The challenges of recruiting never-smokers with chronic obstructive pulmonary disease from the large population-based Swedish CArdiopulmonary bioImage study (SCAPIS) cohort.

Background: A substantial proportion of individuals with COPD have never smoked, and it is implied to be more common than previously anticipated but poorly studied. Aim: To describe the process of recruitment of never-smokers with COPD from a population-based cohort (n = 30 154). Methods: We recruited never-smokers with COPD, aged 50-75 years, from six University Hospitals, based on: 1) post broncho-dilator forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) < 0.70 and 2) FEV1 50-100% of predicted value and 3) being never-smokers (self-reported). In total 862 SCAPIS participants were identified, of which 652 were reachable and agreed to a first screening by telephone. Altogether 128 (20%) were excluded due to previous smoking or declined participation. We also applied a lower limit of normal (LLN) of FEV1/FVC (z-score<-1.64) according to the Global Lung Initiative to ensure a stricter definition of airflow obstruction. Results: Data on respiratory symptoms, health status, and medical history were collected from 492 individuals, since 32 were excluded at a second data review (declined or previous smoking), prior to the first visit. Due to not matching the required lung function criteria at a second spirometry, an additional 334 (68%) were excluded. These exclusions were by reason of: FEV1/FVC ≥0.7 (49%), FEV1 > 100% of predicted (26%) or z-score ≥ -1,64 (24%). Finally, 154 never-smokers with COPD were included: 56 (36%) women, (mean) age 60 years, FEV1 84% of predicted, FEV1/FVC: 0.6, z-score: -2.2, Oxygen saturation: 97% and BMI: 26.8 kg/m2. Conclusions: The challenges of a recruitment process of never-smokers with COPD were shown, including the importance of correct spirometry testing and strict inclusion criteria. Our findings highlight the importance of repeated spirometry assessments for improved accuracy in diagnosing COPD.

Pulmonary function and atherosclerosis in the general population: causal associations and clinical implications.

Reduced lung function is associated with cardiovascular mortality, but the relationships with atherosclerosis are unclear. The population-based Swedish CArdioPulmonary BioImage study measured lung function, emphysema, coronary CT angiography, coronary calcium, carotid plaques and ankle-brachial index in 29,593 men and women aged 50-64 years. The results were confirmed using 2-sample Mendelian randomization. Lower lung function and emphysema were associated with more atherosclerosis, but these relationships were attenuated after adjustment for cardiovascular risk factors. Lung function was not associated with coronary atherosclerosis in 14,524 never-smokers. No potentially causal effect of lung function on atherosclerosis, or vice versa, was found in the 2-sample Mendelian randomization analysis. Here we show that reduced lung function and atherosclerosis are correlated in the population, but probably not causally related. Assessing lung function in addition to conventional cardiovascular risk factors to gauge risk of subclinical atherosclerosis is probably not meaningful, but low lung function found by chance should alert for atherosclerosis.

Real-Time Monitoring of Lysosomal Membrane Permeabilization Using Acridine Orange.

Loss of lysosomal membrane integrity results in leakage of lysosomal hydrolases to the cytosol which might harm cell function and induce cell death. Destabilization of lysosomes often precede apoptotic or necrotic cell death and occur during both physiological and pathological conditions. The weak base acridine orange readily enters cells and accumulates in the acidic environment of lysosomes. Vital staining with acridine orange is a well-proven technique to observe lysosomal destabilization using fluorescence microscopy and flow cytometry. These analyses are, however, time consuming and only adapted for discrete time points, which make them unsuitable for large-scale approaches. Therefore, we have developed a time-saving, high-throughput microplate reader-based method to follow destabilization of the lysosomal membrane in real-time using acridine orange. This protocol can easily be adopted for patient samples since the number of cells per sample is low and the time for analysis is short.

Unleashing the Power of Very Small Data to Predict Acute Exacerbations of Chronic Obstructive Pulmonary Disease.

