Measurement of interleukin 8 in combination with C-reactive protein reduced unnecessary antibiotic therapy in newborn infants: a multicenter, randomized, controlled trial

Changes in microcirculation as early markers for infection in preterm infants--an observational prospective study

In adults with severe sepsis, the disturbances of the sublingual microcirculation can be quantified with orthogonal polarization spectral imaging. We investigated the cutaneous microcirculation of preterm infants with proven infection (PosInf) and with suspected but unproven infection (NegInf). In 25 infants, orthogonal polarization spectral images were obtained daily, videos of the images were blinded, and analyzed off-line. Functional small vessel density (FSVD) was prospectively calculated from day 3 to day 30 of life. There were 17 episodes of proven and nine episodes of suspected but unproven nosocomial late onset infection. Four infants remained healthy. The data were analyzed for the 5 d before the start of antibiotics (day -5 until day -1). FSVD varied widely, but in the PosInf-group, we found a 10% decline from day -5 to day -1 (p = 0.013). There was no significant change over time in the NegInf-group (p = 0.58). Thus, in infants with proven infection, FSVD decreases already 1 d before changes in laboratory parameters. However, these changes in FSVD during infection are not represented by absolute values, but must be identified by daily intraindividual observation.

Cytokines and perinatal brain damage

Perinatal brain damage has been implicated in the pathogenesis of neurodevelopmental impairments and psychiatric illnesses. This article reviews evidence that infection outside of the brain can damage the brain, and discusses specific cytokines and pathomechanisms that probably mediate the putative effect of remote infection on the developing brain. Events associated with increased circulating inflammatory cytokines, chemokines, and immune cells are described. Finally, studies of genetic variation in susceptibility to cytokine-related brain damage are reviewed.

Update on group B streptococcal infections: perinatal and neonatal periods

Group B Streptococcus (GBS), one of the beta-Hemolytic streptococci, remains a leading cause of neonatal sepsis in the United States. The first consensus guidelines for the prevention of neonatal GBS disease were published in 1996, recommending intrapartum antibiotic prophylaxis on the basis of screening-based or risk-based strategies. Since then, there has been a 70% decrease in the rate of early-onset GBS disease. On the basis of evidence-validating superiority of this screening-based strategy, new national guidelines were released in 2002. Data from the Centers for Disease Control and Prevention in 2005 showed a continued decrease in the annual incidence of early-onset GBS infection. The screening-based strategy involves universal screening of all pregnant women at 35 to 37 weeks' gestation for vaginal and rectal GBS colonization and recommends intrapartum antibiotic prophylaxis for all GBS carriers (unless delivered by planned cesarean section before the onset of labor in a woman with intact membranes) with penicillin-G (or ampicillin). For mothers with severe penicillin allergy, clindamycin or erythromycin is recommended, when GBS' sensitivity is known; otherwise, vancomycin is recommended. Cefazolin is recommended for individuals with mild penicillin allergy. Severe anaphylactic reactions to penicillin were extremely rare. Emergence of antibiotic resistance to penicillin is still a theoretical possibility. This article provides a detailed account of recommendations for screening, diagnosing, and treating GBS disease in newborns.

C-Reactive Protein, Detected with a Highly Sensitive Assay, in Non-Infected Newborns and Those with Early Onset Infection

SUMMARY: BACKGOUND: The aim of this study was to investigate C-reactive protein (CRP), measured by a highly sensitive method (hsCRP) in non-infected newborns and in those with suspected early onset bacterial infection (EOBI) as well as to test whether EOBI would be detectable earlier by hsCRP than by a nephelometric CRP (nsCRP) assay (thresholds > 10 mg/l) or IL-8. PATIENTS AND METHODS: 106 neonates with signs of infection comprised the suspected EOBI group. 134 neonates with risk factors but confirmed exclusion of EOBI served as non-infected controls. RESULTS: In the non-infected group, hsCRP in the first 6 h after birth was low (0.7 mg/l; SD 0.16 mg/l) but showed an increase to 4.11 mg/l (SD 3.33 mg/l) at 72 h (p < 0.001 vs. 6 h). The sensitivity of hsCRP (cut-off 0.3 mg/l) vs. nsCRP for EOBI was 0.46 vs. 0.23 at 6 h after clinical suspicion. Of all parameters measured, IL-8 had the highest sensitivity and specificity to detect EOBI at 6 h (0.60 and 0.90), but declined after 12 and 24 h. CONCLUSION: Lowering the CRP detection threshold by a highly sensitive assay did not improve diagnostic accuracy for EOBI.

