Balancing precision versus cohort transcriptomic analysis of acute and recovery phase of viral bronchiolitis.

Viral infections affecting the lower respiratory tract place enormous burdens on hospitals. As neither vaccines nor antiviral agents exist for many viruses, understanding risk factors and outcomes in each patient using minimally invasive analysis, such as blood, can lead to improved health care delivery. A cohort of PAXgene RNA sequencing of infants admitted with moderate or severe acute bronchiolitis and respiratory syncytial virus were compared with case-control statistical analysis and cohort-based outlier mapping for precision transcriptomics. Patients with severe bronchiolitis had signatures connected to the immune system, interferon signaling, and cytokine signaling, with marked sex differences in XIST, RPS4Y1, KDM5D, and LINC00278 for severity. Several patients had unique secondary infections, cytokine activation, immune responses, biological pathways, and immune cell activation, highlighting the need for defining patient-level transcriptomic signatures. Balancing relative contributions of cohort-based biomarker discoveries with patient's biological responses is needed to understand the totality of mechanisms of adverse outcomes in viral bronchiolitis.

Sex differences in blood pro-oxidant status and platelet activation in children admitted with respiratory syncytial virus bronchiolitis: a pilot study.

BACKGROUND: Respiratory syncytial virus (RSV) is the most common cause of bronchiolitis in the pediatric population worldwide and an important cause of death in developing countries. It has been demonstrated that the balance between oxidant and antioxidant systems is disrupted in children with bronchiolitis and that oxidative stress contributes to the pathogenesis of this disease. Platelets play an important role in antimicrobial host defenses and contribute to pulmonary vascular repair being either targets or source of reactive oxidizing species. The main purpose of this study was to assessing sex differences in clinical characteristics and platelets activation during RSV bronchiolitis in infancy. METHODS: In this retrospective study a total of 203 patients (112 boys and 91 girls) with bronchiolitis, aged 12 months or less, admitted to the Bambino Gesù Pediatric Hospital of Rome (Italy) in the period from January to December 2017, were enrolled. Moreover, in a select group of patients (15 boys and 12 girls) with diagnosis of moderate bronchiolitis from RSV, a pilot study on oxidative stress and platelet characteristics was carried out by electron paramagnetic resonance and flow cytometry respectively. Age-matched healthy control subjects (10 boys and 10 girls) were chosen as controls. Data were analyzed using Student' T test, Chi Squared test and one-way ANOVA test. RESULTS: This study highlights the influence of sex in the clinical course of bronchiolitis. In particular we found: i) a higher incidence of bronchiolitis in boys than in girls (55% vs 45%); ii) higher C reactive protein values in girls than boys (1.11 mg/dL vs 0.92 mg/dL respectively; p < 0.05); iii) a different degree of thrombocytosis during hospitalization (mild in the girls and severe in the boys). Moreover, in selected patients we found that compared to girls with bronchiolitis, boys showed: i) higher percentage of activated platelets (8% vs 2% respectively; p < 0.05) and iii) higher number of platelets forming homotypic aggregates (2.36% vs 0.84% respectively, p < 0.05). CONCLUSION: The present study affirm that the bronchiolitis is an infection in which sex seems to act as a modulating factor only in the clinical course, influencing also the choice of the therapy should be made.

[γ-secretase inhibitor MW167 reduces the level of GATA3 in peripheral blood mononuclear cells in children with respiratory syncytial virus bronchiolitis].

Objective To study the changes of GATA3 in peripheral blood mononuclear cells (PBMCs) of children with respiratory syncytial virus (RSV) bronchiolitis after γ-secretase inhibitor (GSI) MW167 blocks Notch signaling. Methods The study enrolled 30 patients with RSV bronchiolitis and 25 normal controls. PBMCs were separated and divided into normal control group, RSV group, and MW167 treated group. The level of interleukin-4 (IL-4) in supernatant was detected by ELISA; level of GATA3 mRNA was determined by real-time fluorescent quantitative PCR; and the expressions of Notch1 intracellular domain (NICD) and GATA3 proteins were examined by Western blotting. Results Compared with RSV group, the levels of IL-4 decreased, and the levels of GATA3 mRNA, NICD and GATA3 proteins also significantly decreased in MW167 treated group. Conclusion GSI can block the Notch signaling pathway and decrease the level of GATA3.

