{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,3]],"date-time":"2026-10-03T05:37:20Z","timestamp":1791005840977,"version":"4.1.0"},"reference-count":86,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2026,6,23]],"date-time":"2026-06-23T00:00:00Z","timestamp":1782172800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Italian Ministry of university and research","award":["PRIN B53D23003760006\/G53D23000700001"],"award-info":[{"award-number":["PRIN B53D23003760006\/G53D23000700001"]}]},{"DOI":"10.13039\/501100003196","name":"Italian Ministry of Health","doi-asserted-by":"crossref","award":["Ricerca Corrente"],"award-info":[{"award-number":["Ricerca Corrente"]}],"id":[{"id":"10.13039\/501100003196","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Pathogens"],"abstract":"<jats:p>Chronic obstructive pulmonary disease (COPD) is characterized by systemic inflammation, immune dysregulation, and increased susceptibility to infections. Obesity may influence these processes and has been proposed as a potential contributor to the so-called \u201cobesity paradox\u201d, although its effects on immune competence, viral burden, and survival are not yet fully understood. Seventy patients with severe to very severe COPD (GOLD stage 3\u20134) were stratified according to BMI (&lt;30 vs. \u226530 kg\/m2). Clinical and functional parameters were assessed together with biomarkers of oxidative stress, DNA damage, systemic inflammation, and T-cell subsets. A comprehensive viral panel, including Torque Teno virus (TTV), was also analyzed. Five-year survival was evaluated using Kaplan\u2013Meier curves and Cox regression models. Patients with BMI \u2265 30 showed higher lymphocyte counts and increased CD4+ and CD8+ T-cell levels, accompanied by lower systemic inflammatory indices. No significant differences were observed in oxidative stress or DNA damage markers. In addition, TTV viremia (\u22654 log10 copies\/mL) was more frequently observed among patients with lower BMI. Despite these differences, five-year survival did not significantly differ between the two groups. These findings suggest that BMI alone may have limited value as a predictor of outcomes in patients with advanced COPD. Conversely, immune-inflammatory indices and viral burden, particularly TTV viremia, could provide complementary information for risk assessment and may deserve further investigation as potential tools for personalized patient stratification.<\/jats:p>","DOI":"10.3390\/pathogens15070664","type":"journal-article","created":{"date-parts":[[2026,6,25]],"date-time":"2026-06-25T05:48:16Z","timestamp":1782366496000},"page":"664","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Obesity in Chronic Obstructive Pulmonary Disease (COPD): Effects on Inflammation, Immune System, Susceptibility to Viral Infections, and Mortality"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0776-3601","authenticated-orcid":false,"given":"Laura","family":"Vitiello","sequence":"first","affiliation":[{"name":"Department of Human Sciences and Promotion of the Quality of Life, San Raffaele University, Via di Val Cannuta 247, 00166 Rome, Italy"},{"name":"Clinical and Molecular Epidemiology, IRCCS San Raffaele Roma, Via di Val Cannuta 247, 00166 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Stefania","family":"Proietti","sequence":"additional","affiliation":[{"name":"AgEA Coordinating Body, 00185 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dolores","family":"Limongi","sequence":"additional","affiliation":[{"name":"Department of Human Sciences and Promotion of the Quality of Life, San Raffaele University, Via di Val Cannuta 247, 00166 Rome, Italy"},{"name":"Laboratory of Microbiology, IRCCS San Raffaele Roma, Via di Val Cannuta 247, 00166 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8377-0742","authenticated-orcid":false,"given":"Carla","family":"Prezioso","sequence":"additional","affiliation":[{"name":"Department