Introduction: In this article, we explore to what extent it is possible to leverage on very small data to build machine learning (ML) models that predict acute exacerbations of chronic obstructive pulmonary disease (AECOPD). Methods: We build ML models using the small data collected during the eHealth Diary telemonitoring study between 2013 and 2017 in Sweden. This data refers to a group of multimorbid patients, namely 18 patients with chronic obstructive pulmonary disease (COPD) as the major reason behind previous hospitalisations. The telemonitoring was supervised by a specialised hospital-based home care (HBHC) unit, which also was responsible for the medical actions needed. Results: We implement two different ML approaches, one based on time-dependent covariates and the other one based on time-independent covariates. We compare the first approach with standard COX Proportional Hazards (CPH). For the second one, we use different proportions of synthetic data to build models and then evaluate the best model against authentic data. Discussion: To the best of our knowledge, the present ML study shows for the first time that the most important variable for an increased risk of future AECOPDs is "maintenance medication changes by HBHC". This finding is clinically relevant since a sub-optimal maintenance treatment, requiring medication changes, puts the patient in risk for future AECOPDs. Conclusion: The experiments return useful insights about the use of small data for ML.

The Exacerbation of Chronic Obstructive Pulmonary Disease: Which Symptom is Most Important to Monitor?

Background: GOLD 2023 defines an exacerbation of COPD (ECOPD) by a deterioration of breathlessness at rest (BaR), mucus and cough. The severity of an ECOPD is determined by the degree of BaR, ranging from 0 to 10. However, it is not known which symptom is the most important one to detect early of an ECOPD, and which symptom that predicts future ECOPDs best. Thus, the purpose of the present study was to find out which symptom is the most important one to monitor. Methods: We analysed data on COPD symptoms from the telehealth study The eHealth Diary. Frequent exacerbators (n = 27) were asked to daily monitor BaR and breathlessness at physical activity (BaPA), mucus and cough, employing a digital pen and symptom scales (0-10). Twenty-seven patients with 105 ECOPDs were analysed. The association between symptom development and the occurrence of exacerbations was evaluated using the Andersen-Gill formulation of the Cox proportional hazards model for the analysis of recurrent time-to-event data with time-varying predictors. Results: According to the criteria proposed by GOLD 2023, 42% ECOPDs were mild, 48% were moderate and 5% were severe, while 6% were undefinable. Mucus and cough improved over study time, while BaR and BaPA deteriorated. Mucus appeared earliest, which was the most prominent feature of the average exacerbation, and worsening of mucus increased the risk for a future ECOPD. There was a 58% increase in the risk of exacerbation per unit increase in mucus score. Conclusion: This study suggests that mucus worsening is the most important COPD symptom to monitor to detect ECOPDs early and to predict future risk för ECOPDs. In the present study, we also noticed a pronounced difference between GOLD 2022 and 2023. Hence, GOLD 2023 defined the ECOPD severity much lower than GOLD 2022 did.

Skeletal Myosteatosis is Associated with Systemic Inflammation and a Loss of Muscle Bioenergetics in Stable COPD.

Background: Common features among patients with more advanced chronic obstructive pulmonary disease (COPD) are systemic inflammation and a loss of both muscle mass and normal muscle composition. In the present study, we investigated COPD subjects to better understand how thigh muscle fat infiltration (MFI) and energy metabolism relate to each other and to clinical features of COPD with emphasis on systemic inflammation. Methods: Thirty-two Caucasians with stable COPD were investigated using questionnaires, lung function tests, blood analysis and magnetic resonance imaging (MRI) for analysis of body- and thigh muscle composition. Bioenergetics in the resting thigh muscle, expressed as the PCr/Pi ratio, were analysed using 31phosphorus magnetic resonance spectroscopy (31P-MRS). Results: Based on the combination of the MFI adjusted for sex (MFIa) and the thigh fat-tissue free muscle volume, expressed as the deviation from the expected muscle volume of a matched virtual control group (FFMVvcg), all COPD subjects displayed abnormally composed thigh muscles. Clinical features of increased COPD severity, including a decrease of blood oxygenation (r = -0.44, p < 0.05) and FEV1/FVC ratio, reflecting airway obstruction (r = -0.53, p < 0.01) and an increase of COPD symptoms (r = 0.37, p < 0.05) and breathing frequency at rest (r = 0.41, p < 0.05), were all associated with a raise of the PCr/Pi ratio in the thigh muscle. Increased MFIa of the thigh muscle correlated positively with markers of systemic inflammation (white blood cell count, r = 0.41, p < 0.05; fibrinogen, r = 0.44, p < 0.05), and negatively with weekly physical activity (r = -0.40, p < 0.05) and the PCr/Pi ratio in the resting thigh muscle (r = -0.41, p < 0.05). Conclusion: The present study implies a link between systemic inflammation, excessive MFI and a loss of bioenergetics in subjects with stable COPD.