Serum LL-37 Levels Associated With Severity of Bronchiolitis and Viral Etiology.

BACKGROUND: LL-37 is a host defense peptide with antimicrobial and immunomodulatory properties. We examined the relation of serum LL-37 levels to the severity of bronchiolitis and viral etiology. METHODS: We performed a 17-center prospective cohort study in infants hospitalized with bronchiolitis over 3 winters (2011-2014). Site teams collected clinical data, nasopharyngeal aspirates and serum. We used real-time polymerase chain reaction to test nasopharyngeal aspirates for 16 viruses. We tested serum for LL-37. Severity of bronchiolitis was defined by intensive care use and hospital length of stay. Viral etiology was defined as respiratory syncytial virus (RSV) or rhinovirus (RV), including coinfections with other viruses. RESULTS: The median age of the 1005 enrolled infants was 3 months (interquartile range, 2-6 months). After adjustment for 12 variables, LL-37 levels in the lowest quartile, compared with the highest, were associated both with intensive care use (adjusted odds ratio [aOR], 1.97; P = .01) and longer hospital stay (1.34; P < .001). In separate multivariable models, infants with LL-37 levels in the lowest 3 quartiles, compared with the highest, were more likely to have RSV (eg, aOR, 2.6 [lowest quartile]; P < .001 [all quartiles]). By contrast, infants with the lowest 3 LL-37 quartiles were less likely to have RV (eg, aOR, 0.5 [lowest quartile]; Pall quartiles ≤ .03 [all quartiles]). CONCLUSIONS: In a large multicenter study of infants hospitalized with bronchiolitis, lower levels of serum LL-37 were associated with increased severity of illness. There was also an inverse relationship between LL-37 levels and the most common virus causing bronchiolitis, RSV. These findings highlight the role of LL-37 in the pathogenesis of bronchiolitis.

Differential lower airway dendritic cell patterns may reveal distinct endotypes of RSV bronchiolitis.

RATIONALE: The pathogenesis of respiratory syncytial virus (RSV) bronchiolitis in infants remains poorly understood. Mouse models implicate pulmonary T cells in the development of RSV disease. T cell responses are initiated by dendritic cells (DCs), which accumulate in lungs of RSV-infected mice. In infants with RSV bronchiolitis, previous reports have shown that DCs are mobilised to the nasal mucosa, but data on lower airway DC responses are lacking. OBJECTIVE: To determine the presence and phenotype of DCs and associated immune cells in bronchoalveolar lavage (BAL) and peripheral blood samples from infants with RSV bronchiolitis. METHODS: Infants intubated and ventilated due to severe RSV bronchiolitis or for planned surgery (controls with healthy lungs) underwent non-bronchoscopic BAL. Immune cells in BAL and blood samples were characterised by flow cytometry and cytokines measured by Human V-Plex Pro-inflammatory Panel 1 MSD kit. MEASUREMENTS AND MAIN RESULTS: In RSV cases, BAL conventional DCs (cDCs), NK T cells, NK cells and pro-inflammatory cytokines accumulated, plasmacytoid DCs (pDCs) and T cells were present, and blood cDCs increased activation marker expression. When stratifying RSV cases by risk group, preterm and older (≥4 months) infants had fewer BAL pDCs than term born and younger (<4 months) infants, respectively. CONCLUSIONS: cDCs accumulate in the lower airways during RSV bronchiolitis, are activated systemically and may, through activation of T cells, NK T cells and NK cells, contribute to RSV-induced inflammation and disease. In addition, the small population of airway pDCs in preterm and older infants may reveal a distinct endotype of RSV bronchiolitis with weak antiviral pDC responses.

Oxygen saturation targets in infants with bronchiolitis (BIDS): a double-blind, randomised, equivalence trial.

