To evaluate the optimal tracer uptake time, the minimal amount of radioactivity and the inter-observer agreement for 11C-choline positron emission tomography/computed tomography (PET/CT) in patients with primary hyperparathyroidism (pHPT). Twenty-one patients with biochemically proven pHPT were retrospectively studied after injection of 6.3 ± 1.2 MBq/kg 11C-choline. PET data of the first nine patients, scanned for up to 60 min, were reconstructed in 10-min frames from 10- to 60-min postinjection (p.i.), mimicking varying 11C-choline uptake times. Parathyroid adenoma to background contrast ratios were calculated and compared, using standardized uptake values (SUVs). Data was reconstructed with varying scan durations (1, 2.5, 5, and 10 min) at 20–30-min p.i. (established optimal uptake time), mimicking less administered radioactivity. To establish the minimal required radioactivity, the SUVs in the shorter scan durations (1, 2.5, and 5 min) were compared to the 10-min scan duration to determine whether increased variability and/or statistical differences were observed. Four observers analyzed the 11C-choline PET/CT in four randomized rounds for all patients. SUVpeak of the adenoma decreased from 30 to 40 p.i. onwards. All adenoma/background contrast ratios did not differ from 20- to 30-min p.i. onwards. The SUVs of adenoma in the scan duration of 1, 2.5, and 5 min all differed significantly from the same SUV in the 10-min scan duration (all p = 0.012). However, the difference in absolute SUV adenoma values was well below 10% and therefore not considered clinically significant. The inter-observer analysis showed that the Fleiss’ kappa of the 1-min scan were classified as “moderate,” while these values were classified as “good” in the 2.5-, 5-, and 10-min scan duration. Observers scored lower certainty scores in the 1- and 2.5-min scans compared to the 5- and 10-min scan durations. The optimal time to start PET/CT scanning in patients with pHPT is 20 min after mean injection of 6.3 MBq/kg 11C-choline, with a recommended scan duration of at least 5 min. Alternatively, the radioactivity dose can be lowered by 50% while keeping a 10-min scan duration without losing the accuracy of 11C-choline PET/CT interpretation.

Acute allograft rejection is one of the major complications after lung transplantation, and adequate and early recognition is important. Till now, the reference standard to detect acute rejection is the histopathological grading of transbronchial biopsies (TBBs). Acute rejection is characterised by high levels of activated T lymphocytes. Interleukin-2 (IL-2) binds specifically to high-affinity IL-2 receptors expressed on the cell membrane of activated T lymphocytes. The aim of this proof-of-concept study was to evaluate if non-invasive imaging with 99mTc-HYNIC-IL-2 is able to detect acute rejection after lung transplantation. 99mTc-HYNIC-IL-2 scintigraphy (static, SPECT/CT of the lungs) was performed shortly before routine transbronchial biopsy (pathology as reference standard). Scans were scored as likely or unlikely for rejection, and semiquantitative analysis (target-to-background ratio) was performed. Thirteen patients were included of which 3 showed acute rejection at transbronchial biopsy; in 2 of these patients (scored as graded 2–3 at pathology), the scan was scored likely for rejection, and in 1 patient (scored grade 1 at pathology), the scan was scored unlikely. No correlation was found between biopsy results and semiquantitative analysis. 99mTc-HYNIC-IL-2 scintigraphy proved to be a good technique to detect grade 2 and 3 acute rejection in a small sample population of patients after lung transplantation. Larger studies are necessary to really show the added value of this non-invasive specific imaging technique over transbronchial biopsy. Alternatively, imaging with the PET tracer 18F-IL-2 may be useful for this purpose.