Mixed Airway and Pulmonary Parenchymal Disease in Patients With Primary Sjögren Syndrome: A 6-year Follow-up.

OBJECTIVE: To assess pulmonary function and chronic obstructive pulmonary disease (COPD) development over time in patients with primary Sjögren syndrome (pSS), as well as the association between pulmonary function, radiographic findings, respiratory symptoms, and clinical features of pSS, taking cigarette consumption into account. METHODS: Forty patients with pSS (mean age 66 yrs; range 42-81 yrs; 39 women), previously participating in a cross-sectional study on pulmonary involvement in pSS, were reassessed by pulmonary function tests after a mean follow-up time of 6 years. At follow-up, patients were also assessed by high-resolution computed tomography of the chest, as well as for pSS disease activity, respiratory symptoms, and cigarette consumption. RESULTS: Patients with pSS showed significantly decreased percentages of predicted total lung capacity (TLC), residual volume (RV), RV/TLC ratio, and diffusing capacity of the lungs for carbon monoxide, as well as an increase in predicted forced expiratory volume in 1 second/vital capacity (FEV1/VC) ratio from baseline to follow-up. The proportion of COPD in patients with pSS did not change significantly from baseline to follow-up (38% vs 40%, respectively). Radiographic signs of bronchial involvement and interstitial lung disease were each found in 38% of the patients. CONCLUSION: Both airway and pulmonary parenchymal disease were commonly found in patients with pSS, with a coexistence of both an obstructive and restrictive pulmonary function pattern, where the latter tended to deteriorate over time. COPD was a common finding. Airway and pulmonary involvement may be underdiagnosed in pSS, which is why special attention to clinical assessment of pulmonary involvement in patients with pSS is mandated.

Human Lung Macrophages Challenged to Oxidants ex vivo: Lysosomal Membrane Sensitization is Associated with Inflammation and Chronic Airflow Limitation.

BACKGROUND: The lung macrophage (LM) is involved in most inflammatory processes of the human lung by clearance of dying cells and by wound repair. Upon cellular stress by oxidant challenge in vivo lysosomes may rupture in LMs and leakage of cellular content and cell debris may trigger airway inflammation and fibrosis, which may lead to chronic airflow limitation (CAL). OBJECTIVE: The aim of this study was to determine whether lysosomal membrane permeabilization (LMP) in LMs challenged to oxidants ex vivo is associated with airway inflammation and CAL, the latter assessed as the reduced forced expiratory volume in one second (FEV1) expressed as % of predicted. MATERIALS AND METHODS: Twenty-eight subjects were investigated; 13 lung-healthy subjects and 15 subjects with a variety of inflammatory disorders, demonstrating CAL on dynamic spirometry (defined as an FEV1/FVC ratio < 0.70). LMs were harvested by broncho-alveolar lavage (BAL) and challenged ex vivo by oxidants. LMP in oxidant-exposed LMs was assessed as the emitted acridine orange (AO) green fluorescence from oxidant-exposed LMs (using macrophage-like murine J774 cells as positive controls). Inflammatory cells in BAL were counted and lung volumes were recorded. RESULTS: Oxidant-induced LMP in LMs was significantly greater among subjects with CAL and particularly among those with ongoing inflammation. Previous tobacco history did not influence LMP. Among subjects with CAL, oxidant-induced LMP correlated negatively with FEV1% of predicted. CONCLUSION: Lysosomes of LMs harvested from patients with CAL demonstrate an increased sensitivity to oxidants, which may trigger mechanisms behind CAL, eg, chronic airway inflammation and fibrotic re-modelling. The study suggests a mechanistic role for LMP in LMs on airway inflammation, suggesting an anti-inflammatory effect by drugs that prevent increased LMP.

