{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,22]],"date-time":"2026-09-22T22:03:58Z","timestamp":1790114638163,"version":"4.0.1"},"reference-count":44,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2023,1,6]],"date-time":"2023-01-06T00:00:00Z","timestamp":1672963200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100005416","name":"Norges Forskningsr\u00e5d","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100005416","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Immunol."],"abstract":"<jats:sec><jats:title>Introduction<\/jats:title><jats:p>Both public and scientific attention have shifted from the acute COVID-19 illness to the chronic disability experienced by a proportion of COVID-19 convalescents. Post COVID-19 condition, a term used for long-lasting symptoms after COVID-19, can affect individuals across all disease severity and age groups. Data on post-COVID-19 symptomatology, epidemiology and pathophysiology in adolescents and young adults are scarce. To date, little is known on the immunological and pulmonary trends in these patients after COVID-19. This study investigated immunological markers and pulmonary function in non-hospitalized patients in this group at 6 months after initial mild COVID-19 infection.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>Non-hospitalized SARS-CoV-2 positive (n = 405) and SARS-CoV-2 negative (n = 111) adolescents and young adults (aged 12-25 years) were followed prospectively for six months after SARS-CoV-2 PCR testing. At baseline and at six months follow-up, all participants underwent an assessment including clinical examination, questionnaires, spirometry, and blood sampling. Cross-sectional comparisons of blood biomarkers; including white blood cell counts, CRP, GDF-15, a 27-multiplex cytokine assay, complement activation products and SARS-CoV-2 antibodies; and spirometry measures were performed after classification of all participants according to their COVID-19 status and adherence to post-COVID-19 case criteria. Associations between biomarkers and COVID-19 symptoms were explored.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>No difference in pulmonary function was detected between the groups. COVID-19 convalescents had higher levels of chemokines eotaxin, MCP-1 and IP-10 than non-infected controls. The increase was modest and not associated with long-lasting COVID-19 symptoms.<\/jats:p><\/jats:sec><jats:sec><jats:title>Discussion<\/jats:title><jats:p>Elevated inflammatory mediators were found in adolescents and young adults six months after mild COVID-19, but there was no association with post-COVID-19 condition.<\/jats:p><\/jats:sec>","DOI":"10.3389\/fimmu.2022.1081718","type":"journal-article","created":{"date-parts":[[2023,1,6]],"date-time":"2023-01-06T19:40:29Z","timestamp":1673034029000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":31,"title":["Inflammatory markers and pulmonary function in adolescents and young adults 6 months after mild COVID-19"],"prefix":"10.3389","volume":"13","author":[{"given":"Silke Lauren","family":"Sommen","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lise Beier","family":"Havdal","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Joel","family":"Selvakumar","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gunnar","family":"Einvik","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Truls Michael","family":"Leegaard","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fridtjof","family":"Lund-Johansen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Annika E.","family":"Michelsen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tom E.","family":"Mollnes","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tonje","family":"Stiansen-Sonerud","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Trygve","family":"Tjade","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Vegard Bruun Bratholm","family":"Wyller","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lise Lund","family":"Berven","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2023,1,6]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1016\/S0140-6736(20)32656-8","article-title":"6-month consequences of COVID-19 in patients discharged