Cardiovascular disease in Alpha 1 antitrypsin deficiency: an observational study assessing the role of neutrophil proteinase activity and the suitability of validated screening tools.

BACKGROUND: Alpha 1 Antitrypsin Deficiency (AATD) is a rare, inherited lung disease which shares features with Chronic Obstructive Pulmonary Disease (COPD) but has a greater burden of proteinase related tissue damage. These proteinases are associated with cardiovascular disease (CVD) in the general population. It is unclear whether patients with AATD have a greater risk of CVD compared to usual COPD, how best to screen for this, and whether neutrophil proteinases are implicated in AATD-associated CVD. This study had three aims. To compare CVD risk in never-augmented AATD patients to non-AATD COPD and healthy controls (HC). To assess relationships between CVD risk and lung physiology. To determine if neutrophil proteinase activity was associated with CVD risk in AATD. Cardiovascular risk was assessed by QRISK2® score and aortic stiffness measurements using carotid-femoral (aortic) pulse wave velocity (aPWV). Medical history, computed tomography scans and post-bronchodilator lung function parameters were reviewed. Systemic proteinase 3 activity was measured. Patients were followed for 4 years, to assess CVD development. RESULTS: 228 patients with AATD, 50 with non-AATD COPD and 51 healthy controls were recruited. In all COPD and HC participants, QRISK2® and aPWV gave concordant results (with both measures either high or in the normal range). This was not the case in AATD. Once aPWV was adjusted for age and smoking history, aPWV was highest and QRISK2® lowest in AATD patients compared to the COPD or HC participants. Higher aPWV was associated with impairments in lung physiology, the presence of emphysema on CT scan and proteinase 3 activity following adjustment for age, smoking status and traditional CVD risk factors (using QRISK2® scores) in AATD. There were no such relationships with QRISK2® in AATD. AATD patients with confirmed CVD at four-year follow up had a higher aPWV but not QRISK2® at baseline assessment. CONCLUSION: aPWV measured CVD risk is elevated in AATD. This risk is not captured by QRISK2®. There is a relationship between aPWV, lung disease and proteinase-3 activity. Proteinase-driven breakdown of elastin fibres in large arteries and lungs is a putative mechanism and forms a potential therapeutic target for CVD in AATD.

Survival following lung volume reduction procedures: results from the UK Lung Volume Reduction (UKLVR) registry.

INTRODUCTION: Lung volume reduction surgery (LVRS) and endobronchial valve (EBV) placement can produce substantial benefits in appropriately selected people with emphysema. The UK Lung Volume Reduction (UKLVR) registry is a national multicentre observational study set up to support quality standards and assess outcomes from LVR procedures at specialist centres across the UK. METHODS: Data were analysed for all patients undergoing an LVR procedure (LVRS/EBV) who were recruited into the study at participating centres between January 2017 and June 2022, including; disease severity and risk assessment, compliance with guidelines for selection, procedural complications and survival to February 2023. RESULTS: Data on 541 patients from 14 participating centres were analysed. Baseline disease severity was similar in patients who had surgery n=244 (44.9%), or EBV placement n=219 (40.9%), for example, forced expiratory volume in 1 s (FEV1) 32.1 (12.1)% vs 31.2 (11.6)%. 89% of cases had discussion at a multidisciplinary meeting recorded. Median (IQR) length of stay postprocedure for LVRS and EBVs was 12 (13) vs 4 (4) days(p=0.01). Increasing age, male gender and lower FEV1%predicted were associated with mortality risk, but survival did not differ between the two procedures, with 50 (10.8%) deaths during follow-up in the LVRS group vs 45 (9.7%) following EBVs (adjusted HR 1.10 (95% CI 0.72 to 1.67) p=0.661) CONCLUSION: Based on data entered in the UKLVR registry, LVRS and EBV procedures for emphysema are being performed in people with similar disease severity and long-term survival is similar in both groups.

Incidence of depression and antidepressant prescription in patients with COPD: A large UK population-based cohort study.

