Seher Zaidi

Novel Analysis of Immune Cells from Nasal Microbiopsy Demonstrates Reliable, Reproducible Data for Immune Populations, and Superior Cytokine Detection Compared to Nasal Wash

The morbidity and mortality related to respiratory tract diseases is enormous, with hundreds of millions of individuals afflicted and four million people dying each year. Understanding the immunological processes in the mucosa that govern outcome following pathogenic encounter could lead to novel therapies. There is a need to study responses at mucosal surfaces in humans for two reasons: (i) Immunological findings in mice, or other animals, often fail to translate to humans. (ii) Compartmentalization of the immune system dictates a need to study sites where pathogens reside. In this manuscript, we describe two novel non-invasive nasal mucosal microsampling techniques and their use for measuring immunological parameters: 1) using nasal curettes to collect cells from the inferior turbinate and; 2) absorptive matrices to collect nasal lining fluid. Both techniques were well tolerated and yielded reproducible and robust data. We demonstrated differences in immune populations and activation state in nasal mucosa compared to blood as well as compared to nasopharyngeal lumen in healthy adults. We also found superior cytokine detection with absorptive matrices compared to nasal wash. These techniques are promising new tools that will facilitate studies of the immunological signatures underlying susceptibility and resistance to respiratory infections.

Defining and managing risk in asthma

Asthma attacks are a major global source of morbidity and cost. The incidence and impact of asthma attacks have not improved despite widespread adoption of effective universal treatment guidelines. Consequently, there is increasing interest in managing asthma based on specific assessments of both current symptoms and future risk. In this review, we consider ‘risk’ in asthma, and how it might be assessed from the patients history and objective measurements. We also discuss the potential for encouraging shared decision‐making and improving medical consensus through explicit communication of risk and highlight the potential opportunities and challenges in risk assessment to improve asthma management through individualised treatment strategies.

Effect of Live Attenuated Influenza Vaccine on Pneumococcal Carriage

The widely used nasally-administered Live Attenuated Influenza Vaccine (LAIV) alters the dynamics of naturally occurring nasopharyngeal carriage of Streptococcus pneumoniae in animal models. Using a human experimental model (serotype 6B) we tested two hypotheses: 1) LAIV increased the density of S. pneumoniae in those already colonised; 2) LAIV administration promoted colonisation. Randomised, blinded administration of LAIV or nasal placebo either preceded bacterial inoculation or followed it, separated by a 3-day interval. The presence and density of S. pneumoniae was determined from nasal washes by bacterial culture and PCR. Overall acquisition for bacterial carriage were not altered by prior LAIV administration vs. controls (25/55 [45.5%] vs 24/62 [38.7%] respectively, p=0.46). Transient increase in acquisition was detected in LAIV recipients at day 2 (33/55 [60.0%] vs 25/62 [40.3%] in controls, p=0.03). Bacterial carriage densities were increased approximately 10-fold by day 9 in the LAIV recipients (2.82 vs 1.81 log10 titers, p=0.03). When immunisation followed bacterial acquisition (n=163), LAIV did not change area under the bacterial density-time curve (AUC) at day 14 by conventional microbiology (primary endpoint), but significantly reduced AUC to day 27 by PCR (p=0.03). These studies suggest that LAIV may transiently increase nasopharyngeal density of S. pneumoniae. Transmission effects should therefore be considered in the timing design of vaccine schedules. Trial registration The study was registered on EudraCT (2014-004634-26) Funding The study was funded by the Bill and Melinda Gates Foundation and the UK Medical Research Council.

Inflammation induced by influenza virus impairs innate control of human pneumococcal carriage

Secondary bacterial pneumonia following influenza infection is a significant cause of mortality worldwide. Upper respiratory tract pneumococcal carriage is important as both determinants of disease and population transmission. The immunological mechanisms that contain pneumococcal carriage are well-studied in mice but remain unclear in humans. Loss of this control of carriage following influenza infection is associated with secondary bacterial pneumonia during seasonal and pandemic outbreaks. We used a human type 6B pneumococcal challenge model to show that carriage acquisition induces early degranulation of resident neutrophils and recruitment of monocytes to the nose. Monocyte function associated with clearance of pneumococcal carriage. Prior nasal infection with live attenuated influenza virus induced inflammation, impaired innate function and altered genome-wide nasal gene responses to pneumococcal carriage. Levels of the cytokine IP-10 promoted by viral infection at the time of pneumococcal encounter was positively associated with bacterial density. These findings provide novel insights in nasal immunity to pneumococcus and viral-bacterial interactions during co-infection.

Predictors of repeated acute hospital attendance for asthma in children: A systematic review and meta-analysis

Asthma attacks are common and have significant physical, psychological, and financial consequences. Improving the assessment of a childs risk of subsequent asthma attacks could support front‐line clinicians’ decisions on augmenting chronic treatment or specialist referral. We aimed to identify predictors for emergency department (ED) or hospital readmission for asthma from the published literature.

