Deficiency of mannose-binding lectin-associated serine protease-2 associated with increased risk of fever and neutropenia in pediatric cancer patients

BACKGROUND: Mannose-binding lectin-associated serine protease-2 (MASP-2) is an essential component of the lectin pathway of complement activation. MASP-2 deficiency is common because of genetic polymorphisms, but its impact on susceptibility to infection is largely unknown. The aim of the present study was to determine whether children with cancer and MASP-2 deficiency develop more frequent or more severe episodes of fever and severe chemotherapy-induced neutropenia (FN). METHODS: Serum MASP-2 was measured by enzyme-linked immunosorbent assay at the time of diagnosis in children treated with chemotherapy for cancer. Association of FN episodes with MASP-2 concentration was analyzed using Poisson regression accounting for chemotherapy intensity and duration. RESULTS: Median MASP-2 in 94 children was 527 ng/mL (interquartile range, 367-686). Nine (10%) children had MASP-2 deficiency (<200 ng/mL). During a cumulative chemotherapy exposure time of 82 years, 177 FN episodes were recorded. MASP-2 deficient children had a significantly increased risk of developing FN (multivariate risk ratio, 2.08; 95% confidence interval, 1.31-3.21; P = 0.002), translating into significantly prolonged cumulative duration of hospitalization and of intravenous antimicrobial therapy. They experienced significantly more episodes of FN without a microbiologically defined etiology, and there was a trend toward more frequent episodes of FN with bacteremia. CONCLUSION: In this study, MASP-2 deficiency was associated with an increased risk of FN in children treated with chemotherapy for cancer. MASP-2 deficiency represents a novel risk factor for chemotherapy-related infections.

Real-time broad-range PCR versus blood culture. A prospective pilot study in pediatric cancer patients with fever and neutropenia

MATERIALS AND METHODS: In a pilot study, results of real-time broad-range (16S rRNA) polymerase chain reaction (PCR) performed on 45 blood samples of pediatric cancer patients with fever and neutropenia were compared with blood culture results. RESULTS: The PCR assay used, having proven a high sensitivity in artificially spiked blood samples, was positive in only three of ten blood culture-positive samples, and it was positive in 10 of 35 (29%) culture-negative samples. CONCLUSION: This broad-range PCR assay, which may identify not-grown bacteria potentially contributing to fever, needs improvement in sensitivity, and different reasons for positive PCR in negative blood culture samples need to be assessed before clinical application.

Airway epithelial IL-15 transforms monocytes into dendritic cells

IL-15 has recently been shown to induce the differentiation of functional dendritic cells (DCs) from human peripheral blood monocytes. Since DCs lay in close proximity to epithelial cells in the airway mucosa, we investigated whether airway epithelial cells release IL-15 in response to inflammatory stimuli and thereby induce differentiation and maturation of DCs. Alveolar (A549) and bronchial (BEAS-2B) epithelial cells produced IL-15 spontaneously and in a time- and dose-dependent manner after stimulation with IL-1beta, IFN-gamma, or TNF-alpha. Airway epithelial cell supernatants induced an increase of IL-15Ralpha gene expression in ex vivo monocytes, and stimulated DCs enhanced their IL-15Ralpha gene expression up to 300-fold. Airway epithelial cell-conditioned media induced the differentiation of ex vivo monocytes into partially mature DCs (HLA-DR+, DC-SIGN+, CD14+, CD80-, CD83+, CD86+, CCR3+, CCR6(+), CCR7-). Based on their phenotypic (CD123+, BDCA2+, BDCA4+, BDCA1(-), CD1a-) and functional properties (limited maturation upon stimulation with LPS and limited capacity to induce T cell proliferation), these DCs resembled plasmacytoid DCs. The effects of airway epithelial cell supernatants were largely blocked by a neutralizing monoclonal antibody to IL-15. Thus, our results demonstrate that airway epithelial cell-conditioned media have the capacity to differentiate monocytes into functional DCs, a process substantially mediated by epithelial-derived IL-15.