from hospital: A cohort study","volume":"397","author":"Huang","year":"2021","journal-title":"Lancet"},{"key":"B2","doi-asserted-by":"publisher","DOI":"10.1038\/s41591-021-01433-3","article-title":"Long COVID in a prospective cohort of home-isolated patients","volume":"27","author":"Blomberg","year":"2021","journal-title":"Nat Med"},{"key":"B3","doi-asserted-by":"publisher","DOI":"10.1038\/s41586-021-03553-9","article-title":"High-dimensional characterization of post-acute sequelae of COVID-19","volume":"594","author":"Al-Aly","year":"2021","journal-title":"Nature"},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.1016\/S2352-4642(21)00198-X","article-title":"Illness duration and symptom profile in symptomatic UK school-aged children tested for SARS-CoV-2","volume":"5","author":"Molteni","year":"2021","journal-title":"Lancet Child Adolesc Health"},{"key":"B5","doi-asserted-by":"publisher","DOI":"10.1007\/s10654-022-00847-8","article-title":"Excess risk and clusters of symptoms after COVID-19 in a large Norwegian cohort","volume":"37","author":"Caspersen","year":"2022","journal-title":"Eur J Epidemiol"},{"key":"B6","doi-asserted-by":"publisher","DOI":"10.1093\/infdis\/jiac136","article-title":"Global prevalence of post COVID-19 condition or long COVID: A meta-analysis and systematic review","volume":"6","author":"Chen","year":"2022","journal-title":"J Infect Dis"},{"key":"B7","doi-asserted-by":"publisher","DOI":"10.1016\/S1473-3099(21)00703-9","article-title":"A clinical case definition of post-COVID-19 condition by a Delphi consensus","volume":"22","author":"Soriano","year":"2022","journal-title":"Lancet Infect Dis"},{"key":"B8","doi-asserted-by":"publisher","DOI":"10.1016\/S2352-4642(22)00022-0","article-title":"Physical and mental health 3 months after SARS-CoV-2 infection (long COVID) among adolescents in England (CLoCk): A national matched cohort study","volume":"6","author":"Stephenson","year":"2022","journal-title":"Lancet Child Adolesc Health"},{"key":"B9","unstructured":"All data related to prevalence of ongoing symptoms following coronavirus (COVID-19) infection in the UK"},{"key":"B10","doi-asserted-by":"publisher","DOI":"10.1016\/j.jinf.2021.11.011","article-title":"Persistent symptoms following SARS-CoV-2 infection amongst children and young people: A meta-analysis of controlled and uncontrolled studies","volume":"84","author":"Behnood","year":"2022","journal-title":"J Infect"},{"key":"B11","doi-asserted-by":"publisher","first-page":"418","DOI":"10.3390\/medicina57050418","article-title":"Long COVID and myalgic Encephalomyelitis\/Chronic fatigue syndrome (ME\/CFS)-a systemic review and comparison of clinical presentation and symptomatology","volume":"57","author":"Wong","year":"2021","journal-title":"Med (Kaunas)"},{"key":"B12","doi-asserted-by":"publisher","DOI":"10.1016\/j.bbi.2019.04.040","article-title":"Clinical symptoms and markers of disease mechanisms in adolescent chronic fatigue following Epstein-Barr virus infection: An exploratory cross-sectional study","volume":"80","author":"Kristiansen","year":"2019","journal-title":"Brain Behav Immun"},{"key":"B13","doi-asserted-by":"publisher","DOI":"10.3389\/fimmu.2021.715102","article-title":"Lasting immunological imprint of primary Epstein-Barr virus infection with associations to chronic low-grade inflammation and fatigue","volume":"12","author":"Fevang","year":"2021","journal-title":"Front Immunol"},{"key":"B14","doi-asserted-by":"publisher","DOI":"10.1038\/s41590-021-01113-x","article-title":"Immunological dysfunction persists for 8 months following initial mild-to-moderate SARS-CoV-2 infection","volume":"23","author":"Phetsouphanh","year":"2022","journal-title":"Nat Immunol"},{"key":"B15","doi-asserted-by":"publisher","DOI":"10.1093\/infdis\/jiab490","article-title":"Markers of immune activation and inflammation in individuals with postacute sequelae of severe acute respiratory syndrome coronavirus 2 infection","volume":"224","author":"Peluso","year":"2021","journal-title":"J Infect Dis"},{"key":"B16","doi-asserted-by":"publisher","first-page":"93","DOI":"10.1016\/j.bbi.2021.12.020","article-title":"Fatigue and cognitive impairment in post-COVID-19 syndrome: A systematic review and