Electronic-Cigarette Use Alters Nasal Mucosal Immune Response to Live-attenuated Influenza Virus. A Clinical Trial.

Inhalation of tobacco smoke has been linked to increased risk of viral infection, such as influenza. Inhalation of electronic-cigarette (e-cigarette) aerosol has also recently been linked to immune suppression within the respiratory tract, specifically the nasal mucosa. We propose that changes in the nasal mucosal immune response modify antiviral host-defense responses in e-cigarette users. Nonsmokers, cigarette smokers, and e-cigarette users were inoculated with live-attenuated influenza virus (LAIV) to safely examine the innate immune response to influenza infection. Before and after LAIV inoculation, we collected nasal epithelial-lining fluid, nasal lavage fluid, nasal-scrape biopsy specimens, urine, and blood. Endpoints examined include cytokines and chemokines, influenza-specific IgA, immune-gene expression, and markers of viral load. Statistical analysis included primary comparisons of cigarette and e-cigarette groups with nonsmokers, as well as secondary analysis of demographic factors as potential modifiers. Markers of viral load did not differ among the three groups. Nasal-lavage-fluid anti-LAIV IgA levels increased in nonsmokers after LAIV inoculation but did not increase in e-cigarette users and cigarette smokers. LAIV-induced gene-expression changes in nasal biopsy specimens differed in cigarette smokers and e-cigarette users as compared with nonsmokers, with a greater number of genes changed in e-cigarette users, mostly resulting in decreased expression. The top downregulated genes in cigarette smokers were SMPD3, NOS2A, and KLRB1, and the top downregulated genes in e-cigarette users were MR1, NT5E, and HRAS. Similarly, LAIV-induced cytokine levels in nasal epithelial-lining fluid differed among the three groups, including decreased antiviral host-defense mediators (IFNγ, IL6, and IL12p40). We also detected that sex interacted with tobacco-product exposure to modify LAIV-induced immune-gene expression. Our results demonstrate that e-cigarette use altered nasal LAIV-induced immune responses, including gene expression, cytokine and chemokine release, and LAIV-specific IgA levels. Together, these data suggest that e-cigarette use induces changes in the nasal mucosa that are consistent with the potential for altered respiratory antiviral host-defense function.Clinical trial registered with www.clinicaltrials.gov (NCT02019745).

A novel and non-invasive approach utilising nasal washings for the detection of nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is an epithelial cancer of the nasopharynx which is highly associated with Epstein-Barr virus (EBV). Worldwide, most of the top 20 countries with the highest incidence and mortality rates of NPC are low- and middle-income countries. Many studies had demonstrated that EBV could be detected in the tissue, serum and plasma of NPC patients. In this study, we explored the potential of assays based on non-invasive nasal washings (NW) as a diagnostic and prognostic tool for NPC. A total of 128 patients were evaluated for NW EBV DNA loads and a subset of these samples were also tested for 27 EBV and human miRNAs shortlisted from literature. EBV DNA and seven miRNAs showed area under the receiver operating characteristic curve (AUC) values of more than 0.7, suggestive of their potential utility to detect NPC. Logistic regression analyses suggested that combination of two NW assays that test for EBNA-1 and hsa-miR-21 had the best performance in detecting NPC. The trend of NW EBV DNA load matched with clinical outcome of 71.4% (10 out of 14) NPC patients being followed-up. In summary, the non-invasive NW testing panel may be particularly useful for NPC screening in remote areas where healthcare facilities and otolaryngologists are lacking, and may encourage frequent testing of individuals in the high risk groups who are reluctant to have their blood tested. However, further validation in an independent cohort is required to strengthen the utility of this testing panel as a non-invasive detection tool for NPC.

Effect of probiotic on innate inflammatory response and viral shedding in experimental rhinovirus infection - a randomised controlled trial.

