Efficacy and mechanisms of Traditional Chinese Medicine prevention and treatment for respiratory viruses

Respiratory virus infection was the most common viral infection in clinical practice with the greatest impact,including the Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),posing a huge threat to the world's public health and human life safety.Commonly used antiviral drugs have obvious side effects and a narrow scope of application.Respiratory viruses are susceptible to infection,mutation,and prevalence,which also pose challenges to traditional antiviral drugs and vaccine development.Traditional Chinese Medicine(TCM)has a long history of treating infectious diseases,with many herbs and compounds.Its multi-component,multi-target and multi-path characteristics have made it have great advantages and potential in the development of new anti-respiratory virus drugs.This review summarized TCM for the prevention and treatment of common respiratory viruses,and provided new strategies for the research and development of new TCM antiviral drugs and for responding to infectious respiratory virus diseases.

Antiviral Effect of Emodin from Rheum palmatum against Coxsakievirus B_5 and Human Respiratory Syncytial Virus In Vitro

Summary： Viral infections are the major causes of morbidity and mortality in elderly people and young children throughout the world. The most common pathogens include coxsackie virus （CV） and respira- tory syncytial virus （RSV）. However, no antiviral agents with low toxicity and drug resistance are cur- rently available in clinic therapy. The present study aimed to examine the antiviral activities of emodin （an ingredient of Rheum palmatum） against CVB5 and RSV infections, in an attempt to discover new antiviral agents for virus infection. The monomer emodin was extracted and isolated from Rheum pal- matum. The antiviral activities of emodin on HEp-2 cells were evaluated, including virus replication in- hibition, virucidal and anti-absorption effects, by 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyl-2H-tet- razolium bromide （MTT） assay and plaque reduction assay （PRA）. The kinetics of virus inhibition by emodin in a period of 14 h was further determined by plaque assay and quantitative real time PCR （qPCR）. Cytokine （IFN-γ, TNF-α） mRNA expressions after emodin treatment （7.5, 15, 30 μmol/L） were also assessed by qPCR post-infection. The results showed that emodin had potent inhibitory activities against CVB5 and RSV, with the 50% effective concentration （EC50） ranging from 13.06 to 14.27 μmol/L and selectivity index （SI） being 5.38-6.41 μmol/L. However, emodin couldn＇t directly inacti- vate the viruses or block their absorption to cells. It acted as a biological synthesis inhibitor against CVB4 and RSV in a concentration- and time-dependent manner, especially during the first 0-4 h post-infection. Moreover, emodin could decrease the mRNA expression of IFN-α but enhance TNF-γ expression significantly compared to the viral controls in vitro. Our results provide a molecular basis for development of emodin as a novel and safe antiviral agent for human enterovirus and respiratory virus infection in the clinical therapy.

Qingfei oral liquid downregulates TRPV1 expression to reduce airway inflammation and mucus hypersecretion injury caused by respiratory syncytial virus infection and asthma in mice