meta-analysis","volume":"101","author":"Ceban","year":"2022","journal-title":"Brain Behav Immun"},{"key":"B17","doi-asserted-by":"publisher","DOI":"10.1101\/2021.05.07.21256539","article-title":"Immune profile of children with post-acute sequelae of SARS-CoV-2 infection (Long covid)","author":"Sante","year":"2021","journal-title":"medRxiv"},{"key":"B18","doi-asserted-by":"publisher","DOI":"10.3389\/fimmu.2022.837288","article-title":"Inflammatory markers, pulmonary function, and clinical symptoms in acute COVID-19 among non-hospitalized adolescents and young adults","volume":"13","author":"Lund Berven","year":"2022","journal-title":"Front Immunol"},{"key":"B19","doi-asserted-by":"publisher","DOI":"10.3389\/fneur.2022.915712","article-title":"Neurological involvement in COVID-19 among non-hospitalized adolescents and young adults","volume":"13","author":"Havdal","year":"2022","journal-title":"Front Neurol"},{"key":"B20","volume-title":"Prevalence and predictors of long COVID among non-hospitalised adolescents and young adults: A prospective controlled cohort study","author":"Selvakumar","year":"2022"},{"key":"B21","doi-asserted-by":"publisher","DOI":"10.1016\/j.molimm.2013.05.221","article-title":"An international serum standard for application in assays to detect human complement activation products","volume":"56","author":"Bergseth","year":"2013","journal-title":"Mol Immunol"},{"key":"B22","doi-asserted-by":"publisher","DOI":"10.1101\/2022.03.26.484261","article-title":"Titers of antibodies the receptor-binding domain (RBD) of ancestral SARS-CoV-2 are predictive for levels of neutralizing antibodies to multiple variants","author":"Tran","year":"2022","journal-title":"bioRxiv"},{"key":"B23","doi-asserted-by":"publisher","DOI":"10.1016\/0022-3999(93)90081-P","article-title":"Development of a fatigue scale","volume":"37","author":"Chalder","year":"1993","journal-title":"J Psychosom. Res"},{"key":"B24","doi-asserted-by":"publisher","DOI":"10.1080\/21641846.2019.1653471","article-title":"The DePaul symptom questionnaire-2: A validation study","volume":"7","author":"Bedree","year":"2019","journal-title":"Fatigue"},{"key":"B25","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pmed.1003777","article-title":"Predictive symptoms for COVID-19 in the community: REACT-1 study of over 1 million people","volume":"18","author":"Elliott","year":"2021","journal-title":"PloS Med"},{"key":"B26","doi-asserted-by":"publisher","first-page":"94","DOI":"10.1016\/j.bbi.2018.09.023","article-title":"Predictors of chronic fatigue in adolescents six months after acute Epstein-Barr virus infection: A prospective cohort study","volume":"75","author":"Pedersen","year":"2019","journal-title":"Brain Behav Immun"},{"key":"B27","doi-asserted-by":"publisher","DOI":"10.1016\/S0022-3999(98)00022-1","article-title":"Exploring the validity of the chalder fatigue scale in chronic fatigue syndrome","volume":"45","author":"Morriss","year":"1998","journal-title":"J Psychosom. Res"},{"key":"B28","doi-asserted-by":"publisher","DOI":"10.7326\/0003-4819-121-12-199412150-00009","article-title":"The chronic fatigue syndrome: A comprehensive approach to its definition and study. international chronic fatigue syndrome study group","volume":"121","author":"Fukuda K","year":"1994","journal-title":"Ann Intern Med"},{"key":"B29","doi-asserted-by":"publisher","DOI":"10.1164\/rccm.201908-1590ST","article-title":"Standardization of spirometry 2019 update. an official American thoracic society and European respiratory society technical statement","volume":"200","author":"Graham","year":"2019","journal-title":"Am J Respir Crit Care Med"},{"key":"B30","doi-asserted-by":"publisher","DOI":"10.1183\/09031936.00080312","article-title":"Multi-ethnic reference values for spirometry for the 3-95-yr age range: the global lung function 2012 equations","volume":"40","author":"Quanjer","year":"2012","journal-title":"Eur Respir J"},{"key":"B31","doi-asserted-by":"publisher","DOI":"10.1038\/s41586-021-03207-w","article-title":"Evolution of antibody immunity to SARS-CoV-2","volume":"591","author":"Gaebler","year":"2021","journal-title":"Nature"},{"key":"B32","doi-asserted-by":"publisher","first-page":"763","DOI":"10.3390\/pathogens10060763","article-title":"Investigation