Ingestion of probiotics appears to have modest effects on the incidence of viral respiratory infection. The mechanism of these effects is not clear; however, there is evidence from animal models that the probiotic may have an effect on innate immune responses to pathogens. The purpose of this randomised, placebo-controlled study was to determine the effect of administration of Bifidobacterium animalis subspecies lactis Bl-04 on innate and adaptive host responses to experimental rhinovirus challenge. The effect on the response of chemokine (C-X-C motif) ligand 8 (CXCL8) to rhinovirus infection was defined as the primary endpoint for the study. 152 seronegative volunteers who had been supplemented for 28 days, 73 with probiotic and 79 with placebo, were challenged with RV-A39. Supplement or placebo administration was then continued for five days during collection of specimens for assessment of host response, infection, and symptoms. 58 probiotic and 57 placebo-supplemented volunteers met protocol-defined criteria for analysis. Probiotic resulted in higher nasal lavage CXCL8 on day 0 prior to virus challenge (90 vs 58 pg/ml, respectively, P=0.04, ANCOVA). The CXCL8 response to rhinovirus infection in nasal lavage was significantly reduced in the probiotic treated group (P=0.03, ANCOVA). Probiotic was also associated with a reduction in nasal lavage virus titre and the proportion of subjects shedding virus in nasal secretions (76% in the probiotic group, 91% in the placebo group, P=0.04, Fisher Exact test). The administration of probiotic did not influence lower respiratory inflammation (assessed by exhaled nitric oxide), subjective symptom scores, or infection rate. This study demonstrates that ingestion of Bl-04 may have an effect on the baseline state of innate immunity in the nose and on the subsequent response of the human host to rhinovirus infection. Clinicaltrials.gov registry number: NCT01669603.

Clinical outcomes associated with respiratory virus detection before allogeneic hematopoietic stem cell transplant.

BACKGROUND: The management of respiratory virus infections prior to hematopoietic cell transplant (HCT) is difficult. We examined whether respiratory virus detection before HCT influenced the requirement for bronchoscopy, hospitalization, and overall survival following HCT. METHODS: Pre-HCT and weekly post-HCT nasal washes were collected through day 100 from patients with and without symptoms. Samples were tested by multiplex polymerase chain reaction for respiratory syncytial virus, parainfluenza viruses 1-4, influenza A and B, human metapneumovirus, adenovirus, and human rhinoviruses, coronaviruses, and bocavirus. RESULTS: Of 458 patients, 116 (25%) had respiratory viruses detected pre-HCT. Overall, patients with viruses detected pre-HCT had fewer days alive and out of the hospital and lower survival at day 100 (adjusted hazard ratio [aHR], 2.4; 95% confidence interval [CI], 1.3-4.5; P = .007) than patients with negative samples; this risk was also present with rhinovirus alone (aHR for mortality, 2.6; 95% CI, 1.2-5.5; P = .01). No difference in bronchoscopy incidence was seen in patients with and without respiratory viruses (aHR, 1.3; 95% CI, .8-2.0; P = .32). In symptomatic patients, those with respiratory viruses detected had increased overall mortality compared with patients without viruses detected (unadjusted HR, 3.5; 95% CI, 1.0-12.1; P = .05); among asymptomatic patients, detection of respiratory viruses was not associated with increased mortality. CONCLUSIONS: These data support routine testing for respiratory viruses among symptomatic patients before HCT, and delay of transplant with virus detection when feasible, even for detection of rhinovirus alone. Further study is needed to address whether asymptomatic patients should undergo screening for respiratory virus detection before HCT.

Association between respiratory viruses and exacerbation of COPD: a case-control study.