BACKGROUND: The American Academy of Pediatrics recommends a permissive hypoxaemic target for an oxygen saturation of 90% for children with bronchiolitis, which is consistent with the WHO recommendations for targets in children with lower respiratory tract infections. No evidence exists to support this threshold. We aimed to assess whether the 90% or higher target for management of oxygen supplementation was equivalent to a normoxic 94% or higher target for infants admitted to hospital with viral bronchiolitis. METHODS: We did a parallel-group, randomised, controlled, equivalence trial of infants aged 6 weeks to 12 months of age with physician-diagnosed bronchiolitis newly admitted into eight paediatric hospital units in the UK (the Bronchiolitis of Infancy Discharge Study [BIDS]). A central computer randomly allocated (1:1) infants, in varying length blocks of four and six and without stratification, to be clipped to standard oximeters (patients treated with oxygen if pulse oxygen saturation [SpO2] <94%) or modified oximeters (displayed a measured value of 90% as 94%, therefore oxygen not given until SpO2 <90%). All parents, clinical staff, and outcome assessors were masked to allocation. The primary outcome was time to resolution of cough (prespecified equivalence limits of plus or minus 2 days) in the intention-to-treat population. This trial is registered with ISRCTN, number ISRCTN28405428. FINDINGS: Between Oct 3, and March 30, 2012, and Oct 1, and March 29, 2013, we randomly assigned 308 infants to standard oximeters and 307 infants to modified oximeters. Cough resolved by 15·0 days (median) in both groups (95% CI for difference -1 to 2) and so oxygen thresholds were equivalent. We recorded 35 serious adverse events in 32 infants in the standard care group and 25 serious adverse events in 24 infants in the modified care group. In the standard care group, eight infants transferred to a high-dependency unit, 23 were readmitted, and one had a prolonged hospital stay. In the modified care group, 12 infants were transferred to a high-dependency unit and 12 were readmitted to hospital. Recorded adverse events did not differ significantly. INTERPRETATION: Management of infants with bronchiolitis to an oxygen saturation target of 90% or higher is as safe and clinically effective as one of 94% or higher. Future research should assess the benefits and risks of different oxygen saturation targets in acute respiratory infection in older children, particularly in developing nations where resources are scarce. FUNDING: National Institute for Health Research, Health Technology Assessment programme.

Bronchiolitis of Infancy Discharge Study (BIDS): a multicentre, parallel-group, double-blind, randomised controlled, equivalence trial with economic evaluation.