BACKGROUND: Depression is frequently reported in patients with Chronic Obstructive Pulmonary Disease (COPD). However, there is little information available on the incidence of depression following a COPD diagnosis. OBJECTIVE: To determine the incidence of a new diagnosis of depression or antidepressant prescription in people with and without a COPD diagnosis. METHODS: A matched cohort study was conducted using The Health Improvement Network database. Patients with confirmed COPD diagnosis were matched to up to four subjects without a COPD diagnosis by age, sex and GP practice. Cox proportional hazards models were used to assess the incidence rates of depression and antidepressant prescription. RESULTS: 44,362 patients with COPD and 124,140 subjects without COPD were included. The incidence rate of depression per 1000 person-years following COPD diagnosis was greater (11.4; 95% CI: 10.9-11.8) compared to subjects without COPD (5.7; 95% CI: 5.5-5.8) (p < 0.001). Patients with COPD were 42% more likely to have an incident depression (adjusted hazard ratio [aHR]: 1.42; 95% CI: 1.32-1.53; p < 0.001), and 40% more likely to be prescribed an antidepressant (aHR: 1.40; 95% CI: 1.35-1.45; p < 0.001). The incidence to either depression or antidepressant prescription was also greater for patients with COPD (aHR: 1.41; 95% CI: 1.36-1.46; p < 0.001). Patients with COPD and worse breathlessness had a higher risk of incident depression compared to patients with less breathlessness. CONCLUSION: Healthcare providers managing patients with COPD should be alert to the existence of depression and aware of its symptoms and consequences.

Risk of incident dementia and cognitive impairment in patients with chronic obstructive pulmonary disease (COPD): A large UK population-based study.

BACKGROUND: Although cognitive impairment and dementia are common comorbidities in patients with chronic obstructive pulmonary disease (COPD), estimates of incidence following a diagnosis of COPD are inconclusive. OBJECTIVE: To determine the incidence of cognitive impairment and dementia in people with and without a COPD diagnosis. METHODS: A population-based study using UK General Practice (GP) health records from The Health Improvement Network database was conducted. Patients with confirmed COPD diagnosis, ≥40 years old, were matched to up to four subjects without a COPD diagnosis by age, sex and GP practice. Cox proportional hazards models were used to assess the incidence rates of cognitive impairment and dementia. RESULTS: Of patients with COPD (n = 62,148), 9% developed cognitive impairment, compared with 7% of subjects without COPD (n = 230,076), p < 0.001. The incidence of cognitive impairment following COPD diagnosis was greater than in subjects without COPD following index date (adjusted Hazard Ratio (aHR), 1.21; 95% CI: 1.16 ─ 1.26, p < 0.001). The coded incidence of either cognitive impairment or dementia was also greater in patients with COPD following adjustment for confounders (aHR: 1.13, 95% CI: 1.09 ─ 1.18, p < 0.001). Coded incident dementia alone was not different between patients with COPD and subjects without COPD (aHR, 0.91, 95% CI: 0.83 ─ 1.01, p = 0.053). CONCLUSION: Despite the increased incidence of cognitive impairment in patients with COPD, incidence of dementia was not as frequently recorded in patients with COPD. This raises the concern of undiagnosed dementia and emphasises the need for a systematic assessment in this population.

Levels of circulating MMP-7 degraded elastin are elevated in pulmonary disorders.

OBJECTIVES: Elastin is a signature protein of the lungs. Matrix metalloproteinase-7 (MMP-7) is important in lung defence mechanisms and degrades elastin. However, MMP-7 activity in regard to elastin degradation has never been quantified serologically in patients with lung diseases. An assay for the quantification of MMP-7 generated elastin fragments (ELM7) was therefore developed to investigate MMP-7 derived elastin degradation in pulmonary disorders such as idiopathic pulmonary fibrosis (IPF) and lung cancer. DESIGN AND METHODS: Monoclonal antibodies (mABs) were raised against eight carefully selected MMP-7 cleavage sites on elastin. After characterisation and validation of the mABs, one mAB targeting the ELM7 fragment was chosen. ELM7 fragment levels were assessed in serum samples from patients diagnosed with IPF (n=123, baseline samples, CTgov reg. NCT00786201), and lung cancer (n=40) and compared with age- and sex-matched controls. RESULTS: The ELM7 assay was specific towards in vitro MMP-7 degraded elastin and the ELM7 neoepitope but not towards other MMP-7 derived elastin fragments. Serum ELM7 levels were significantly increased in IPF (113%, p<0.0001) and lung cancer (96%, p<0.0001) compared to matched controls. CONCLUSIONS: MMP-7-generated elastin fragments can be quantified in serum and may reflect pathological lung tissue turnover in several important lung diseases.

