrate that levels of Pgp in the small intestine of newborn rodents dramatically increase during breastfeeding, but not during formula feeding (FF). In rats and mice, levels of intestinal Pgp peak on days 3-7 and 1-5 of breastfeeding, respectively. The mdr1a(-/-) neonatal mice subjected to FF, hypoxia, and hypothermia have significantly higher incidence and pathology, as well as significantly earlier onset of necrotizing enterocolitis (NEC) than congenic wild type mice. Breast-fed mdr1a(-/-) neonatal mice are also more susceptible to intestinal damage caused by the opportunistic pathogen Cronobacter sakazakii that has been associated with hospital outbreaks of NEC. Breast milk, but not formula, induces Pgp expression in enterocyte cell lines in a dose- and time-dependent manner. High levels of ectopically expressed Pgp protect epithelial cells in vitro from apoptosis induced by C. sakazakii. Taken together, these results show that breast milk-induced expression of Pgp may have a role in the protection of the neonatal intestinal epithelium from injury associated with nascent bacterial colonization.

Oral lactoferrin for the prevention of sepsis and necrotizing enterocolitis in preterm infants

BACKGROUND

Lactoferrin, a normal component of human colostrum, milk, tears and saliva can enhance host defence and may be effective in the prevention of sepsis and necrotizing enterocolitis (NEC) in preterm neonates.

OBJECTIVES

To assess the safety and effectiveness of oral lactoferrin in the prevention of sepsis and NEC in preterm neonates.

SEARCH STRATEGY

We used the search strategy of the Cochrane Neonatal Review Group (CNRG) including searches of CENTRAL (The Cochrane Library), MEDLINE and PREMEDLINE, EMBASE and CINAHL. We also searched trials registries and the conference proceedings of Pediatric Academic Society. Searches updated in July 2011.

SELECTION CRITERIA

Randomized or quasi-randomized controlled trials evaluating oral lactoferrin at any dose or duration for the prophylaxis of sepsis or NEC in preterm neonates.

DATA COLLECTION AND ANALYSIS

Data collection and analysis were performed according to the standard methods of the CNRG.

MAIN RESULTS

One trial (Manzoni 2008) that randomized 472 very low birth weight infants was eligible. A statistically significant reduction in late-onset sepsis was observed in the groups that received either lactoferrin alone (RR 0.34, 95% CI 0.17 to 0.70) or in combination with Lactobacillus rhamnosus GG (RR 0.27, 95% CI 0.12 to 0.60).In subgroup analyses, infants weighing less than 1000 g and those fed exclusively on maternal milk had a significant reduction in late-onset sepsis after oral lactoferrin supplementation alone. In the group supplemented with oral lactoferrin and Lactobacillus rhamnosus, infants weighing less than 1000 g had a significant reduction in late-onset sepsis, a result not seen in infants fed maternal milk exclusively.Prophylaxis with oral lactoferrin alone did not reduce the incidence of NEC (RR 0.33, 95% CI 0.09 to 1.17), but a significant reduction in NEC with a combination of lactoferrin and Lactobacillus rhamnosus GG was noted (RR 0.05, 95% CI 0.00 to 0.90).No adverse effects due to lactoferrin were observed in this study. Long-term neurological outcomes were not assessed in this trial.

AUTHORS' CONCLUSIONS

Oral lactoferrin prophylaxis reduces the incidence of late-onset sepsis in infants weighing less than 1500 g and most effective in infants weighing less than 1000 g. There is no evidence of efficacy of oral lactoferrin (given alone) in the prevention of NEC in preterm neonates.Well designed, randomized trials should address dosing, duration, type of lactoferrin (bovine or human) prophylaxis in prevention of sepsis and NEC. The effect of exclusive maternal milk feeding should be clarified.