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RSV Infection (rsv + infection)
Selected AbstractsRespiratory Syncytial Viral Infection in an Infant with Unrepaired Anomalous Left Coronary Artery from the Pulmonary ArteryCONGENITAL HEART DISEASE, Issue 4 2007Karen McClard MD ABSTRACT Abnormal origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare coronary anomaly in children that requires necessary and urgent repair. We report a child who was hospitalized with respiratory failure due respiratory syncytial viral (RSV) infection and was subsequently diagnosed with ALCAPA. Aggressive treatment for RSV included synagis and nebulized ribavirin prior to surgical repair. After waiting 4 weeks for the RSV infection to resolve, she underwent successful left coronary artery reimplantation on hospital day 27 and has regained normal left ventricular size and function. [source] Influenza A in Young Children with Suspected Respiratory Syncytial Virus InfectionACADEMIC EMERGENCY MEDICINE, Issue 12 2003Marla J. Friedman DO Objectives: To determine the prevalence of influenza A in young children suspected of having respiratory syncytial virus (RSV) infection and to compare the clinical presentation of these patients with those who have proven RSV infection. Methods: Children younger than or at 36 months of age who presented to a pediatric emergency department (ED) with suspected RSV infection during the influenza A season of 2001,2002 were eligible. Eligible children had an RSV antigen test ordered as part of their initial clinical management. A consecutive sample of children was enrolled for prospective observational analysis. The main outcome measure was the prevalence of influenza A in young children with suspected RSV infection. The secondary outcome measure was a comparison of the clinical presentations, of the two groups. Results: During the study period, 420 patients presented for evaluation of respiratory illness. RSV tests were ordered on 251 patients. Of 197 eligible patients, 124 (63%) tested positive for RSV and 33 (17%) for influenza A. Influenza A patients were more likely to have temperatures at or above 39°C than RSV patients (36% vs. 15%; p = 0.01). RSV patients were more tachypneic (54 vs. 43 breaths/minute; p < 0.0001) and more often had wheezing (90% vs. 8%; p < 0.0001). Twenty influenza patients (61%) were hospitalized. Conclusions: This study found a high prevalence of influenza A in young children suspected of having RSV infection. Clinicians should consider influenza A in young febrile children presenting with respiratory illnesses. [source] Intranasal immunisation with inactivated RSV and bacterial adjuvants induces mucosal protection and abrogates eosinophilia upon challengeEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 5 2006Nathalie Etchart Abstract We have previously shown that following intranasal exposure to influenza virus, specific plasma cells are generated in the nasal-associated lymphoid tissue (NALT) and maintained for the life of the animal. However, we also showed that following infection with respiratory syncytial virus (RSV), specific plasma cells are generated in the NALT but wane quickly and are not maintained even after challenge, even though RSV-specific serum antibody responses remain robust. Only infection with influenza virus generated sterilising immunity, implying a role for these long-lived plasma cells in protection. We show here that the RSV-specific IgA NALT plasma cell population and lung antibody levels can be substantially boosted, both at acute and memory time points, by intranasal immunisation with inactivated RSV (iRSV) in combination with bacterial outer membrane vesicles (OMV) compared to live RSV alone. Finally, challenge with live RSV showed that immunisation with iRSV and OMV protect against both virus replication in the lung and the eosinophil infiltrate generated by either live RSV or iRSV alone. These data show that immunisation with iRSV and OMV maintains a NALT RSV-specific plasma cell population and generates an efficient protective immune response following RSV infection. See accompanying commentary: http://dx.doi.org/10.1002/eji.200636118 [source] Inhalation efficacy of RFI-641 in an African green monkey model of RSV infectionJOURNAL OF MEDICAL PRIMATOLOGY, Issue 2 2003W.J. Weiss Abstract: Human respiratory syncytial virus (RSV) is a major cause of acute upper and lower respiratory tract infections. RFI-641 is a novel RSV fusion inhibitor with potent in vitro activity. In vivo efficacy of RFI was determined in an African green monkey model of RSV infection involving prophylactic and therapeutic administration