of Human Sciences and Promotion of the Quality of Life, San Raffaele University, Via di Val Cannuta 247, 00166 Rome, Italy"},{"name":"Laboratory of Microbiology, IRCCS San Raffaele Roma, Via di Val Cannuta 247, 00166 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Caterina","family":"Mammi","sequence":"additional","affiliation":[{"name":"Laboratory of Cardiovascular Endocrinology, IRCCS San Raffaele Roma, Via di Val Cannuta 247, 00166 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0722-7163","authenticated-orcid":false,"given":"Massimiliano","family":"Caprio","sequence":"additional","affiliation":[{"name":"Department of Human Sciences and Promotion of the Quality of Life, San Raffaele University, Via di Val Cannuta 247, 00166 Rome, Italy"},{"name":"Laboratory of Cardiovascular Endocrinology, IRCCS San Raffaele Roma, Via di Val Cannuta 247, 00166 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7489-5271","authenticated-orcid":false,"given":"Fabrizio","family":"Maggi","sequence":"additional","affiliation":[{"name":"National Institute for Infectious Diseases \u201cLazzaro Spallanzani\u201d-INMI IRCCS, Via Portuense 292, 00149 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2533-2939","authenticated-orcid":false,"given":"Guido","family":"Antonelli","sequence":"additional","affiliation":[{"name":"Department of Molecular Medicine, Sapienza University, 00185 Rome, Italy"},{"name":"Microbiology and Virology Unit, Sapienza University Hospital Policlinico Umberto I, 00186 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3833-6717","authenticated-orcid":false,"given":"Stefano","family":"Bonassi","sequence":"additional","affiliation":[{"name":"Department of Human Sciences and Promotion of the Quality of Life, San Raffaele University, Via di Val Cannuta 247, 00166 Rome, Italy"},{"name":"Clinical and Molecular Epidemiology, IRCCS San Raffaele Roma, Via di Val Cannuta 247, 00166 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Patrizia","family":"Russo","sequence":"additional","affiliation":[{"name":"Department of Human Sciences and Promotion of the Quality of Life, San Raffaele University, Via di Val Cannuta 247, 00166 Rome, Italy"},{"name":"Clinical and Molecular Epidemiology, IRCCS San Raffaele Roma, Via di Val Cannuta 247, 00166 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,6,23]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"813","DOI":"10.1016\/S0140-6736(25)00355-1","article-title":"Global, Regional, and National Prevalence of Adult Overweight and Obesity, 1990\u20132021, with Forecasts to 2050: A Forecasting Study for the Global Burden of Disease Study 2021","volume":"405","author":"Ng","year":"2025","journal-title":"Lancet"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Edwards, C.H., Aas, E., and Kinge, J.M. (2019). Body Mass Index and Lifetime Healthcare Utilization. BMC Health Serv. Res., 19.","DOI":"10.1186\/s12913-019-4577-0"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"951","DOI":"10.1016\/S0140-6736(25)02474-2","article-title":"Adult Obesity and Risk of Severe Infections: A Multicohort Study with Global Burden Estimates","volume":"407","author":"Nyberg","year":"2026","journal-title":"Lancet"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"350","DOI":"10.1016\/S2213-8587(21)00089-9","article-title":"Associations between Body-Mass Index and COVID-19 Severity in 6\u00b79 Million People in England: A Prospective, Community-Based, Cohort Study","volume":"9","author":"Gao","year":"2021","journal-title":"Lancet Diabetes Endocrinol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"e13216","DOI":"10.1111\/obr.13216","article-title":"The Impact of Obesity on Immune Response to Infection: Plausible Mechanisms and Outcomes","volume":"22","author":"Muscogiuri","year":"2021","journal-title":"Obes. Rev."