Chronic disease influences over 40 major life-changing decisions (MLCDs): a qualitative study in dermatology and general medicine.

BACKGROUND: Chronic disease not only impairs patients' psycho-social well-being but also influences major life-changing decisions (MLCDs). There is little information about the types of MLCDs affected and the long-term consequences. OBJECTIVES: The aims were to identify the MLCDs influenced by chronic disease, to define 'MLCD' and to suggest support strategies for patients taking MLCDs. METHODS: Adult dermatology patients explained how their chronic disease had influenced MLCDs in individual interviews. Adult patients from other medical specialities gave similar information by postal survey. NVivo8 software was used for qualitative analysis of data. Themes were categorized through a coding-recoding iterative process. RESULTS: There were 308 evaluable responses (male 55.2%; mean age = 51.8 years, mean disease duration = 19 years) from the 365 (55.7%) responses to the 655 patient invitations. These were used to generate themes to conceptualize 'MLCDs'. The most frequently reported MLCDs in the dermatology interviews concerned career choice (66%), job (58%), choice of clothing (54%), relationships (52%), education (44%), stopping swimming (34%), moving abroad (32%), not socializing (34%), wearing make-up (22%) and having children (22%). In the postal survey early retirement (40.6%), impact on job (29.4%), having children (24.8%), career choice (22.4%) and relationships (15.5%) were most commonly reported. The number of MLCDs reported by individuals was inversely related to age. Forty-one affected MLCD themes were grouped into 18 MLCD categories. A definition of MLCD was developed and strategies suggested to support patients. CONCLUSIONS: Chronic diseases influence a wide range of MLCDs. MLCDs are a novel domain in disease burden assessment. Clinicians' knowledge about this is important in patient management.

Increased augmentation index in patients with cystic fibrosis.

Increased large artery stiffness occurs in a range of inflammatory conditions indicating an ageing of the vasculature and additionally being an independent risk factor for cardiovascular events. We determined large artery parameters in adults with cystic fibrosis (CF). 50 clinically stable adult patients with CF (mean+/-sd age 28.0+/-8.2 yrs) and 26 controls matched for age, sex and body mass index were studied. Central aortic blood pressure, augmentation index (AIx) and aortic pulse wave velocity (PWV) were determined using applanation tonometry. Lung function, diabetic status and C-reactive protein (CRP) were also determined. Mean+/-sd AIx was greater in patients than controls, 8.5+/-11.1% and -1.8+/-13.1%, respectively (p<0.001), while PWV was similar. Although AIx was greatest in the sub-group with CF-related diabetes (CFRD), it was also increased in the non-CFRD sub-group when compared with controls. In patients, AIx was related to log(10) CRP (r = 0.33) and forced vital capacity (r = -0.34; both p<0.05), and CRP remained predictive in multiple regression. AIx is increased in adults with CF, in the presence of a normal blood pressure and independent of diabetic status. AIx was related to the systemic inflammatory status. These findings have implications for management and require further exploration so that cardiovascular health can be maintained.

Circulating matrix metalloproteinase-9 and osteoporosis in patients with chronic obstructive pulmonary disease.