Chronic airflow limitation and its relation to respiratory symptoms among ever-smokers and never-smokers: a cross-sectional study.

BACKGROUND: The diagnosis of chronic obstructive pulmonary disease is based on the presence of persistent respiratory symptoms and chronic airflow limitation (CAL). CAL is based on the ratio of forced expiratory volume in 1 s to forced vital capacity (FEV1:FVC) after bronchodilation, and FEV1:FVC less than the fifth percentile is often used as a cut-off for CAL. The aim was to investigate if increasing percentiles of FEV1:FVC were associated with any respiratory symptom (cough with phlegm, dyspnoea or wheezing) in a general population sample of never-smokers and ever-smokers. METHODS: In a cross-sectional study comprising 15 128 adults (50-64 years), 7120 never-smokers and 8008 ever-smokers completed a respiratory questionnaire and performed FEV1 and FVC after bronchodilation. We calculated their z-scores for FEV1:FVC and defined the fifth percentile using the Global Lung Function Initiative (GLI) reference value, GLI5 and increasing percentiles up to GLI25. We analysed the associations between different strata of percentiles and prevalence of any respiratory symptom using multivariable logistic regression for estimation of OR. RESULTS: Among all subjects, regardless of smoking habits, the odds of any respiratory symptom were elevated up to the GLI15-20 strata. Among never-smokers, the odds of any respiratory symptom were elevated at GLI<5 (OR 3.57, 95% CI 2.43 to 5.23) and at GLI5-10 (OR 2.57, 95% CI 1.69 to 3.91), but not at higher percentiles. Among ever-smokers, the odds of any respiratory symptom were elevated from GLI<5 (OR 4.64, 95% CI 3.79 to 5.68) up to GLI≥25 (OR 1.33, 95% CI 1.00 to 1.75). CONCLUSIONS: The association between percentages of FEV1:FVC and respiratory symptoms differed depending on smoking history. Our results support a higher percentile cut-off for FEV1:FVC for never-smokers and, in particular, for ever-smokers.

The Health Diary Telemonitoring and Hospital-Based Home Care Improve Quality of Life Among Elderly Multimorbid COPD and Chronic Heart Failure Subjects.

Background: Elderly, multimorbid patients with advanced chronic obstructive pulmonary disease (COPD) and/or chronic heart failure (CHF) exhibit poor health-related quality of life (HRQoL). Telemonitoring, based on digital pen technology, supported by hospital-based home care (HBHC) significantly reduces the number of hospitalizations. We hypothesized that the same intervention would prevent the deterioration of HRQoL that follows upon disease progression. Methods: Elderly computer-illiterate subjects with ≥2 hospitalizations the previous year were included. HRQoL was assessed at inclusion (baseline) and at 1, 6 and 12 months employing EuroQol-5 Dimensions (EQ-5D) and RAND-36 for general HRQoL, and Minnesota Living with Heart Failure Questionnaire (MLHFQ) and St. Georges Respiratory Questionnaire (SGRQ) for disease-specific HRQoL. Healthcare contacts, hospitalizations, as-needed medications, prescription changes and healthcare costs were registered. Results: Ninety-four patients were enrolled of which 53 subjects completed the 12-month study period. Compared to baseline, most domains of RAND-36 were improved significantly at 1 time-point or more. Only among COPD subjects, the disease-specific HRQoL was worsened at the 12 month evaluation. Measures of healthcare dependency were associated with poor HRQoL. Conclusion: The Health Diary system and HBHC together improve general HRQoL, and measures of healthcare dependency are associated with HRQoL variables.

Elderly patients with COPD require more health care than elderly heart failure patients do in a hospital-based home care setting.