BACKGROUND: There are no randomised trials of peripheral capillary oxygen saturation (SpO2) targets in acute respiratory infection. Two national guidelines recommended different targets for the management of acute viral bronchiolitis. OBJECTIVES: To compare the American Academy of Pediatrics guideline target of SpO2 ≥ 90% with the Scottish Intercollegiate Guidelines Network target of SpO2 ≥ 94%. DESIGN: A multicentre, parallel-group, double-blind, randomised controlled, equivalence trial with economic evaluation. SETTING: Eight paediatric hospital departments in the UK. PARTICIPANTS: Infants > 6 weeks and ≤ 12 months of age (corrected for prematurity) with physician-diagnosed bronchiolitis admitted to hospital from a paediatric emergency assessment area. Follow-up for 6 months by standardised telephone contacts. INTERVENTION: Infants were randomised to a target oxygen saturation of ≥ 94% (standard care) or ≥ 90% (modified care) displayed by a pulse saturation oximeter (Masimo Corporation Limited, CA, USA). ROUTINE CARE: All infants received routine care in addition to the study intervention. Infants were eligible for discharge when they exhibited a SpO2 of ≥ 94% in room air for 4 hours including a period of sleep and were also feeding adequately (≥ 75% usual volume). PRIMARY OUTCOME: A total of 615 infants were recruited, of whom 308 were allocated to the standard care group and 307 to the modified care group. The primary outcome was time to cough resolution. There was equivalence at the prespecified variance of ± 2 days [time to cough resolution: standard care group, 15 days; modified care group, 15 days; median difference 1 day (benefit modified), 95% confidence interval (CI) -1 to 2 days]. SECONDARY RESULTS: Return to adequate feeding occurred sooner in infants in the modified care group than in those in the standard care group (19.5 vs. 24.1 hours). This difference was non-equivalent [median difference 2.7 hours (95% CI -0.3 to 7.0 hours) versus prespecified ± 4 hours; post-hoc hazard ratio 1.22 (95% CI 1.04 to 1.44 (p-value = 0.015)]. Parent perspective of the time taken to return to normal was not equivalent, being 12 days in the standard care group compared with 11 days in the modified care group [median difference 1.0 day (95% CI 0.0 to 3.0 days) versus prespecified ± 2 days; post-hoc hazard ratio 1.19 (95% CI 1.00 to 1.41); p-value = 0.043]. At 28 days, SpO2 was equivalent [mean difference 0.11% (95% CI -0.35% to 0.57%), within the 1% prespecified]. The modified care group (55.6%) required oxygen less than the standard care group (73.1%), and for a shorter period (5.7 hours vs. 27.6 hours). Infants in the modified care group were fit for discharge (30.2 hours vs. 44.2 hours, hazard ratio 1.46, 95% CI 1.23 to 1.73; p-value < 0.001) and were discharged (40.9 hours vs. 50.9 hours; hazard ratio 1.28, 95% CI 1.06 to 1.50; p-value < 0.003) sooner than those in the standard care group. There were 35 serious adverse events in the standard care group, compared with 25 in the modified care group. Eight infants in the standard care group and 12 in the modified care group were admitted to a high-dependency unit. By 28 days, 23 infants had been readmitted to hospital in the standard care group and 12 infants in the modified care group. Parents of infants in the modified care group did not experience higher levels of anxiety and, by 14 days, had lost 28% fewer hours to usual activities. NHS costs were £290 lower in the modified care group than in the standard care group, with additional societal costs also being lower in the modified care group. CONCLUSIONS: Management of infants to a SpO2 target of ≥ 90% is as clinically effective as ≥ 94%, gives rise to no additional safety concerns, and appears to be cost-effective. Future work could focus on the safety and effectiveness of using intermittent oxygen saturation monitoring in secondary care, and to consider what are safe and effective oxygen saturation targets for children with bronchiolitis managed in primary care. TRIAL REGISTRATION: This trial is registered as ISRCTN28405428. FUNDING: This project was funded by the NIHR Health Technology Assessment programme. Masimo Corporation Limited, CA, USA, kindly provided oxygen saturation monitors with standard and altered algorithms.

Randomized trial to evaluate azithromycin's effects on serum and upper airway IL-8 levels and recurrent wheezing in infants with respiratory syncytial virus bronchiolitis.

BACKGROUND: Respiratory syncytial virus (RSV) bronchiolitis in infancy is a major risk factor for recurrent wheezing and asthma. Because azithromycin attenuated neutrophilic airway inflammation in a murine viral bronchiolitis model, demonstration of similar effects in human subjects might provide a strategy for the prevention of postbronchiolitis recurrent wheezing. OBJECTIVES: We sought to investigate whether azithromycin treatment during RSV bronchiolitis reduces serum and nasal lavage IL-8 levels and the occurrence of postbronchiolitis recurrent wheezing. METHOD: We performed a randomized, double-masked, placebo-controlled proof-of-concept trial in 40 otherwise healthy infants hospitalized with RSV bronchiolitis who were treated with azithromycin or placebo for 14 days. IL-8 levels were measured in nasal lavage fluid and serum on randomization, day 8, and day 15 (nasal lavage only). The occurrence of wheezing episodes was assessed monthly over the ensuing 50 weeks. RESULTS: Compared with placebo, azithromycin treatment did not reduce serum IL-8 levels at day 8 (P = .6) but resulted in a greater decrease in nasal lavage fluid IL-8 levels by day 15 (P = .03). Twenty-two percent of azithromycin-treated participants experienced at least 3 wheezing episodes compared with 50% of participants in the placebo group (P = .07). Azithromycin treatment resulted in prolonged time to the third wheezing episode (P = .048) and in fewer days with respiratory symptoms over the subsequent year in comparison with placebo (36.7 vs 70.1 days, P = .01). CONCLUSION: In this proof-of-concept study azithromycin treatment during RSV bronchiolitis reduced upper airway IL-8 levels, prolonged the time to the third wheezing episode, and reduced overall respiratory morbidity over the subsequent year.