Matrix metalloproteinase-9 (MMP-9) has been implicated in airways injury in chronic obstructive pulmonary disease (COPD). Osteoporosis is common in patients with COPD, and MMP-9 is an indicator of activated osteoclasts. We hypothesized that circulating MMP-9 would be related to bone mineral density (BMD) in COPD. We explored the relationship between MMP-9, tissue inhibitors of metalloproteinases (TIMP)-1 and -2, and BMD status in patients with COPD. A total of 70 clinically stable patients with confirmed COPD and 39 control subjects underwent spirometry, dual-energy x-ray absorptiometry to determine BMD, and venous sampling for measurement of cytokines and MMP-9 and TIMP-1 and -2. In patients, circulating MMP-9 was increased: mean (SD) 38.5 (2.2) compared with control subjects 20.1 (2.0) ng/mL, P < 0.001, whereas TIMP-1 and -2 were not different. In the patients, MMP-9 was greater in those with osteoporosis, compared with those with osteopenia, no bone disease or control subjects, and patients with osteopenia had greater MMP-9 than control subjects. The adjusted receiver operating characteristics curve area for MMP-9 detecting osteoporosis was 0.86. Patients had elevated systemic inflammatory mediators compared with control subjects, but these were unrelated to bone status. Increased circulating MMP-9 in patients with COPD was related to the presence of osteoporosis and not to lung function. MMP-9 may be a biomarker of increased bone resorption.

What community measurements can be used to predict bone disease in patients with COPD?

BACKGROUND: Osteoporosis is common in patients with COPD. Previously we have reported that loss of fat-free mass (FFM), measured by dual X-ray absorptiometry (DXA) is associated with loss of bone mineral density (BMD). In addition, in patients with a low body mass index (BMI) and a low FFM, all had evidence of bone thinning, 50% having osteopenia and 50% osteoporosis. We explored the utility of different anthropometric measures in detecting osteoporosis in a community-based COPD population. METHODS: Patients with confirmed COPD and not on long-term oral corticosteroids (n=58) performed spirometry. They underwent nutritional assessment by skinfold anthropometry, midarm circumference, calculation of both % ideal body weight (IBW) and BMI. All had DXA assessment of BMD. RESULTS: A total of 58 COPD patients had anthropometric measurements taken, with a mean age of 66.8 (SD 8.7) years, 31 (58%) were male, with a forced expiratory volume in 1s (FEV(1)) of 54.17 (20.18)% predicted. Osteoporosis was present at either the hip or lumbar region in 14 patients (24%). The useful anthropometric measurements identifying those with osteoporosis were both % IBW and BMI. The adjusted odds ratio for %IBW was 0.93 (95% confidence interval (CI) 0.87, 0.99), p=0.016 and for BMI: 0.79 (0.64-0.98), p=0.03. The receiver operating characteristics (ROC) score for both was 0.88, indicating a good fit. CONCLUSION: Osteoporosis is common, even in patients with mild airways obstruction. Nutritional assessment, incorporating a calculation of their BMI or %IBW may confer an additional benefit in detecting those at risk of osteoporosis and guide referral for BMD measurement.

Insulin resistance and inflammation - A further systemic complication of COPD.

Chronic obstructive pulmonary disease (COPD) is associated with a continuous systemic inflammatory response. Furthermore, COPD is associated with an excess risk for cardiovascular disease and type II diabetes. Systemic inflammation in other populations is a factor in atherogenesis and has been associated with insulin resistance. We assessed the association between systemic inflammation and insulin resistance in non-hypoxaemic patients with COPD. Fasting plasma glucose, insulin and inflammatory mediators were measured in 56 patients and 29 healthy subjects. Body mass index (BMI) and height squared fat- and fat-free-mass index were similar between subject groups. Using homeostatic modelling techniques, mean (SD) insulin resistance was greater in the patients, 1.68 (2.58) and 1.13 (2.02) in healthy subjects, p=0.032. Fasting plasma insulin was increased in patients while glucose was similar to that in healthy subjects. Patients had increased circulating inflammatory mediators. Insulin resistance was related to interleukin-6 (IL-6), r=0.276, p=0.039, and tumour necrosis factor alpha soluble receptor I, r=0.351, p=0.008. Both IL-6 and BMI were predictive variables of insulin resistance r(2)=0.288, p<0.05. We demonstrated greater insulin resistance in non-hypoxaemic patients with COPD compared with healthy subjects, which was related to systemic inflammation. This relationship may indicate a contributory factor in the excess risk of cardiovascular disease and type II diabetes in COPD.

