scholarly journals The Role of the Immune Response in the Pathogenesis of Bronchiectasis

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Paul T. King

Bronchiectasis is a prevalent respiratory condition characterised by permanent and abnormal dilation of the lung airways (bronchi). There are a large variety of causative factors that have been identified for bronchiectasis; all of these compromise the function of the immune response to fight infection. A triggering factor may lead to the establishment of chronic infection in the lower respiratory tract. The bacteria responsible for the lower respiratory tract infection are usually found as commensals in the upper respiratory tract microbiome. The consequent inflammatory response to infection is largely responsible for the pathology of this condition. Both innate and adaptive immune responses are activated. The literature has highlighted the central role of neutrophils in the pathogenesis of bronchiectasis. Proteases produced in the lung by the inflammatory response damage the airways and lead to the pathological dilation that is the pathognomonic feature of bronchiectasis. The small airways demonstrate infiltration with lymphoid follicles that may contribute to localised small airway obstruction. Despite aggressive treatment, most patients will have persistent disease. Manipulating the immune response in bronchiectasis may potentially have therapeutic potential.

2019 ◽  
pp. 173-182
Author(s):  
I. N. Zakharova ◽  
I. V. Berezhnaya ◽  
L. Ya. Klimov ◽  
A. N. Kasyanova ◽  
O. V. Dedikova ◽  
...  

Today, the composition of the gut microbiota has been studied in sufficient detail. Increasing number of studies show that the respiratory tract, both the upper and lower respiratory tract, have their own microbiota. The article presents the main today’s data about the species diversity of microorganisms in the respiratory and gastrointestinal tracts, describes the role of a healthy microbiota in providing local and general immunity. The authors specify the role of probiotic strains of microorganisms and their effect on various parts of the immune response and present the data of studies on the effect of probiotic products on the immunological resistance of humans, especially the respiratory tract with high viral load. Restoration of a healthy microbiota in the human tract using probiotic products administered through the gastrointestinal tract can reduce the risk and severity of manifestation of the respiratory infections.


Cytokine ◽  
2017 ◽  
Vol 97 ◽  
pp. 108-116 ◽  
Author(s):  
Sharon A. McGrath-Morrow ◽  
Roland Ndeh ◽  
Joseph M. Collaco ◽  
Amy K. Poupore ◽  
Dustin Dikeman ◽  
...  

PEDIATRICS ◽  
1965 ◽  
Vol 36 (1) ◽  
pp. 21-39
Author(s):  
Robert M. Chanock ◽  
Robert H. Parrott

DURING the past ten years there has been an exponential increase in our understanding of the etiology and epidemiology of acute respiratory disease. Unfortunately development of the means for control of these illnesses has not kept pace with etiologic or epidemiologic understanding. In this presentation an attempt will he made to summarize the role of a number of viruses and mycoplasmas in acute respiratory disease of infancy and childhood. In addition the ecology of such infections will be discussed, particularly those aspects of infection which have relevance to the problem of immunoprophylaxis. Much of the information to be discussed is derived from studies at the Children's Hospital of D.C. and the Junior Village Welfare Nursery of D.C. In many instances similar findings have been reported from other localities so that the conclusions which can be drawn from the Washington, D.C., studies would appear to have more than local significance. Since the Washington D.C., studies represent the longest continuous inquiry into the nature of acute pediatric respiratory disease primary emphasis will be placed on the interpretation of these findings. Bacteria Although group A beta hemolytic streptococci play an important role in upper respiratory tract disease it would appear that these organisms are relatively unimportant in the more serious types of illness in which lower respiratory tract involvement occurs. The careful studies of Babe, Beem, and co-workers indicate that pathogenic bacteria are not important primary etiologic agents in lower respiratory tract disease of infancy and childhood. For this reason major emphasis in this presentation will be given to the role of viruses and mycoplasmas in respiratory disease.


2021 ◽  
Author(s):  
Alejandra Hernández-Terán ◽  
Angel E. Vega-Sánchez ◽  
Fidencio Mejía-Nepomuceno ◽  
Ricardo Serna-Muñoz ◽  
Sebastián Rodríguez-Llamazares ◽  
...  