Airway remodelling in children with cystic fibrosis

BACKGROUND: The relationship between airway structural changes and inflammation is unclear in early cystic fibrosis (CF) lung disease. A study was undertaken to determine changes in airway remodelling in children with CF compared with appropriate disease and healthy controls. METHODS: Bronchoalveolar lavage and endobronchial biopsy were performed in a cross-sectional study of 43 children with CF (aged 0.3-16.8 years), 7 children with primary ciliary dyskinesia (PCD), 26 with chronic respiratory symptoms (CRS) investigated for recurrent infection and/or cough and 7 control children with no lower airway symptoms. Inflammatory cells, cytokines, proteases and matrix constituents were measured in bronchoalveolar lavage fluid (BALF). Reticular basement membrane (RBM) thickness was measured on biopsy specimens using light microscopy. RESULTS: Increased concentrations of elastin, glycosaminoglycans and collagen were found in BALF from children with CF compared with the CRS group and controls, each correlating positively with age, neutrophil count and proteases (elastase activity and matrix metalloproteinase-9 (MMP-9) concentration). There were significant negative correlations between certain of these and pulmonary function (forced expiratory volume in 1 s) in the CF group (elastin: r = -0.45, p<0.05; MMP-9:TIMP-1 ratio: r = -0.47, p<0.05). Median RBM thickness was greater in the CF group than in the controls (5.9 microm vs 4.0 microm, p<0.01) and correlated positively with levels of transforming growth factor-beta(1) (TGF-beta(1); r = 0.53, p = 0.01), although not with other inflammatory markers or pulmonary function. CONCLUSIONS: This study provides evidence for two forms of airway remodelling in children with CF: (1) matrix breakdown, related to inflammation, proteolysis and impaired pulmonary function, and (2) RBM thickening, related to TGF-beta(1) concentration but independent of other markers of inflammation.

rFVIIa in the treatment of persistent hemorrhage in pediatric patients on ECMO following surgery for congenital heart disease

BACKGROUND: Patients who require extracorporeal membrane oxygenation (ECMO) postsurgery for congenital heart disease (CHD) frequently experience severe bleeding episodes. Whereas recombinant-activated factor VII (rFVIIa) has proven efficacy in counteracting intractable hemorrhage in various scenarios, its use in patients on ECMO is limited by the increased risk for thrombotic events. METHODS: Between December 2004 and January 2006, ECMO was used in 10 pediatric patients following cardiac surgery, of whom seven were treated with rFVIIa because of intractable hemorrhage. Their medical records were reviewed with respect to variations in chest tube output and transfusion requirements, occlusion of or thrombus formation in the ECMO circuit and the occurrence of thromboembolic events. Outcome and rate of ECMO circuit occlusion were compared with historic controls. RESULTS: Three patients died, and four survived (none of the deaths was attributable to thrombus formation or bleeding). All patients were treated with aprotinin prior to and during rFVIIa therapy. Two patients developed an occlusion of the oxygenator, one after receiving co-medication with a FXIII concentrate, another after RBC transfusion in the ECMO system. In two patients, thrombus formation was observed in the ECMO system on inspection after discontinuation. Thromboembolic events were not observed. CONCLUSIONS: Recombinant-activated factor VII in a median dosage of 90 microg.kg(-1) was used in seven pediatric patients on ECMO. Rates of ECMO system occlusions and mortality did not differ from historic controls. Neither the reduction of chest tube output nor the blood product transfusion requirements did reach statistical significance.

Translocation of particles and inflammatory responses after exposure to fine particles and nanoparticles in an epithelial airway model