Inflammation induced by influenza virus impairs human innate immune control of pneumococcus

Colonization of the upper respiratory tract by pneumococcus is important both as a determinant of disease and for transmission into the population. The immunological mechanisms that contain pneumococcus during colonization are well studied in mice but remain unclear in humans. Loss of this control of pneumococcus following infection with influenza virus is associated with secondary bacterial pneumonia. We used a human challenge model with type 6B pneumococcus to show that acquisition of pneumococcus induced early degranulation of resident neutrophils and recruitment of monocytes to the nose. Monocyte function was associated with the clearance of pneumococcus. Prior nasal infection with live attenuated influenza virus induced inflammation, impaired innate immune function and altered genome-wide nasal gene responses to the carriage of pneumococcus. Levels of the cytokine CXCL10, promoted by viral infection, at the time pneumococcus was encountered were positively associated with bacterial load.Pneumococcal carriage in the upper respiratory tract is an important determinant of influenza severity. Jochems et al. use human systems analysis to show that influenza-induced inflammation increases bacterial burden in the nasal cavity with implications for secondary bacterial pneumonia.

Hands are vehicles for transmission of Streptococcus pneumoniae in novel controlled human infection study

Streptococcus pneumoniae (pneumococcus) is a major cause of acute otitis media, sinusitis, pneumonia and meningitis worldwide [1]. More than 1.2 million infant deaths are attributed to S. pneumoniae annually [2]. Hands can be vehicles for of transmission of pneumococcus leading to nasopharyngeal colonisation, even after drying http://ow.ly/svlu30liKqP

P243 Specific antibody deficiency to streptococcus pneumoniae and haemophilus influenzae in asthma and fungal disease

Introduction Recurrent exacerbations are a characteristic feature of uncontrolled asthma, often due to viral or bacterial infections. We have reported in a retrospective study that immune deficiency is common in asthma and correlates with reduced lung function. We set up a prospective study to determine if this predisposes to a more severe disease. Aim Our aim is to ascertain if immune deficiency is associated with a more severe disease potentially with radiological changes and clinically with low lung function and frequent exacerbations. Methods We prospectively collected data from new patients attending the regional asthma and fungal clinics. Demographics, markers of disease severity and specific antibody levels to Haemophilus iInfluenzae (HI), and Streptococcus pneumoniae (SP), were recorded. Patients with specific antibody deficiency (HI: ≤ 0.15 iu and SP: ≤ 0.35 iu to 6+ of 12 strains tested) received appropriate vaccination(s) in primary care (Pneumovax® and Meniotrix®), with repeat samples collected two months later. We also recorded blood and sputum eosinophil counts, radiological findings such as bronchiectasis and bronchial wall thickening, total IgE, smoking status, exacerbations in the last year and ITU admissions. Results 101 patients were followed up (69 asthma, 32 fungal) 67 female, mean (SD) age 53 (15) years, FEV1 69 (21.9)% predicted, ICS dose 1818 (1244) μg, and BMI 29.9 (8.9) kg/m2. Specific antibody levels and responses to vaccination are presented in Figure 1. Immune deficiency at baseline and post vaccination did not correlate with lung function, radiological findings such as bronchial wall thickening or exacerbation frequency. Conclusion Specific antibody deficiency is commonly seen in patients with asthma and fungal disease. Vaccination can provide protection and should be considered in this patient group. We need further analysis with a larger cohort of patients to study the association between antibody deficiency, lung function, radiological changes and disease progression. Abstract P243 Figure 1 Specific antibody levels at baseline and following vaccination for Haemophilus influenza and streptococcus pneumonia

P48 Research BAL using single use disposable bronchoscope

Background Broncho alveolar lavage (BAL) is widely used for investigative research to study innate, cellular and humoral immune responses, and in early phase drug trials. Conventional (multiple use) flexible bronchoscopes have time and monetary costs associated with cleaning, and may also carry a small risk of cross infection. Single use bronchoscopes may provide an alternative, but have not been evaluated in this context. Methods Healthy volunteers underwent bronchoscopy on a day-case clinical research unit using the Ambu® Scope single-use flexible intubation bronchoscope. The bronchoscopy protocol was identical to previous studies using multiple-use equipment: fasted volunteers had local anaesthesia to the nasopharynx, and were intubated with further sequential local anaesthetic (2% lidocaine throughout). Lavage was performed from a sub segmental bronchus within the right middle lobe. A total of 200ml of warmed normal saline divided into four aliquots. Fluid was aspirated using handheld suction. Supplemental oxygen was used to maintain saturations above 90% throughout the procedure. The lab processing of BAL was identical to earlier studies. BAL volume was recorded, mucus plugs removed by filtration through a double layered gauze swab into sterile centrifuge tubes. The cells were pelleted by centrifugation and washed by vortexing in 50 mls of cold normal saline, then re-suspended in culture medium for differential counting and viability staining with trypan blue stain. Results Ten volunteers, (mean age 23 years, 6 male) participated. The procedure was well tolerated by all the participants and all were carried out by two operators. The results were compared to 50 (mean age 23, 14 male) procedures done using the conventional scope by the same two operators. The total volume yield was significantly higher in the disposable group mean (SD) 149 mls (24.6) compared to 123 mls (20.6) p = 0.0007 Mann-Whitney Test. The total cell yield and viability were similar in both groups, with no significant differences. Conclusions BAL using single use bronchoscopes are safe with no risk of cross infection, and well tolerated, with potentially reduced side effects post procedure such as pleuritic chest pain and cough as the volume yield is better. The cell yield and viability are comparable to the conventional bronchoscopes. Abstract P48 Figure 1 Graph showing total BAL volume yield from conventional and disposable procedures

Are we failing our trainees in providing opportunities to attain procedural confidence

Practical procedures play a crucial role in clinical outcome. High proportions of Mersey trainees report a lack of procedural confidence despite the fact that the majority want to perform more procedures. Training has to be carefully analysed to address these shortcomings.