by inhalation exposure. Inhalation was with an RFI-641 nebulizer reservoir concentration of 15 mg/ml for 15 minutes (short exposure) or 2 hours (long exposure). Efficacy and RFI-641 exposure was determined by collection of throat swabs, nasal washes and bronchial alveolar lavage (BAL) on selected days. The short-exposure group (15 minutes) exhibited no effect on the nasal, throat or BAL samples. The throat and nasal samples for the long-exposure group failed to show a consistent reduction in viral titers. RFI-641 2 hours exposure-treated monkeys showed a statistically significantly log reduction for BAL samples of 0.73,1.34 PFU/ml (P -value 0.003) over all the sampling days. Analysis indicates that the long-exposure group titer was lower than the control titer on day 7 and when averaged across days. The results of this study demonstrate the ability of RFI-641 to reduce the viral load of RSV after inhalation exposure in the primate model of respiratory infection. [source] Matrix metalloproteinase-9 and tissue inhibitor of matrix metalloproteinase-1 in the respiratory tracts of human infants following paramyxovirus infectionJOURNAL OF MEDICAL VIROLOGY, Issue 4 2007Matthew B. Elliott Abstract Respiratory syncytial (RSV) and parainfluenza (PIV) viruses are primary causes of acute bronchiolitis and wheezing illnesses in infants and young children. To further understand inflammation in the airways following infection, we tested for the presence of matrix metalloproteinases (MMP) and natural tissue inhibitors of MMP (TIMP) in primary and established human cell lines, and in the nasopharyngeal secretions (NPS) of human infants infected with RSV or PIV. Using ELISA and multiplex-based assays, MMP-9 and TIMP-1 proteins were, respectively, detected in 66/67 and 67/67 NPS. During PIV or RSV infection TIMP-1 concentrations were associated with hypoxic bronchiolitis. TIMP-1 amounts were also negatively correlated with O2 saturation, and positively correlated with IL-6, MIP-1,, and G-CSF amounts following RSV infection. IL-6, MIP-1,, and G-CSF were negatively correlated with O2 saturation during RSV infection. Acute respiratory tract disease was not associated with MMP-9 protein/protease activity. Additional studies using real-time quantitative PCR suggested that MMP-9 mRNA copy numbers were elevated in normal human bronchial epithelial (NHBE) cells infected with RSV, while TIMP-1 and TIMP-2 were not increased. However, ELISA did not reveal MMP-9 protein in the NHBE cell culture supernatants. Hence, the data implied that airway epithelial cells were not the primary source of MMP or TIMP following paramyxovirus infection. Taken together, the data suggested that paramyxovirus infection perturbs MMP-9/TIMP-1 homeostasis that in turn may contribute to the severity of respiratory tract disease. J. Med. Virol. 79:447,456, 2007. © 2007 Wiley-Liss, Inc. [source] Melatonin decreases TLR3-mediated inflammatory factor expression via inhibition of NF-,B activation in respiratory syncytial virus-infected RAW264.7 macrophagesJOURNAL OF PINEAL RESEARCH, Issue 1 2008Sheng-Hai Huang Abstract:, Double-stranded (ds) RNA has been identified as a ligand for Toll-like receptor 3 (TLR3). Respiratory syncytial virus (RSV), a single-stranded RNA virus and a major respiratory pathogen and pneumovirus in human infants pathogenesis of which relies on early inflammatory and immune events of the host in response to RSV, could be recognized by TLR3 sensing viral dsRNA produced during replication. The downstream signaling pathway from TLR3 leads to activation of IFN regulatory factor (IRF)-3 and/or NF-,B and subsequent expression of numerous proinflammatory factors. Melatonin (MT) is an effective regulator of the immune system. To determine the molecular mechanisms responsible for the suppressive effect of MT on RSV infection, we analyzed signaling molecules involved in the TLR3-mediated activation of inflammatory factors in macrophages infected with RSV and the modulatory role of MT on these mediators. We report that RSV infection of RAW264.7 macrophages time-dependently stimulate the rapid activation of TLR3 and NF-,B, as well as subsequent NF-,B-dependent gene expression such as those encoding TNF-, and inducible nitric oxide synthase. Moreover, we demonstrate that MT decreased TLR3-mediated downstream gene expression in RSV-infected macrophages in a dose- and time-dependent manner, and that MT inhibition of NF-,B activity seemed to be the key event required to explain the reduction in inflammatory gene expression caused by MT. But MT did not influence TLR3 at either the protein or mRNA level or MyD88 transcription. These