Laboratory Findings and Biomarkers in Long COVID: What Do We Know So Far? Insights into Epidemiology, Pathogenesis, Therapeutic Perspectives and Challenges
Long COVID (LC) encompasses a constellation of long-term symptoms experienced by at least 10% of people after the initial SARS-CoV-2 infection, and so far it has affected about 65 million people. The etiology of LC remains unclear; however, many pathophysiological pathways may be involved, including...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-06-01
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| Series: | International Journal of Molecular Sciences |
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| Online Access: | https://www.mdpi.com/1422-0067/24/13/10458 |
| _version_ | 1797591657129967616 |
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| author | Dimitrios Tsilingiris Natalia G. Vallianou Irene Karampela Gerasimos Socrates Christodoulatos Georgios Papavasileiou Dimitra Petropoulou Faidon Magkos Maria Dalamaga |
| author_facet | Dimitrios Tsilingiris Natalia G. Vallianou Irene Karampela Gerasimos Socrates Christodoulatos Georgios Papavasileiou Dimitra Petropoulou Faidon Magkos Maria Dalamaga |
| author_sort | Dimitrios Tsilingiris |
| collection | DOAJ |
| description | Long COVID (LC) encompasses a constellation of long-term symptoms experienced by at least 10% of people after the initial SARS-CoV-2 infection, and so far it has affected about 65 million people. The etiology of LC remains unclear; however, many pathophysiological pathways may be involved, including viral persistence; a chronic, low-grade inflammatory response; immune dysregulation and a defective immune response; the reactivation of latent viruses; autoimmunity; persistent endothelial dysfunction and coagulopathy; gut dysbiosis; hormonal and metabolic dysregulation; mitochondrial dysfunction; and autonomic nervous system dysfunction. There are no specific tests for the diagnosis of LC, and clinical features including laboratory findings and biomarkers may not specifically relate to LC. Therefore, it is of paramount importance to develop and validate biomarkers that can be employed for the prediction, diagnosis and prognosis of LC and its therapeutic response, although this effort may be hampered by challenges pertaining to the non-specific nature of the majority of clinical manifestations in the LC spectrum, small sample sizes of relevant studies and other methodological issues. Promising candidate biomarkers that are found in some patients are markers of systemic inflammation, including acute phase proteins, cytokines and chemokines; biomarkers reflecting SARS-CoV-2 persistence, the reactivation of herpesviruses and immune dysregulation; biomarkers of endotheliopathy, coagulation and fibrinolysis; microbiota alterations; diverse proteins and metabolites; hormonal and metabolic biomarkers; and cerebrospinal fluid biomarkers. At present, there are only two reviews summarizing relevant biomarkers; however, they do not cover the entire umbrella of current biomarkers, their link to etiopathogenetic mechanisms or the diagnostic work-up in a comprehensive manner. Herein, we aim to appraise and synopsize the available evidence on the typical laboratory manifestations and candidate biomarkers of LC, their classification based on pathogenetic mechanisms and the main LC symptomatology in the frame of the epidemiological and clinical aspects of the syndrome and furthermore assess limitations and challenges as well as potential implications in candidate therapeutic interventions. |
| first_indexed | 2024-03-11T01:40:24Z |
| format | Article |
| id | doaj.art-cc1dffa31c7046a9a4b86739d35bd185 |
| institution | Directory Open Access Journal |
| issn | 1661-6596 1422-0067 |
| language | English |
| last_indexed | 2024-03-11T01:40:24Z |
| publishDate | 2023-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | International Journal of Molecular Sciences |
| spelling | doaj.art-cc1dffa31c7046a9a4b86739d35bd1852023-11-18T16:38:28ZengMDPI AGInternational Journal of Molecular Sciences1661-65961422-00672023-06-0124131045810.3390/ijms241310458Laboratory Findings and Biomarkers in Long COVID: What Do We Know So Far? Insights into Epidemiology, Pathogenesis, Therapeutic Perspectives and ChallengesDimitrios Tsilingiris0Natalia G. Vallianou1Irene Karampela2Gerasimos Socrates Christodoulatos3Georgios Papavasileiou4Dimitra Petropoulou5Faidon Magkos6Maria Dalamaga7First Department of Internal Medicine, University Hospital of Alexandroupolis, Democritus University of Thrace, Dragana, 68100 Alexandroupolis, GreeceDepartment of Internal Medicine, Evangelismos General Hospital, 45-47 Ipsilantou Street, 10676 Athens, Greece2nd Department of Critical