Davinder Dosanjh

Pro-inflammatory effects of e-cigarette vapour condensate on human alveolar macrophages

Objective Vaping may increase the cytotoxic effects of e-cigarette liquid (ECL). We compared the effect of unvaped ECL to e-cigarette vapour condensate (ECVC) on alveolar macrophage (AM) function. Methods AMs were treated with ECVC and nicotine-free ECVC (nfECVC). AM viability, apoptosis, necrosis, cytokine, chemokine and protease release, reactive oxygen species (ROS) release and bacterial phagocytosis were assessed. Results Macrophage culture with ECL or ECVC resulted in a dose-dependent reduction in cell viability. ECVC was cytotoxic at lower concentrations than ECL and resulted in increased apoptosis and necrosis. nfECVC resulted in less cytotoxicity and apoptosis. Exposure of AMs to a sub-lethal 0.5% ECVC/nfECVC increased ROS production approximately 50-fold and significantly inhibited phagocytosis. Pan and class one isoform phosphoinositide 3 kinase inhibitors partially inhibited the effects of ECVC/nfECVC on macrophage viability and apoptosis. Secretion of interleukin 6, tumour necrosis factor α, CXCL-8, monocyte chemoattractant protein 1 and matrix metalloproteinase 9 was significantly increased following ECVC challenge. Treatment with the anti-oxidant N-acetyl-cysteine (NAC) ameliorated the cytotoxic effects of ECVC/nfECVCu2009to levels not significantly different from baseline and restored phagocytic function. Conclusions ECVC is significantly more toxic to AMs than non-vaped ECL. Excessive production of ROS, inflammatory cytokines and chemokines induced by e-cigarette vapour may induce an inflammatory state in AMs within the lung that is partly dependent on nicotine. Inhibition of phagocytosis also suggests users may suffer from impaired bacterial clearance. While further research is needed to fully understand the effects of e-cigarette exposure in humans in vivo, we caution against the widely held opinion that e-cigarettes are safe.

Statin therapy in patients with community-acquired pneumonia.

ABSTRACT Community-acquired pneumonia (CAP) is the leading cause of death from infection in developed countries. There is evidence of an association between improved survival from infection and statin use. The possible beneficial effects of statins are complicated by the common use of macrolide antibiotics for pneumonia, with current guidance suggesting that concurrent macrolide and statin use is contraindicated. We conducted an observational study of statin use in patients with CAP. Of 2,067 patients with CAP, 30.4% were on statin therapy at admission. Statin users were more likely to survive the admission (p<0.001). In addition, we conducted a survey of doctors and found that knowledge regarding concurrent macrolide and statin use was lacking. These data suggest a potential role of statins in the management of CAP. Further research using high-dose statins is required to assess their safe use in subjects with mild to moderate infections.

Sepsis Induces a Dysregulated Neutrophil Phenotype That Is Associated with Increased Mortality

Background Neutrophil dysfunction in sepsis has been implicated in the pathogenesis of multiorgan failure; however, the role of neutrophil extracellular traps (NETs) remains uncertain. We aimed to determine the sequential changes in ex vivo NETosis and its relationship with mortality in patients with sepsis and severe sepsis. Methods This was a prospective observational cohort study enrolling 21 healthy age-matched controls and 39 sepsis and 60 severe sepsis patients from acute admissions to two UK hospitals. Patients had sequential bloods for the ex vivo assessment of NETosis in response to phorbol-myristate acetate (PMA) using a fluorometric technique and chemotaxis using time-lapse video microscopy. Continuous data was tested for normality, with appropriate parametric and nonparametric tests, whilst categorical data was analysed using a chi-squared test. Correlations were performed using Spearmans rho. Results Ex vivo NETosis was reduced in patients with severe sepsis, compared to patients with sepsis and controls (p = 0.002). PMA NETosis from patients with septic shock was reduced further (p < 0.001) compared to controls. The degree of metabolic acidosis correlated with reduced NETosis (p < 0.001), and this was replicated when neutrophils from healthy donors were incubated in acidotic media. Reduced NETosis at baseline was associated with an increased 30-day (p = 0.002) and 90-day mortality (p = 0.014) in sepsis patients. These findings were accompanied by defects in neutrophil migration and delayed apoptosis. Resolution of sepsis was not associated with the return to baseline levels of NETosis or migration. Conclusions Sepsis induces significant changes in neutrophil function with the degree of dysfunction corresponding to the severity of the septic insult which persists beyond physiological recovery from sepsis. The changes induced lead to the failure to effectively contain and eliminate the invading pathogens and contribute to sepsis-induced immunosuppression. For the first time, we demonstrate that reduced ex vivo NETosis is associated with poorer outcomes from sepsis.