results could be related to the beneficial immunoregulatory role of MT in RSV-infected macrophages and address the possible therapeutic potential of this indoleamine in human RSV diseases. [source] Ability of low-molecular-weight heparin to alleviate proteinuria by inhibiting respiratory syncytial virus infectionNEPHROLOGY, Issue 7 2008YANNAN GUO SUMMARY: Aim: Low-molecular-weight heparin (LMWH) is a negatively charged glycoprotein and has a very similar structure to that of cell surface heparin sulfate (HS). Thus, LMWH, an analog of HS, may inhibit positively charged respiratory syncytial virus (RSV) infection through cooperative electrostatic association. Methods: In this study, rats were respectively treated with 400 IU/kg LMWH before, during or after being inoculated with 6 × 106 plaque-forming unit (PFU) RSV. RSV and normal control groups were respectively inoculated by RSV and virus-free Dulbecco's modified Eagle's medium (DMEM). HeLa cells in vitro were pretreated with LMWH, elastase (ELA), heparinase (HpaIII) and protamine before being inoculated with 6 × 101 PFU RSV. RSV infectivity was determined by in situ hybridization and plaque assay. Results: After inoculation, the urinary protein excretion and serum parameters in LMWH-treated rats were significantly lower than those in the RSV group. No abnormalities of glomerular structure were observed in LMWH-treated groups whereas swelling and slight hypercellularity in minority glomeruli and foot process effacement were observed in the RSV group. RSV RNA of LMWH-treated rats had weaker expression than that of the RSV group. In vitro, RSV infection in RSV + LMWH, HpaIII + ELAI, protamine + ELAI, ELAI, HpaIII and protamine treatment cells were significantly lower than that of the RSV control, and that in RSV + LMWH was the least. There were no significant differences in RSV infection between ELAI + LMWH and RSV control. Conclusion: Our study confirmed that there is a correlation between RSV and proteinuria in rats. LMWH can alleviate proteinuria in rats through inhibiting RSV from binding with HS which plays an important role in the onset of RSV infection. [source] Suppression of IFN-gamma production in atopic group at the acute phase of RSV infectionPEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 5 2006Hideo Kaneko Several studies have suggested that respiratory syncytial virus (RSV) bronchiolitis induced the change of cytokine production profile in childhood. We sought to determine whether the RSV-induced cytokine production was affected by the patient's atopic background. We quantified interferon-gamma (IFN-gamma) and interleukin (IL)-4 in the supernatant of peripheral blood mononuclear cells (PBMCs) cultured for 24 h and in the presence of phytohemaglutinin (PHA), IL-12, or IL-18, from 14 infants who were divided into two groups, those who are non-atopic and an atopic group. In RSV-infected infants with atopic diseases, IFN-gamma production from IL-12- or especially IL-18-stimulated PBMCs was subtotally suppressed in the acute phase, whereas in RSV-infected infants without atopic diseases IFN-gamma production was not suppressed on acute phase. The IFN-gamma suppression observed in the atopic group is not caused by the immaturity of an infant's immune system since reduced IFN-gamma production to RSV is not observed in the infants of non-atopic group. IFN-gamma suppression in regard to RSV infection might be caused by some genetic factor involved in the development of atopic disease such as IL-18 signal cascade. [source] Age and sex as factors of response to RSV infections among those with previous history of wheezingPEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 5 2006Yoko Nagayama Although enhanced immune reaction caused by the respiratory syncytial virus (RSV) in allergen-sensitized animal model has been reported, RSV illnesses in children already sensitized or having recurrent wheezing episodes have not been completely studied. In addition, the reason for male dominances in RSV infection at young ages was also inconclusive. Therefore, gender analysis in recurrent wheezing children with RSV infection can shed light on asthma pathogenesis. We studied the clinical features and the laboratory data of RSV infections in children who had recurrent wheezing histories. The subjects with RSV infection consisted of 98 boys and 58 girls. The children under 4 yr of age were 123 (78.8%) in number. Children with pneumonia were 78 and those with febrile episode were 119. Children above 1 yr of age were highly sensitized with mite antigen (75/96, 78.1%). The clinical symptoms and signs differed according to their