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"11885","DOI":"10.2147\/DDDT.S564912","article-title":"The Effects of Obesity on Lung Physiology, the Prevalence and Severity of Chronic Pulmonary Diseases, and Inhalation Treatment","volume":"19","year":"2025","journal-title":"Drug Des. Dev. Ther."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1470","DOI":"10.1378\/chest.103.5.1470","article-title":"Effects of Obesity on Respiratory Resistance","volume":"103","author":"Zerah","year":"1993","journal-title":"Chest"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"827","DOI":"10.1378\/chest.130.3.827","article-title":"The Effects of Body Mass Index on Lung Volumes","volume":"130","author":"Jones","year":"2006","journal-title":"Chest"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1016\/j.rmed.2017.01.004","article-title":"The Effects of Obesity on Lung Volumes and Oxygenation","volume":"124","author":"Littleton","year":"2017","journal-title":"Respir. Med."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"956","DOI":"10.1164\/rccm.202306-1120PP","article-title":"Dysanapsis as a Determinant of Lung Function in Development and Disease","volume":"208","author":"McGinn","year":"2023","journal-title":"Am. J. Respir. Crit. Care Med."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"67","DOI":"10.1152\/jappl.1974.37.1.67","article-title":"Variability of Maximum Expiratory Flow-Volume Curves","volume":"37","author":"Green","year":"1974","journal-title":"J. Appl. Physiol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1900857","DOI":"10.1183\/13993003.00857-2019","article-title":"Fatty Airways: Implications for Obstructive Disease","volume":"54","author":"Elliot","year":"2019","journal-title":"Eur. Respir. J."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"L179","DOI":"10.1152\/ajplung.00288.2022","article-title":"Distribution, Composition, and Activity of Airway-Associated Adipose Tissue in the Porcine Lung","volume":"324","author":"Wang","year":"2023","journal-title":"Am. J. Physiol. Lung Cell. Mol. Physiol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"212","DOI":"10.13181\/mji.oa.236991","article-title":"Effect of a High-Calorie Diet on pro- to Anti-Inflammatory Macrophage Ratio through Fat Accumulation in Rat Lung Tissue","volume":"32","author":"Lestari","year":"2024","journal-title":"Med. J. Indones."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"S37","DOI":"10.1016\/j.resp.2010.01.007","article-title":"Leptin Integrates Vertebrate Evolution: From Oxygen to the Blood\u2013Gas Barrier","volume":"173","author":"Torday","year":"2010","journal-title":"Respir. Physiol. Neurobiol."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Lv, Y.-Q., Dhlamini, Q., Chen, C., Li, X., Bellusci, S., and Zhang, J.-S. (2021). FGF10 and Lipofibroblasts in Lung Homeostasis and Disease: Insights Gained From the Adipocytes. Front. Cell Dev. Biol., 9.","DOI":"10.3389\/fcell.2021.645400"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"451","DOI":"10.2147\/COPD.S124750","article-title":"Ectopic Fat Accumulation in Patients with COPD: An ECLIPSE Substudy","volume":"12","author":"Martin","year":"2017","journal-title":"Int. J. Chronic Obstr. Pulm. Dis."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"L406","DOI":"10.1152\/ajplung.00114.2024","article-title":"Obesity Impairs Ciliary Function and Mucociliary Clearance in the Murine Airway Epithelium","volume":"327","author":"Tanaka","year":"2024","journal-title":"Am. J. Physiol. Lung Cell. Mol. Physiol."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Hornung, F., Rogal, J., Loskill, P., L\u00f6ffler, B., and Deinhardt-Emmer, S. (2021). The Inflammatory Profile of Obesity and the Role on Pulmonary Bacterial and Viral Infections. Int. J. Mol. Sci., 22.","DOI":"10.3390\/ijms22073456"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Oppenheimer, B.W., Berger, K.I., Ali, S., Segal, L.N., Donnino, R., Katz, S., Parikh, M., and Goldring, R.M. (2016). Pulmonary Vascular Congestion: A Mechanism for Distal Lung Unit Dysfunction in Obesity. PLoS ONE, 11.","DOI":"10.1371\/journal.pone.0152769"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"S3","DOI":"10.1016\/j.alit.2019.04.002","article-title":"Leptin Enhances Cytokine\/Chemokine Production by Normal Lung Fibroblasts by Binding to Leptin Receptor","volume":"68","author":"Watanabe","year":"2019","journal-title":"Allergol. Int."