Objective:Qingfei oral liquid(QF),an experimental Chinese medicine prescription developed from the ancient priscription of traditional Chinese medicines Ma Xin Shi Gan decoction and Tingli Dazao Xie Fei decoction,has been effectively used since decades to treat patients with viral pneumonia and asthma.In our previous study,we had demonstrated that QF can significantly reduce airway hyperresponsiveness,hyperemia,lung tissue edema,inflammatory lung tissue infiltration in mice,airway mucus secretion,and peripheral airway collagen hyperplasia;however,its mechanism of action is unknown.Methods:Fifty 6–8-week-old male BALB/c mice were equally and randomly divided into five groups:the control,ovalbumin(OVA),OVA+respiratory syncytial virus(RSV),QF,and dexamethasone(Dxms)groups.The QF group was administered QF at 1.17 g·kg−1·d−1,the Dxms group received dexamethasone injections at 0.2 mg·kg−1·d−1,and the remaining groups were administered PBS.Inflammation in the lung tissue was assessed by hematoxylin and eosin(HE),periodic acid–Schiff(PAS),and Van Gieson staining.ELISA was used to evaluate the IL-13,IL-25,and IL-33 in the mice.Western blotting was used to examine changes in the proteins levels of transient receptor potential vanilloid-1(TRPV1)and mucin 5AC(MUC5AC)in the lung tissues of mice.Results:Histopathological evaluation revealed that the OVA and OVA+RSV groups exhibited lung tissue edema and inflammatory lung tissue infiltration in the HE staining and airway secretions in the PAS staining;collagen hyperplasia around the airway was increased in these two groups compared with the control group.The QF group exhibited significantly reduced lung tissue edema,inflammatory lung tissue infiltration,airway secretions,and collagen hyperplasia around the airway compared with the OVA+RSV group.We analyzed the serum levels of IL-13,IL-25,and IL-33 in the mice and found that these levels were higher in the OVA and OVA+RSV groups than in the control group(P<0.05 in the OVA group,P<0.01 in the OVA+RSV group).The QF group exhibited significantly decreased serum levels of IL-13,IL-25,and IL-33 compared with the OVA+RSV group(all P<0.05).The Dxms group also exhibited significant decreases in the serum levels of IL-13 and IL-33(all P<0.05)but no significant decrease in the serum levels of IL-25 compared with the RSV+OVA group.Finally,we examined the protein levels of TRPV1 and MUC5AC in the lung tissues of mice using Western blotting.After identifying RSV infection in the mice with asthma,the protein levels of TRPV1 and MUC5AC in the lung tissues of mice were significantly higher than those in the control group(P<0.05,P<0.01).We found that compared with RSV+OVA,QF can significantly downregulate the protein level of TRPV1;further,the protein level of MUC5AC was also significantly reduced(all P<0.001).Conclusion:QF can inhibit RSV replication and reduce airway inflammation and mucus hypersecretion injury caused by RSV infection and asthma,and its mechanism of action may be associated with the downregulation of TRPV1 expression and a decrease in airway mucus hypersecretion injury.

The Association of Respiratory Syncytial Virus Infection and Childhood Asthma: A Meta-Analysis

Objective: To explore the close relationship between respiratory syncytial virus (RSV) infection and acute attack of childhood asthma. Methods: A computer-based search of database from Pumbed, CNKI, Wanfang, Baidu Scholar, Chongqing VIP, GeenMedica was performed to screen the articles about respiratory syncytial virus infection and childhood asthma. Then the literatures were screened out by the selection criteria. The RevMan5.3 software was used to test the heterogeneity and effect values of each study, analyze the sensitivity and publication bias of the literature, and draw on Meta forest plot and Funnel plot. Results: 5 articles conformed to the selection criteria. There were totally 881 cases in the case group, 826 cases in the control group. The results of heterogeneity test showed no heterogeneity between each study (P > 0.05). The fixed-effects model showed the 6.68 (5.06 - 8.82), (Z = 13.38, P < 0.00001). Conclusion: The infection rate of respiratory syncytial virus in children with acute asthma attack is higher than that in remission period. Respiratory syncytial virus infection rate can be used as an indicator of the severity of asthma in children.

Cytokine responses in infants infected with respiratory syncytial virus

Introduction: Variability in severity of Respiratory Syncytial Virus (RSV) infection is reportedly due to differences in inflammatory response. Objective: To characterize the cytokine response in RSV+ infants aged 0 - 36 months and to relate their responses to disease severity. Methods: Nasopharyngeal aspirations (NPAs) were analyzed for RSV and IL-1β, IL-2, IL-4, IL-5, IL-6, IL-10, IL-12, IL-1RA, IL-4R, IFN-γ, sTNFR1, sTNFR2, and TNF-α. Clinical data were collected from the medical records. Results: We included 331 infants of whom 214 were RSV+. In comparison to RSV- infants, they had significantly higher levels of TNF-α, IL-6, IL-1β, and IFN-γ (p α, IL-6, and IL-1β. sTNFR1/2 were significantly increased in RSV+ infants. Hospitalized patients had significantly higher levels of TNF-α, sTNFR2, and IL-10 (p < 0.05) than non-hospitalized patients. The cytokine response could not be related to disease severity. We found no evidence of a skewed Th1/Th2 immune profile. Conclusion: In acute RSV disease, infected infants’ NPAs contain a significant amount of pro-inflammatory cytokines. Whether this response is beneficial or deleterious remains unanswered. Interpersonal variations in cytokine responses might be linked to an inherited tendency to variations in disease severity.