Background: Elderly patients with advanced stages of COPD or chronic heart failure (CHF) often require hospitalization due to exacerbations. We hypothesized that telemonitoring supported by hospital-based home care (HBHC) would detect exacerbations early, thus, reducing the number of hospitalization. We also speculated that patients with advanced COPD or CHF would present differences regarding exacerbation frequency and the need of HBHC. Methods: The Health Diary system, based on digital pen technology, was employed. Patients aged ≥65 years with ≥2 hospitalizations the previous year were included. Exacerbations were categorized and treated as either COPD or CHF exacerbation by an experienced physician. All HBHC contacts (home visits or telephone consultations) were registered. Results: Ninety-four patients with advanced diseases were enrolled (36 COPD and 58 CHF subjects) of which 53 subjects (19 COPD and 34 CHF subjects) completed the 1-year study period. Death was the major reason for not finalizing the study. Compared to the 1-year prior inclusion, the intervention significantly reduced hospitalization. Although COPD subjects were younger with less comorbidity, exacerbations and HBHC contacts were significantly greater in this group. Conclusions: COPD subjects exhibit exacerbations more frequently, mainly due to disease characteristics, thus, demanding much more HBHC.

The influence of disease severity and lifestyle factors on the peak annual 25(OH)D value of COPD patients.

BACKGROUND: The prevalence of individuals deficient in vitamin D (defined as a serum level of the stable metabolite 25(OH)D <50 nmol/L) is increasing in countries with low annual ultraviolet (UV) radiation and among individuals unable to perform outdoor activities, for example, COPD patients. OBJECTIVE: To assess the role of vitamin D deficiency, independently of seasonal variation, the peak annual value of 25(OH)D was measured in subjects with advanced COPD ± long-term oxygen therapy (LTOT) and lung healthy control subjects. A method to grade the individual annual UV light exposure was designed and tested. SUBJECTS AND METHODS: Sixty-six Caucasians with advanced COPD (28 with LTOT) and 47 control subjects were included, and the levels of 25(OH)D were determined in late summer/early fall when the annual peak was assumed. Questionnaires about COPD symptoms, general health, lifestyle, dietary habits and QoL were used to collect data. Lung function tests and blood sampling were performed. RESULTS: The peak annual 25(OH)D of COPD subjects was significantly lower than in the control subjects, but there was no significant difference between COPD patients with and without LTOT. Ongoing vitamin D supplementation was the single most important intervention to maintain 25(OH)D levels ≥50 nmol/L. Among vitamin D-deficient COPD subjects, 25(OH) D correlated positively with forced expiratory volume in 1 second as % predicted, Modified British Medical Research Council score, blood oxygenation, food portion size, Mediterranean Diet Score and Ultraviolet Score. CONCLUSION: Vitamin D deficiency was common among healthy individuals and COPD subjects. Peak annual 25(OH)D levels of COPD subjects correlated with clinically important outcomes. The present study emphasizes the need to routinely monitor vitamin D status among patients with advanced COPD and to consider to medicate those with vitamin D deficiency with vitamin D supplementation.

Oxidant-induced autophagy and ferritin degradation contribute to epithelial-mesenchymal transition through lysosomal iron.

PURPOSE: Transforming growth factor (TGF)-ß1 triggers epithelial-mesenchymal transition (EMT) through autophagy, which is partly driven by reactive oxygen species (ROS). The aim of this study was to determine whether leaking lysosomes and enhanced degradation of H-ferritin could be involved in EMT and whether it could be possible to prevent EMT by iron chelation targeting of the lysosome. MATERIALS AND METHODS: EMT, H-ferritin, and autophagy were evaluated in TGF-ß1-stimulated A549 human lung epithelial cells cultured in vitro using Western blotting, with the additional morphological assessment of EMT. By using immunofluorescence and flow cytometry, lysosomes and ROS were assessed by acridine orange and 6-carboxy-2',7'-dichlorodihydrofluorescein acetate assays, respectively. RESULTS: TGF-ß1-stimulated cells demonstrated a loss of H-ferritin, which was prevented by the antioxidant N-acetyl-L-cysteine (NAC) and inhibitors of lysosomal degradation. TGF-ß1 stimulation generated ROS and autophagosome formation and led to EMT, which was further promoted by the additional ROS-generating cytokine, tumor necrosis factor-α. Lysosomes of TGF-ß1-stimulated cells were sensitized to oxidants but also completely protected by lysosomal loading with dextran-bound deferoxamine (DFO). Autophagy and EMT were prevented by NAC, DFO, and inhibitors of autophagy and lysosomal degradation. CONCLUSION: The findings of this study support the role of enhanced autophagic degradation of H-ferritin as a mechanism for increasing the vulnerability of lysosomes to iron-driven oxidant injury that triggers further autophagy during EMT. This study proposes that lysosomal leakage is a novel pathway of TGF-ß1-induced EMT that may be prevented by iron-chelating drugs that target the lysosome.