Oxygen prescription: improving compliance using methods from BMJ Open Quality journal

Oxygen is an important drug frequently used in the management of acutely unwell hospital patients. However, oxygen overuse can have fatal side effects particularly for those patients at risk of iatrogenic hypercapnia. British Thoracic Society Guidelines state that oxygen must be prescribed for all patients, with target saturations stipulated on the prescription for patient safety. A quality improvement project was undertaken with the aim to improve the oxygen prescription rate across the respiratory ward at a district general hospital, over a period of 3u2009months. Quality improvement methods were implemented based on data analysis at each stage, following discussion with senior doctors and specialist nurses, and after reviewing previous quality improvement projects published on BMJ Open Quality. The initial interventions of poster reminders and multidisciplinary team education failed to significantly improve the rates of oxygen prescription. Use of a targeted intervention where stickers were placed above oxygen taps significantly improved prescription rate from 20% in the non-targeted group to 60% in the targeted group. This was based on a BMJ Open Quality published improvement method. The current guidelines from the British Thoracic Society, and hospital’s own guidelines, advise good oxygen prescribing. However, these recommendations alone are ineffective at achieving compliance among prescribers. Further targeted interventions have shown improvements in oxygen prescriptions and could lead to better clinical practice, patient care and safety.

LSC - 2017 - Effects of e-cigarette vapour condensate upon human alveolar macrophage function

The process of vaping may increase the cytotoxic effects of e-cigarette liquid (ECL) and increase the negative effects on alveolar macrophages yet many studies have used only unvaped fluid. We sought to examine the potential cytotoxic and functional effects of vaped and unvaped e-cigarette fluid on alveolar macrophages (AM). AMs were treated with e-cigarette vapour condensate (ECVC)/ECL +/- nicotine. Viability, apoptosis/necrosis, cytokine release, phagocytosis and ROS generation were then assessed. AM culture with ECL/ECVC resulted in dose dependent reduction in cell viability. ECVC was cytotoxic at lower concentrations than ECL (0.8% vs 5%, n=6). 24hr culture with 0.8% ECVC resulted in a 25% increase in apoptosis and necrosis (p ECVC is significantly more toxic to AMs than non-vaped ECL. Elevated inflammatory cytokine production and ROS suggests ECIG users may be inducing a chronic inflammatory state in vapour exposed AMs. Impaired phagocytic ability following ECVC exposure suggests AMs in the lung of ECIG users may show impaired bacterial clearance. Taken together this suggests ECIG users may experience more frequent and more severe bacterial infections due to impaired innate immune response by AMs.

S122 Effects of vaped e-cigarette liquid condensate upon human alveolar macrophage function. to vape or not to vape that is the question?

Introduction and objectives Electronic cigarette usage or “vaping” has risen exponentially in recent years in smokers and ex-smokers. Published data suggests that vaping e-cigarette liquid (ECL) may not be as benign as propounded by e-cigarette companies which are increasingly owned by “big tobacco”. Much of the current literature has focused on the effect of non-vaporised ECL – such studies do not fully reflect the exposure of the user, as the process of vaping causes chemical changes in ECL. To investigate the effect of unvaped ECL and vaped e-cig condensate (ECVC) using our novel system, with and without nicotine, on alveolar macrophage (AM) viability and immune responses. Methods We developed a novel method to produce ECVC to allow direct comparison with unvaped ECL. Nicotine concentration as assessed by GFID was 31 mg/ml in ECL and 26 mg/ml in ECVC. AMs were obtained from lung resection tissue and treated with ECVC/ECL ± nicotine. Cell viability was assessed by cell titre aqueous assay, apoptosis, necrosis and markers of macrophage phenotype (CD68, CD80, CD163, CD206) were assessed by flow cytometry. IL-8 release by AMs was assessed by ELISA. Results AM culture with ECL or ECVC resulted in dose dependent reduction in cell viability. ECVC was cytotoxic at lower concentrations than ECL (0.8% ECVC vs 5 %ECL, n = 6). 24 hour culture with 1% ECVC resulted in a 5fold increase in AM apoptosis and 2 fold increase in necrosis compared with 1%ECL (p = 0.079, n = 5). Nicotine containing ECVC caused more apoptosis vs nicotine free ECVC (27.2% vs 13.4%, (p = 0.0079,n = 4). Culture with 0.6%ECVC significantly increased supernatant levels of IL-8 compared with 1% ECL (p = 0.015, n = 4). ECVC was also found to affect macrophage phenotype, showing both nicotine dependent/independent regulations of markers of macrophage m1/m2 polarisation (CD80 p = 0.0357, CD163 p = 0.0179, CD206 p = 0.0357, n = 6). Conclusions Our novel system creates ECVC which is sterile, minimises loss of nicotine and prevents dilution of the vapour. Vaped E-cigarette condensate is significantly more toxic to AMs than non-vaped e cigarette liquid. Furthermore, ECVC with nicotine is significantly more toxic than ECVC without Nicotine. Effects shown on inflammatory cytokine production and markers of macrophage polarisation indicate both nicotine dependent and independent effects of ECVC on alveolar macrophages.