STUDY OF T－LYMPHOCYTE SUBSETS AND INTERLEUKIN－2 AND INTERLEUKIN－2 RECEPTOR OF RESPIRATORY SYNCYTIAL VIRUS PNEUMONIA

T-Lymphocyte subsets and humoral immune and the activity of IL-2 and IL-2R in respiratory syncytial virus (RSV) pneumonia in 26 cases were tested. The result showed in the patients with RSV pneumonia the averages of T3 and T4 were 37.56±1.46% and 27. 15±8. 02% respectively,They were significantly lower than 53.4 ±9.2% and 35.5±7.7% of averages of T3 and T4 in healthy controlled group (both. P< 0. 001 ), the average of T3 was 22. 73±7.06%, it was lower an 26. 7±6. 3 % of T8 in controlled group (P<0. 02 );the ratio of T4/T8 was 1. 245±0. 399 ,there was no significant difference from 1. 35 ±0. 17 of the ratio in controlled group (P > 0. 1). The mean value of IgG was 1. 177± 0. 3685g/L, it was significantly lower than 1. 427± 0. 498g/L of that in controlled group(P < 0. 005). The mean values of IgA and IgM were 0. 1136±0.0393g/L and 0. 768±0. 353g/L respectively, they were significantly lower than 0. 2706 ±0. 876g/L and 0. 122±0. 061g/L of IgA and IgM in controlled group. The activity of IL-2 and IL-2R were 17. 46 ±5. 79%, and 28. 32 ±5. 924% respectively, they were significantly lower than 30. 22 ±14. 55% and 39. 53±8. 61 % of those in healthy group (both P < 0. 001). The severe the pneuumonia, the greater the lowering of IL-2 and IL-2R. These about results suggested that RSV could greatly suppress the immune function of the patients, inducing secondary immunodeficiency, leading to repeated breather and asthma.

In vitro study on the antiviral activity of 9 extracts of traditional Chinese herbal medicine against the human respiratory syncytial virus

Objective:To study the in vitro virucidal activity of 9 extracts of traditional Chinese herbal medicine(the water extracts of Evodia lepta,Clausena lansium,Clerodendrum cyrtophyllum,Callicarpa nudiflora,Nauclea officinalis and Elaeagnus gonyanthes,the alcohol extracts of Nauclea officinalis,Elaeagnus gonyanthes and Zanthoxylumarmatum)on human respiratory syncytial virus(HRSV).Methods:The cytotoxic effect of the extracts on cells was evaluated by a cell viability assay using the CCK-8 method,a concentration of the extracts with cell viability greater than 50%was selected for the follow-up anti-HRSV effect assay,the 50%effective concentration(EC50)was assessed by an in vitro cell infection model.Results:The EC50s of the water extract from Clerodendrum cyrtophyllum,Callicarpa nudiflora and Elaeagnus gonyanthes were 0.05 mg/mL,0.03 mg/mL and 0.05 mg/mL,and the therapeutic index(TI)of them were 18.60,21.67 and 56.80 respectively.Conclusion:The water extracts of Clerodendrum cyrtophyllum,Callicarpa nudiflora and Elaeagnus gonyanthes possess the activity of anti-HRSV virus.

Surfactant Protein D for Pathological Evaluation of Infant Acute Respiratory Distress Syndrome Caused by Respiratory Syncytial Virus Infection

Pediatric respiratory syncytial viral infection (RS) usually shows relatively good outcome;however, when it accompanies acute respiratory distress syndrome (ARDS), this becomes fatal. We experienced three pediatric patients with RS + ARDS, with all showing good outcome with steroid pulse therapy. We wish to emphasize;1) steroid pulse therapy may become an option for this condition, and 2) plasma KL-6 and surfactant protein D levels may become a biomarker reflecting the disease progression/condition. Patients were, aged 1 month, 1 year 5 months, and 1 year 11 months. In all three, the respiratory condition deteriorated rapidly, requiring invasive ventilator management. Although the effectiveness of steroid treatment for ARDS is controversial, very severe condition prompted us to employ steroid pulse therapy, after which, oxygenation rapidly improved without adverse events. Plasma KL-6 and surfactant protein D levels were measured during exacerbations of ARDS, steroid pulse therapy, and recovery. Surfactant protein D levels were closely associated with oxygenation, suggesting this substance level might be a biomarker of ARDS caused by the disruption of the alveolar epithelial lining and to understand oxygenation without time lag.