AbstractSeveral factors are associated with the severity of the respiratory disease caused by the influenza virus. Although viral factors are one of the most studied, in recent years the role of the microbiota and co-infections in severe and fatal outcomes has been recognized. However, most of the work has focused on the microbiota of the upper respiratory tract (URT), hindering potential insights from the lower respiratory tract (LRT) that may help to understand the role of the microbiota in Influenza disease. In this work, we characterized the microbiota of the LRT of patients with Influenza A using 16S rRNA sequencing. We tested if patients with different outcomes (deceased/recovered), use of antibiotics, and different days of symptoms onset differ in their microbial community composition. We found striking differences in the diversity and composition of the microbiota depending on the days of symptoms onset and with mortality of the studied patients. We detected a high abundance of opportunistic pathogens such as Enterococcus, Granulicatella, and Staphylococcus in patients either deceased or with antibiotic treatment. Also, we found that antibiotic treatment deeply perturbs the microbial communities in the LRT and affect the probability of survival in Influenza A patients. Altogether, the loss of microbial diversity could, in turn, generate a disequilibrium in the community, potentially compromising the immune response increasing viral infectivity, promoting the growth of potentially pathogenic bacteria that, together with altered biochemical parameters, can be leading to severe forms of the disease. Overall, the present study gives one of the first characterizations of the diversity and composition of microbial communities in the LRT of Influenza patients and its relationship with clinical variables and disease severity.


2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S279-S279
Author(s):  
Eimear Kitt ◽  
Julia S Sammons ◽  
Kathleen Chiotos ◽  
Susan E Coffin ◽  
Susan E Coffin ◽  
...  

Abstract Background The Centers for Disease Control and Prevention (CDC) recommends upper respiratory tract (URT) polymerase chain reaction (PCR) testing as the initial diagnostic test for Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2). Lower respiratory tract (LRT) testing for patients requiring mechanical ventilation is also recommended. The goal of this study was to evaluate concordance between paired URT and LRT specimens in children undergoing pre-admission/procedure screening or diagnostic testing. We hypothesized that < 10% of paired tests would have discordant results. Methods Single center cross-sectional study including children with artificial airways who had paired URT and LRT SARS-CoV-2 PCR testing between 4/1/2020 and 6/8/2020. URT specimens included nasopharyngeal (NP) swabs and aspirates. LRT specimens included tracheal aspirates and bronchoalveolar lavages. URT and LRT specimens were classified as paired if the two specimens were collected within 24 hours. Artificial airways included tracheostomies and endotracheal tubes. Tests were classified as diagnostic versus screening based on the indication selected in the order. Results 102 paired specimens were obtained during the study period. Fifty-nine were performed for screening and 43 were performed for diagnosis of suspected SARS-CoV-2. Overall, 94 specimens (92%) were concordant, including 89 negative from both sources and 5 positive from both sources. Eight specimens (8%) were discordant, all of which were positive from the URT and negative from the LRT (Figure 1). Among patients undergoing screening, 3 of 4 positive tests were discordant and among symptomatic patients, 5 of 9 positive tests were discordant. There were no instances of a positive LRT specimen with a negative URT specimen. Figure 1. Performance of upper and lower respiratory tract SARS-CoV-2 PCR testing in children with artificial airways Conclusion Overall, most paired samples from the URT and LRT yielded concordant results with no pairs positive from the LRT and negative from the URT. These data support the CDC recommendation that URT specimens are the preferred initial SARS-CoV-2 test, while LRT specimens should be collected only from mechanically ventilated with suspected SARS-CoV-2. Disclosures All Authors: No reported disclosures


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Sung-Yoon Kang ◽  
Hyojung Kim ◽  
Sungwon Jung ◽  
Sang Min Lee ◽  
Sang Pyo Lee

Abstract Background The microbiota of the lower respiratory tract in patients with non-tuberculous mycobacterial pulmonary disease (NTM-PD) has not been fully evaluated. We explored the role of the lung microbiota in NTM-PD by analyzing protected specimen brushing (PSB) and bronchial washing samples from patients with NTM-PD obtained using a flexible bronchoscope. Results Bronchial washing and PSB samples from the NTM-PD group tended to have fewer OTUs and lower Chao1 richness values compared with those from the control group. In both bronchial washing and PSB samples, beta diversity was significantly lower in the NTM-PD group than in the control group (P = 2.25E-6 and P = 4.13E-4, respectively). Principal component analysis showed that the PSBs and bronchial washings exhibited similar patterns within each group but differed between the two groups. The volcano plots indicated differences in several phyla and genera between the two groups. Conclusions The lower respiratory tract of patients with NTM-PD has a unique microbiota distribution that is low in richness/diversity.


2021 ◽  
Vol 22 (15) ◽  
pp. 7868
Author(s):  
Su Young Jung ◽  
Dokyoung Kim ◽  
Dong Choon Park ◽  
Sung Soo Kim ◽  
Tong In Oh ◽  
...  