P264 Predicting mortality in hospital acquired pneumonia: a multivariate analysis

Background Hospital Acquired Pneumonia (HAP) is defined as lung infection in a non-intubated patient with new infiltrates on chest X-ray, >48 hours after hospital admission. Prediction scores exist for Community Acquired Pneumonia (CAP); no such scores exist in HAP. We aimed to identify features which are predictive of mortality in HAP. Methods All cases coded as HAP in Heart of England Foundation NHS trust in 2013 trust were identified (293 cases). For each of these cases the chest X-ray (including radiologists report) was reviewed; if X-ray did not show infiltrates consistent with pneumonia, cases were excluded leaving 153 cases for whom case notes were reviewed. Cases were excluded if diagnosis of HAP was made <48 hours after admission leaving 136 cases. Data was collected regarding demographics, co-morbidities, investigations, observations, mortality during admission and within 12 months. Univariate analysis was conducted to identify features associated with mortality. Multivariate analysis was completed using identified associated features. Results Sixty-four cases (47.0%) died during admission; and a further 32 within 12 months (70.5%). Demographics: Mean age was 81.6 years (range 52–98); mean number of co-morbidities was 5 (range 0–11). Mean haemoglobin was 110.9 g/dL. The mean white cell count (WCC) was 13.68 × 109/L (range 1.87–51.7 × 109/L). Mean urea was 10.5 mmol/L (range 1.9–6.1 mmol/L) Univariate analysis: Table 1 shows the results of the univariate analysis. Multivariate analysis: Only combination of raised urea and raised or low WCC were significantly associated with mortality (p = 0.024). Adding features of age, observations and co-morbidities did not improve prediction of mortality. Abstract P264 Table 1 Death during Admission Death within 12 months Feature and cut-off used P-value Odds Ratio and 95% Confidence Interval P-value Odds Ratio and 95% Confidence Interval Age > 65 0.376 OR 1.51 [CI: 0.422–5.437] 0.295 OR 1.707 [CI: 0.492–5.924] >5 co-morbidities 0.610 OR 0.821 [CI: 0.396–1.699] 0.081 OR 0.457 [CI: 0.185–1.107] Haemoglobin <120g/L 0.226 OR 1.40 [CI: 0.689–2.847] 0.181 OR 1.541 [CI: 0.713–3.330] Urea >7.8 mmol 0.005** OR 2.663 [CI: 1.312–5.40] <0.001** OR 3.412 [CI: 1.63–7.17] White Cell Count (WCC) >12 × 109/L or <4 × 109/L 0.082 1.72 [CI: 0.870–3.401] <0.039** OR 2.034 [CI: 0.986–4.197] New confusion 0.821 OR 0.882 [CI: 0.325-2.391] 0.030** OR 0.347 [CI: 0.117–1.00] Respiratory rate >20 breaths per minute 0.541 OR 1.027 [CI: 0.510–2.067] 0.441 OR 1.138 [0.542–2.389] Pulse >90 beats per minute 0.044** OR 1.921 [CI: 0.969–3.801] 0.030** OR 2.132 [CI: 1.029–4.420] Systolic BP <100 mmHg 0.439 OR 1.226 [CI: 0.455–3.309] 0.595 OR 1.026 [CI: 0.358–2.94] Diastolic BP <60 mmHg 0.415 OR 0.844 [CI: 0.383–1.863] 0.439 OR 0.862 [CI: 0.380–1.96] **Represents significance at p <0.05. Fishers exact test on 2 × 2 table, using R statistical package. OR = Odds Ratio CI = 95% confidence interval Conclusion Prediction of mortality in HAP is more complex than in CAP. On multivariate analysis, raised urea and raised or low WCC were predictive of mortality. Other features including age, number of comorbidities and observations at the time of diagnosis were not associated with mortality. This perhaps reflects our elderly cohort, with the majority having multiple co-morbidities, with very small numbers aged <65 years or with few co-morbidities. Further work with a larger dataset is ongoing.