Comparison of an oxygen concentrator and wall oxygen in the assessment of patients undergoing long term oxygen therapy assessment.

Long term oxygen therapy (LTOT) is a recognised management option for hypoxaemic patients with chronic respiratory disease. Formal assessment is required which is usually conducted in the hospital and performed on piped oxygen to ensure correction of the hypoxaemia. However, an oxygen concentrator is the standard oxygen source for the patient at home who requires LTOT. The oxygen concentration delivered is lower from a concentrator than piped oxygen. Here, we present a study of ten hypoxaemic patients using both delivery sources in a cross-over design. The partial pressure of oxygen was lower in patients when receiving oxygen from a concentrator, p < 0.05. This encourages the Clinician to consider formal assessments on an oxygen concentrator in order to ensure that the hypoxaemia will be corrected when they are prescribed a concentrator for home use.

Attaining a correct diagnosis of COPD in general practice.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is common. Diagnosis should include objective evidence of airways obstruction and spirometry is recommended in guidelines and the general medical services contract in the UK. We assessed the impact of spirometry in general practice. METHOD: We determined by questionnaire the availability, staff training, use and the interpretation results of spirometry in 72% of general practices in Wales. We reviewed the diagnosis of COPD previously made in two general practices without spirometry. RESULTS: Most practices had a spirometer (82.4%) and used it (85.6%). Confidence in use and interpretation of results varied widely: 58.1% were confident in use and 33.8% confident in interpretation. Spirometry was performed more often if confident in use and interpretation (both P<0.001) and was related to greater training periods (P<0.001). Spirometric confirmation of COPD varied widely (0-100%, median 37%). Of the 125 patients previously diagnosed with COPD 61 had spirometric confirmation, while 25 had reversible obstruction (range 210-800 mls), 34 had normal and 5 had restrictive spirometry. CONCLUSION: Despite incentives to perform spirometry in general practice, lack of adequate training in use and interpretation suggests use is confounded and the diagnosis of COPD is likely to be made on imprecise clinical grounds.

Altered tissue distribution in adults with cystic fibrosis.

BACKGROUND: Regional body composition was determined in adults with cystic fibrosis (CF). Our hypothesis was that dual energy x ray absorptiometry (DXA) scanning could assess the fat free mass, bone mineral content, and fat mass and determine the distribution of the changes. METHOD: Height squared indices were derived for fat mass (FMI), fat free mass (FFMI), and bone mineral content (BMCI) of the arm, leg, and trunk by DXA in 51 patients and 18 age/sex matched healthy subjects. RESULTS: The arm and leg FFMI in patients were less than in healthy controls (p<0.05); the deficit was leg>arm>trunk (-18.19%, -14.86%, +0.09%, p<0.02) and was related to severity of lung disease. Patients with a normal BMI and low total FFM (hidden loss) had a lower arm, leg and trunk FFMI than those with a normal BMI and total FFM (p<0.05). The BMCI for all body segments was lower in patients than in controls (p<0.001). The BMCI was lower in the leg and trunk (p<0.01) in patients with severe disease than in those with mild lung disease. In those with hidden FFM loss the BMCI was lower (p<0.05 in leg and trunk). There was no difference in the BMCI deficit between body segments. Fat mass in patients was not reduced. CONCLUSION: Preferential loss of FFM is related to severity of lung disease and occurs in patients with a normal BMI. A similar loss of BMC occurs while FM is preserved. A hierarchical pattern of FFM loss of legs>arms>trunk was shown; BMC loss was evenly distributed.

Modelling of DNA damage induced by energetic electrons (100 eV to 100 keV).