Biomarkers in neonatal infection

Infected newborn infants are often difficult to differentiate from patients suffering from noninfective diseases. Whilst delaying treatment with antibiotics of infected infants may be fatal, widespread indiscriminate use in all cases with suspected bacterial infection could lead to both drug-induced complications and the development of multidrug-resistant organisms. Conventional biomarkers, such as blood cell counts and morphology, have serious limitations. Investigators in this area of research have, therefore, made strenuous efforts to discover more reliable biomarkers with superior diagnostic utilities and clinically relevant characteristics to help neonatal clinicians differentiate between infected and noninfected infants. The major classes of biomarkers in neonatal infection of recent interest will be discussed, including: acute phase reactants, cytokines, chemokines and leukocyte surface antigens. The application of these biomarkers to derive prognostic information useful to neonatal clinicians will also be considered.

A review of antimicrobial control strategies in hospitalized and ambulatory pediatric populations

Antimicrobial resistance is a growing crisis in healthcare. Various antimicrobial stewardship strategies have been used to control antibiotic use in efforts to reduce antibiotic resistance. We conducted a systematic review of antimicrobial stewardship programs in pediatric settings. Twenty-eight published studies met inclusion criteria. The majority (21 of 28) of studies had positive outcomes, but only 6 measured the impact of interventions on antimicrobial resistance. Prescriber education for a specific diagnosis (eg, otitis media) was the most effective intervention in the outpatient setting. Ancillary laboratory tests (eg, rapid diagnostic assays for viral pathogens) were most effective in the inpatient setting. Most studies had moderate to high risk of bias, mainly because of selection bias, inadequate preintervention data for time series analysis, and contamination between treatment groups. To date, there are a limited number of studies assessing antimicrobial stewardship in pediatric settings and these have heterogeneous study designs. Thus, it is difficult to determine the most effective interventions. Future studies should be designed to overcome the biases encountered in current publications.

Serum amyloid A: an early and accurate marker of neonatal early-onset sepsis

OBJECTIVES

To evaluate the accuracy of serum amyloid A (SAA), an acute phase protein in the detection of neonatal early-onset sepsis, by means of a fast automated SAA kit.

STUDY DESIGN

Full-term infants <72 h of age, who had risk factors and/or were suspected of having sepsis, were eligible for study. The levels of SAA were taken at 0, 24 and 48 h post sepsis evaluation. Thirty matched infants served as a control group for comparing SAA concentrations.

RESULTS

Of 104 infants eligible for entry to the study, 23 had sepsis and 81 had not sepsis. The SAA levels of the septic group were significantly higher than those of the nonseptic group at 0, 24 and 48 h (P<0.01 for all time points). In comparison with C-reactive protein (CRP), SAA levels rose earlier and in a sharper manner, had higher levels and returned faster to normal values in infants with early onset sepsis. At 0 h post-sepsis evaluation, serum SAA had an overall better diagnostic accuracy for predicting early onset sepsis than CRP (sensitivity (96 vs 30%), specificity (95 vs 98%), positive predictive value (85 vs 78%), negative predictive value (99 vs 83%), positive likelihood ratio (19 vs 12), and negative likelihood ratio (0.05 vs 0.71).

CONCLUSIONS

SSA is advocated as an inflammatory marker of neonatal early-onset sepsis.

Interleukin-8 and monocyte chemotactic protein-1 mRNA expression in perinatally infected and asphyxiated preterm neonates

BACKGROUND

Inflammation due to perinatal infection (PI) and perinatal asphyxia (PA) may cause damage to various tissues and very often to the immature brain of the fetus and the newborn. Previously, we have shown that the neonatal immune system has the ability to produce increased chemokine protein levels in the serum during the inflammatory response caused by PI and PA.

AIM

The aim of our present study was to investigate mRNA levels of the proinflammatory chemokines interleukin-8 (IL-8) and monocyte chemotactic protein-1 (MCP-1) in peripheral blood leukocytes from infected and asphyxiated neonates.

METHODS

Forty-two premature neonates were studied; 11 with PI, 16 with PA and 15 without PA and PI, were used as controls. IL-8 and MCP-1 mRNA levels were investigated in whole blood and in phytohemagglutinin-activated lymphocytes using semi-quantitative polymerase chain reaction and real-time polymerase chain reaction, respectively.