BACKGROUND: Respiratory viral infection is the main cause of exacerbations of chronic obstructive pulmonary disease (COPD) in all age groups. The present study aimed to find out the association between viral infection in exacerbated and stable patients with COPD as well as evaluating the frequency of respiratory viruses in the Iranian exacerbated patients. METHODS: The study included 170 patients as the sample group with acute exacerbations and a control group consisting of 96 stable patients over a period of 3 years. Reverse transcription- nested polymerase chain reaction (RT-nested PCR) and nested PCR methods were used to diagnose the presence of 16 respiratory viruses. RESULTS: Viral infection was detected in 81 (47.6%) exacerbations and 24 (25%) stable patients (p < 0.05). Adenovirus was more frequent among the exacerbated patients than the stable patients (p < 0.05). Furthermore, influenza virus, respiratory syncytial virus, and enterovirus turned out to be the most common viruses in both groups. Moreover, respiratory viral co-infection has a possible role in exacerbation, severity, and longer hospitalization. Muscle pain and fever were found as significant symptoms in the infected patients with exacerbations. CONCLUSIONS: The current study investigated the probable roles of the respiratory viruses, and dual infections during acute exacerbations of COPD. Since climate-dependent respiratory viral incidence patterns in Iran are often dissimilar, preparing a comprehensive global model of respiratory infections with seasonal details in different geographical zones might decrease the morbidity and mortality rate in exacerbations of COPD.

Epidemiological aspects of influenza A related to climatic conditions during and after a pandemic period in the city of Salvador, Northeastern Brazil.

During the influenza pandemic of 2009, the A(H1N1)pdm09, A/H3N2 seasonal and influenza B viruses were observed to be co-circulating with other respiratory viruses. To observe the epidemiological pattern of the influenza virus between May 2009-August 2011, 467 nasopharyngeal aspirates were collected from children less than five years of age in the city of Salvador. In addition, data on weather conditions were obtained. Indirect immunofluorescence, real-time transcription reverse polymerase chain reaction (RT-PCR), and sequencing assays were performed for influenza virus detection. Of all 467 samples, 34 (7%) specimens were positive for influenza A and of these, viral characterisation identified Flu A/H3N2 in 25/34 (74%) and A(H1N1)pdm09 in 9/34 (26%). Influenza B accounted for a small proportion (0.8%) and the other respiratory viruses for 27.2% (127/467). No deaths were registered and no pattern of seasonality or expected climatic conditions could be established. These observations are important for predicting the evolution of epidemics and in implementing future anti-pandemic measures.

Epidemiological aspects of influenza A related to climatic conditions during and after a pandemic period in the city of Salvador, northeastern Brazil

During the influenza pandemic of 2009, the A(H1N1)pdm09, A/H3N2 seasonal and influenza B viruses were observed to be co-circulating with other respiratory viruses. To observe the epidemiological pattern of the influenza virus between May 2009-August 2011, 467 nasopharyngeal aspirates were collected from children less than five years of age in the city of Salvador. In addition, data on weather conditions were obtained. Indirect immunofluorescence, real-time transcription reverse polymerase chain reaction (RT-PCR), and sequencing assays were performed for influenza virus detection. Of all 467 samples, 34 (7%) specimens were positive for influenza A and of these, viral characterisation identified Flu A/H3N2 in 25/34 (74%) and A(H1N1)pdm09 in 9/34 (26%). Influenza B accounted for a small proportion (0.8%) and the other respiratory viruses for 27.2% (127/467). No deaths were registered and no pattern of seasonality or expected climatic conditions could be established. These observations are important for predicting the evolution of epidemics and in implementing future anti-pandemic measures.

Influenza A/H1N1 in pediatric oncology patients.