Purpose: To evaluate the optimal tracer uptake time, the minimal amount of radioactivity and the inter-observer agreement for C-choline positron emission tomography/computed tomography (PET/CT) in patients with primary hyperparathyroidism (pHPT). Methods: Twenty-one patients with biochemically proven pHPT were retrospectively studied after injection of 6.3 ± 1.2 MBq/kg C-choline. PET data of the first nine patients, scanned for up to 60 min, were reconstructed in 10-min frames from 10to 60-min postinjection (p.i.), mimicking varying C-choline uptake times. Parathyroid adenoma to background contrast ratios were calculated and compared, using standardized uptake values (SUVs). Data was reconstructed with varying scan durations (1, 2.5, 5, and 10 min) at 20–30-min p.i. (established optimal uptake time), mimicking less administered radioactivity. To establish the minimal required radioactivity, the SUVs in the shorter scan durations (1, 2.5, and 5 min) were compared to the 10-min scan duration to determine whether increased variability and/or statistical differences were observed. Four observers analyzed the C-choline PET/CT in four randomized rounds for all patients. Results: SUVpeak of the adenoma decreased from 30 to 40 p.i. onwards. All adenoma/background contrast ratios did not differ from 20to 30-min p.i. onwards. The SUVs of adenoma in the scan duration of 1, 2.5, and 5 min all differed significantly from the same SUV in the 10-min scan duration (all p = 0.012). However, the difference in absolute SUV adenoma values was well below 10% and therefore not considered clinically significant. The inter-observer analysis showed that the Fleiss’ kappa of the 1-min scan were classified as “moderate,” while these values were classified as “good” in the 2.5-, 5-, and 10-min scan duration. Observers scored lower certainty scores in the 1and 2.5-min scans compared to the 5and 10-min scan durations. (Continued on next page) © The Author(s). 2019 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. * Correspondence: a.h.brouwers@umcg.nl The data presented in this paper has been presented at the EANM’18 31st Annual Congress Meeting (Oct 13–17, 2018, Düsseldorf, Germany) as an oral presentation. University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, P.O. Box 30 001, 9700, RB, Groningen, The Netherlands Full list of author information is available at the end of the article Noltes et al. EJNMMI Research (2019) 9:73 Page 2 of 10 (Continued from previous page) Conclusion: The optimal time to start PET/CT scanning in patients with pHPT is 20min after mean injection of 6.3 MBq/kg C-choline, with a recommended scan duration of at least 5 min. Alternatively, the radioactivity dose can be lowered by 50% while keeping a 10-min scan duration without losing the accuracy of C-choline PET/CT interpretation.

Nasal gene expression profiling is a promising method to characterize COPD non-invasively. We aimed to identify a nasal gene expression profile to distinguish COPD patients from healthy controls. We investigated whether this COPD-associated gene expression profile in nasal epithelium is comparable with the profile observed in bronchial epithelium.

To investigate if age, gender and smoking are associated with airway wall thickness (AWT) measured by high resolution computed tomography (HRCT) and if higher AWT is associated with lower levels of pulmonary function in healthy current- and never-smokers with a wide age range.

Introduction: Nasal gene expression profiling is a promising method to characterize COPD non-invasively. First, we aimed to identify a nasal gene expression profile that distinguishes COPD patients from healthy controls. Next, we investigated whether this COPD-associated gene expression profile in nasal epithelium is comparable with the profile in the lower airways, i.e. the bronchial epithelium. Methods: Genome wide gene expression analysis was performed on nasal epithelial brushes of 76 COPD patients and 39 healthy controls, using Affymetrix Human Gene 1.0 ST Arrays. To compare findings in nasal and bronchial epithelium, we repeated the gene expression analysis on bronchial epithelial brushes in 2 independent cohorts of COPD patients and controls. Results: We found 2673 genes to be significantly differentially expressed in nasal epithelium between COPD patients and controls, 1158 being up- and 1515 downregulated in COPD (false discovery rate <0.05). Gene Set Enrichment Analysis (GSEA) showed significant concordant enrichment of nasal and bronchial COPD-associated changes in gene expression in both independent cohorts (FDR GSEA < 0.001). We found 591 genes significantly associated with COPD in the same direction in nasal and bronchial epithelium, 350 genes being up- and 241 downregulated. Conclusion: We identified a nasal gene expression profile that differentiates individuals with and without COPD. Of interest, part of the nasal gene expression changes in COPD is comparable to differentially expressed genes in the bronchus. These findings indicate that nasal gene expression has the potential to be developed as a non-invasive biomarker in COPD.

