Epithelial Barrier Integrity Profiling: Combined Approach Using Cellular Junctional Complex Imaging and Transepithelial Electrical Resistance.

A core aspect of epithelial cell function is barrier integrity. A loss of barrier integrity is a feature of a number of respiratory diseases, including asthma, allergic rhinitis, and chronic obstructive pulmonary disease. Restoration of barrier integrity is a target for respiratory disease drug discovery. Traditional methods for assessing barrier integrity have their limitations. Transepithelial electrical resistance (TEER) and dextran permeability methods can give poor in vitro assay robustness. Traditional junctional complex imaging approaches are labor-intensive and tend to be qualitative but not quantitative. To provide a robust and quantitative assessment of barrier integrity, high-content imaging of junctional complexes was combined with TEER. A scalable immunofluorescent high-content imaging technique, with automated quantification of junctional complex proteins zonula occludens-1 and occludin, was established in 3D pseudostratified primary human bronchial epithelial cells cultured at an air-liquid interface. Ionic permeability was measured using TEER on the same culture wells.The improvements to current technologies include the design of a novel 24-well holder to enable scalable in situ confocal cell imaging without Transwell membrane excision, the development of image analysis pipelines to quantify in-focus junctional complex structures in each plane of a Z stack, and the enhancement of the TEER data analysis process to enable statistical evaluation of treatment effects on barrier integrity. This novel approach was validated by demonstrating measurable changes in barrier integrity in cells grown under conditions known to perturb epithelial cell function.

Not yet 90-90-90: A quality improvement approach to human immunodeficiency virus viral suppression in paediatric patients in the rural Eastern Cape, South Africa.

BACKGROUND: A strategy implemented by the South African Department of Health to manage the high burden of human immunodeficiency virus (HIV) has been to task-shift services to primary health care clinics. Outcomes of paediatric patients with HIV are poorer than those of adults, particularly in rural areas. Viral suppression in paediatric patients at the feeder clinics of a rural South African hospital was anecdotally far below the aim of the Joint United Nations Programme on HIV/AIDS (UNAIDS) of 90%. METHODS: A quality improvement approach was used to conduct a baseline assessment of HIV viral suppression in paediatric patients and other process measures, implement a clinical mentorship intervention and evaluate its effectiveness. RESULTS: An initial audit of 235 clinical folders of paediatric patients with HIV revealed a viral suppression of 55.3%. Other poor measures included prescription accuracy, viral loads performed within schedule and response to successive high viral loads. A clinical mentorship intervention using dedicated doctor outreach was implemented and the audit repeated after 12 months (263 folders). Viral suppression improved to 67.4%, as did most other process measures. CONCLUSION: The quality improvement approach regarding the aim to significantly improve viral suppression in paediatric patients through the implementation of clinical mentorship was successful.

Turnaround times - the Achilles' heel of community screening and testing in Cape Town, South Africa: A short report.

Early in the course of the coronavirus infection disease 2019 (COVID-19) pandemic in South Africa, the Department of Health implemented a policy of community screening and testing (CST). This was based on a community-orientated primary care approach and was a key strategy in limiting the spread of the pandemic, but it struggled with long turnaround times (TATs) for the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) reverse transcriptase polymerase chain reaction test. The local experience at Symphony Way Community Day Centre (Delft, Cape Town), highlighted these challenges. The first positive tests had a median TAT of 4.5 days, peaking at 29 days in mid-May 2020. Issues that contributed to long TATs were unavailability of viral transport medium, sample delivery and storage difficulties, staffing problems, scarcity of testing supplies and other samples prioritised over CST samples. At Symphony Way, many patients who tested COVID-19 positive had abandoned their self-isolation because of the delay in results. Employers were unhappy with prolonged sick leave whilst waiting for results and patients were concerned about not getting paid or job loss. The CST policy relies on a rapid TAT to be successful. Once the TAT is delayed, the process of contacting patients, and tracing and quarantining contacts becomes ineffective. With hindsight, other countries' difficulties in upscaling testing should have served as warning. Community screening and testing was scaled back from 18 May 2020, and testing policy was changed to only include high-risk patients from 29 May 2020. The delayed TATs meant that the CST policy had no beneficial impact at local level.

Corticosteroid suppression of antiviral immunity increases bacterial loads and mucus production in COPD exacerbations.

Inhaled corticosteroids (ICS) have limited efficacy in reducing chronic obstructive pulmonary disease (COPD) exacerbations and increase pneumonia risk, through unknown mechanisms. Rhinoviruses precipitate most exacerbations and increase susceptibility to secondary bacterial infections. Here, we show that the ICS fluticasone propionate (FP) impairs innate and acquired antiviral immune responses leading to delayed virus clearance and previously unrecognised adverse effects of enhanced mucus, impaired antimicrobial peptide secretion and increased pulmonary bacterial load during virus-induced exacerbations. Exogenous interferon-ß reverses these effects. FP suppression of interferon may occur through inhibition of TLR3- and RIG-I virus-sensing pathways. Mice deficient in the type I interferon-α/ß receptor (IFNAR1-/-) have suppressed antimicrobial peptide and enhanced mucin responses to rhinovirus infection. This study identifies type I interferon as a central regulator of antibacterial immunity and mucus production. Suppression of interferon by ICS during virus-induced COPD exacerbations likely mediates pneumonia risk and raises suggestion that inhaled interferon-ß therapy may protect.