Repurposing Antidiabetic Drugs against Respiratory Syncytial Viral Infection: A Docking Study

Respiratory Syncytial Viral Infection is one of the most common viral infections in the respiratory airways and is more common in infants, younger children and some adults. Although ribavirin has been used in the management of RSV infection, many effective drugs are still under development. Also, structured based drug design using computational tools has shifted the paradigm of drug design and discovery. The fusion core of the Respiratory Syncytial Viral (RSV) structure is crucial for its fusion, entry and replication in the host cell. Herein, we investigated the interruption of the formation and/or the stability of the fusion core. 15 ligands were screened and 4 (Glimepiride, Glipizide, Canagloflozin, Glibenclamide) of them are potential drug candidate for experimental validation, preclinical trials, clinical trials and route of administration optimization. To the best of our knowledge, this is the first time of reporting lead molecules against RSV from oral hypoglycemic agents. It also suggests the ligands for consideration as prophylactics in infants and adults via the inhalation route.

Genetic Characterization of Fusion Protein of Human Respiratory Syncytial Virus: Beijing

Objective Fusion protein is a subunit of the human respiratory syncytial virus(HRSV)and a potential vaccine candidate.Thus,a study on the genetic characteristics of F protein was considered important for further investigations in this field.The aim of this study was to determine the prevalence and genetic diversity of the F gene of HRSV infections in hospitalized pediatric patients in Beijing with acute lower respiratory tract infections and to compare the circulating genotypes that are currently found worldwide.Methods HRSV particles were amplified by RT-PCR and the PCR products were purified for sequencing.Further analysis was carried out by Bioedit and MEGA 3.0 biological software programs.Results Seventy-six samples(23.1%)were positive for HRSV.The percentage of cases in patients younger than 1year was 84.21%.Among the six Beijing isolates,four belonged to subgroup A,whose respective F genes shared97.0%-97.4%nucleotide sequence identity and 92.1%-93.0%amino acid sequence identity.The other two isolates belonged to subgroup B.Here,97.3%and 98.2%sequence identity were found at nucleotide and amino acid levels,respectively.Conclusions Phylogenetic analysis of nucleotide sequences revealed that those four isolates within subgroup A were monophyletic and closely related to each other,but those two within subgroup B distributed in two distinct clusters.Subgroup A and B strains co-circulated,indicating that two different transmission chains occurred in Beijing from 2003-2004.

Expert consensus on the diagnosis, treatment, and prevention of respiratory syncytial virus infections in children

Background Respiratory syncytial virus(RSV)is the leading global cause of respiratory infections and is responsible for about 3 million hospitalizations and more than 100,000 deaths annually in children younger than 5 years,representing a major global healthcare burden.There is a great unmet need for new agents and universal strategies to prevent RSV infections in early life.A multidisciplinary consensus development group comprising experts in epidemiology,infectious diseases,respiratory medicine,and methodology aims to develop the current consensus to address clinical issues of RSV infections in children.Data sources The evidence searches and reviews were conducted using electronic databases,including PubMed,Embase,Web of Science,and the Cochrane Library,using variations in terms for"respiratory syncytial virus","RSV","lower respiratory tract infection","bronchiolitis","acute","viral pneumonia","neonatal","infant""children",and"pediatric".Results Evidence-based recommendations regarding diagnosis,treatment,and prevention were proposed with a high degree of consensus.Although supportive care remains the cornerstone for the management of RSV infections,new monoclonal antibodies,vaccines,drug therapies,and viral surveillance techniques are being rolled out.Conclusions This consensus,based on international and national scientific evidence,reinforces the current recommendations and integrates the recent advances for optimal care and prevention of RSV infections.Further improvements in the management of RSV infections will require generating the highest quality of evidence through rigorously designed studies that possess little bias and sufficient capacity to identify clinically meaningful end points.