ages. Children in each age group behaved differently in their immune reaction to RSV. Above all, 3-yr-old children deteriorated clinically during acute RSV infection, accompanied by transient elevated C-reactive protein (CRP) and suppressed blood eosinophil counts. Clinical features differed in several points between boys and girls. In general, the white blood cell count and the CRP levels were higher in girls in every age group. Blood eosinophil counts at the acute illness were significantly higher in boys than girls aged 2 and 3< yr. Age and gender comparison in already sensitized children might suggest a clue to asthma pathogenesis. [source] A whisper from the silent lung zonePEDIATRIC PULMONOLOGY, Issue 8 2009Fatma Aljassim MD Abstract Multiple breath inert gas washout (MBW) is now regarded as "an insightful, sound, and useful tool to explore the lung and its response to injury in all of its compartments". We describe the important finding of pronounced intra-acinar airways response to indirect challenge testing, detected using MBW but missed by spirometry, in an adolescent with evidence of airway inflammation, and a background of severe respiratory syncytial virus (RSV) infection as an infant. These tests were performed as part of an 18-year follow up of a cohort with severe RSV infection (requiring hospitalization) in the first year of life, and has previously reported significantly higher rates of symptoms of allergic asthma and other features of atopic disease at 13 years in comparison to age matched controls. Small airway dysfunction and ventilation inhomogeneity have emerged as important features of early respiratory disease processes, and this case report provides further evidence supporting its important role in reactive airways disease. Pediatr Pulmonol. 2009; 44:829,832. © 2009 Wiley-Liss, Inc. [source] Readmission with respiratory syncytial virus (RSV) infection among graduates from a Neonatal Intensive Care UnitPEDIATRIC PULMONOLOGY, Issue 4 2002Jonathan McCormick MRCPCH Abstract We evaluated the incidence of readmission with respiratory syncytial virus (RSV) infection among the graduates of a regional Neonatal Intensive Care Unit (NICU), and characterized those who were rehospitalized. These data were used as a predictive tool to estimate the number of babies likely to suffer readmission with RSV for the year 2000 cohort. Using the published efficacies of palivizumab, the costs and benefits of protecting this cohort were assessed. Retrospective analysis of 2,507 NICU inpatient records from January 1, 1994,December 31, 1999 from the Royal Maternity Hospital, Belfast, were compared with data on positive RSV samples from 1,790 patients between January 1, 1995,December 31, 1999 from the Northern Ireland Regional Virus Laboratory. The analysis yielded 136 (7.6%) ex-NICU patients among the positive RSV samples over this 5-year period. Characteristic seasonal peaks of RSV infection with interseasonal variability were observed. Of those readmitted, 86.9% were hospitalized with RSV before their first birthday. A calculated readmission rate of 5.4% for all NICU graduates, and 6.4% for those ,35 weeks, was found, leading to an expectation of 36 readmissions from the 668 NICU graduates in the year 2000 over the next 1,2 years, 20 of whom would be ,35 weeks and 12 would be ,32 weeks. A cost of Ł1.3 million would be required to protect the ,35-week year 2000 cohort and prevent 11 readmissions. This equals Ł120,000 per admission prevented, or 28.2 patients treated to prevent 1 readmission. A readmission rate of 6.4% may differ from other studies, as it represents analysis of a greater number of RSV seasons. Using economic arguments alone, the cost of routine administration of Palivizumab to ex-NICU ,35-week infants is prohibitive. A selective practice of immunizing those with chronic lung disease with a background of extreme prematurity over the November to March RSV season may be more cost-effective. Pediatr Pulmonol. 2002; 34:262,266. © 2002 Wiley-Liss, Inc. [source] Severe respiratory syncytial virus pneumonia associated with primary Epstein-Barr virus infectionPEDIATRIC PULMONOLOGY, Issue 5 2002Nazha Abughali MD Abstract This is a case report of a child with severe respiratory syncytial virus (RSV) pneumonia and concurrent infection with Epstein-Barr virus. We hypothesize that immunosuppression due to EBV may have contributed to the severity of his RSV infection. The diagnosis of RSV infection was facilitated by bronchoalveolar lavage. Pediatr Pulmonol. 