Background Chronic obstructive pulmonary disease (COPD) is a chronic lung disease characterized by chronic airway inflammation and emphysema, and is caused by exposure to noxious particles or gases, e.g. cigarette smoke. Smoking and oxidative stress lead to accelerated formation and accumulation of advanced glycation end products (AGEs), causing local tissue damage either directly or by binding the receptor for AGEs (RAGE). This study assessed the association of AGEs or RAGE in plasma, sputum, bronchial biopsies and skin with COPD and lung function, and their variance between these body compartments. Methods Healthy smoking and never-smoking controls ( n = 191) and COPD patients ( n = 97, GOLD stage I-IV) were included. Autofluorescence (SAF) was measured in the skin, AGEs (pentosidine, CML and CEL) and sRAGE in blood and sputum by ELISA, and in bronchial biopsies by immunohistochemistry. eQTL analysis was performed in bronchial biopsies. Results COPD patients showed higher SAF values and lower plasma sRAGE levels compared to controls and these values associated with decreased lung function ( p <0.001; adjusting for relevant covariates). Lower plasma sRAGE levels significantly and independently predicted higher SAF values ( p < 0.001). One SNP (rs2071278) was identified within a region of 50 kB flanking the AGER gene, which was associated with the gene and protein expression levels of AGER and another SNP (rs2071278) which was associated with the accumulation of AGEs in the skin. Conclusion In COPD, AGEs accumulate differentially in body compartments, i.e. they accumulate in the skin, but not in plasma, sputum and bronchial biopsies. The association between lower sRAGE and higher SAF levels supports the hypothesis that the protective mechanism of sRAGE as a decoy-receptor is impaired in COPD.

Background: COPD patients have a higher risk of pneumonia when treated with fluticasone propionate (FP) than with placebo, and a lower risk with budesonide (BUD).We hypothesized that BUD and FP differentially affect the mucosal barrier in response to viral infection and/or cigarette smoke.Methods: We assessed protective effects of equivalent concentrations of BUD and FP on cytokine production and barrier function (electrical resistance) in human bronchial epithelial 16HBE cells and primary bronchial epithelial cells (PBECs) upon exposure to viral mimetic poly-(I:C) and/or cigarette smoke extract (CSE) or epidermal growth factor (EGF).Results: BUD and FP were equally effective in suppressing poly-(I:C)-and/or CSE-induced IL-8 secretion in 16HBE and PBECs.Poly-(I:C) substantially decreased electrical resistance in 16HBE cells and both BUD and FP fully counteracted this effect.However, FP hardly affected 16HBE barrier dysfunction induced by CSE with/without poly-(I:C), whereas BUD (16 nM) provided full protection, an effect likely mediated by affecting EGFR-downstream target GSK-3β.Similarly, BUD, but not FP, significantly improved CSE-induced barrier dysfunction in PBECs.Finally, BUD, but not FP, exerted a modest but significant protective effect against Streptococcus Pneumoniae-induced barrier dysfunction, and BUD, but not FP, prevented cellular adhesion and/or internalization of these bacteria induced by poly-(I:C) in 16HBE.Conclusions: Collectively, both BUD and FP efficiently control epithelial pro-inflammatory responses and barrier function upon mimicry of viral infection.Of potential clinical relevance, BUD more effectively counteracted CSE-induced barrier dysfunction, reinforcing the epithelial barrier and potentially limiting access of pathogens upon smoking in vivo.

Induced lung sputum is a valuable matrix in the study of respiratory diseases. Although the methodology of sputum collection has evolved to a point where it is repeatable and responsive to inflammation, its use in molecular profiling studies is still limited. Here, an in-depth lipid profiling of induced lung sputum using high-resolution liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (LC-Q-TOF MS) is described. An enormous complexity in lipid composition could be revealed. Over 1500 intact lipids, originating from 6 major lipid classes, have been accurately identified in 120 μL of induced sputum. By number and measured intensity, glycerophospholipids represent the largest lipid class, followed by sphingolipids, glycerolipids, fatty acyls, sterol lipids, and prenol lipids. Several prenol lipids, originating from tobacco, could be detected in the lung sputum of smokers. To illustrate the utility of the methodology in studying respiratory diseases, a comparative lipid screening was performed on lung sputum extracts in order to study the effect of Chronic Obstructive Pulmonary Disease (COPD) on the lung barrier lipidome. Results show that sphingolipid expression in induced sputum significantly differs between smokers with and without COPD.

Chronic obstructive pulmonary disease (COPD) is an obstructive lung disease often caused by cigarette smoke, and characterised by inflammation and abnormalities of the large and small airways ( i.e. those with an internal diameter <2 mm), as well as by alveolar destruction (emphysema). Recent evidence suggests that small airway disease precedes emphysema [1] and, therefore, it may be useful to identify the presence and extent of small airway disease and emphysema in early COPD, or preferably, even before the onset of disease. Parametric response mapping can distinguish small airway disease, emphysema and parenchymal disease on pulmonary CT The authors thank Jennifer Boes (Department of Radiology and Center for Molecular Imaging, University of Michigan, Ann Arbor, MI, USA) for optimising the registration algorithm used for the PRM analysis.