Clinical manifestations of respiratory syncytial virus infection and the risk of wheezing and recurrent wheezing illness:a systematic review and meta‑analysis

Background Respiratory syncytial virus(RSV)infection in infants is a global health priority.We aimed to investigate the common manifestations of RSV infection by age group and human development index(HDI)level and to assess its association with the development of wheezing and recurrent wheezing illness.Methods We searched the literature published between January 1,2010 and June 2,2022 in seven databases.Outcomes included common manifestations and long-term respiratory outcomes of RSV infection in children.Random-and fixed-effect models were used to estimate the effect size and their 95%confidence intervals.Subgroup analysis was conducted by age and HDI levels.This review was registered in PROSPERO(CRD42022379401).Results The meta-analysis included 47 studies.The top five manifestations were cough(92%),nasal congestion(58%),rhinorrhea(53%),shortness of breath(50%),and dyspnea(47%).The clinical symptoms were most severe in infants.In our analysis,compared to very high and high HDI countries,fewer studies in medium HDI countries reported related manifestations,and no study in low HDI countries reported that.The RSV-infected infants were more likely to develop wheezing than the non-infected infants[odds ratio(OR),3.12;95%CI,2.59–3.76]and had a higher risk of developing wheezing illnesses after recovery(OR,2.60;95%CI,2.51–2.70).Conclusions Cough and shortness of breath are common manifestations of RSV infection.More attention should be given to infants and areas with low HDI levels.The current findings confirm an association between RSV infection and wheezing or recurrent wheezing illness.

In vitro and in vivo evaluation of cerium oxide nanoparticles in respiratory syncytial virus infection

Respiratory syncytial virus(RSV)is the most common cause of viral bronchiolitis among children worldwide,yet there is no vaccine for RSV disease.This study investigates the potential of cube and sphere-shaped cerium oxide nanoparticles(CNP)to modulate reactive oxygen(ROS)and nitrogen(RNS)species and immune cell phenotypes in the presence of RSV infection in vitro and in vivo.Cube and sphere-shaped CNP were synthesized by hydrothermal and ultrasonication methods,respectively.Physico-chemical characterization confirmed the shape of sphere and cube CNP and effect of various parameters on their particle size distribution and zeta potential.In vitro results revealed that sphere and cube CNP differentially modulated ROS and RNS levels in J774 macrophages.Specifically,cube CNP significantly reduced RSV-induced ROS levels without affecting RNS levels while sphere CNP increased RSV-induced RNS levels with minimal effect on ROS levels.Cube CNP drove an M1 phenotype in RSV-infected macrophages in vitro by increasing macrophage surface expression of CD80 and CD86 with a concomitant increase in TNFαand IL-12p70,while simultaneously decreasing M2 CD206 expression.Intranasal administration of sphere and cube-CNP were well-tolerated with no observed toxicity in BALB/c mice.Notably,cube CNP preferentially accumulated in murine alveolar macrophages and induced their activation,avoiding enhanced uptake and activation of other inflammatory cells such as neutrophils,which are associated with RSV-mediated inflammation.In conclusion,we report that sphere and cube CNP modulate macrophage polarization and innate cellular responses during RSV infection.

Prevalence,variation,and transmission patterns of human respiratory syncytial virus from pediatric patients in Hubei,China during 2020–2021

Human respiratory syncytial virus(RSV)is a severe threat to children and a main cause of acute lower respiratory tract infections.Nevertheless,the intra-host evolution and inter-regional diffusion of RSV are little known.In this study,we performed a systematic surveillance in hospitalized children in Hubei during 2020–2021,in which 106 RSV-positive samples were detected both clinically and by metagenomic next generation sequencing(mNGS).RSV-A and RSV-B groups co-circulated during surveillance with RSV-B being predominant.About 46 high-quality genomes were used for further analyses.A total of 163 intra-host nucleotide variation(iSNV)sites distributed in 34 samples were detected,and glycoprotein(G)gene was the most enriched gene for iSNVs,with non-synonymous substitutions more than synonymous substitutions.Evolutionary dynamic analysis showed that the evolutionary rates of G and NS2 genes were higher,and the population size of RSV groups changed over time.We also found evidences of inter-regional diffusion from Europe and Oceania to Hubei for RSV-A and RSV-B,respectively.This study highlighted the intra-host and inter-host evolution of RSV,and provided some evi-dences for understanding the evolution of RSV.