2002; 33:395,398. © 2002 Wiley-Liss, Inc. [source] Eosinophil cationic protein in infants with respiratory syncytial virus bronchiolitis: Predictive value for subsequent development of persistent wheezingPEDIATRIC PULMONOLOGY, Issue 6 2001Massimo Pifferi MD Abstract Infants with acute bronchiolitis during the first months of life are at increased risk of developing persistent wheezing and bronchial asthma later in life. The study of eosinophil cationic protein (ECP) suggests that eosinophil-related inflammatory mechanisms may play a role in respiratory syncytial virus (RSV) bronchiolitis. The aim of our study was to verify whether serum ECP (s-ECP) measurements are useful in predicting the development of persistent wheezing in children affected by RSV bronchiolitis during a 5 years follow-up period. Forty-eight infants were enrolled prospectively (mean age: 153.5 days). All had a clinical and radiological diagnosis of acute bronchiolitis and confirmed RSV infection. Peripheral eosinophil counts, levels of s-ECP, and serum IgE concentrations were measured during bronchiolitis. Five years later the children were re-evaluated in regard to their respiratory symptoms (standardized questionnaires) and atopic status (specific IgE levels). We observed significantly higher s-ECP levels (P <,0.001) at enrollment in subjects who developed persistent wheezing compared to subjects who did not show late wheezing. Initial s-ECP values allowed significant and correct prediction of persistent wheezing (P <,0.001). The risk to develop respiratory symptoms was 9.73 higher for infants with s-ECP levels ,,8,,g/L than for those with s-ECP levels <8,,g/L (P <,0.0001). In conclusion, our study suggests that s-ECP levels in infants with bronchiolitis are useful in predicting the risk to develop wheezing in the subsequent 5 years. Pediatr Pulmonol. 2001; 31:419,424. © 2001 Wiley-Liss, Inc. [source] Serum regulated upon activation, normal T cell expressed and presumably secreted concentrations and eosinophils in respiratory syncytial virus infectionPEDIATRICS INTERNATIONAL, Issue 3 2006YUKIHIKO KAWASAKI Abstract Background: The aim of this study was to characterize respiratory syncytial virus (RSV) infection. To do this, the authors evaluated eosinophil counts and chemokines including regulated upon activation, normal T cell expressed and presumably secreted (RANTES) in children with RSV, adenoviral, and influenza virus infections. Methods: The authors enrolled 80 patients who had been diagnosed with acute viral respiratory infection caused by RSV, adenoviral, or influenza viruses. In total, 35 patients (Group A) had RSV infection, 18 (Group B) had adenoviral infection, and 27 (Group C) had influenza virus infection. The authors evaluated clinical manifestations, white blood cell and eosinophil counts, and serum chemokines including RANTES concentrations in the acute and recovery phases in each group. Results: In recovery phase, eosinophil counts were higher in Group A than Groups B and C. In Group A, eosinophil counts were higher in recovery phase than in the acute phase. In Group A, serum RANTES concentration was significantly higher in the recovery phase than in the acute phase (132 ± 76 pg/mL vs 52 ± 25 pg/mL, P < 0.05). Conclusion: The findings suggest that high values of RANTES in children with RSV infection may be associated with the presence of eosinophils and be an important mediator of inflammatory response. [source] The interaction of neutrophils with respiratory epithelial cells in viral infectionRESPIROLOGY, Issue 1 2000Shan-Ze Wang Abstract: Viral respiratory infection is very common. Respiratory syncytial virus (RSV) infects almost all children during the first 2 years of life. Respiratory syncytial virus is the most frequent cause of bronchiolitis, which is strongly linked with asthma. However, the pathophysiology of RSV bronchiolitis is unclear. Neutrophils are the predominant airway leucocytes in RSV bronchiolitis and other viral infections. Neutrophils and their products are likely to play an important role in viral infection. Current evidence indicates that: (i) viral infection of epithelial cells increases the production of neutrophil chemoattractants or chemokines, which induce neutrophil migration into the inflammatory sites; (ii) the expression of adhesion molecules on neutrophils and epithelial cells is up-regulated in viral infection, and neutrophil-epithelial adhesion is increased; (iii) neutrophils augment epithelial damage and detachment induced by viral infection and contribute to the pathophysiology of viral disease; (iv) neutrophil apoptosis is up-regulated in RSV infection, which may be an in vivo mechanism to limit neutrophil-induced epithelial damage; (v) inhibitors of chemokines, adhesion molecules