A retrospective chart review of pirfenidone-treated patients in Sweden: the REPRIS study.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive lung disease that usually results in respiratory failure and death. Pirfenidone was approved as the first licensed therapy for IPF in Europe based on phase III trials where patients with a forced vital capacity (FVC) >50% of predicted were included. The aim of this study was to characterise patients treated with pirfenidone in Swedish clinical practice and to describe the adherence to the reimbursement restriction since reimbursement was only applied for patients with FVC below 80% of predicted. METHODS: This was a retrospective, observational chart review of IPF patients treated with pirfenidone from three Swedish university clinics. Patients initiated on treatment during the period 28 June 2012 to 20 November 2014 were included. Data on patient characteristics, basis of diagnosis, treatment duration, quality of life, and adverse drug reactions (ADRs) were collected from medical charts. RESULTS: Forty-four patients were screened and 33 were included in the study. The mean treatment duration from start of pirfenidone until discontinuation or end of study was 38 weeks. At the initiation of pirfenidone treatment, FVC was 62.7% (12.1) [mean (SD)], diffusion capacity (DLco) was 45.1% (13.8) of predicted, and the ratio of forced expiratory volume on 1 sec (FEV1) to FVC was 0.78 (0.1). The percentage of patients with an FVC between 50 and 80% was 87%. Ten of the patients had ADRs including gastrointestinal and skin-related events, cough and signs of impaired hepatic function, but this led to treatment discontinuation in only two patients. CONCLUSION: Data from this chart review showed that adherence to the Swedish reimbursement restriction was followed in the majority of patients during the study period. At the start of pirfenidone treatment, lung function, measured as FVC, was lower in the present cohort of Swedish IPF patients compared with other registry and real-life data. About a third of the patients had ADRs, but discontinuation of the treatment because of ADRs was relatively uncommon.

Does quantitative lung SPECT detect lung abnormalities earlier than lung function tests? Results of a pilot study.

BACKGROUND: Heterogeneous ventilation in lungs of individuals with allergies, cigarette smokers, asthmatics and chronic obstructive pulmonary disease (COPD) patients has been demonstrated using imaging modalities such as positron emission tomography (PET), magnetic resonance imaging (MRI) and single-photon emission computed tomography (SPECT). These individuals suffer from narrow and/or closed airways to various extents. By calculating regional heterogeneity in lung ventilation SPECT images as the coefficient of variation (CV) in small elements of the lung, heterogeneity maps and CV-density curves can be generated and used to quantitatively measure heterogeneity. This work explores the potential to use such measurements to detect mild ventilation heterogeneities in lung-healthy subjects. METHOD: Fourteen healthy subjects without documented lung disease or respiratory symptoms, and two patients with documented airway disease, inhaled on average approximately 90 MBq (99m)Tc-Technegas immediately prior to the 20-min SPECT acquisition. Variation in activity uptake between subjects was compensated for in resulting CV values. The area under the compensated CV density curve (AUC), for CV values greater than a threshold value CVT, AUC(CV > CVT), was used as the measure of ventilation heterogeneity. RESULTS: Patients with lung function abnormalities, according to lung function tests, generated higher AUC(CV > 20%) values compared to healthy subjects (p = 0.006). Strong linear correlations with the AUC(CV > 20%) values were found for age (p = 0.006) and height (p = 0.001). These demonstrated that ventilation heterogeneities increased with age and that they depend on lung size. Strong linear correlations were found for the lung function value related to indices of airway closure/air trapping, residual volume/total lung capacity (RV/TLC; p = 0.009), and diffusion capacity of the lung for carbon monoxide adjusted for haemoglobin concentration in the blood (DLCOc; p = 0.009), a value partly related to supposed ventilation/perfusion mismatch. These findings support the association between conventional lung function tests and the AUC(CV > 20%) value. CONCLUSIONS: Among the healthy subjects, there is a group with increased AUC(CV > 20%) values, but with normal lung function tests, which implies that it might be possible to differentiate ventilation heterogeneities earlier in a disease process than by lung function tests.