BACKGROUND: Our aim was to determine the clinical and epidemiological features of pandemic influenza A/H1N1 in immunocompromised children with solid tumors and hematological malignancies. PATIENTS AND METHODS: A prospective study was conducted during the H1N1 pandemic between August 2009 and February 2010 in a pediatric hematology-oncology unit. Demographic and clinical data were obtained from all children with suspected H1N1 infection (high fever with or without respiratory symptoms). Laboratory diagnosis of influenza A/H1N1 was performed by means of polymerase chain reaction analysis of nasopharyngeal wash specimens. RESULTS: We identified 57 episodes of suspected influenza A/H1N1 infection in 40 children. In all episodes, children were treated with oseltamivir and antibiotics until influenza A/H1N1 results were received. Of all episodes, 13 (22.8%) tested positive for influenza A/H1N1. Two of the H1N1-positive children (15.4%) had been previously immunized against influenza A/H1N1. No differences between H1N1-positive and H1N1-negative children were noted in terms of demographic features, clinical presentation, laboratory findings, and underlying disease.Three polymerase chain reaction-positive (23.0%) children and 1 H1N1-negative (2.3%) child were admitted to the pediatric intensive care unit and were mechanically ventilated (P=0.03). One (7.7%) H1N1-positive patient died versus none of the H1N1-negative patients (P=0.2). The condition of all other children in both the groups improved rapidly during hospitalization. CONCLUSIONS: Febrile hospitalized pediatric oncology patients, with and without pandemic influenza A/H1N1, had a similar demographic and clinical presentation with a relatively good outcome. This was probably because of early antiviral treatment and possibly because of the relatively low virulence of the virus. Immunization should be encouraged in these patients.

High rates of detection of respiratory viruses in the nasal washes and mucosae of patients with chronic rhinosinusitis.

Respiratory viral infections are often implicated as triggers of chronic rhinosinusitis (CRS) flare-ups. However, there is a paucity of respiratory viral surveillance studies in CRS patients, and such studies could elucidate the potential role of viruses in promoting symptoms and aggravating mucosal inflammation. Therefore, a prospective case-control study was conducted to determine the prevalence of respiratory viruses in CRS patients and non-CRS controls. Nasal lavage fluids and turbinate epithelial cells were collected prospectively from 111 CRS patients and 50 controls. Multiplex PCR was used to identify common respiratory viruses in both sample types and the infection rate was compared between groups. Respiratory viruses were detected in 50.5% of lavage samples and in 64.0% of scraping samples from CRS patients. The overall infection rate was significantly different in CRS patients and controls (odds ratio, 2.9 in lavage and 4.1 in scraping samples). Multiple viral infections were detected more frequently in lavage samples from CRS patients than those from controls (P < 0.01; odds ratio, 7.7). Rhinovirus was the most prevalent virus and the only virus with a significantly different infection rate in CRS patients and controls in both samples (odds ratio, 3.2 in lavage and 3.4 in scraping samples). This study detected a higher prevalence of respiratory viruses in CRS patients than controls, suggesting that there may be significant associations between inflammation of CRS and respiratory viruses, particularly rhinovirus. Further studies should investigate the exact role of highly prevalent respiratory viruses in CRS patients during symptomatic aggravation and ongoing mucosal inflammation.

An outbreak of respiratory syncytial virus infection in hematopoietic stem cell transplantation outpatients: good outcome without specific antiviral treatment.

BACKGROUND: Respiratory syncytial virus (RSV) is a common cause of seasonal respiratory viral infection in hematopoietic stem cell transplantations (HSCT) patients. The efficacy of treatment, however, remains controversial. We describe an outbreak of 31 cases of RSV that occurred in an HSCT outpatient care unit in the fall season from March through May 2010, with a good outcome without any specific antiviral treatment. METHODS: During these 3 months, 222 nasal wash samples were tested and, of these, 31 outpatients were positive for RSV. In 2009, 99 samples had been tested and only 10 outpatients were positive for RSV in the same period. RESULTS: Seven (22.5%) patients had severe neutropenia (<500 cells/µL); severe lymphopenia (<200 cells/µL) was present in 13 (41.9%) patients, and 14 (45%) had received intravenous broad-spectrum antibiotics. Hospitalization was necessary only for 8 patients (25.8%); 20 had lower respiratory tract infection (64.5%). Only 1 patient died as a result of proven invasive aspergillosis. CONCLUSION: This report suggests that HSCT outpatients with no risk factors may not always require specific treatment for RSV.

Nasal lavage natural killer cell function is suppressed in smokers after live attenuated influenza virus.