or neutrophil proteases may be useful in prevention of neutrophil-induced epithelial damage. In conclusion, neutrophils play an important role in viral infection, and intervention to prevent neutrophil-induced epithelial damage may be a potential clinical therapy. [source] Binding and entry of respiratory syncytial virus into host cells and initiation of the innate immune responseCELLULAR MICROBIOLOGY, Issue 10 2003James Harris Summary Respiratory syncytial virus (RSV) is the most common cause of severe lower respiratory tract infection in infants and the elderly. There is currently no effective antiviral treatment for the infection, but advances in our understanding of RSV uptake, especially the role of surfactant proteins, the attachment protein G and the fusion protein F, as well as the post-binding events, have revealed potential targets for new therapies and vaccine development. RSV infection triggers an intense inflammatory response, mediated initially by the infected airway epithelial cells and antigen-presenting cells. Humoral and cell-mediated immune responses are important in controlling the extent of infection and promoting viral clearance. The initial innate immune response may play a critical role by influencing the subsequent adaptive response generated. This review summarizes our current understanding of RSV binding and uptake in mammalian cells and how these initial interactions influence the subsequent innate immune response generated. [source] Increased prevalence of otitis media following respiratory syncytial virus infectionACTA PAEDIATRICA, Issue 6 2010S Kristjánsson Abstract Aim:, The aim of this study was to analyse whether, during the 18 months following a respiratory syncytial virus (RSV) infection in infants, there were differences in the prevalence of common infections such as acute otitis media (AOM), compared with controls. We also wanted to see whether passive smoking could be a contributory factor. Methods:, In a longitudinal study, 33 children who attended the emergency room with an RSV infection (age ,7 months) were compared with 37 age-matched controls recruited from routine infant check-ups. The 18-month follow-up consisted of a questionnaire focusing on environmental factors and the child's health during the last 12 months. An allergy skin prick test (SPT) was performed and venous blood was obtained. Results:, The prevalence of AOM and the use of antibiotics were higher in the RSV group than in the controls (p = 0.009 and p = 0.027 respectively). The number of AOMs and the use of antibiotics correlated, r = 0.8. In the RSV group, one or both parents smoked in 52% compared with 14% in the controls (p < 0.001). There were no differences in allergy SPT results. Conclusion:, The infants with RSV infection had AOM and were prescribed antibiotics more frequently during the follow-up period. Furthermore, smoking was far more common among the parents of the RSV group. We speculate that passive smoking could be a contributory factor to the infections noted here. [source] Detection of new respiratory viruses in hospitalized infants with bronchiolitis: a three-year prospective studyACTA PAEDIATRICA, Issue 6 2010C Calvo Abstract Aim:, We have designed a study with the objective of describing the clinical impact of other viruses different from the respiratory syncytial virus (RSV) in hospitalized infants with bronchiolitis. Methods:, A 3 year prospective study was conducted on infants admitted to the Paediatrics Department of the Severo Ochoa Hospital (Spain). We studied the frequency of 16 respiratory viruses. Clinical characteristics of RSV-only infections were compared with other single agent viral infections. Results:, Positive results were confirmed in 275 (86.5%) of the 318 children studied. A single virus was detected in 196 patients and 79 were dual or multiple viral infections. RSV was detected in 61.3% of total bronchiolitis. Rhinovirus (RV) was 17.4% of the identified virus, followed by human bocavirus (HBoV), adenovirus and metapneumovirus (hMPV). Only RV, HBoV and hMPV were significant as single infections. RSV patients were younger than HBoV (p > 0.0001) and hMPV (p = 0.025). Seasonality was clearly different between them. Children with RSV infection needed treatment in the intensive care unit more frequently than others. Conclusions:, In hospitalized infants, RSV was the most frequent agent in bronchiolitis in winter, but other viruses were present in 47% of the patients. RV, HBoV and hMPV had a significant proportion of single infections. Clinical characteristics were similar amongst them, but seasonality was clearly different. [source] Influence