Otitis media is mainly caused by upper respiratory tract infection and eustachian tube dysfunction. If external upper respiratory tract infection is not detected early in the middle ear, or an appropriate immune response does not occur, otitis media can become a chronic state or complications may occur. Therefore, given the important role of Toll-like receptors (TLRs) in the early response to external antigens, we surveyed the role of TLRs in otitis media. To summarize the role of TLR in otitis media, we reviewed articles on the expression of TLRs in acute otitis media (AOM), otitis media with effusion (OME), chronic otitis media (COM) with cholesteatoma, and COM without cholesteatoma. Many studies showed that TLRs 1–10 are expressed in AOM, OME, COM with cholesteatoma, and COM without cholesteatoma. TLR expression in the normal middle ear mucosa is absent or weak, but is increased in inflammatory fluid of AOM, effusion of OME, and granulation tissue and cholesteatoma of COM. In addition, TLRs show increased or decreased expression depending on the presence or absence of bacteria, recurrence of disease, tissue type, and repeated surgery. In conclusion, expression of TLRs is associated with otitis media. Inappropriate TLR expression, or delayed or absent induction, are associated with the occurrence, recurrence, chronicization, and complications of otitis media. Therefore, TLRs are very important in otitis media and closely related to its etiology.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Cheng Lei ◽  
Lisong Yang ◽  
Cheong Tat Lou ◽  
Fan Yang ◽  
Kin Ian SiTou ◽  
...  

Abstract Background Acute respiratory infections (ARIs) are among the leading causes of hospitalization in children. Understanding the local dominant viral etiologies is important to inform infection control practices and clinical management. This study aimed to investigate the viral etiology and epidemiology of respiratory infections among pediatric inpatients in Macao. Methods A retrospective study using electronic health records between 2014 and 2017 at Kiang Wu Hospital was performed. Nasopharyngeal swab specimens were obtained from hospitalized children aged 13 years or younger with respiratory tract diseases. xMAP multiplex assays were employed to detect respiratory agents including 10 respiratory viruses. Data were analyzed to describe the frequency and seasonality. Results Of the 4880 children enrolled in the study, 3767 (77.1%) were positive for at least one of the 13 viral pathogens tested, of which 2707 (55.5%) being male and 2635 (70.0%) under 2 years old. Among the positive results, there were 3091 (82.0%) single infections and 676 (18.0%) multiple infections. The predominant viruses included human rhinovirus/enterovirus (HRV/EV 27.4%), adenovirus (ADV, 15.8%), respiratory syncytial virus B (RSVB, 7.8%) and respiratory syncytial virus A (RSVA, 7.8%). The detection of viral infection was the most prevalent in autumn (960/1176, 81.6%), followed by spring (1095/1406, 77.9%), winter (768/992, 77.4%), and summer (944/1306, 72.3%), with HRV/EV and ADV being most commonly detected throughout the 4 years of study period. The detection rate of viral infection was highest among ARI patients presented with croup (123/141, 87.2%), followed by lower respiratory tract infection (1924/2356, 81.7%) and upper respiratory tract infection (1720/2383, 72.2%). FluA, FluB and ADV were positive factors for upper respiratory tract infections. On the other hand, infection with RSVA, RSVB, PIV3, PIV4, HMPV, and EV/RHV were positively associated with lower respiratory tract infections; and PIV1, PIV2, and PIV3 were positively associated with croup. Conclusions This is the first study in Macao to determine the viral etiology and epidemiology of pediatric patients hospitalized for ARIs. The study findings can contribute to the awareness of pathogen, appropriate preventative measure, accurate diagnosis, and proper clinical management of respiratory viral infections among children in Macao.


1920 ◽  
Vol 32 (6) ◽  
pp. 719-744 ◽  
Author(s):  
Russell L. Cecil ◽  
Francis G. Blake

1. Virulent influenza bacilli, when injected into the nose and throat of monkeys (Cebus capucinus and Macacus syrichtus), excite an acute inflammation of the upper respiratory tract, characterized by swelling and hyperemia of the mucous membrane, infiltration of the mucosa and subrnucosa with leucocytes, desquamation of epithelial cells, and the production of a mucopurulent exudate. The accessory sinuses are often implicated in the infection. 2. Experimental Bacillus influenzæ infections of the upper respiratory tract are frequently accompanied or followed by bronchiolitis, peribronchial infiltration, and bronchopneumonia with hemorrhage and edema in the early stage, emphysema and bronchiectasis in the later stages. In general, the process closely resembles uncomplicated Bacillus influenzæ pneumonia in man. 3. The injection of virulent influenza bacilli directly into the trachea of monkeys induces in them an experimental bronchiolitis and hemorrhagic bronchopneumonia, similar in all respects to spontaneous Bacillus influenzæ pneumonia. 4. In experimental Bacillus influenzæinfections of either the upper or lower respiratory tract the influenza bacillus can usually be recovered during .the acute stage by culture, either pure or in association with other bacteria. 5. In experimental Bacillus influenzæ infections in monkeys characteristic changes occur in the thymus gland—hyperplasia of the follicles, distention of the lymphatic channels, and infiltration of the parenchyma with leucocytes. This enlargement appears to be merely part of a general hyperplasia of the lymphoid structures in the cervical and thoracic regions.


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