BACKGROUND: Modified function of immune cells in nasal secretions may play a role in the enhanced susceptibility to respiratory viruses that is seen in smokers. Innate immune cells in nasal secretions have largely been characterized by cellular differentials using morphologic criteria alone, which have successfully identified neutrophils as a significant cell population within nasal lavage fluid (NLF) cells. However, flow cytometry may be a superior method to fully characterize NLF immune cells. We therefore characterized immune cells in NLF by flow cytometry, determined the effects of live attenuated influenza virus (LAIV) on NLF and peripheral blood immune cells, and compared responses in samples obtained from smokers and nonsmokers. METHODS: In a prospective observational study, we characterized immune cells in NLF of nonsmokers at baseline using flow cytometry and immunohistochemistry. Nonsmokers and smokers were inoculated with LAIV on day 0 and serial nasal lavages were collected on days 1-4 and day 9 post-LAIV. LAIV-induced changes of NLF cells were characterized using flow cytometry. Cell-free NLF was analyzed for immune mediators by bioassay. Peripheral blood natural killer (NK) cells from nonsmokers and smokers at baseline were stimulated in vitro with LAIV followed by flow cytometric and mediator analyses. RESULTS: CD45(+)CD56(-)CD16(+) neutrophils and CD45(+)CD56(+) NK cells comprised median 4.62% (range 0.33-14.52) and 23.27% (18.29-33.97), respectively, of non-squamous NLF cells in nonsmokers at baseline. LAIV did not induce changes in total NK cell or neutrophil percentages in either nonsmokers or smokers. Following LAIV inoculation, CD16(+) NK cell percentages and granzyme B levels increased in nonsmokers, and these effects were suppressed in smokers. LAIV inoculation enhanced expression of activating receptor NKG2D and chemokine receptor CXCR3 on peripheral blood NK cells from both nonsmokers and smokers in vitro but did not induce changes in CD16(+) NK cells or granzyme B activity in either group. CONCLUSIONS: These data are the first to identify NK cells as a major immune cell type in the NLF cell population and demonstrate that mucosal NK cell cytotoxic function is suppressed in smokers following LAIV. Altered NK cell function in smokers suggests a potential mechanism that may enhance susceptibility to respiratory viruses.

Differential effects of corticosteroids on serum eosinophil cationic protein and cytokine production in rhinovirus- and respiratory syncytial virus-induced acute exacerbation of childhood asthma.

BACKGROUND: Little information is available on eosinophil activation and the cytokine profile in virus-induced acute exacerbation of bronchial asthma; therefore, we examined the effects of treatments that included systemic corticosteroids on serum eosinophil cationic protein (ECP) and 17 cytokines/chemokines in rhinovirus- and respiratory syncytial (RS) virus-induced acute exacerbation of childhood asthma. METHODS: We measured the peripheral eosinophil count, as well as the serum levels of ECP and 17 types of cytokines/chemokines (IL-1ß, 2, 4, 5, 6, 7, 8, 10, 12, 13, and 17 and IFN-γ, TNF-α, GM-CSF, G-CSF, MCP-1, and MIP-1ß), using a multiplex bead-based assay in 21 cases of rhinovirus- and 12 cases of RS virus-induced acute exacerbation of childhood asthma and 13 controls. We also compared the clinical data and the effects of systemic corticosteroids on these responses between rhinovirus and RS virus groups. RESULTS: The serum levels of ECP, IL-5, and IL-6 were significantly elevated in patients with rhinovirus-induced acute exacerbation of asthma compared with controls, while serum IL-1ß and IFN-γ were significantly lower in patients with rhinovirus-induced acute exacerbation of asthma than in controls. On the other hand, in RS virus-induced acute exacerbation of asthma, only the peripheral eosinophil count was significantly decreased compared with that in rhinovirus-induced acute exacerbation of asthma and controls. Furthermore, the serum levels of ECP, IL-5, and IL-6 in rhinovirus-induced acute exacerbation of asthma and levels of G-CSF in RS virus-induced acute exacerbation of asthma were significantly reduced after treatments that included systemic corticosteroids, respectively. CONCLUSION: These results suggest that the effects of systemic corticosteroids on serum ECP and the cytokine profile are different between rhinovirus- and RS virus-induced acute exacerbation of childhood asthma.