A protective human antibody against respiratory syncytial virus by targeting a prefusion epitope across sites IV and V of the viral fusion glycoprotein

Respiratory syncytial virus(RSV)is one of the leading pathogens that cause lower respiratory tract infections in infants and the elderly.Passive immunoprophylaxis with monoclonal antibody(mAb)has been approved to prevent morbidity and mortality from RSV infection in infants.Here we report the isolation of two neutralizing mAbs against RSV from convalescent children by prefusion form of fusion(F)glycoprotein as bait.One mAb RV11 exhibited good potency in neutralization of RSV strains from both A and B subtypes in cell-based assay,and protected mice from RSV infection in vivo.An RV11 escape mutant was identified,which contains an S443P mutation in F protein.Crystal structure showed the RV11 bound to a conserved prefusion epitope across the antigenic sites IV and V of the F glycoprotein.RV11 showed a strong synergistic effect when combined with two RSV antivirals,an F-targeting small molecular inhibitor ziresovir and a siteØneutralizing mAb D25(the parental mAb for nirsevimab).The study extended our knowledge to the neutralizing and protective epitopes of RSV,and the mAb RV11 deserves further development for clinical translation.

Effects of respiratory syncytial virus infection on the airway neuronal plasticity and its relationship to the bronchial hyperresponsiveness in rats

Despite intense research efforts, the specific pathogenic mechanisms that underlie the link between respiratory syncytial virus （RSV） and childhood asthma remain unclear. Recent researches suggest that changes in the structure and function of the nerves themselves in response to changing conditions, a phenomenon known as neuronal plasticity, may also contribute to the pathophysiology of airway diseases. Therefore.

TOLL样受体TRIF信号因子与RSV关系的研究进展

呼吸道合胞病毒(respiratory syncytial virus,RSV)是婴幼儿急性下呼吸道感染最常见和最重要的病毒病原,尤其是肺炎和毛细支气管炎。Toll样受体(Toll-like receptors,TLRs)是近年来发现在抗感染及免疫反应起到重要作用的受体蛋白,可广泛识别多种病原微生物的病原分子相关模式(Pathogen Molecular Associated Pattern,PMAP)。机体可通过TLRs识别病毒成分介导细胞因子分泌,激活效应免疫细胞以抵抗病毒病原体入侵。其中TLR3、TLR4信号通路与其关系最为密切,而含TIR结构域诱导β干扰素的接头蛋白(TIR-domain-containing adaptor inducing interferon-β,TRIF)作为两者的共同重要衔接分子,在信号途径中发挥着关键的作用,通过调控细胞因子的分泌影响适应性免疫应答。

Qingkailing Injection(清开灵注射液)for Treatment of Children Pneumonia Induced by Respiratory Syncytial Virus:A Meta-Analysis of Rando mized Controlled Trials

Objective： To evaluate the efficacy and safety of Qingkailing Injection（清开灵注射液, QKL） for treatment of children pneumonia caused by respiratory syncytial virus（RSV）. Methods： Randomized clinical trials（RCTs） comparing QKL with ribavirin injection in the treatment of children pneumonia induced by RSV were searched in Pub Med, Science Direct, Cochrane Library, Chinese VIP database, CNKI and Wanfang databases from their inception to March 2014. Meta-analyses were performed using RevMan 5.2 software. The methodological quality of the selected RCTs was evaluated by the Modified Jadad Score. The primary outcome measures were effective rate and the secondary outcomes were relief time of fever and cough. Results： Seven RCTs with 992 cases published from 2008 to 2013 were identified. The meta-analysis results indicated that QKL was more effective in cure rate [risk ratios（RR）=1.32, 95% CI（1.17, 1.50）, P〈0.01], total effective rate [RR=1.07, 95% CI（1.02, 1.13）, P=0.009] and less fever clearance time [mean difference=–0.73, 95% CI（–1.22, –0.23）, P=0.004], compared with ribavirin injection in the treatment of RSV-induced children pneumonia. No dead case was reported in all trials. There were 3 trials mentioned adverse events, 2 reported no obvious adverse event occurred while 1 reported adverse events described as skin hypersensitivity, elevation of ALT, a mild abnormal of hepatic and renal function in both QKL and ribavirin group. Conclusions： QKL was an effective and relatively safe option for the treatment of RSV-induced children pneumonia. These therapeutic effects were promising but need to be interpreted with caution due to variations in the treatment and methodological weakness in the studies.

