A prospective study of the sensitivity, specificity and diagnostic performance of soluble intercellular adhesion molecule 1, highly sensitive C-reactive protein, soluble E-selectin and serum amyloid A in the diagnosis of neonatal infection.

BACKGROUND: Diagnosis of neonatal infection is difficult, because of it's non-specific clinical presentation and the lack of reliable diagnostic tests. The purpose of this study was to examine the potential diagnostic value of serum soluble intercellular adhesion molecule-1 (sICAM-1), soluble E-selectin (sE-selectin), highly sensitive C-reactive protein (hsCRP) and serum amyloid A (SAA) measurements, both individually and in combination in the setting of a neonatal intensive care unit. METHODS: 219 consecutive serum samples were taken from 149 infants undergoing sepsis work up in a neonatal intensive care unit. Clinical diagnosis was established in a prospective manner, blind to the results of the study measurements. Infants were classified by an experienced paediatrician as infected or not-infected, one week after presentation. Classification was based on clinical presentation, routine laboratory and radiological investigations and response to therapy. The infected group were sub-classified as (a) culture positive infection or (b) culture negative infection. sICAM-1, sE-selectin, hsCRP and SAA levels were determined from stored serum samples after diagnosis was established. Further sub-group analysis of results was undertaken according to early or late onset of infection and preterm or term status. Statistical analysis utilised Mann Whitney U test and ROC curve analysis. RESULTS: There were significantly increased serum levels of sICAM-1, hsCRP, E selectin (p < 0.001) and SAA (p = 0.004) in infected infants compared with non-infected. ROC curve analysis indicated area under the curve values of 0.79 (sICAM-1), 0.73 (hsCRP), 0.72 (sE-selectin) and 0.61 (SAA). ROC curve analysis also defined optimum diagnostic cut-off levels for each measurement. The performance characteristics of sICAM-1, hsCRP and sE-selectin included a high negative predictive value (NPV) for culture positive infection and this was enhanced by combination of all 4 measurements. Clinical subgroup analysis suggested particularly high NPV for early onset symptoms, however further studies are required to elucidate this finding. CONCLUSIONS: All four study measurements demonstrated some diagnostic value for neonatal infection however sICAM-1, hsCRP and sE-selectin demonstrated the highest NPV individually. The optimum diagnostic cut off level for hsCRP measurement in this study was much lower than currently used in routine clinical practice. Use of a combination of measurements enhanced diagnostic performance, demonstrating sensitivity of 90.3% and NPV of 91.3%. This study suggests there may be value in use of several of these markers, individually and in combination to assist in excluding neonatal infection. Further work is needed to confirm a specific role in the exclusion of early onset infection.

Neonatal enteral feeding tubes as loci for colonisation by members of the Enterobacteriaceae.

BACKGROUND: The objective of this study was to determine whether neonatal nasogastric enteral feeding tubes are colonised by the opportunistic pathogen Cronobacter spp. (Enterobacter sakazakii) and other Enterobacteriaceae, and whether their presence was influenced by the feeding regime. METHODS: One hundred and twenty-nine tubes were collected from two neonatal intensive care units (NICU). A questionnaire on feeding regime was completed with each sample. Enterobacteriaceae present in the tubes were identified using conventional and molecular methods, and their antibiograms determined. RESULTS: The neonates were fed breast milk (16%), fortified breast milk (28%), ready to feed formula (20%), reconstituted powdered infant formula (PIF, 6%), or a mixture of these (21%). Eight percent of tubes were received from neonates who were 'nil by mouth'. Organisms were isolated from 76% of enteral feeding tubes as a biofilm (up to 107 cfu/tube from neonates fed fortified breast milk and reconstituted PIF) and in the residual lumen liquid (up to 107 Enterobacteriaceae cfu/ml, average volume 250 mul). The most common isolates were Enterobacter cancerogenus (41%), Serratia marcescens (36%), E. hormaechei (33%), Escherichia coli (29%), Klebsiella pneumoniae (25%), Raoultella terrigena (10%), and S. liquefaciens (12%). Other organisms isolated included C. sakazakii (2%),Yersinia enterocolitica (1%),Citrobacter freundii (1%), E. vulneris (1%), Pseudomonas fluorescens (1%), and P. luteola (1%). The enteral feeding tubes were in place between < 6 h (22%) to > 48 h (13%). All the S. marcescens isolates from the enteral feeding tubes were resistant to amoxicillin and co-amoxiclav. Of additional importance was that a quarter of E. hormaechei isolates were resistant to the 3rd generation cephalosporins ceftazidime and cefotaxime. During the period of the study, K. pneumoniae and S. marcescens caused infections in the two NICUs. CONCLUSION: This study shows that neonatal enteral feeding tubes, irrespective of feeding regime, act as loci for the bacterial attachment and multiplication of numerous opportunistic pathogens within the Enterobacteriaceae family. Subsequently, these organisms will enter the stomach as a bolus with each feed. Therefore, enteral feeding tubes are an important risk factor to consider with respect to neonatal infections.

Auditory neuropathy: unexpectedly common in a screened newborn population.

Auditory neuropathy, or dyssynchrony, is defined by an abnormal or absent auditory brainstem response but intact otoacoustic emissions or cochlear microphonics. It is associated with impaired hearing on behavioural pure-tone audiometry, absent acoustic reflexes, and poor speech perception, particularly in noisy environments. These results suggest a disorder of inner hair-cell and or eighth-nerve function. We describe a case-note survey of patients with and without auditory neuropathy, using data from the local newborn hearing screening programme collected prospectively from 2002 to 2007. During this period, 45 050 infants were screened with otoacoustic emissions, 30 patients were diagnosed with suspected severe to profound hearing loss (16 males, 14 females), and 12 of those 30 had auditory neuropathy (six males, six females). Mean gestational age was 33 weeks 1 day in the auditory neuropathy group and 35 weeks in the non-auditory neuropathy group. The most significant risk factors for auditory neuropathy were hyperbilirubinaemia (p=0.018), sepsis (p=0.024), and gentamicin exposure (p=0.024). Children with auditory neuropathy comprise a subgroup of patients with hearing impairment involving different pathologies most commonly associated with the risk factors related to admission to neonatal intensive care units. Improvement is possible with maturity, at least in a minority.