The diagnosis of bronchiolitis obliterans syndrome (BOS), an obstructive lung disease that occurs following hematopoietic stem cell transplantation (HCT), is clinically challenging due to the presence of pulmonary infections. We evaluated parametric response mapping (PRM) as an indicator of BOS in HCT patients with acute pulmonary infection. PRM was performed in four subject cohorts: HCT patients diagnosed with acute infection (n=11), BOS (n=34), BOS plus infection (n=9), and age-matched, non-HCT subjects (n=23). The PRM analysis includes a 3D map and joint density histogram of voxels color-coded based on classification: green for normal, yellow for fSAD, red for emphysema and purple for parenchymal disease. Presented in the figure is the PRM analysis of a HCT recipient with BOS that was found to have extensive fSAD (yellow; PRM fSAD =40%). Significantly greater PRM fSAD values were identified in patients with BOS (38±2%) as compared to infection alone (17±4%, p fSAD were observed in patients with BOS, whether a concurrent infection was present or not. PRM is a useful indicator of BOS even in the presence of concurrent pulmonary infection. The PRM biomarker may provide a significant advance in the ability to definitively identify the non-emphysematous small airway obstruction characteristic of BOS.

Background. Cigarette smoking is the main cause of chronic obstructive pulmonary disease (COPD) inducing oxidative stress and local tissue injury, resulting in pulmonary inflammation. Advanced glycation end products (AGEs) are produced by glycation and oxidation processes and their formation is accelerated in inflammatory conditions. In this study we assessed whether AGE accumulation in the skin is elevated in COPD and associates with disease severity.Methods. 202 mild-to-very-severe COPD patients and 83 old (40-75 years) and 110 young (18-40 years) healthy smokers and never-smokers were included. AGEs were measured by skin autofluorescence (SAF). Demographic variables, smoking habits, co-morbidities and lung function values were obtained.Results. COPD patients (FEV1 = 55% predicted) had significantly higher SAF values than old and young healthy controls: 2.5 vs. 1.8 and 1.2 (arbitrary units, p < 0.05). No differences in SAF values were found between GOLD stages I-IV (2.4, 2.3, 2.5, 2.5 respectively). Lower function (FEV1/FVC, MEF50/FVC, RV/TLC) and higher number of packyears were significantly associated with SAF (p < 0.05).Conclusions. SAF is increased in mild-to-very severe COPD patients compared with healthy controls. Interestingly, SAF was not associated with disease severity as values were comparable between different GOLD stages (stage I-IV) of COPD. This may suggest that AGEs play a role in the induction phase of COPD in susceptible smokers. Future studies should further investigate the mechanisms underlying AGEs formation and accumulation in COPD. (C) 2014 Elsevier Inc. All rights reserved.

Background: Smoking is associated with small airways disease, emphysema and airway inflammation. Parametric response mapping (PRM) of pulmonary CT-scans is a new diagnostic tool to evaluate the presence of functional small airways disease (PRMfSAD), emphysema (PRMemph) and parenchymal disease (PRMPD).Objective: To evaluate PRM for assessment of fSAD, emphysema and PD in smokers and never-smokers.Methods: Healthy smokers and never-smokers without respiratory symptoms were recruited. We assessed pulmonary function (spirometry and body plethysmography). PRM was performed to quantify the relative volumes of PRMfSAD, PRMemph and PRMPD in the lung parenchyma.Results: 98 subjects participated, 55 males. Characteristics are shown in table 1. In smokers , the percentage PRMPD of total lung volume was significantly higher than in non-smokers, whereas the percentage PRMfSAD and PRMemph did not differ significantly (table 1). A higher age correlated with more PRMfSAD and PRMemph, both in current-smokers (PRMfSAD: ρ=0.6, p<0.01; PRMemph: ρ=0.5, p<0.01) and never-smokers (PRMfSAD: ρ=0.7, p<0.01; PRMemph: ρ=0.6, p<0.01). PRMPD was not associated with age.Conclusion: We found that current-smokers had more parenchymal disease as defined by PRM than never-smokers. Of interest, a higher age was associated with more small airways disease and emphysema, irrespective of smoking status.![Figure][1] [1]: pending:yes