Transcutaneous PCO2 monitoring in infants hospitalized with viral bronchiolitis.

UNLABELLED: Our objective was to assess within a feasibility study the correlation and agreement of transcutaneous carbon dioxide (PtcCO2) monitoring with venous carbon dioxide (PvCO2) in infants with bronchiolitis in the emergency room (ER) and pediatric department. Sixty infants (aged 3.6 ± 3.3 months) admitted to our ER with bronchiolitis were included. PtcCO2 measurements (SenTec Digital Monitoring System) collected prospectively were compared with simultaneous PvCO2 drawn for patient care. Analysis included 100 measurements. The correlation of PtcCO2 and PvCO2 (r = 0.71, p < 0.001) was good, and the agreement (mean difference ± standard deviation of the differences 1.9 ± 7.0 mmHg) was adequate; average PtcCO2 was slightly lower than PvCO2. Changes in PtcCO2 and PvCO2 for consecutive measurements within each patient correlated (r = 0.41, p < 0.01). The level of PtcCO2 correlated with disease severity clinical score (p < 0.001). CONCLUSIONS: PtcCO2 monitoring was feasible in the ER and pediatric department and was found to have a good correlation and adequate agreement with PvCO2 in infants with bronchiolitis. Because the standard deviation of the differences was relatively high, though comparable to the literature, we suggest that PtcCO2 should not replace blood gas but rather serve as a complementary tool for trending and for real-time continuous assessment of the CO2 levels.

Infants with viral bronchiolitis demonstrate two distinct patterns of nocturnal oxyhaemoglobin desaturation.

AIM: This study aimed to demonstrate that viral bronchiolitis is associated with intermittent oxygen saturation of haemoglobin (SpO2 ) drops (≥3%) and low basal SpO2 between episodes of haemoglobin desaturation. METHODS: Infants with bronchiolitis underwent pulse oximetry during the first night following hospital admission and a subgroup of them underwent repeat oximetry before hospital discharge. Oximetry was also performed in infants with partial upper airway obstruction (UAO) and without lung disease and in control participants without UAO or lung disease. RESULTS: We enrolled 53 infants: 21 with bronchiolitis, 11 with UAO and 21 healthy controls. Participants with bronchiolitis had lower basal SpO2 (median 93.7% [10th-90th percentiles: 91.1-96.8]) than the subjects with UAO (96.9% [95.3-98.1]; p < 0.01) or the controls (98.7% [96.9-99.3]; p < 0.01). The bronchiolitis group was not different from the UAO group regarding the desaturation index (23.3 episodes/hour [10.3-46.6] and 15.5 episodes/hour [5.4-36.4], respectively; p = 0.08), but differed significantly from the controls (3.1 episodes/hour [0.3-5.5]; p < 0.01). The basal SpO2 and desaturation index improved in 10 subjects with bronchiolitis who had follow-up oximetry before discharge, but these indices remained abnormal when compared to values in the control group. CONCLUSION: Bronchiolitis was characterised by low nocturnal basal SpO2 and intermittent SpO2 drops.

Vitamin D-binding protein haplotype is associated with hospitalization for RSV bronchiolitis.