Identification of diagnostic biomarkers for infection in premature neonates.

Infection is a leading cause of neonatal morbidity and mortality worldwide. Premature neonates are particularly susceptible to infection because of physiologic immaturity, comorbidity, and extraneous medical interventions. Additionally premature infants are at higher risk of progression to sepsis or severe sepsis, adverse outcomes, and antimicrobial toxicity. Currently initial diagnosis is based upon clinical suspicion accompanied by nonspecific clinical signs and is confirmed upon positive microbiologic culture results several days after institution of empiric therapy. There exists a significant need for rapid, objective, in vitro tests for diagnosis of infection in neonates who are experiencing clinical instability. We used immunoassays multiplexed on microarrays to identify differentially expressed serum proteins in clinically infected and non-infected neonates. Immunoassay arrays were effective for measurement of more than 100 cytokines in small volumes of serum available from neonates. Our analyses revealed significant alterations in levels of eight serum proteins in infected neonates that are associated with inflammation, coagulation, and fibrinolysis. Specifically P- and E-selectins, interleukin 2 soluble receptor alpha, interleukin 18, neutrophil elastase, urokinase plasminogen activator and its cognate receptor, and C-reactive protein were observed at statistically significant increased levels. Multivariate classifiers based on combinations of serum analytes exhibited better diagnostic specificity and sensitivity than single analytes. Multiplexed immunoassays of serum cytokines may have clinical utility as an adjunct for rapid diagnosis of infection and differentiation of etiologic agent in neonates with clinical decompensation.

WT1 mutations in Meacham syndrome suggest a coelomic mesothelial origin of the cardiac and diaphragmatic malformations.

Meacham syndrome is a rare sporadically occurring multiple malformation syndrome characterized by male pseudohermaphroditism with abnormal internal female genitalia comprising a uterus and double or septate vagina, complex congenital heart defect and diaphragmatic abnormalities. We report on eight new cases of this condition, two of whom were shown to have heterozygous missense mutations in the C-terminal zinc finger domains of WT1: Arg366Cys and Arg394Trp. These data represent clinical and molecular evidence that the WT1 gene plays a central role in normal development of the diaphragm and the proepicardially derived tissues. Identification of WT1 expression in the region of coelomic mesothelium which will form the proepicardium and diaphragm provides a plausible unifying patterning defect in these cases. Interestingly, the Arg366Cys mutation has been previously reported in Denys-Drash syndrome and Arg394Trp mutation has been previously reported in both isolated Wilms tumor and Denys-Drash syndrome. This phenotypic diversity with a single mutation suggests there are other factors modulating all aspects of WT1 function during human development. If genetic modifiers of WT1 can be identified in animal models these become good candidate genes for the cases with Meacham syndrome we report on here where WT1 mutations cannot be identified.

Health status and health-related quality of life in adolescent survivors of cancer in childhood.

PURPOSE: Adolescent survivors of cancer in childhood face particular challenges due to their maturational trajectory, including psychosocial adjustments, self-help skills, intellectual functioning and socialization. To better understand these, we assessed the health status and health-related quality of life (HRQL) in a 20-year cohort of such survivors in a single institution. METHODS: Health status and HRQL were measured with a self-complete questionnaire from the Health Utilities Index (HUI) family of multi-attribute, preference-based instruments that provide utility scores for single attributes and overall HRQL. RESULTS: Eighty-four (42 males, 42 females) of 129 eligible subjects (65%) participated. More than 80% of the respondents reported some form of morbidity. Overall HRQL utility scores were lower for both the males and females than for corresponding members of the Canadian general population. Female survivors self-reported a significantly greater burden of morbidity (mean overall HUI2/HUI3 scores: .83/.73 vs. .90/.84 for males, p < .02), which was most evident in the attributes of emotion and cognition. CONCLUSIONS: The majority of adolescent survivors of cancer in childhood carry a morbidity burden into their teen and young adult years. These findings may guide the support required by this population.

Tracheal agenesis with unique anatomy.

A premature infant with a unique form of tracheal agenesis is described. The combination of difficulty in intubation, abnormal course of the nasogastric tube on plain x-ray, and gastric perforation raised the suspicion of an upper airway malformation. Tracheal agenesis is an extremely rare, typically fatal, congenital anomaly with scattered case reports of its successful management. On many occasions, the diagnosis is a retrospective one at postmortem examination. The possibility of surgical correction rests on early diagnosis, anatomy, birth weight, and associated anomalies. Early recognition is mandatory, but in our case, the low birth weight precluded consideration for reconstructive surgery.

A low serum sICAM-1 level may assist in the exclusion of neonatal infection.

Serum levels of soluble intercellular adhesion molecule-1 (sICAM-1) in 46 samples from 46 infants undergoing intensive care were studied. Residual serum remaining after routine electrolyte analysis was utilised. sICAM-1 levels were determined by ELISA. Blind retrospective chart review was employed to determine whether infants were infected. Serum levels were significantly elevated in infants with proven and probable infection, compared with non-infected infants (p < 0.001). sICAM-1 levels in serum were comparable to levels previously established in plasma samples. The results suggest that serum sICAM-1 measurement is a simple and robust test that differentiates infected from non-infected infants and that a low level of serum sICAM-1 may particularly assist in the exclusion of infection.