ABSTRACT: BACKGROUND: Experimental studies provide evidence that inhaled nanoparticles may translocate over the airspace epithelium and cause increased cellular inflammation. Little is known, however, about the dependence of particle size or material on translocation characteristics, inflammatory response and intracellular localization. RESULTS: Using a triple cell co-culture model of the human airway wall composed of epithelial cells, macrophages and dendritic cells we quantified the entering of fine (1 mum) and nano-sized (0.078 mum) polystyrene particles by laser scanning microscopy. The number distribution of particles within the cell types was significantly different between fine and nano-sized particles suggesting different translocation characteristics. Analysis of the intracellular localization of gold (0.025 mum) and titanium dioxide (0.02-0.03 mum) nanoparticles by energy filtering transmission electron microscopy showed differences in intracellular localization depending on particle composition. Titanium dioxide nanoparticles were detected as single particles without membranes as well as in membrane-bound agglomerations. Gold nanoparticles were found inside the cells as free particles only. The potential of the different particle types (different sizes and different materials) to induce a cellular response was determined by measurements of the tumour necrosis factor-alpha in the supernatants. We measured a 2-3 fold increase of tumour necrosis factor-alpha in the supernatants after applying 1 mum polystyrene particles, gold nanoparticles, but not with polystyrene and titanium dioxide nanoparticles. CONCLUSION: Quantitative laser scanning microscopy provided evidence that the translocation and entering characteristics of particles are size-dependent. Energy filtering transmission electron microscopy showed that the intracellular localization of nanoparticles depends on the particle material. Both particle size and material affect the cellular responses to particle exposure as measured by the generation of tumour necrosis factor-alpha.

Correlation of atrophy and fatty infiltration on strength and integrity of rotator cuff repairs: a study in thirteen patients

In 13 patients, the development of supraspinatus muscle atrophy and fatty infiltration after rotator cuff tendon repair was quantified prospectively via magnetic resonance imaging. Intraoperative electrical nerve stimulation at repair showed that the maximal supraspinatus tension (up to 200 N) strongly correlated with the anatomic cross-sectional muscle area and with muscle fatty infiltration (ranging from 12 N/cm(2) in Goutallier stage 3 to 42 N/cm(2) in Goutallier stage 0). Within 1 year after successful tendon repair (n = 8), fatty infiltration did not recover, and atrophy improved partially at best; however, if the repair failed (n = 5), atrophy and fatty infiltration progressed significantly. The ability of the rotator cuff muscles to develop tension not only correlates with their atrophy but also closely correlates with their degree of fatty infiltration. With current repair techniques, atrophy and fatty infiltration appear to be irreversible, despite successful tendon repair. Unexpectedly, not only weak but also very strong muscles are at risk for repair failure.

Electroencephalographic changes after pediatric cardiac surgery with cardiopulmonary bypass: is slow wave activity unfavorable?

Pediatric cardiac surgery with cardiopulmonary bypass (CPB) is frequently associated with neurologic deficits. We describe the postoperative EEG changes, assess their possible causes, and evaluate their relevance to neurologic outcome. Thirty-one children and five neonates with congenital heart disease were included. EEG recording started after intubation and continued until 22-96 h after CPB. In addition to conventional analysis, spectral analysis was performed for occipital and frontal electrodes, and differences between pre- and postoperative delta power (delta-deltaP) were calculated. Maximum values of occipital delta-deltaP that occurred within 48 h after CPB were correlated with clinical variables and with perioperative markers of oxidative stress and inflammation. Occipital delta-deltaP correlated with frontal delta-deltaP, and maximum delta-deltaP correlated with conventional rating. Distinct rise of deltaP was detected in 18 of 21 children without any acute or long-term neurologic deficits but only in five of 10 children with temporary or permanent neurologic deficits. Furthermore, maximally registered delta-deltaP was inversely associated with duration of CPB and postoperative ventilation. Maximal delta-deltaP was also inversely associated with the loss of plasma ascorbate (as an index of oxidative stress) and plasma levels of IL-6 and IL-8. Slow wave activity frequently occurs within 48 h after CPB. However, our data do not support the notion that EEG slowing is associated with adverse neurologic outcome. This is supported by the fact that EEG slowing was associated with less oxido-inflammatory stress.