of viral infection on the development of nasal hypersensitivityCLINICAL & EXPERIMENTAL ALLERGY, Issue 5 2005Y. Okamoto Summary Background The underlying relationship between viral infections and allergic diseases of the upper respiratory tract has not been well clarified. Methods In order to clarify the relationship between viral infection and nasal hypersensitivity, mice were sensitized with ovalbumin (OVA) and then infected intranasally with respiratory syncytial virus (RSV), after which their nasal sensitivity to histamine or antigen was examined. Results Non-sensitized mice showed transient mild nasal hypersensitivity following nasal administration of histamine after intranasal RSV inoculation. In mice sensitized with OVA, RSV infection significantly exaggerated their nasal hypersensitivity to histamine and OVA. Treatment of these mice with a neurokinin (NK)-1/NK-2 receptor antagonist, but not with anti-IL-5 antibodies, reduced their hypersensitivity. The infiltration of nasal mucosa with eosinophils was temporarily associated with accelerated rate of RSV elimination in these animals. Conclusion RSV infection induced transient nasal hypersensitivity. Several mechanisms, including impairment of nasal epithelial cells are thought to mediate this effect. In allergen-sensitized mice, RSV inoculation strongly enhanced nasal hypersensitivity. [source] Serum concentrations of interferon-, and intercellular adhesion molecule-1 eight years after an early respiratory syncytial virus infectionCLINICAL & EXPERIMENTAL ALLERGY, Issue 1 2005H. Juntti Summary Background Respiratory syncytial virus (RSV) infection may influence the development of recurrent wheezing and atopy, but the mechanisms are unclear. Objective The purpose was to evaluate serum concentrations of soluble intercellular adhesion molecule-1 (sICAM-1), CD14, IgE, IL-5 and IFN-, in children 6,10 years after an RSV infection and their correlation with subsequent asthma and atopy. Methods Fifty-one subjects admitted to hospital for RSV infection during the first year of life and controls matched for birth date and sex underwent clinical examinations including lung function, skin prick and blood tests. Results The RSV subjects had significantly higher serum concentrations of IFN-, and sICAM-1 than the controls (for IFN-, 224.9 pg/mL (standard deviation (SD) 271.3) vs. 187.1 pg/mL (372.9), difference 37.8 pg/mL, 95% confidence interval (CI) ,90.3 to 166.0, P=0.05; for sICAM-1 170.2 ng/mL (SD 63) vs. 147.8 ng/mL (SD 57), difference 22.4 ng/mL, 95% CI ,1.4 to 46.1, P=0.04). The RSV subjects with asthma had significantly higher concentrations of IFN-, than the controls with asthma, and the RSV subjects with wheezing during the previous 12 months had significantly higher concentrations of both IFN-, and sICAM-1 than the controls with wheezing. Conclusions Children hospitalized for RSV infection in infancy still differ in IFN-, and sICAM-1 production 6,10 years after the infection. The data suggest that the pathomechanism of asthma and wheezing after an early RSV infection may be different from that of children without an early RSV infection. [source] Differentiation and immune function of human dendritic cells following infection by respiratory syncytial virusCLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2006A. Jones Summary RSV causes annual epidemics of bronchiolitis in winter months resulting in the hospitalization of many infants and the elderly. Dendritic cells (DCs) play a pivotal role in coordinating immune responses to infection and some viruses skew, or subvert, the immune functions of DCs. RSV infection of DCs could alter their function and this could explain why protection after natural RSV infection is incomplete and of short duration. In this study, this interaction between DCs and RSV was investigated using a human primary culture model. DCs were generated from purified healthy adult volunteer peripheral blood monocytes. Effects of RSV upon DC phenotype with RSV primed DCs was measured using flow cytometry. Changes to viability and proliferation of cocultured DCs and T-cells were determined using microscopy with fluorescent dyes (Hoechst 33342 and propidium iodide). DC maturation was not prevented by the RSV challenge. RSV infected a fraction of DCs (10,30%) but the virus replicated slowly in these cells with only small reduction to cell viability. DCs challenged with RSV stimulated T-cell proliferation less well than lipopolysaccharide. This is the first study to demonstrate RSV infection of human monocyte derived DCs and suggests that the virus does not significantly interfere with the function of