RESULTS

IL-8 mRNA levels were significantly increased in whole blood both during PA and PI, while MCP-1 mRNA levels were not. In vitro activated lymphocytes expressed significantly increased IL-8 mRNA levels during PI, whereas no increase was observed during PA. MCP-1 mRNA levels were significantly increased in activated lymphocytes during PA, while no increase was observed during PI.

CONCLUSIONS

Our data show that chemokine mRNA levels expressed by activated lymphocytes during inflammation caused by PIs are different to those expressed during PAs. These findings might have important implications during the administration of specific chemokine antagonists in order to prevent or reduce tissue damage caused by inflammation.

Application of Adaptive Designs – a Review

A literature search has been performed to review applications of the adaptive design methodology based on the combination test or conditional error function approach. Some features of the 60 papers identified are summarized, e.g., the specific methodology used, calendar year, country, impact factor of the journal, number of planned and performed stages respectively, stopping for futility boundaries, type of adaptations and others. A selection of the ten recent publications in journals with the highest impact factors is discussed in more detail. Most applications up to now aim at sample size reassessment, the majority of papers is coming from Germany. Although we found that renowned journals allow for sufficient space to present the new statistical methodology in all its necessary details, the general impression is that the presentation of the adaptive designs methodology in applied papers has to be improved. Education and development of standards could help to achieve this.

The diagnostic value of serum interleukins 6 and 8 in children with acute gastroenteritis

OBJECTIVES

Early identification of the pathogen causing acute gastroenteritis in children helps the physicians managing the disease and prevents unnecessary antibiotic treatment. C-reactive protein (CRP), interleukin (IL) 6 and IL-8 play a major role in immune responses and have been studied in a large number of infectious and noninfectious inflammatory diseases. The purpose of this study was to determine the serum IL-6 and IL-8 concentrations early in the course of acute gastroenteritis to see if these cytokines were useful diagnostic markers in differentiating viral from bacterial gastroenteritis.

METHODS

Interleukin 6, IL-8 and CRP were measured in 18 patients with bacterial gastroenteritis, 21 patients with viral gastroenteritis and 17 healthy children.

RESULTS

Interleukin 6 and CRP concentrations in patients with bacterial gastroenteritis were significantly higher than those in patients with viral gastroenteritis and healthy controls (P < 0.001). IL-8 concentrations in patients with viral and bacterial gastroenteritis were both increased and were not statistically different. IL-6 and IL-8 levels had diagnostic sensitivities of 79% and 50% and specificities of 86% and 67%, respectively. The combination of IL-6 and CRP had a sensitivity of 94%, specificity of 71%, a positive predictive value of 74% and a negative predictive value of 93.75%.

CONCLUSIONS

Serum IL-6 may be a useful marker for early differentiation of viral and bacterial gastroenteritis in children, especially in combination with CRP.

Effects of childhood primary hypertension on carotid intima media thickness: a matched controlled study

To determine whether carotid intima media thickness is increased in children with primary hypertension, the current study compared carotid intima media thickness in hypertensive children with that of normotensive control subjects matched closely for body mass index and determined the relationship between carotid intima media thickness and hypertension severity determined by ambulatory blood pressure monitoring. Children with newly diagnosed office hypertension (n=28) had carotid intima media thickness, left ventricular mass index, and ambulatory blood pressure monitoring performed. Carotid intima media thickness was performed in normotensive control subjects (n=28) matched pairwise to hypertensive subjects for age (+/-1 year), gender, and body mass index (+/-10%). Eighty-two percent of subjects were overweight or obese (body mass index > or =85th percentile). The median carotid intima media thickness of hypertensive subjects was greater than that of matched controls (0.67 versus 0.63 mm; P=0.045). In the hypertensive subjects, carotid intima media thickness correlated strongly with several ambulatory blood pressure monitoring parameters, with the strongest correlation for daytime systolic blood pressure index (r=0.57; P=0.003). In the hypertensive group, the prevalence of left ventricular hypertrophy was 32%, but unlike carotid intima media thickness, left ventricular mass index did not correlate with ambulatory blood pressure monitoring. Together, the findings that hypertensive subjects had increased carotid intima media thickness compared with matched controls and that higher carotid intima media thickness correlated with more severe hypertension by ambulatory blood pressure monitoring provide strong evidence that carotid intima media thickness is increased in childhood primary hypertension, independent of the effects of obesity.