Oxidative stress precedes peak systemic inflammatory response in pediatric patients undergoing cardiopulmonary bypass operation

Oxidative stress seems to contribute to cardiopulmonary bypass (CPB)-related postoperative complications. Pediatric patients are particularly prone to these complications. With this in mind, we measured oxidative stress markers in blood plasma of 20 children undergoing elective heart surgery before, during, and up to 48 h after cessation of CPB, along with inflammatory parameters and full analysis of iron status. Ascorbate levels were decreased by approximately 50% (P < 0.001) at the time of aorta cross-clamp removal (or pump switch-off in 4 patients with partial CPB), and associated with corresponding increases in dehydroascorbate (P < 0.001, r = -0.80) and malondialdehyde (P < 0.01, r = -0.59). In contrast to the immediate oxidative response, peak levels of IL-6 and IL-8 were not observed until 3-12 h after CPB cessation. The early loss of ascorbate correlated with duration of CPB (P < 0.002, r = 0.72), plasma hemoglobin after cross-clamp removal (P < 0.001, r = 0.70), and IL-6 and IL-8 levels at 24 and 48 h after CPB (P < 0.01), but not with postoperative lactate levels, strongly suggesting that hemolysis, and not inflammation or ischemia, was the main cause of early oxidative stress. The correlation of ventilation time with early changes in ascorbate (P < 0.02, r = 0.55), plasma hemoglobin (P < 0.01, r = 0.60), and malondialdehyde (P < 0.02, r = 0.54) suggests that hemolysis-induced oxidative stress may be an underlying cause of CPB-associated pulmonary dysfunction. Optimization of surgical procedures or therapeutic intervention that minimize hemolysis (e.g., off-pump surgery) or the resultant oxidative stress (e.g., antioxidant treatment) should be considered as possible strategies to lower the rate of postoperative complications in pediatric CPB.

Pediatric craniofacial trauma

PURPOSE: Maxillofacial and skull fractures occur with concomitant injuries in pediatric trauma patients. The aim of this study was to determine the causes and distributions of maxillofacial and skull fractures as well as concomitant injuries of pediatric patients in Switzerland. Results were compared with worldwide studies. MATERIALS AND METHODS: A retrospective review was conducted of 291 pediatric patients with maxillofacial and skull fractures presenting to a level-I trauma center over a 3-year span. Data concerning the mechanism of the accident and the topographic location of the injuries were analyzed. RESULTS: The most common causes were falls (64%), followed by traffic (22%) and sports-related accidents (9%). Fifty-four percent of the fractures occurred in the skull vault and 37% in the upper and middle facial third. One third of the patients (n = 95) suffered concomitant injuries, mostly cerebral concussions (n = 94). CONCLUSIONS: The spectrum of craniofacial injuries is related to the specific developmental stage of the craniofacial skeleton. It is probable that national prevention programs will have a positive effect on reducing the incidence of falls. Standardization of studies is needed for international comparison.

Targeted cell replacement with bone marrow cells for airway epithelial regeneration

It has been suggested that some adult bone marrow cells (BMC) can localize to the lung and develop tissue-specific characteristics including those of pulmonary epithelial cells. Here, we show that the combination of mild airway injury (naphthalene-induced) as a conditioning regimen to direct the site of BMC localization and transtracheal delivery of short-term cultured BMC enhances airway localization and adoption of an epithelial-like phenotype. Confocal analysis of airway and alveolar-localized BMC (fluorescently labeled) with epithelial markers shows expression of the pulmonary epithelial proteins, Clara cell secretory protein, and surfactant protein C. To confirm epithelial gene expression by BMC, we generated transgenic mice expressing green fluorescent protein (GFP) driven by the epithelial-specific cytokeratin-18 promoter and injected BMC from these mice transtracheally into wild-type recipients after naphthalene-induced airway injury. BMC retention in the lung was observed for at least 120 days following cell delivery with increasing GFP transgene expression over time. Some BMC cultured in vitro over time also expressed GFP transgene, suggesting epithelial transdifferentiation of the BMC. The results indicate that targeted delivery of BMC can promote airway regeneration.