Care, Medical School, University of Athens, Attikon General University Hospital, 1 Rimini Street, 12462 Athens, GreeceDepartment of Microbiology, Sismanogleio General Hospital, 1 Sismanogleiou Street, 15126 Athens, GreeceDepartment of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, 75 Mikras Asias Street, 11527 Athens, GreeceDepartment of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, 75 Mikras Asias Street, 11527 Athens, GreeceDepartment of Nutrition, Exercise, and Sports, University of Copenhagen, DK-2200 Frederiksberg, DenmarkDepartment of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, 75 Mikras Asias Street, 11527 Athens, GreeceLong COVID (LC) encompasses a constellation of long-term symptoms experienced by at least 10% of people after the initial SARS-CoV-2 infection, and so far it has affected about 65 million people. The etiology of LC remains unclear; however, many pathophysiological pathways may be involved, including viral persistence; a chronic, low-grade inflammatory response; immune dysregulation and a defective immune response; the reactivation of latent viruses; autoimmunity; persistent endothelial dysfunction and coagulopathy; gut dysbiosis; hormonal and metabolic dysregulation; mitochondrial dysfunction; and autonomic nervous system dysfunction. There are no specific tests for the diagnosis of LC, and clinical features including laboratory findings and biomarkers may not specifically relate to LC. Therefore, it is of paramount importance to develop and validate biomarkers that can be employed for the prediction, diagnosis and prognosis of LC and its therapeutic response, although this effort may be hampered by challenges pertaining to the non-specific nature of the majority of clinical manifestations in the LC spectrum, small sample sizes of relevant studies and other methodological issues. Promising candidate biomarkers that are found in some patients are markers of systemic inflammation, including acute phase proteins, cytokines and chemokines; biomarkers reflecting SARS-CoV-2 persistence, the reactivation of herpesviruses and immune dysregulation; biomarkers of endotheliopathy, coagulation and fibrinolysis; microbiota alterations; diverse proteins and metabolites; hormonal and metabolic biomarkers; and cerebrospinal fluid biomarkers. At present, there are only two reviews summarizing relevant biomarkers; however, they do not cover the entire umbrella of current biomarkers, their link to etiopathogenetic mechanisms or the diagnostic work-up in a comprehensive manner. Herein, we aim to appraise and synopsize the available evidence on the typical laboratory manifestations and candidate biomarkers of LC, their classification based on pathogenetic mechanisms and the main LC symptomatology in the frame of the epidemiological and clinical aspects of the syndrome and furthermore assess limitations and challenges as well as potential implications in candidate therapeutic interventions.https://www.mdpi.com/1422-0067/24/13/10458biomarkersCOVID-19epidemiologylaboratorylong COVIDpathogenesis |
| spellingShingle | Dimitrios Tsilingiris Natalia G. Vallianou Irene Karampela Gerasimos Socrates Christodoulatos Georgios Papavasileiou Dimitra Petropoulou Faidon Magkos Maria Dalamaga Laboratory Findings and Biomarkers in Long COVID: What Do We Know So Far? Insights into Epidemiology, Pathogenesis, Therapeutic Perspectives and Challenges International Journal of Molecular Sciences biomarkers COVID-19 epidemiology laboratory long COVID pathogenesis |
| title | Laboratory Findings and Biomarkers in Long COVID: What Do We Know So Far? Insights into Epidemiology, Pathogenesis, Therapeutic Perspectives and Challenges |
| title_full | Laboratory Findings and Biomarkers in Long COVID: What Do We Know So Far? Insights into Epidemiology, Pathogenesis, Therapeutic Perspectives and Challenges |
| title_fullStr | Laboratory Findings and Biomarkers in Long COVID: What Do We Know So Far? Insights into Epidemiology, Pathogenesis, Therapeutic Perspectives and Challenges |
| title_full_unstemmed | Laboratory Findings and Biomarkers in Long COVID: What Do We Know So Far? Insights into Epidemiology, Pathogenesis, Therapeutic Perspectives and Challenges |
| title_short | Laboratory Findings and Biomarkers in Long COVID: What Do We Know So Far? Insights into Epidemiology, Pathogenesis, Therapeutic Perspectives and Challenges |
| title_sort | laboratory findings and biomarkers in long covid what do we know so far insights into epidemiology pathogenesis therapeutic perspectives and challenges |
| topic | biomarkers COVID-19 epidemiology laboratory long COVID pathogenesis |
| url | https://www.mdpi.com/1422-0067/24/13/10458 |
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