of long COVID prevalence and its relationship to Epstein-Barr virus reactivation","volume":"10","author":"Gold","year":"2021","journal-title":"Pathogens"},{"key":"B33","doi-asserted-by":"publisher","first-page":"881","DOI":"10.1016\/j.cell.2022.01.014","article-title":"Multiple early factors anticipate post-acute COVID-19 sequelae","volume":"185","author":"Su","year":"2022","journal-title":"Cell"},{"key":"B34","doi-asserted-by":"publisher","DOI":"10.1016\/S1357-4310(99)01635-4","article-title":"Eotaxin and eosinophil recruitment: Implications for human disease","volume":"6","author":"Rankin","year":"2000","journal-title":"Mol Med Today"},{"key":"B35","doi-asserted-by":"publisher","first-page":"675","DOI":"10.1146\/annurev.immunol.15.1.675","article-title":"Human chemokines: An update","volume":"15","author":"Baggiolini","year":"1997","journal-title":"Annu Rev Immunol"},{"key":"B36","doi-asserted-by":"publisher","first-page":"08","DOI":"10.1101\/2022.08.09.22278592","article-title":"Distinguishing features of long COVID identified through immune profiling","volume":"2022","author":"Klein","year":"2022","journal-title":"medRxiv"},{"key":"B37","doi-asserted-by":"publisher","DOI":"10.1136\/gutjnl-2021-324280","article-title":"Residual SARS-CoV-2 viral antigens detected in GI and hepatic tissues from five recovered patients with COVID-19","volume":"71","author":"Cheung","year":"2022","journal-title":"Gut"},{"key":"B38","doi-asserted-by":"publisher","first-page":"1257","DOI":"10.1016\/j.immuni.2021.05.010","article-title":"Longitudinal analysis reveals that delayed bystander CD8+ T cell activation and early immune pathology distinguish severe COVID-19 from mild disease","volume":"54","author":"Bergamaschi","year":"2021","journal-title":"Immunity"},{"key":"B39","doi-asserted-by":"publisher","first-page":"26","DOI":"10.1186\/s12916-021-02228-6","article-title":"Long-term perturbation of the peripheral immune system months after SARS-CoV-2 infection","volume":"20","author":"Ryan","year":"2022","journal-title":"BMC Med"},{"key":"B40","doi-asserted-by":"publisher","first-page":"988","DOI":"10.1186\/s12889-020-09109-2","article-title":"Symptoms in the general Norwegian adult population - prevalence and associated factors","volume":"20","author":"Krogstad","year":"2020","journal-title":"BMC Public Health"},{"key":"B41","doi-asserted-by":"publisher","DOI":"10.1192\/bjp.173.6.475","article-title":"Incidence, risk and prognosis of acute and chronic fatigue syndromes and psychiatric disorders after glandular fever","volume":"173","author":"White","year":"1998","journal-title":"Br J Psychiatry"},{"key":"B42","doi-asserted-by":"publisher","first-page":"575","DOI":"10.1136\/bmj.38933.585764.AE","article-title":"Post-infective and chronic fatigue syndromes precipitated by viral and non-viral pathogens: Prospective cohort study","volume":"333","author":"Hickie","year":"2006","journal-title":"BMJ"},{"key":"B43","doi-asserted-by":"publisher","first-page":"95","DOI":"10.1016\/j.aca.2014.10.009","article-title":"Bioanalytical chemistry of cytokines\u2013a review","volume":"853","author":"Stenken","year":"2015","journal-title":"Anal Chim Acta"},{"key":"B44","doi-asserted-by":"publisher","first-page":"86","DOI":"10.1016\/j.cyto.2017.05.014","article-title":"Effect of the anticoagulant, storage time and temperature of blood samples on the concentrations of 27 multiplex assayed cytokines - consequences for defining reference values in healthy humans","volume":"97","author":"Henno","year":"2017","journal-title":"Cytokine"}],"container-title":["Frontiers in Immunology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fimmu.2022.1081718\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,1,6]],"date-time":"2023-01-06T19:40:33Z","timestamp":1673034033000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fimmu.2022.1081718\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,1,6]]},"references-count":44,"alternative-id":["10.3389\/fimmu.2022.1081718"],"URL":"https:\/\/doi.org\/10.3389\/fimmu.2022.1081718","relation":{},"ISSN":["1664-3224"],"issn-type":[{"value":"1664-3224","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,1,6]]},"article-number":"1081718"}}