these cells and potentially may promote cellular rather than humoral responses. [source] Respiratory syncytial virus and neutrophil activationCLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2005E. L. Bataki Summary Respiratory syncytial virus infects almost all children by 2 years of age. Neutrophils are the predominant airway leucocytes in RSV bronchiolitis and they are activated in the presence of infection. However it is not clear whether RSV can directly signal to activate neutrophil cytotoxic function. To investigate this we have used a preparation of RSV washed using a new centrifugal diafiltration method to rapidly remove inflammatory molecules produced by the epithelial cells used to propagate the RSV stock. Human neutrophils were isolated from peripheral blood and activated with either the unwashed crude RSV preparations or the purified intact RSV. Neutrophils were also challenged with purified RSV G-glycoprotein. The effect of challenging human neutrophils with these preparations of intact RSV, or the RSV G-glycoprotein, was assessed by measuring the cell surface expression of CD11b and CD18b, the phagocytic oxidative burst, and intracellular release of calcium pools. Neutrophils challenged with the washed RSV exhibited significantly lower activation of surface marker expression (P < 0·001) and oxidative burst (P < 0·001) than those challenged with unwashed virus or with virus free supernatant. There was no increase in intracellular calcium release on exposure to the washed RSV. Purified G glycoprotein did not stimulate neutrophils, whilst the use of a blocking antibody to the F protein did not prevent unwashed RSV from activating cytotoxic responses. These results suggest that neutrophils have no innate signalling system that recognizes RSV but they are activated at sites of RSV infection as a result of the cytokines and inflammatory molecules released by virally infected cells. [source] Efficient generation of respiratory syncytial virus (RSV)-neutralizing human MoAbs via human peripheral blood lymphocyte (hu-PBL)-SCID mice and scFv phage display librariesCLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 1 2000H. Nguyen RSV is one of the major causes of pneumonia and bronchiolitis in infants and young children and is associated with high mortality. RSV neutralizing human antibody (hu-Ab) is known to mediate resistance to viral infection as well as to be an effective treatment for severe lower respiratory tract RSV infection. We have previously demonstrated that human primary and secondary immune responses can be established in severe combined immunodeficient mice engrafted with human peripheral blood lymphocytes (hu-PBL-SCID). By combining this animal model with the single-chain Fv antibody (scFv) phage display library technique, we were able to investigate further its clinical potential by generating a panel of human scFvs that exhibit both high F glycoprotein (RSV-F) binding affinities (,108 M,1) and strong neutralizing activities against RSV infection in vitro. Sequencing analysis of the randomly isolated anti-RSV-F scFv clones revealed that they were derived from different VH families with mutations in the complementarity-determining region 1 (CDR1). The results suggest that: (i) RSV-F-specific human immune responses and affinity maturation can be induced in hu-PBL-SCID mice; and (ii) this approach can be applied to generate large numbers of human scFvs with therapeutic potential. Despite the fact that hu-PBL-SCID mouse and human scFv phage display library have individually been established, our approach contributes a simple and significant step toward the generalization of antigen-specific human monoclonal antibody (hu-MoAb) production and their clinical applications. [source] Characteristics of respiratory syncytial virus-related apnoea in three infantsACTA PAEDIATRICA, Issue 6 2004M Rayyan Apnoea is a common sign in respiratory syncytial virus (RSV) infections in young infants and can be the first presentation of an acquired RSV infection. We describe polysomnographic recordings of three infants revealing prolonged RSV-related apnoea before RSV infection was diagnosed. The apnoeas were of central origin. The caregivers had not noted any apparent life-threatening events (ALTE) prior to the polysomnography. Cardiorespiratory monitoring after the acute infection did not reveal any further apnoeas. Conclusion: Central, prolonged apnoea can be the first sign of an acquired RSV infection in young infants in the absence of other respiratory symptoms and without any previous observation of apnoea by the caregivers. [source] | |||||||||||||||||||||||||||||||