Acute respiratory infection and influenza-like illness viral etiologies in Brazilian adults.

Influenza-like illness (ILI) definitions have been used worldwide for influenza surveillance. These different case definitions can vary with regard to sensitivity and predictive values for laboratory confirmed influenza. The literature has indicated the inclusion of other viruses may be the cause of these variable results. The objective of the study was to evaluate ILI national sentinel criteria and viral etiologies in adults diagnosed with acute respiratory infection (ARI) and/or ILI from 2001 to 2003 in Sao Paulo, Brazil. Clinical and laboratory evaluations were observed from 420 adults and collected on a daily basis from outpatient care units at University Hospital. The ILI definition included: fever plus at least one respiratory symptom (cough and/or sore throat) and one constitutional symptom (headache, malaise, myalgia, sweat or chills, or fatigue). DFA and RT-PCR for influenza, parainfluenza, respiratory syncytial virus, adenovirus, enterovirus, coronavirus, rhinovirus, and metapneumovirus were performed on nasal washes and 61.8% resulted positive. The respiratory viruses detected most often were influenza and rhinovirus. ILI was reported for 240/420 patients (57.1%), with influenza and rhinovirus etiologies accounting for 30.9% and 19.6%, respectively. Rhinovirus peak activity was concurrent with the influenza season. These findings highlight the implications of other viruses in ILI etiology and suggest that during the influenza season, this clinical overlap must be considered in the diagnosis and clinical management of patients.

Performance of indirect immunofluorescence assay, immunochromatography assay and reverse transcription-polymerase chain reaction for detecting human respiratory syncytial virus in nasopharyngeal aspirate samples

Comparison of the use of indirect immunofluorescence assay (IFA), immunochromatography assay (ICA-BD) and reverse transcription-polymerase chain reaction (RT-PCR) for detecting human respiratory syncytial virus (HRSV) in 306 nasopharyngeal aspirates samples (NPA) was performed in order to assess their analytical performance. By comparing the results obtained using ICA-BD with those using IFA, we found relative indices of 85.0 percent for sensitivity and 91.2 percent for specificity, and the positive (PPV) and negative (NPV) predictive values were 85.0 percent and 91.2 percent, respectively. The relative indices for sensitivity and specificity as well as the PPV and NPV for RT-PCR were 98.0 percent, 89.0 percent, 84.0 percent and 99.0 percent, respectively, when compared to the results of IFA. In addition, comparison of the results of ICA-BD and those of RT-PCR yielded relative indices of 79.5 percent for sensitivity and 95.4 percent for specificity, as well as PPV and NPV of 92.9 percent and 86.0 percent, respectively. Although RT-PCR has shown the best performance, the substantial agreement between the ICA-BD and IFA results suggests that ICA-BD, also in addition to being a rapid and facile assay, could be suitable as an alternative diagnostic screening for HRSV infection in children.

Development of real-time PCR assays for detection and quantification of human bocavirus.

BACKGROUND: Human bocavirus (HBoV) is a parvovirus that has been recently detected in patients with respiratory illness. OBJECTIVES: We developed a sensitive, specific, and quantitative real-time PCR assay based on the TaqMan method for HBoV detection and quantification in respiratory specimens. STUDY DESIGN: Three individual real-time PCR assays were designed to amplify HBoV NS1, NP-1, and VP1 genes. For clinical evaluation, 506 nasal aspirates obtained from patients with acute respiratory tract infections during December 2006 to May 2007 were tested. RESULTS: Each assay had a broad dynamic range (50 x 10(7) to 5 x 10(7)copies of plasmid DNA) and high inter- and intra-assay reproducibility. The detection limit of each assay was 10 genome copies per reaction, and no crossreactivity with other major respiratory viruses or bacteria was detected. Clinical evaluation revealed that 11 (2.1%) of 506 patients diagnosed with upper respiratory tract infections, pneumonia, bronchitis, pharyngitis, or sinusitis had HBoV detected by all three assays, with viral loads ranging from 8.2 x 10(4) to 8.1 x 10(9)copies/ml of specimen. CONCLUSIONS: The three assays for HBoV diagnosis and quantification are highly sensitive, specific real-time tools for the reliable epidemiological and pathogenetic study of HBoV infection.