Effects of low birth weight in 8- to 13-year-old children: implications in endothelial function and uric acid levels

Low birth weight has been associated with an increased incidence of adult cardiovascular disease. Endothelial dysfunction and high levels of serum uric acid are associated with hypertension. In this study, we have determined whether uric acid is related to blood pressure and vascular function in children with low birth weight. We evaluated vascular function using high-resolution ultrasound, blood pressure, and uric acid levels in 78 children (35 girls, 43 boys, aged 8 to 13 years). Increasing levels of uric acid and systolic blood pressure were observed in children with low birth weight. Birth weight was inversely associated with both systolic blood pressure and uric acid; on the other hand, uric acid levels were directly correlated with systolic blood pressure in children of the entire cohort. Low birth weight was associated with reduced flow-mediated dilation (r=0.427, P<0.001). Because the children with low birth weight had elevated uric acid as well as higher systolic blood pressure levels, we evaluated the correlation between these variables. In the low birth weight group, multiple regression analysis revealed that uric acid (beta=-2.886; SE=1.393; P=0.040) had a graded inverse relationship with flow-mediated dilation, which was not affected in a model adjusting for race and gender. We conclude that children with a history of low birth weight show impaired endothelial function and increased blood pressure and uric acid levels. These findings may be early expressions of vascular compromise, contributing to susceptibility to disease in adult life.

Newer approaches to the diagnosis of early onset neonatal sepsis

Accurate and timely diagnosis of early onset neonatal sepsis remains challenging to the clinician and the laboratory. A test with a rapid turnaround time with 100% sensitivity, rather than high specificity, which allows accurate diagnosis and appropriate antimicrobial treatment or which allows antibiotics to be safely withheld in non-infected infants, is desirable. Many potential markers (acute phase reactants, cell surface markers, cytokines) are not routinely available to the laboratory, and most likely combinations of markers will ensure greater diagnostic accuracy. In the future, molecular biology techniques offer the prospect of rapid identification of both pathogens and antimicrobial resistance markers.

Diagnostic markers for neonatal sepsis

PURPOSE OF REVIEW

To review the current evidence on the use of infection markers for diagnostic evaluation of sepsis in neonates.

RECENT FINDINGS

Recent research in immunology has led to the discovery of cell surface antigens, chemokines, cytokines and acute phase proteins that can potentially be used to 'rule in' or 'rule out' sepsis. The diagnostic utilities of key inflammatory mediators, including CD11b, CD64, interleukin-6 and interleukin-8, are promising and likely to become increasingly used as markers of infection for both diagnostic and prognostic purposes.

SUMMARY

Serial measurements and use of combinations of markers have been reported to improve sensitivity and negative predictive value of these tests. Current markers are not infallible, however, and do not permit neonatologists to withhold antibiotics in sick infants with suspected infection. Thus, many have emerged as useful indicators for early discontinuation of unnecessary antimicrobial therapy. Some infection markers are also useful for identifying infants with severe infection and adverse prognosis. Advances in flow cytometry have allowed simultaneous measurement of key markers using only minimal blood volume. Judicious selection of a panel of markers with complementary properties could greatly increase the ability of neonatologists to diagnose infection and discern valuable prognostic information.

Inflammatory mediators for the diagnosis and treatment of sepsis in early infancy

Interleukin-6 (IL-6), interleukin-8 (IL-8), and procalcitonin (PCT) are important parameters in the diagnosis of sepsis and for differentiating between viral and bacterial infection in children. We compared the value of IL-6, IL-8, and PCT with C-reactive protein (CRP) in the diagnosis and treatment of late-onset sepsis among infants admitted to the neonatal intensive care unit (group I) and febrile infants admitted to general hospitals from home (group II). Group I was divided into subgroups Ia, positive blood culture (all Gram-positive cocci); Ib, negative blood culture; and Ic, controls. Group II was divided into subgroups IIa, systemic enterovirus infection, and IIb, no enterovirus infection. Enterovirus was identified by real-time (RT) polymerase chain reaction (PCR) and/or by culture in blood and cerebrospinal fluid (CSF). The positive predictive values of IL-6, IL-8, and PCT (78%, 72%, and 83%, respectively) were better than that of CRP (63%) in the diagnosis of neonatal sepsis. After 48 h of antibiotic treatment, IL-6 and IL-8 levels significantly decreased and PCT stabilized in clinically recovered patients, suggesting that these markers may be useful in distinguishing patients in which antibiotic treatment may be discontinued. Among infants of subgroup IIa, 80%-90% had normal values of IL-6, IL-8, and PCT, whereas CRP was increased in 40%. In conclusion, IL-6, IL-8, and PCT are better parameters than CRP in the diagnosis and follow-up of neonatal sepsis due to coagulase-negative staphylococci (CoNS) and in the exclusion of bacterial infection among those with enteroviral infection among febrile infants presenting from home.