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"131","DOI":"10.1186\/s12931-022-02048-z","article-title":"Exogenous Leptin Enhances Markers of Airway Fibrosis in a Mouse Model of Chronic Allergic Airways Disease","volume":"23","author":"Ihrie","year":"2022","journal-title":"Respir. Res."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Bidan, C.M., Veldsink, A.C., Meurs, H., and Gosens, R. (2015). Airway and Extracellular Matrix Mechanics in COPD. Front. Physiol., 6.","DOI":"10.3389\/fphys.2015.00346"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1169","DOI":"10.1016\/j.jaci.2018.02.004","article-title":"Obesity and Asthma","volume":"141","author":"Peters","year":"2018","journal-title":"J. Allergy Clin. Immunol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"206","DOI":"10.1152\/japplphysiol.00694.2009","article-title":"Physiology of Obesity and Effects on Lung Function","volume":"108","author":"Salome","year":"2010","journal-title":"J. Appl. Physiol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"2","DOI":"10.1164\/rccm.2211002","article-title":"Tethering Tracheobronchial Airways within the Lungs","volume":"167","author":"Plopper","year":"2003","journal-title":"Am. J. Respir. Crit. Care Med."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"724","DOI":"10.1016\/j.annepidem.2009.05.003","article-title":"Waist-Hip-Ratio as a Predictor of All-Cause Mortality in High-Functioning Older Adults","volume":"19","author":"Srikanthan","year":"2009","journal-title":"Ann. Epidemiol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"180097","DOI":"10.1183\/16000617.0097-2018","article-title":"Obesity Hypoventilation Syndrome","volume":"28","author":"Masa","year":"2019","journal-title":"Eur. Respir. Rev."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"477","DOI":"10.1016\/j.rmed.2010.08.011","article-title":"Smoking Prevalence, Behaviours, and Cessation among Individuals with COPD or Asthma","volume":"105","author":"Vozoris","year":"2011","journal-title":"Respir. Med."},{"key":"ref_30","first-page":"6149263","article-title":"A Strong Graded Relationship between Level of Obesity and COPD: Findings from a National Population-Based Study of Lifelong Nonsmokers","volume":"2018","author":"Howden","year":"2018","journal-title":"J. Obes."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1110","DOI":"10.1136\/thx.2007.086827","article-title":"Obesity and the Lung: 5 \u00b7 Obesity and COPD","volume":"63","author":"Franssen","year":"2008","journal-title":"Thorax"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"00368504251406570","DOI":"10.1177\/00368504251406570","article-title":"Association between Visceral Adiposity Index and Chronic Obstructive Pulmonary Disease: A Cross-Sectional Analysis","volume":"108","author":"Zhang","year":"2025","journal-title":"Sci. Prog."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"779","DOI":"10.1056\/NEJMoa054017","article-title":"Body-Mass Index and Mortality in Korean Men and Women","volume":"355","author":"Jee","year":"2006","journal-title":"N. Engl. J. Med."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1856","DOI":"10.1164\/ajrccm.160.6.9902115","article-title":"Prognostic Value of Nutritional Status in Chronic Obstructive Pulmonary Disease","volume":"160","author":"Landbo","year":"1999","journal-title":"Am. J. Respir. Crit. Care Med."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"240284","DOI":"10.1183\/16000617.0284-2024","article-title":"The Respiratory Tract Virome: Unravelling the Role of Viral Dark Matter in Respiratory Health and Disease","volume":"34","author":"Purcell","year":"2025","journal-title":"Eur. Respir. Rev."