BACKGROUND: Between 75 000 and 125 000 U.S. infants are hospitalized for respiratory syncytial virus (RSV) bronchiolitis every year. Up to half will be diagnosed with asthma in later childhood. Vitamin D deficiency has been associated with susceptibility to asthma and respiratory infections. Measured vitamin D is largely bound to vitamin D-binding protein (VDBP); VDBP levels are influenced by its gene (GC) haplotype. OBJECTIVE: We assessed the relationship between polymorphisms rs7041 and rs4588, which define haplotypes GC1s, GC1f, and GC2, and RSV bronchiolitis susceptibility and subsequent asthma. METHODS: We retrospectively recruited 198 otherwise healthy children (93% White) hospitalized for severe RSV bronchiolitis in Boston and 333 parents into a follow-up study to assess asthma diagnosis. Data were analysed using family-based genetic association tests. We independently validated our results in 465 White children hospitalized with RSV bronchiolitis and 930 White population controls from the Netherlands. RESULTS: The rs7041_C allele (denoting haplotype GC1s) was overtransmitted (P = 0.02, additive model) in the entire Boston cohort, in Whites (P = 0.03), and especially in children subsequently diagnosed with asthma (P = 0.006). The GC1f haplotype was undertransmitted in the asthma subgroups (all races and White, both P < 0.05). The rs7041_C allele was also more frequent in the RSV bronchiolitis group compared with controls (OR 1.12, 95% CI 1.02, 1.4, P = 0.03) in the Netherlands, especially in mechanically ventilated patients (P = 0.009). CONCLUSION AND CLINICAL RELEVANCE: GC1s haplotype carriage may increase the risk of RSV bronchiolitis in infancy and subsequent asthma development. The GC1s haplotype is associated with higher VDBP levels, resulting in less freely available vitamin D. KEY MESSAGES: Vitamin D-binding protein (VDBP) haplotypes influence free vitamin D levels. We report an association between a VDBP haplotype and hospitalization for RSV bronchiolitis in infancy in two independent cohorts.

[Correlation between the numbers of peripheral blood dendritic cells and the clinical manifestations in children with respiratory syncytial virus bronchiolitis].

OBJECTIVE: To detect the quantity of peripheral blood myeloid dendritic cells (mDCs) and plasmacytoid dendritic cells (pDCs) in children with bronchiolitis infected by respiratory syncytial virus (RSV) and analyze the correlation with the severity of the disease. METHODS: PCR was used to detect RSV in nasopharyngeal secretions. Flow cytometry was performed on the peripheral blood to detect the quantity of mDCs and pDCs in 71 children with bronchiolitis by RSV infection (including mild, moderate and severe infection) and 48 healthy control infants. RESULTS: The quantity of peripheral blood mDCs in the children with bronchiolitis by RSV infection was significantly higher than that of healthy controls (P<0.01), while the number of pDCs was significantly lower than that of healthy controls (P<0.01). The children with severe bronchiolitis by RSV infection had significantly lower quantity of peripheral blood mDCs and pDCs as compared with the mild group (P<0.05). CONCLUSION: The number of mDCs in peripheral blood of the children with RSV bronchiolitis significantly increased at the early stage, and in contrast pDCs were reduced. The increased number of mDCs indicates that the clinical manifestations are slighter, and the decreased number of pDCs suggests more wheezing of the children.

Eosinophil-derived neurotoxin levels at 3 months post-respiratory syncytial virus bronchiolitis are a predictive biomarker of recurrent wheezing.

OBJECTIVE: To determine whether eosinophil-derived neurotoxin (EDN) is a predictive marker of recurrent wheezing episodes in post-respiratory syncytial virus (RSV) bronchiolitis. METHODS: EDN levels and recurrent wheezing episodes were serially measured in 200 infants hospitalized with RSV bronchiolitis. RESULTS: Serum EDN levels at 3 months correlated significantly with total wheezing episodes at 12 months in the RSV-PLC (n = 71; r = 0.720, p < 0.0001) and RSV-MONT groups (n = 79; r = 0.531, p < 0.001). Positive predictive value of 3-mo EDN level for total wheezing episodes was 57%; negative predictive value, 76%; sensitivity, 72%; specificity, 62%. CONCLUSION: EDN levels have predictive value for the development of recurrent wheezing post-RSV bronchiolitis.

Antiviral effects of modified dingchuan decoction against respiratory syncytial virus infection in vitro and in an immunosuppressive mouse model.