RATIONALECigarette smoke is the major risk factor in the development of chronic obstructive pulmonary disease (COPD). Lipidomics is a novel and emerging research field that may provide new insights in the origins of chronic inflammatory diseases, such as COPD.OBJECTIVESTo investigate whether expression of the sputum lipidome is affected by COPD or cigarette smoking.METHODSLipid expression was investigated with liquid chromatography and high-resolution quadrupole time-of-flight mass spectrometry in induced sputum comparing smokers with and without COPD, and never-smokers. Changes in lipid expression after 2-month smoking cessation were investigated in smokers with and without COPD.MEASUREMENTS AND MAIN RESULTSMore than 1,500 lipid compounds were identified in sputum. The class of sphingolipids was significantly higher expressed in smokers with COPD than in smokers without COPD. At single compound level, 168 sphingolipids, 36 phosphatidylethanolamine lipids, and 5 tobacco-related compounds were significantly higher expressed in smokers with COPD compared with smokers without COPD. The 13 lipids with a high fold change between smokers with and without COPD showed high correlations with lower lung function and inflammation in sputum. Twenty (glyco)sphingolipids and six tobacco-related compounds were higher expressed in smokers without COPD compared with never-smokers. Two-month smoking cessation reduced expression of 26 sphingolipids in smokers with and without COPD.CONCLUSIONSExpression of lipids from the sphingolipid pathway is higher in smokers with COPD compared with smokers without COPD. Considering their potential biologic properties, they may play a role in the pathogenesis of COPD.

The management of bronchiolitis obliterans syndrome (BOS) after hematopoietic cell transplantation presents many challenges, both diagnostically and therapeutically. We developed a computed tomography (CT) voxel-wise methodology termed parametric response mapping (PRM) that quantifies normal parenchyma, functional small airway disease (PRM(fSAD)), emphysema, and parenchymal disease as relative lung volumes. We now investigate the use of PRM as an imaging biomarker in the diagnosis of BOS. PRM was applied to CT data from 4 patient cohorts: acute infection (n = 11), BOS at onset (n = 34), BOS plus infection (n = 9), and age-matched, nontransplant control subjects (n = 23). Pulmonary function tests and bronchoalveolar lavage were used for group classification. Mean values for PRM(fSAD) were significantly greater in patients with BOS (38% ± 2%) when compared with those with infection alone (17% ± 4%, P < .0001) and age-matched control subjects (8.4% ± 1%, P < .0001). Patients with BOS had similar PRM(fSAD) profiles, whether a concurrent infection was present or not. An optimal cut-point for PRM(fSAD) of 28% of the total lung volume was identified, with values >28% highly indicative of BOS occurrence. PRM may provide a major advance in our ability to identify the small airway obstruction that characterizes BOS, even in the presence of concurrent infection.

Background: Chronic obstructive pulmonary disease (COPD) is characterized by chronic airflow limitation caused by ongoing inflammatory and remodeling processes of the airways and lung tissue. Inflammation can be targeted by corticosteroids. However, airway inflammation is generally less responsive to steroids in COPD than in asthma. The underlying mechanisms are yet unclear. This study aimed to assess whether skin corticosteroid insensitivity is associated with COPD and COPD severity using the corticosteroid skin blanching test.Methods: COPD patients GOLD stage I-IV (n = 27, 24, 22, and 16 respectively) and healthy never-smokers and smokers (n = 28 and 56 respectively) were included. Corticosteroid sensitivity was assessed by the corticosteroid skin blanching test. Budesonide was applied in 8 logarithmically increasing concentrations (0-100 mu g/ml) on subject's forearm. Assessment of blanching was performed after 7 hours using a 7-point scale (normal skin to intense blanching). All subjects performed spirometry and body plethysmography.Results: Both GOLD III and GOLD IV COPD patients showed significantly lower skin blanching responses than healthy never-smokers and smokers, GOLD I, and GOLD II patients. Their area under the dose-response curve values of the skin blanching response were 586 and 243 vs. 1560, 1154, 1380, and 1309 respectively, p<0.05. Lower FEV1 levels and higher RV/TLC ratios were significantly associated with lower skin blanching responses (p = 0.001 and p = 0.004 respectively). GOLD stage I, II, III and IV patients had similar age and packyears.Conclusions: In this study, severe and very severe COPD patients had lower skin corticosteroid sensitivity than mild and moderate COPD patients and non-COPD controls with comparable age and packyears. Our findings together suggest that the reduced skin blanching response fits with a subgroup of COPD patients that has an early-onset COPD phenotype.