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Morgan, O.W., Bramley, A., Fowlkes, A., Freedman, D.S., Taylor, T.H., Gargiullo, P., Belay, B., Jain, S., Cox, C., and Kamimoto, L. (2010). Morbid Obesity as a Risk Factor for Hospitalization and Death Due to 2009 Pandemic Influenza A(H1N1) Disease. PLoS ONE, 5.","DOI":"10.1371\/journal.pone.0009694"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"301","DOI":"10.1093\/cid\/ciq152","article-title":"A Novel Risk Factor for a Novel Virus: Obesity and 2009 Pandemic Influenza A (H1N1)","volume":"52","author":"Louie","year":"2011","journal-title":"Clin. Infect. Dis."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"e487","DOI":"10.1111\/j.1750-2659.2011.00249.x","article-title":"Epidemiologic and Virologic Assessment of the 2009 Influenza A (H1N1) Pandemic on Selected Temperate Countries in the Southern Hemisphere: Argentina, Australia, Chile, New Zealand and South Africa: Southern Hemisphere H1N1pdm","volume":"5","author":"Mounts","year":"2011","journal-title":"Influenza Other Respir. Viruses"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"160","DOI":"10.1111\/j.1750-2659.2012.00377.x","article-title":"Evaluation of Obesity as an Independent Risk Factor for Medically Attended Laboratory-confirmed Influenza","volume":"7","author":"Coleman","year":"2013","journal-title":"Influenza Resp. Viruses"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"220051","DOI":"10.1183\/16000617.0051-2022","article-title":"Respiratory Viruses: Their Importance and Lessons Learned from COVID-19","volume":"31","author":"Cilloniz","year":"2022","journal-title":"Eur. Respir. Rev."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"589","DOI":"10.1016\/j.cmi.2016.04.007","article-title":"Torquetenovirus: The Human Virome from Bench to Bedside","volume":"22","author":"Focosi","year":"2016","journal-title":"Clin. Microbiol. Infect."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"392","DOI":"10.1002\/rmv.668","article-title":"Human Anelloviruses and the Central Nervous System","volume":"20","author":"Maggi","year":"2010","journal-title":"Rev. Med. Virol."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"320","DOI":"10.1016\/j.healun.2013.12.007","article-title":"Plasma DNA Levels of Torque Teno Virus and Immunosuppression after Lung Transplantation","volume":"33","author":"Haloschan","year":"2014","journal-title":"J. Heart Lung Transplant."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"180","DOI":"10.1038\/bmt.2017.235","article-title":"The Kinetics of Torque Teno Virus Plasma DNA Load Shortly after Engraftment Predicts the Risk of High-Level CMV DNAemia in Allogeneic Hematopoietic Stem Cell Transplant Recipients","volume":"53","author":"Albert","year":"2018","journal-title":"Bone Marrow Transpl."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"1139","DOI":"10.1111\/ajt.15145","article-title":"Monitoring of Alphatorquevirus DNA Levels for the Prediction of Immunosuppression-Related Complications after Kidney Transplantation","volume":"19","author":"Albert","year":"2019","journal-title":"Am. J. Transplant."},{"key":"ref_46","doi-asserted-by":"crossref","unstructured":"Vitiello, L., Proietti, S., Limongi, D., Prezioso, C., Checconi, P., Fortugno, P., Quaranta, M., Maggi, F., Antonelli, G., and Bonassi, S. (2026). TTV Virome Marks Immune Exhaustion, \u03b17nAChR Alteration, and Mortality in Elderly Patients with Severe COPD. GeroScience.","DOI":"10.1007\/s11357-026-02330-8"},{"key":"ref_47","unstructured":"(2015). Quality Management Systems\u2014Requirements (Standard No. ISO 9001:2015)."},{"key":"ref_48","unstructured":"(2016). Medical Devices\u2014Quality Management Systems\u2014Requirements for Regulatory Purposes (Standard No. ISO 13485:2016)."