Structured training in intraosseous infusion to improve potentially life saving skills in pediatric emergencies - Results of an open prospective national quality development project over 3 years

BACKGROUND: Children in emergencies need peripheral intravenous (IV) access in order to receive drugs or fluids. The success of IV access is associated with the age of patients and fails in up to 50% of children younger than 6 years. In such situations, it is essential that physicians and paramedics have a tool and easily learnable skills with a high chance of success. According to international guidelines intraosseous (IO) access would be the next step after failed IV access. Our hypothesis was that the success rate in IO puncturing can be improved by standardizing the training; so we developed an IO workshop. METHODS: Twenty-eight hospitals and ambulance services participated in an evaluation process over 3 years. IO workshops and the distribution of standardized IO sets were coordinated by the study group of the University Hospital of Berne. Any attempted or successful IO punctures were evaluated with a standardized interview. RESULTS: We investigated 35 applications in 30 patients (a total of 49 punctures) between November 2001 and December 2004. IO puncture was not successful in 5 patients. The success rate depended neither on the occupation nor the experience of users. Attendance at a standardized IO workshop increased the overall success rate from 77% to 100%, which was statistically not significant (P = 0.074). CONCLUSIONS: Standardized training in IO puncturing seems to improve success more than previous experience and occupation of providers. However, we could not show a significant increase in success rate after this training. Larger supranational studies are needed to show a significant impact of teaching on rarely used emergency skills.

Cardiovascular risk factors and the metabolic syndrome in pediatric nonalcoholic fatty liver disease

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD), the most common cause of liver disease in children, is associated with obesity and insulin resistance. However, the relationship between NAFLD and cardiovascular risk factors in children is not fully understood. The objective of this study was to determine the association between NAFLD and the presence of metabolic syndrome in overweight and obese children. METHODS AND RESULTS: This case-control study of 150 overweight children with biopsy-proven NAFLD and 150 overweight children without NAFLD compared rates of metabolic syndrome using Adult Treatment Panel III criteria. Cases and controls were well matched in age, sex, and severity of obesity. Children with NAFLD had significantly higher fasting glucose, insulin, total cholesterol, low-density lipoprotein cholesterol, triglycerides, systolic blood pressure, and diastolic blood pressure than overweight and obese children without NAFLD. Subjects with NAFLD also had significantly lower high-density lipoprotein cholesterol than controls. After adjustment for age, sex, race, ethnicity, body mass index, and hyperinsulinemia, children with metabolic syndrome had 5.0 (95% confidence interval, 2.6 to 9.7) times the odds of having NAFLD as overweight and obese children without metabolic syndrome. CONCLUSIONS: NAFLD in overweight and obese children is strongly associated with multiple cardiovascular risk factors. The identification of NAFLD in a child should prompt global counseling to address nutrition, physical activity, and avoidance of smoking to prevent the development of cardiovascular disease and type 2 diabetes.

Recurrent rearrangements of chromosome 1q21.1 and variable pediatric phenotypes

BACKGROUND: Duplications and deletions in the human genome can cause disease or predispose persons to disease. Advances in technologies to detect these changes allow for the routine identification of submicroscopic imbalances in large numbers of patients. METHODS: We tested for the presence of microdeletions and microduplications at a specific region of chromosome 1q21.1 in two groups of patients with unexplained mental retardation, autism, or congenital anomalies and in unaffected persons. RESULTS: We identified 25 persons with a recurrent 1.35-Mb deletion within 1q21.1 from screening 5218 patients. The microdeletions had arisen de novo in eight patients, were inherited from a mildly affected parent in three patients, were inherited from an apparently unaffected parent in six patients, and were of unknown inheritance in eight patients. The deletion was absent in a series of 4737 control persons (P=1.1x10(-7)). We found considerable variability in the level of phenotypic expression of the microdeletion; phenotypes included mild-to-moderate mental retardation, microcephaly, cardiac abnormalities, and cataracts. The reciprocal duplication was enriched in nine children with mental retardation or autism spectrum disorder and other variable features (P=0.02). We identified three deletions and three duplications of the 1q21.1 region in an independent sample of 788 patients with mental retardation and congenital anomalies. CONCLUSIONS: We have identified recurrent molecular lesions that elude syndromic classification and whose disease manifestations must be considered in a broader context of development as opposed to being assigned to a specific disease. Clinical diagnosis in patients with these lesions may be most readily achieved on the basis of genotype rather than phenotype.