The epidemiology and antigenic characterization of influenza viruses isolated in Curitiba, South Brazil

Several studies conducted all over the world have reported that the influenza virus is associated with great morbidity and mortality rates. In this study, we analyzed the incidence of the influenza virus between 2000 and 2003 in Curitiba. We studied 1621 samples obtained from outpatients and hospitalized patients of both sexes and all ages. The study was conducted at the local primary care health units (outpatients) and at the tertiary care unit (hospitalized) of the General Hospital of the Federal University in the state of Paraná, Brazil. Nasopharyngeal aspirates and, eventually, bronchoalveolar lavage were assayed for the presence of viral antigens, either by indirect immunofluorescence or cell culture. Of the samples studied, 135 (8.3 percent) were positive for influenza virus, and of those, 103 (76.3 percent) were positive for type A and 32 (23.7 percent) for type B. Additionally, positive samples were analyzed by reverse transcription followed by polymerase chain reaction and subtypes H1 and H3 were identified from this group. A high incidence of positive samples was observed mainly in the months with lower temperatures. Furthermore, outpatients showed a higher incidence of influenza viruses than hospitalized patients.

Comparison of direct immunofluorescence, conventional cell culture and polymerase chain reaction techniques for detecting respiratory syncytial virus in nasopharyngeal aspirates from infants / Comparação entre imunofluorescência direta, cultura convencional de células e reação em cadeia de polimerase para detectar vírus respiratório sincicial em lavados de nasofaringe de crianças

A total of 316 samples of nasopharyngeal aspirate from infants up to two years of age with acute respiratory-tract illnesses were processed for detection of respiratory syncytial virus (RSV) using three different techniques: viral isolation, direct immunofluorescence, and PCR. Of the samples, 36 (11.4 percent) were positive for RSV, considering the three techniques. PCR was the most sensitive technique, providing positive findings in 35/316 (11.1 percent) of the samples, followed by direct immunofluorescence (25/316, 7.9 percent) and viral isolation (20/315, 6.3 percent) (p < 0.001). A sample was positive by immunofluorescence and negative by PCR, and 11 (31.4 percent) were positive only by RT-PCR. We conclude that RT-PCR is more sensitive than IF and viral isolation to detect RSV in nasopharyngeal aspirate specimens in newborn and infants.

Um total de 316 amostras de lavado de nasofaringe obtidas de crianças em acompanhamento ambulatorial com até dois anos de idade durante episódio de doença aguda do trato respiratório foram processadas para detecção do vírus sincicial respiratório (VSR) utilizando três diferentes técnicas: isolamento viral, imunofluorescência direta e reação em cadeia por polimerase (RT-PCR). Destas amostras, 36 (11,4 por cento) foram positivas para o VSR. A RT-PCR foi a técnica mais sensível, com positividade em 35 (11,1 por cento) das amostras, seguindo-se a imunofluorescência direta (25/316, 7,9 por cento) e o isolamento viral (20/315, 6,3 por cento) (p < 0,001). Uma amostra foi positiva pela imunofluorescência e negativa pela RT-PCR, e 11/36 (31,4 por cento) foram positivas somente pela RT-PCR. Concluímos que a RT-PCR é mais sensível que a imunofluorescência e o isolamento viral para detecção do VRS em amostras de aspirado de nasofaringe de recém-nascidos e lactentes.

High-throughput, sensitive, and accurate multiplex PCR-microsphere flow cytometry system for large-scale comprehensive detection of respiratory viruses.