Quantitative lung SPECT applied on simulated early COPD and humans with advanced COPD.

BACKGROUND: Reduced ventilation in lung regions affected by chronic obstructive pulmonary disease (COPD), reflected as inhomogeneities in the single-photon emission computed tomography (SPECT) lung image, is correlated to disease advancement. An analysis method for measuring these inhomogeneities is proposed in this work. The first aim was to develop a quantitative analysis method that could discriminate between Monte Carlo simulated normal and COPD lung SPECT images. A second aim was to evaluate the ability of the present method to discriminate between human subjects with advanced COPD and healthy volunteers. METHODS: In the simulated COPD study, different activity distributions in the lungs were created to mimic the healthy lung (normal) and different levels of COPD. Gamma camera projections were Monte Carlo simulated, representing clinically acquired projections of a patient who had inhaled 125 MBq 99mTc-Technegas followed by a 10-min SPECT examination. Reconstructions were made with iterative ordered subset expectation maximisation. The coefficient of variance (CV) was calculated for small overlapping volumes covering the 3D reconstructed activity distribution. A CV threshold value (CVT) was calculated as the modal value of the CV distribution of the simulated normal. The area under the distribution curve (AUC), for CV values greater than CVT, AUC(CVT), was then calculated. Moreover, five patients with advanced emphysema and five healthy volunteers inhaled approximately 75 MBq 99mTc-Technegas immediately before the 20-min SPECT acquisition. In the human study, CVT was based on the mean CV distribution of the five healthy volunteers. RESULTS: A significant difference (p < 0.001) was found between the Monte-Carlo simulated normal and COPD lung SPECT examinations. The present method identified a total reduction of ventilation of approximately 5%, not visible to the human eye in the reconstructed image. In humans the same method clearly discriminated between the five healthy volunteers and five patients with advanced COPD (p < 0.05). CONCLUSIONS: While our results are promising, the potential of the AUC(CVT) method to detect less advanced COPD in patients needs further clinical studies.

Vitamin D enhances IL-1ß secretion and restricts growth of Mycobacterium tuberculosis in macrophages from TB patients.

The emergence of multidrug-resistant strains of Mycobacterium tuberculosis (MTB), the bacterium responsible for tuberculosis (TB), has rekindled the interest in the role of nutritional supplementation of micronutrients, such as vitamin D, as adjuvant treatment. Here, the growth of virulent MTB in macrophages obtained from the peripheral blood of patients with and without TB was studied. The H37Rv strain genetically modified to express Vibrio harveyi luciferase was used to determine the growth of MTB by luminometry in the human monocyte-derived macrophages (hMDMs) from study subjects. Determination of cytokine levels in culture supernatants was performed using a flow cytometry-based bead array technique. No differences in intracellular growth of MTB were observed between the different study groups. However, stimulation with 100nM 1,25-dihydroxyvitamin D significantly enhanced the capacity of hMDMs isolated from TB patients to control the infection. This effect was not observed in hMDMs from the other groups. The interleukin (IL)-1ß and IL-10 release by hMDMs was clearly increased upon stimulation with 1,25-dihydroxyvitamin D. Furthermore, the 1,25-dihydroxyvitamin D stimulation also led to elevated levels of TNF-α (tumor necrosis factor-alpha) and IL-12p40. It was concluded that vitamin D triggers an inflammatory response in human macrophages with enhanced secretion of cytokines, as well as enhancing the capacity of hMDMs from patients with active TB to restrict mycobacterial growth.