Lipopolysaccharide-binding protein in noninfected neonates and those with suspected early-onset bacterial infection

OBJECTIVES

To investigate postnatal lipopolysaccharide-binding protein (LBP) kinetics in term neonates and to test its diagnostic accuracy for early-onset bacterial infection (EOBI).

STUDY DESIGN

A total of 99 neonates with clinical and serological signs of EOBI comprised the study group; 198 neonates with risk factors, but without EOBI, served as controls. LBP, C-reactive protein (CRP) and interleukin-8 (IL-8) were determined.

RESULTS

LBP in the noninfected group increased until 24 h after birth (P < 0.05 vs 6 h). LBP and CRP correlated strongly in neonates with suspected EOBI (r = 0.63). Although LBP reached a higher sensitivity than CRP 6 and 12 h after clinical suspicion (45 (24-68) and 79% (54-94) vs 9 (0-24) and 39% (17-64); P < 0.05)), EOBI was most reliably detected by IL-8.

CONCLUSION

LBP kinetics were age-dependent. LBP was not sufficiently sensitive in the prediction of EOBI.

[Principles of managing chemotherapy-induced nausea and vomiting]

Chemotherapy-induced nausea and vomiting (emesis) can significantly affect a patient's quality of life, leading to poor compliance with further chemotherapy treatment. For patients treated with emetogenic chemotherapy, it is very important to prevent nausea and vomiting completely. The incidence and severity of nausea and/or vomiting in patients receiving chemotherapy are affected by numerous factors, including: 1) the specific chemotherapeutic agents used; 2) their dosage; 3) the schedule and route of administration; and 4) individual patient variability. Approximately 70 to 80% of all cancer patients receiving chemotherapy experience emesis, whereas 10% to 44% experience anticipatory emesis. The following general principles are recommended. 1) A 5-HT3 receptor antagonist should be administered prior to each day's 1st dose of moderately or highly emetogenic chemotherapy. 2) Dexamethasone should be administered once daily either orally or intravenously for every day of moderately or highly-emetogenic chemotherapy and for 2-3 days after chemotherapy for regimens that are likely to cause significant delayed-emesis. 3) The most effective way to treat anticipatory nausea and/or vomiting is to prevent it by using optimal antiemetic therapy during every cycle of treatment.

Simultaneous Measurement of 25 Inflammatory Markers and Neurotrophins in Neonatal Dried Blood Spots by Immunoassay with xMAP Technology

Background: Inflammatory reactions and other events in early life may be part of the etiology of late-onset diseases, including cerebral palsy, autism, and type 1 diabetes. Most neonatal screening programs for congenital disorders are based on analysis of dried blood spot samples (DBSS), and stored residual DBSS constitute a valuable resource for research into the etiology of these diseases. The small amount of blood available, however, limits the number of analytes that can be determined by traditional immunoassay methodologies.

Methods: We used new multiplexed sandwich immunoassays based on flowmetric Luminex® xMAP technology to measure inflammatory markers and neutrophins in DBSS.

Results: The high-capacity 25-plex multianalyte method measured 23 inflammatory and trophic cytokines, triggering receptor expressed on myeloid cells-1 (TREM-1), and C-reactive protein in two 3.2-mm punches from DBSS. It also measured 26 cytokines and TREM-1 in serum. Standards Recovery in the 25-plex method were 90%–161% (mean, 105%). The low end of the working range for all 25 analytes covered concentrations found in DBSS from healthy newborns. Mean recovery of exogenous analytes added at physiologic concentrations in DBSS models was 174%, mean intra- and interassay CVs were 6.2% and 16%, respectively, and the mean correlation between added and measured analytes was r2 = 0.91. In DBSS routinely collected on days 5–7 from 8 newborns with documented inflammatory reactions at birth, the method detected significantly changed concentrations of inflammatory cytokines. Measurements on DBSS stored at −24 °C for &gt;20 years showed that most cytokines are detectable in equal concentrations over time.

Conclusions: The method can reliably measure 25 inflammatory markers and growth factors in DBSS. It has a large potential for high-capacity analysis of DBSS in epidemiologic case–control studies and, with further refinements, in neonatal screening.