Modelling and calculations are presented for the spectrum of initial DNA damage produced by 100 eV to 100 keV energetic electrons. Analysis of the initial spectrum of damage, based upon the source (direct energy deposition and reactions with diffusing OH radicals) and complexity of damage, indicates that the majority of the interactions cause no damage to DNA and any damage that does occur is most likely to be a simple single strand break (SSB). The fraction of complex damage for energetic electrons is lower than that induced by low energy electrons and ultrasoft X rays but still represents an appreciable fraction (20-30%) of the total double strand breaks (DSBs). Relative yields of strand breaks are investigated for dependence on the assumed energy deposition threshold and on the probability of the hydroxyl radicals to produce a single strand break. The ratio of direct to indirect damage does not change significantly across the electron energy range investigated and the values lie well within the experimental data. The direct energy deposition in DNA represents a larger proportion of the damage although the contribution from the hydroxyl radicals is also substantial, both in terms of the absolute yield of the breaks and the complexity of the damage.

Influence of infected cell growth state on bacteriophage reactivation levels.

Reactivation of UV-C-inactivated Pseudomonas aeruginosa bacteriophages D3C3, F116, G101, and UNL-1 was quantified in host cells infected during the exponential phase, during the stationary phase, and after starvation (1 day, 1 and 5 weeks) under conditions designed to detect dark repair and photoreactivation. Our experiments revealed that while the photoreactivation capacity of stationary-phase or starved cells remained about the same as that of exponential-phase cells, in some cases their capacity to support dark repair of UV-inactivated bacteriophages increased over 10-fold. This enhanced reactivation capacity was correlated with the ca. 30-fold-greater UV-C resistance of P. aeruginosa host cells that were in the stationary phase or exposed to starvation conditions prior to irradiation. The dark repair capacity of P. aeruginosa cells that were infected while they were starved for prolonged periods depended on the bacteriophage examined. For bacteriophage D3C3 this dark repair capacity declined with prolonged starvation, while for bacteriophage G101 the dark repair capacity continued to increase when cells were starved for 24 h or 1 week prior to infection. For G101, the reactivation potentials were 16-, 18-, 10-, and 3-fold at starvation intervals of 1 day, 1 week, 5 weeks, and 1. 5 years, respectively. Exclusive use of exponential-phase cells to quantify bacteriophage reactivation should detect only a fraction of the true phage reactivation potential.

The link between physics and chemistry in track modelling.

The physical structure of a radiation track provides the initial conditions for the modelling of radiation chemistry. These initial conditions are not perfectly understood, because there are important gaps between what is provided by a typical track structure model and what is required to start the chemical model. This paper addresses the links between the physics and chemistry of tracks, with the intention of identifying those problems that need to be solved in order to obtain an accurate picture of the initial conditions for the purposes of modelling chemistry. These problems include the reasons for the increased yield of ionisation relative to homolytic bond breaking in comparison with the gas phase. A second area of great importance is the physical behaviour of low-energy electrons in condensed matter (including thermolisation and solvation). Many of these processes are not well understood, but they can have profound effects on the transient chemistry in the track. Several phenomena are discussed, including the short distance between adjacent energy loss events, the molecular nature of the underlying medium, dissociative attachment resonances and the ability of low-energy electrons to excite optically forbidden molecular states. Each of these phenomena has the potential to modify the transient chemistry substantially and must therefore be properly characterised before the physical model of the track can be considered to be complete.

A novel algorithm for tracing the interaction of a track with molecular targets--use of Delaunay triangulation.

This paper describes an efficient method for tracing interactions between a radiation track and molecular targets in a cell or nucleus. The method is efficient because it ensures that a minimal subset of interactions in the track needs to be tested for each score. It is most useful for high-energy particles since the number of interactions and range of the tracks increase with particle energy. In this method, the set of interactions, i.e. the track, is considered as a collection of points in three-dimensional space. This set, together with the eight vertices of a bounding box, is discretised as a collection of tetrahedra, each of which satisfies the Delaunay criterion. Because of the geometric properties of these tetrahedra, only those points which are connected to vertices of tetrahedra through which the target passes need be tested for scoring. An efficient algorithm is used to follow the track through the cell or the nucleus. The main benefit of the method is that it eliminates the need to test those interactions which are geometrically distant from the target. In particular, in cases where there are no interactions in the target, very few interactions need to be checked.