Characteristics of respiratory syncytial virus-induced bronchiolitis co-infection with Mycoplasma pneumoniae and add-on therapy with montelukast

Background:The influence of Mycoplasma pneumoniae(MP)infection on bronchiolitis remains unclear.Additionally,reports on the efficacies of leukotriene receptor antagonists in the treatment of bronchiolitis have been inconclusive.Methods:Children with respiratory syncytial virus(RSV)-induced bronchiolitis were divided into two groups:RSV+MP group and RSV group.Each group was randomly divided into two subgroups:one received routine and placebo treatment,while the other received routine and montelukast treatment for 9 months.The cumulative numbers of wheezing episodes and recurrent respiratory tract infections were recorded.Blood parameters were determined.Results:Patients in the RSV+MP group exhibited an older average age,fever,more frequent flaky and patchy shadows in chest X-rays,more frequent extrapulmonary manifestations,and longer hospital stays compared with patients in the RSV group.Additionally,higher baseline blood eosinophil counts,eosinophil cationic protein(ECP),total immunoglobulin E(IgE),interleukin(IL)-4,IL-5,IL-4/interferon-γratios,leukotriene(LT)B4,and LTC4,and lower baseline lipoxin A4(LXA4)/LTB4 ratios were observed in the RSV+MP group compared with the RSV group.Montelukast treatment decreased the cumulative numbers of recurrent wheezing episodes and recurrent respiratory tract infections at 9 and 12 months.This efficacy may be related to the montelukast-induced reductions in peripheral eosinophil counts,ECP and total IgE,as well as the montelukast-dependent recovery in T helper(Th)1/Th2 balance and LXA4/LTB4 ratios in children with bronchiolitis.Conclusions:RSV bronchiolitis with MP infection was associated with clinical and laboratory features that differed from those of RSV bronchiolitis without MP infection.Add-on therapy with montelukast for 9 months was benefi cial for children with bronchiolitis at 9 and 12 months after the initiation of treatment.

Effect of respiratory syncytial virus on the activity of matrix metalloproteinase in mice

Background Respiratory syncytial virus （RSV） is a common pathogen in the lower respiratory tract of infants and children. Recent studies have shown that in adults, especially in the eldedy population who have relatively weak immunity, lower respiratory tract infection is not uncommon. RSV was detected in 22% hospitalized patients with acute exacerbation of chronic obstructive pulmonary disease （COPD）, and the detection rate was only next to that of parvovirus and influenza virus respectively. Further studies revealed that lung infection of RSV could lead to inflammatory destruction and structural remodeling. This study was undertaken to examine the effect of infection with RSV on matrix metalloproteinase （MMPs） in mice, and to explore the role of RSV in the pathogenesis of pulmonary diseases. Methods Twenty BALB/c mice were divided randomly into an RSV infection group and a blank control group. The mice in the RSV infection group were given 100 pl liquid containing 10s PFU of RSV by intranasal instillation. Three days after the infection, the bronchoalveolar lavage fluid （BALF） was harvested and RT-PCR and Western blotting were used to detect MMP-9 and the expression of tissue inhibitors of matdx metalloproteinase （TIMP）-I mRNA in lung tissues. Gelatin zymography was employed to detect the activities of MMP-9 and MMP-2 in BALF. Immunohistochemistry was used to determine the expressions of E-cadherin （E-cd） and proliferating call nuclear antigen （PCNA） in the lung tissues. Results In the BALF of the mice infected with RSV, the activities of MMP-9 and MMP-2 were significantly increased （t=-6.08, P〈0.01 and t=5.68, P〈0.01）. The levels of mRNAand proteins of MMP-9 in the lung tissues of the mica infected with RSV were significantly elevated, and the mRNA and protein levels were significantly higher than those of the blank controls. Though the ratio of MMP-9/TIMP-1 mRNA in the lung tissues of the infected mica was not significantly different from that of the normal controls, the ratio of the MMP-9/TIMP-1 protein in the RSV infection group was significantly higher than that in the control group. Moreover, the number of cells with positive E-cd expression was decreased and the number of calls positive for PCNA was increased, with an enhanced expression. Conclusions In mica, infection with RSV can significantly increase the activities of MMP-9 and MMP-2, and conspicuously elevate the mRNA transcription of MMP-9. RSV infection can increase the activity of gelatinase while up-regulating its inhibitory factors but increase its protein ratio of MMP-9/TIMP-1 in lung tissues, thereby facilitating fibrosis after structural destruction of the airway. The resultant status might be an important factor causing chronic reconstruction of the airway.