Is it just religious practice? Exploring patients' reasons for choosing a faith-based primary health clinic over their local public sector primary health clinic.

BACKGROUND: Person-centred, re-engineered primary health care (PHC) is a national and global priority. Faith-based health care is a significant provider of PHC in sub-Saharan Africa, but there is limited published data on the reasons for patient choice of faith-based health care, particularly in South Africa. AIM: The primary objective was to determine and explore the reasons for patient choice of a faith-based primary care clinic over their local public sector primary care clinic, and secondarily to determine to what extent these reasons were influenced by demography. SETTING: The study was conducted at Jubilee Health Centre (JHC), a faith-based primary care clinic attached to Jubilee Community Church in Cape Town, South Africa. METHODS: Focus groups, using the nominal group technique, were conducted with JHC patients and used to generate ranked reasons for attending the clinic. These were collated into the top 15 reasons and incorporated into a quantitative questionnaire which was administered to adult patients attending JHC. RESULTS: A total of 164 patients were surveyed (a response rate of 92.4%) of which 68.3% were female and 57.9% from the Democratic Republic of the Congo (DRC). Of patients surveyed, 98.2% chose to attend JHC because 'the staff treat me with respect', 96.3% because 'the staff are friendly' and 96.3% because 'the staff take time to listen to me'. The reason 'it is a Christian clinic' was chosen by 70.1% of patients. 'The staff speak my home language' was given as a reason by 61.1% of DRC patients and 37.1% of South African patients. 'The clinic is close to me' was chosen by 66.6% of Muslims and 40.8% of Christians. CONCLUSION: Patients chose to attend JHC (a faith-based primary care clinic) because of the quality of care received. They emphasised the staff-patient relationship and patient-centredness rather than the clinic's religious practices (prayer with patients). These findings may be important in informing efforts to improve public sector primary care.

Identification of novel macrolides with antibacterial, anti-inflammatory and type I and III IFN-augmenting activity in airway epithelium.

BACKGROUND: Exacerbations of asthma and COPD are triggered by rhinoviruses. Uncontrolled inflammatory pathways, pathogenic bacterial burden and impaired antiviral immunity are thought to be important factors in disease severity and duration. Macrolides including azithromycin are often used to treat the above diseases, but exhibit variable levels of efficacy. Inhaled corticosteroids are also readily used in treatment, but may lack specificity. Ideally, new treatment alternatives should suppress unwanted inflammation, but spare beneficial antiviral immunity. METHODS: In the present study, we screened 225 novel macrolides and tested them for enhanced antiviral activity against rhinovirus, as well as anti-inflammatory activity and activity against Gram-positive and Gram-negative bacteria. Primary bronchial epithelial cells were grown from 10 asthmatic individuals and the effects of macrolides on rhinovirus replication were also examined. Another 30 structurally similar macrolides were also examined. RESULTS: The oleandomycin derivative Mac5, compared with azithromycin, showed superior induction (up to 5-fold, EC50 = 5-11 µM) of rhinovirus-induced type I IFNß, type III IFNλ1 and type III IFNλ2/3 mRNA and the IFN-stimulated genes viperin and MxA, yet had no effect on IL-6 and IL-8 mRNA. Mac5 also suppressed rhinovirus replication at 48 h, proving antiviral activity. Mac5 showed antibacterial activity against Gram-positive Streptococcus pneumoniae; however, it did not have any antibacterial properties compared with azithromycin when used against Gram-negative Escherichia coli (as a model organism) and also the respiratory pathogens Pseudomonas aeruginosa and non-typeable Haemophilus influenzae. Further non-toxic Mac5 derivatives were identified with various anti-inflammatory, antiviral and antibacterial activities. CONCLUSIONS: The data support the idea that macrolides have antiviral properties through a mechanism that is yet to be ascertained. We also provide evidence that macrolides can be developed with anti-inflammatory, antibacterial and antiviral activity and show surprising versatility depending on the clinical need.

The role of macrolides in asthma: current evidence and future directions.

Macrolides, such as clarithromycin and azithromycin, possess antimicrobial, immunomodulatory, and potential antiviral properties. They represent a potential therapeutic option for asthma, a chronic inflammatory disorder characterised by airway hyper-responsiveness that leads to recurrent episodes of wheezing, breathlessness, chest tightness, and coughing. Results from clinical trials, however, have been contentious. The findings could be confounded by many factors, including the heterogeneity of asthma, treatment duration, dose, and differing outcome measures. Recent evidence suggests improved effectiveness of macrolides in patients with sub-optimally controlled severe neutrophilic asthma and in asthma exacerbations. We examine the evidence from clinical trials and discuss macrolide properties and their relevance to the pathophysiology of asthma. At present, the use of macrolides in chronic asthma or acute exacerbations is not justified. Further work, including proteomic, genomic, and microbiome studies, will advance our knowledge of asthma phenotypes, and help to identify a macrolide-responsive subgroup. Future clinical trials should target this subgroup and place emphasis on clinically relevant outcomes such as asthma exacerbations.