},{"key":"ref_49","doi-asserted-by":"crossref","unstructured":"Ilari, S., Vitiello, L., Russo, P., Proietti, S., Mili\u0107, M., Muscoli, C., Cardaci, V., Tomino, C., Bonassi, G., and Bonassi, S. (2021). Daily Vegetables Intake and Response to COPD Rehabilitation. The Role of Oxidative Stress, Inflammation and DNA Damage. Nutrients, 13.","DOI":"10.20944\/preprints202106.0558.v1"},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"16793","DOI":"10.1038\/s41598-021-95976-7","article-title":"DNA Damage in Circulating Leukocytes Measured with the Comet Assay May Predict the Risk of Death","volume":"11","author":"Bonassi","year":"2021","journal-title":"Sci. Rep."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"108371","DOI":"10.1016\/j.mrrev.2021.108371","article-title":"The hCOMET Project: International Database Comparison of Results with the Comet Assay in Human Biomonitoring. Baseline Frequency of DNA Damage and Effect of Main Confounders","volume":"787","author":"Ceppi","year":"2021","journal-title":"Mutat. Res. Rev. Mutat. Res."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"5494","DOI":"10.4049\/jimmunol.0901000","article-title":"Phenotypical Characterization of Human Th17 Cells Unambiguously Identified by Surface IL-17A Expression","volume":"183","author":"Steinbach","year":"2009","journal-title":"J. Immunol."},{"key":"ref_53","doi-asserted-by":"crossref","unstructured":"Coursey, T.G., Gandhi, N.B., Volpe, E.A., Pflugfelder, S.C., and De Paiva, C.S. (2013). Chemokine Receptors CCR6 and CXCR3 Are Necessary for CD4+ T Cell Mediated Ocular Surface Disease in Experimental Dry Eye Disease. PLoS ONE, 8.","DOI":"10.1371\/journal.pone.0078508"},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"561","DOI":"10.1002\/jmv.2181","article-title":"TTV Infection and Its Relation to Serum Transaminases in Apparently Healthy Blood Donors and in Patients with Clotting Disorders Who Have Been Investigated Previously for Hepatitis C Virus and GBV-C\/HGV Infection in Belgium","volume":"66","author":"Ali","year":"2002","journal-title":"J. Med. Virol."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"112024","DOI":"10.1016\/j.mad.2024.112024","article-title":"The Effect of Torque Teno Virus (TTV) Infection on Clinical Outcomes, Genomic Integrity, and Mortality in COPD Patients","volume":"224","author":"Russo","year":"2025","journal-title":"Mech. Ageing Dev."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"1406","DOI":"10.1016\/j.cmi.2020.01.011","article-title":"Assessment of Prevalence and Load of Torquetenovirus Viraemia in a Large Cohort of Healthy Blood Donors","volume":"26","author":"Focosi","year":"2020","journal-title":"Clin. Microbiol. Infect."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"103","DOI":"10.1016\/j.exger.2018.09.003","article-title":"Torquetenovirus (TTV) Load Is Associated with Mortality in Italian Elderly Subjects","volume":"112","author":"Giacconi","year":"2018","journal-title":"Exp. Gerontol."},{"key":"ref_58","doi-asserted-by":"crossref","unstructured":"Russo, P., Milani, F., De Iure, A., Proietti, S., Limongi, D., Prezioso, C., Checconi, P., Zag\u00e0, V., Novazzi, F., and Maggi, F. (2024). Effect of Cigarette Smoking on Clinical and Molecular Endpoints in COPD Patients. Int. J. Mol. Sci., 25.","DOI":"10.3390\/ijms25115834"},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"411","DOI":"10.1159\/000531792","article-title":"Obesity Paradox in Lung Diseases: What Explains It?","volume":"16","author":"Yao","year":"2023","journal-title":"Obes. Facts"},{"key":"ref_60","first-page":"14","article-title":"Obesity Paradox: Does Fat Alter Outcomes in Chronic Obstructive Pulmonary Disease?","volume":"12","author":"Chittal","year":"2015","journal-title":"COPD J. Chronic Obstr. Pulm. Dis."