ETHNOPHARMACOLOGICAL RELEVANCE: Modified dingchuan decoction (MDD) is used in traditional Chinese medicine for the treatment of cough, chronic bronchitis, asthma and viral pneumonia. AIM OF THE STUDY: To investigate antiviral potentials of MDD in respiratory syncytial virus (RSV) infected mice. MATERIALS AND METHODS: MDD and each component were evaluated for antiviral efficacy against RSV in vitro in cell culture. Mice were were treated with cyclophosphamide and infected with RSV. Then, treatments with MDD at doses of 1.75 g/kg, 3.5 g/kg and 7.0 g/kg, respectively, were oral administrated daily for 5 days after challenge. The levels of Eotaxin, IL-4 and IFN-γ in serum and lung tissue were detected by ELISA, viral loads in lung tissues were detected by RFQ-PCR while expressions of NF-κB and TLR4 mRNA were also detected by RFQ-PCR. RESULTS: A selective index of >36.8 (2.5 times greater than that observed for ribavirin) was determined in the in vitro studies for this herbal medicine. MDD exhibited significant antiviral and anti-inflammatory effects on decreasing levels of Eotaxin, IL-4 and IFN-γ in serum and lung tissue, inhibiting pneumonia, decreasing lung viral loads and reversaling RSV-induced inflammation through down-regulation of TLR4 and NF-κB mRNA expression in the lung tissue of RSV-infected mice. CONCLUSIONS: MDD could exhibit antiviral and anti-inflammatory effects on RSV-infected mice as a suppressor of Eotaxin, IL-4 and IFN-γ. These effects appeared to be mediated by inhibitions of TLR4 and NF-κB activation. Therefore, MDD could provide an effective therapeutic approach for RSV and its subsequent viral bronchitis.

CD4+ T-cell counts and interleukin-8 and CCL-5 plasma concentrations discriminate disease severity in children with RSV infection.

BACKGROUND: Current tools to predict the severity of respiratory syncytial virus (RSV) infection might be improved by including immunological parameters. We hypothesized that a combination of inflammatory markers would differentiate between severe and mild disease in RSV-infected children. METHODS: Blood and nasopharyngeal samples from 52 RSV-infected children were collected during acute infection and after recovery. Retrospectively, patients were categorized into three groups based on disease severity: mild (no supportive treatment), moderate (supplemental oxygen and/or nasogastric feeding), and severe (mechanical ventilation). Clinical data, number of flow-defined leukocyte subsets, and cytokine concentrations were compared. RESULTS: Children with severe RSV infection were characterized by young age; lymphocytopenia; increased interleukin (IL)-8, granulocyte colony-stimulating factor (G-CSF), and IL-6 concentrations; and decreased chemokine (C-C motif) ligand (CCL-5) concentrations in plasma. The combination of plasma levels of IL-8 and CCL-5, and CD4+ T-cell counts, with cutoff values of 67 pg/ml, 13 ng/ml, and 2.3 × 10(6)/ml, respectively, discriminated severe from mild RSV infection with 82% sensitivity and 96% specificity. CONCLUSION: This study demonstrates that the combination of CD4+ T-cell counts and IL-8 and CCL-5 plasma concentrations correlates with disease severity in RSV-infected children. In addition to clinical features, these immunological markers may be used to assess severity of RSV infection and guide clinical management.

Better newborn vitamin D status lowers RSV-associated bronchiolitis in infants.

Each year 1.5 million children under the age of 5 years die from pneumonia. In the United States, respiratory syncytial virus (RSV) is the number one cause of bronchiolitis and pneumonia in children under 1 year of age. Low serum 25(OH)D is associated with an increased risk of lower respiratory tract infections (LRTI). Two recent studies have provided important information concerning the association between cord blood 25(OH)D and subsequent risk of developing respiratory infection in very young children. These findings support the need in future studies to determine the extent to which an intervention to change the vitamin D status of mothers during pregnancy can reduce the risk of RSV-associated LRTI in their offspring. An answer to this question would have significant worldwide public health importance given the high prevalence of low vitamin D status worldwide and the high mortality burden accompanying infectious lung diseases in young children.