Human respiratory viruses are a diverse group of pathogens composed of hundreds of virus strains, and this presents a major challenge for diagnostic laboratories. To efficiently detect numerous viruses in a large epidemiologic study, we developed a fast, multitarget, sensitive, and specific assay named the Respiratory MultiCode-PLx Assay (RMA). The RMA utilizes improved multiplex PCR chemistry (EraGen MultiCode-PLx technology) coupled with high-throughput microsphere flow cytometry (Luminex). Eighteen sets of virus-specific multiplex PCR primers were developed based on the conserved sequences of all available respiratory-virus sequences for eight distinct groups: human rhinovirus (HRV), respiratory syncytial virus (RSV), parainfluenza virus (PIV), influenza virus (InfV), metapneumovirus, adenovirus (Ad), coronavirus, and enterovirus. Each primer set detected 20 cDNA copies of the intended target per sample and had no reaction with 60,000 copies of human genomic DNA. The accuracy and sensitivity of the RMA for detecting respiratory viruses in human samples were tested with two sets of clinical specimens. First, 101 nasal-wash specimens that were positive for HRV, RSV, InfV, PIV, or Ad by traditional techniques were reanalyzed by RMA, and all target viruses were detected with an overall sensitivity of 94% and specificity of 99%. Second, 103 nasal-wash samples from 5-year-old children with asthma and respiratory symptoms were analyzed; RMA detected viruses in 74 specimens (71.8%) compared to only 24 (23.3%) by traditional culture and immunofluorescent-staining techniques. These results show that RMA is an accurate, sensitive, and practical test for respiratory-virus infections.

Infection-induced proinflammatory cytokines are associated with decreases in positive affect, but not increases in negative affect.

Infection commonly triggers nonspecific psychological and behavioral changes including fatigue and malaise, anhedonia, inability to concentrate, and disturbed sleep that collectively are termed "sickness behaviors". Converging evidence from several lines of research implicate the activities of proinflammatory cytokines as a cause of sickness behaviors. Here we elaborate upon the findings of previous research by examining whether infection-associated elevations in local proinflammatory cytokines are associated with increased negative mood and decreased positive mood. One hundred and eighty-nine healthy adults were experimentally exposed to rhinovirus or influenza virus during a 6-day period of quarantine. Infection, objective signs of illness, nasal IL-1beta, IL-6, and TNF-alpha, and self-reported affect were assessed at baseline and on each of the five post-challenge quarantine days. In the 153 persons who became infected following exposure to the challenge virus, daily production of IL-6, but not IL-1beta or TNF-alpha, was associated with reduced concurrent daily positive affect. One-day lagged analyses showed that daily production of all three cytokines was related to lower positive affect on the next day. All lagged associations were independent of previous-day positive affect and objective signs of illness (mucus production, mucociliary clearance function). There were no associations between cytokines and negative affect. Findings support a causal association between pathogen-induced local cytokine production and changes in positive affect over a 24-h timeline.

Detection of rhinovirus in turbinate epithelial cells of chronic sinusitis.

BACKGROUND: In contrast to the well-established association of rhinovirus (RV) with acute sinusitis, little is known about the role of RV infections in the pathogenesis of chronic sinusitis. Therefore, we assayed the nasal cavity mucosae of chronic sinusitis patients lacking signs of acute viral infection for the presence of RV. METHODS: Nasal lavage fluids and turbinate epithelial cells from 39 sinusitis patients and 27 control subjects were tested. Turbinate epithelial cells were collected using a Rhino-probe mucosal curette. Picornavirus was assayed by an initial reverse-transcription polymerase chain reaction (PCR), and picornavirus-positive samples were assayed by nested reverse-transcription PCR to detect RV. RESULTS: All lavage fluids from both groups, as well as control epithelial cells, were negative for picornavirus. In contrast, 8 of 39 (21%) epithelial cell samples from sinusitis patients were positive for picornavirus. RV-specific nested-PCR revealed that all eight of these samples were positive for RV. CONCLUSION: The detection of RV in the turbinate epithelial cells of chronic sinusitis patients suggests that RV may be important in the pathogenesis of chronic sinusitis.