},{"key":"ref_61","doi-asserted-by":"crossref","unstructured":"Cao, C., Wang, R., Wang, J., Bunjhoo, H., Xu, Y., and Xiong, W. (2012). Body Mass Index and Mortality in Chronic Obstructive Pulmonary Disease: A Meta-Analysis. PLoS ONE, 7.","DOI":"10.1371\/journal.pone.0043892"},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"674","DOI":"10.1136\/thx.52.8.674","article-title":"Effect of Long-Term Oxygen Therapy on Survival in Patients with Chronic Obstructive Pulmonary Disease with Moderate Hypoxaemia","volume":"52","author":"Gorecka","year":"1997","journal-title":"Thorax"},{"key":"ref_63","first-page":"672","article-title":"\u201cObesity Paradox\u201d in Chronic Obstructive Pulmonary Disease","volume":"13","author":"Blum","year":"2011","journal-title":"Isr. Med. Assoc. J."},{"key":"ref_64","doi-asserted-by":"crossref","first-page":"00902","DOI":"10.1183\/23120541.00902-2020","article-title":"Challenging the Obesity Paradox: Extreme Obesity and COPD Mortality in the SUMMIT Trial","volume":"7","author":"Brigham","year":"2021","journal-title":"ERJ Open Res."},{"key":"ref_65","doi-asserted-by":"crossref","first-page":"236","DOI":"10.1186\/s12931-019-1209-5","article-title":"BMI Is Associated with FEV1 Decline in Chronic Obstructive Pulmonary Disease: A Meta-Analysis of Clinical Trials","volume":"20","author":"Sun","year":"2019","journal-title":"Respir. Res."},{"key":"ref_66","doi-asserted-by":"crossref","first-page":"492","DOI":"10.1183\/09031936.00074807","article-title":"Possible Mechanisms Underlying the Development of Cachexia in COPD","volume":"31","author":"Wagner","year":"2008","journal-title":"Eur. Respir. J."},{"key":"ref_67","doi-asserted-by":"crossref","first-page":"1642","DOI":"10.1161\/CIRCRESAHA.118.312897","article-title":"Obesity Paradox and Smoking Gun: A Mystery of Statistical Confounding?","volume":"122","author":"Yu","year":"2018","journal-title":"Circ. Res."},{"key":"ref_68","doi-asserted-by":"crossref","first-page":"266","DOI":"10.1016\/j.mayocp.2016.11.001","article-title":"Obesity and Heart Failure: Focus on the Obesity Paradox","volume":"92","author":"Carbone","year":"2017","journal-title":"Mayo Clin. Proc."},{"key":"ref_69","doi-asserted-by":"crossref","first-page":"809","DOI":"10.1164\/rccm.2107031","article-title":"Midthigh Muscle Cross-Sectional Area Is a Better Predictor of Mortality than Body Mass Index in Patients with Chronic Obstructive Pulmonary Disease","volume":"166","author":"Marquis","year":"2002","journal-title":"Am. J. Respir. Crit. Care Med."},{"key":"ref_70","doi-asserted-by":"crossref","first-page":"S389","DOI":"10.1513\/AnnalsATS.201705-371AW","article-title":"Obesity and Metabolic Abnormalities in Chronic Obstructive Pulmonary Disease","volume":"14","author":"Wouters","year":"2017","journal-title":"Ann. Am. Thorac. Soc."},{"key":"ref_71","doi-asserted-by":"crossref","first-page":"831","DOI":"10.1007\/s13679-024-00584-x","article-title":"Correction: Strengths and Limitations of BMI in the Diagnosis of Obesity: What Is the Path Forward?","volume":"13","author":"Sweatt","year":"2024","journal-title":"Curr. Obes. Rep."},{"key":"ref_72","doi-asserted-by":"crossref","first-page":"1043","DOI":"10.1126\/science.3029864","article-title":"Bilirubin Is an Antioxidant of Possible Physiological Importance","volume":"235","author":"Stocker","year":"1987","journal-title":"Science"},{"key":"ref_73","doi-asserted-by":"crossref","unstructured":"MacDonald, D.M., Kunisaki, K.M., Wilt, T.J., and Baldomero, A.K. (2021). Serum Bilirubin and Chronic Obstructive Pulmonary Disease (COPD): A Systematic Review. BMC Pulm. Med., 21.","DOI":"10.1186\/s12890-021-01395-9"},{"key":"ref_74","doi-asserted-by":"crossref","first-page":"18251","DOI":"10.1038\/s41598-025-03075-8","article-title":"The Effects of Heavy Smoking on Oxidative Stress, Inflammatory Biomarkers, Vascular Dysfunction, and Hematological Indices","volume":"15","author":"Khudhur","year":"2025","journal-title":"Sci. Rep."},{"key":"ref_75","doi-asserted-by":"crossref","first-page":"116","DOI":"10.5937\/jomb0-43457","article-title":"The Significance of Biomarkers of Inflammation in Predicting the Activity of Lupus Nephritis","volume":"43","year":"2024","journal-title":"J. Med. Biochem."},{"key":"ref_76","doi-asserted-by":"crossref","first-page":"6212","DOI":"10.1158\/1078-0432.CCR-14-0442","article-title":"Systemic Immune-Inflammation Index Predicts Prognosis of Patients after Curative Resection for Hepatocellular Carcinoma","volume":"20","author":"Hu","year":"2014","journal-title":"Clin. Cancer Res."},{"key":"ref_77","doi-asserted-by":"crossref","unstructured":"Zinellu, A., Collu, C., Nasser, M., Paliogiannis, P., Mellino, S., Zinellu, E., Traclet, J., Ahmad, K., Mangoni, A.A., and Carru, C. (2021). The Aggregate Index of Systemic Inflammation (AISI): A Novel Prognostic Biomarker in Idiopathic Pulmonary Fibrosis. J. Clin. Med., 10.","DOI":"10.3390\/jcm10184134"},{"key":"ref_78","doi-asserted-by":"crossref","first-page":"7887","DOI":"10.1038\/s41598-025-90947-8","article-title":"Relationship between Systemic Immune Response Index (SIRI) and COPD: A Cross-Sectional Study Based on NHANES 2007\u20132012","volume":"15","author":"Jia","year":"2025","journal-title":"Sci. Rep."},{"key":"ref_79","doi-asserted-by":"crossref","first-page":"872","DOI":"10.1093\/jimmun\/vkae033","article-title":"General and Individualized Changes in T Cell Immunity during Aging","volume":"214","author":"Song","year":"2025","journal-title":"J. Immunol."},{"key":"ref_80","doi-asserted-by":"crossref","first-page":"371","DOI":"10.1038\/s41577-021-00635-7","article-title":"Immune and Non-Immune Functions of Adipose Tissue Leukocytes","volume":"22","author":"Trim","year":"2022","journal-title":"Nat. Rev. Immunol."},{"key":"ref_81","doi-asserted-by":"crossref","first-page":"250","DOI":"10.1038\/s41577-024-01103-8","article-title":"Adipokines: Masterminds of Metabolic Inflammation","volume":"25","author":"Tilg","year":"2025","journal-title":"Nat. Rev. Immunol."},{"key":"ref_82","doi-asserted-by":"crossref","first-page":"e00061","DOI":"10.1097\/IN9.0000000000000061","article-title":"Aging Immunity: Unraveling the Complex Nexus of Diet, Gut Microbiome, and Immune Function","volume":"7","author":"Babakhani","year":"2025","journal-title":"Immunometabolism"},{"key":"ref_83","doi-asserted-by":"crossref","unstructured":"Curtis, M., Swan, L., Fox, R., Warters, A., and O\u2019Sullivan, M. (2023). Associations between Body Mass Index and Probable Sarcopenia in Community-Dwelling Older Adults. Nutrients, 15.","DOI":"10.3390\/nu15061505"},{"key":"ref_84","doi-asserted-by":"crossref","unstructured":"Badillo-Pazmay, G.V., Fortunato, C., Cianfruglia, L., Novazzi, F., Spezia, P.G., Rosa, L., Limongi, D., Prezioso, C., D\u2019Argenio, V., and Scudiero, O. (2026). The Gut and Circulating Virome: Emerging Players in Aging and Longevity. Front. Aging, 6.","DOI":"10.3389\/fragi.2025.1731621"},{"key":"ref_85","doi-asserted-by":"crossref","unstructured":"Lv, P., Zhao, X., Zhang, H., Lu, Q., and Liang, X. (2026). Nomogram Integrating Inflammatory Biomarkers Predicts Chronic Obstructive Pulmonary Disease Exacerbation Post-Rehabilitation. BMC Pulm. Med., 26.","DOI":"10.1186\/s12890-026-04138-w"},{"key":"ref_86","unstructured":"Lazio Regional Health Service (SSR) (2016). Riorganizzazione Dei Percorsi Riabilitativi in Ambito Ospedaliero e Territoriale, Lazio Regional Health Service Guidelines."}],"container-title":["Pathogens"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-0817\/15\/7\/664\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,8]],"date-time":"2026-07-08T04:37:15Z","timestamp":1783485435000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-0817\/15\/7\/664"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,6,23]]},"references-count":86,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2026,7]]}},"alternative-id":["pathogens15070664"],"URL":"https:\/\/doi.org\/10.3390\/pathogens15070664","relation":{},"ISSN":["2076-0817"],"issn-type":[{"value":"2076-0817","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,6,23]]}}}