{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,26]],"date-time":"2026-10-26T23:17:56Z","timestamp":1793056676680,"version":"4.5.0"},"reference-count":30,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2025,6,24]],"date-time":"2025-06-24T00:00:00Z","timestamp":1750723200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Immunol."],"abstract":"<jats:sec><jats:title>Introduction<\/jats:title><jats:p>Paediatric acute hepatitis of unknown aetiology (PAHUA) has emerged as a global health concern, yet its cause remains unidentified. This study characterises the clinical and immunological profiles of PAHUA to identify reliable immune biomarkers for accurate diagnosis.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>Samples from 24 PAHUA patients, 6 children with autoimmune hepatitis (AIH), and 13 healthy paediatric volunteers (HVs) were analysed. Immunophenotyping, soluble immune checkpoints (ICs) and cytokine profiling, and <jats:italic>ex vivo<\/jats:italic> immune responses were assessed using spectral flow cytometry. Clustering and logistic regression modelling were used to identify predictive biomarkers.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>PAHUA cases frequently presented with gastrointestinal symptoms and liver damage preceding jaundice, with 59% progressing to paediatric acute liver failure (pALF). Adenovirus was detected in only 17.6% of PAHUA patients, suggesting it is unlikely to be the primary causative agent. Antibodies against the SARS-CoV-2 Spike protein were identified in 88.2% of PAHUA patients, as well as in AIH and HV groups, indicating prior exposure. Immunophenotyping, ICs and cytokine profiling, and <jats:italic>ex vivo<\/jats:italic> immune revealed distinct immune profiles between PAHUA and non-PAHUA individuals. Furthermore, clustering and logistic regression modelling identified potential predictive biomarkers, including the plasmatic ICs Gal-9 and sTim-3, alongside specific immune cell populations. Notably, a combined Gal-9 and sTim-3 model achieved an AUC of 1.000 in differentiating PAHUA patients from non-PAHUA individuals.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusions<\/jats:title><jats:p>Despite the limited cohort analysed, owing to the rarity of cases worldwide, our data provide valuable insights for an accurate, early, and minimally invasive diagnosis of PAHUA. These patients exhibit a distinct immunological profile, with ICs, particularly Gal-9 and sTim-3, showing strong potential as reliable biomarkers.<\/jats:p><\/jats:sec>","DOI":"10.3389\/fimmu.2025.1599982","type":"journal-article","created":{"date-parts":[[2025,6,24]],"date-time":"2025-06-24T09:18:23Z","timestamp":1750756703000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":1,"title":["Comprehensive immune profiling and predictive modelling of paediatric acute hepatitis of unknown aetiology from a Spanish cohort"],"prefix":"10.3389","volume":"16","author":[{"given":"Roberto","family":"Lozano-Rodr\u00edguez","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Loreto","family":"Hierro","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mar\u00eda Jos\u00e9","family":"Quiles","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alejandro","family":"Pascual-Iglesias","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ver\u00f3nica","family":"Terr\u00f3n-Arcos","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gema","family":"Mu\u00f1oz-Bartolo","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Esteban","family":"Frauca","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Francisco J.","family":"Cueto","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cristina","family":"Calvo","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Laura","family":"C\u00f3rdoba-Garc\u00eda","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jes\u00fas","family":"Fern\u00e1ndez-Felipe","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Laura","family":"Hurtado-Navarro","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Julia","family":"del Prado-Montero","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gonzalo","family":"S\u00e1enz de Santa Mar\u00eda-Diez","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Daniel","family":"Arvelo-Rosario","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Paloma","family":"Jara","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Carlos","family":"del Fresno","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Eduardo","family":"L\u00f3pez-Collazo","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2025,6,24]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.15585\/mmwr.mm7118e1","article-title":"Acute hepatitis and adenovirus infection among children \u2014 Alabama, October 2021\u2013February 2022","volume":"71","author":"Baker","year":"2022","journal-title":"MMWR Morb Mortal Wkly Rep"},{"key":"B2","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa2206294","article-title":"A case series of children with acute hepatitis and human adenovirus infection","volume":"387","author":"Gutierrez Sanchez","year":"2022","journal-title":"N Engl J Med"},{"key":"B3","unstructured":"Acute hepatitis of unknown aetiology \u2013 the United Kingdom of Great Britain and Northern Ireland\n          \n          \n          \n          2022"},{"key":"B4","unstructured":"Severe acute hepatitis of unknown origin in children - Multicountry \n          \n          \n          \n          2022"},{"key":"B5","unstructured":"Increase in severe acute hepatitis cases of unknown aetiology in children \n          \n          \n          \n          2022"},{"key":"B6","unstructured":"Severe acute hepatitis of unknown aetiology in children - Multi-country \n          \n          \n          \n          2022"},{"key":"B7","unstructured":"Epidemiological update: Hepatitis of unknown aetiology in children \n          \n          \n          \n          2022"},{"key":"B8","unstructured":"Updated recommendations for adenovirus testing and reporting of children with acute hepatitis of unknown etiology \n          \n          \n          \n          2022"},{"key":"B9","doi-asserted-by":"publisher","DOI":"10.3389\/fmicb.2022.956887","article-title":"Hepatitis of unknown etiology in children: What we know and what we can do","volume":"13","author":"Zhu","year":"2022","journal-title":"Front Microbiol"},{"key":"B10","doi-asserted-by":"publisher","DOI":"10.1111\/ajt.16665","article-title":"Acute hepatitis and adenovirus infection among children\u2014Alabama, October 2021\u2013February 2022","volume":"22","author":"Baker","year":"2022","journal-title":"Am J Transplant"},{"key":"B11","doi-asserted-by":"publisher","DOI":"10.1016\/S2468-1253(22)00166-2","article-title":"Severe acute hepatitis in children: investigate SARS-CoV-2 superantigens","volume":"7","author":"Brodin","year":"2022","journal-title":"Lancet Gastroenterol Hepatol"},{"key":"B12","doi-asserted-by":"publisher","DOI":"10.1016\/S2352-4642(23)00215-8","article-title":"Paediatric acute hepatitis of unknown aetiology: a national investigation and adenoviraemia case-control study in the UK","volume":"7","author":"Mandal","year":"2023","journal-title":"Lancet Child Adolesc Health"},{"key":"B13","doi-asserted-by":"publisher","DOI":"10.1002\/bimj.201700067","article-title":"Variable selection \u2013 A review and recommendations for the practicing statistician","volume":"60","author":"Heinze","year":"2018","journal-title":"Biometrical J"},{"key":"B14","doi-asserted-by":"publisher","first-page":"e0242831","DOI":"10.1371\/journal.pone.0242831","article-title":"Predicting who responds to spinal manipulative therapy using a short-time frame methodology: Results from a 238-participant study","volume":"15","author":"Hadizadeh","year":"2020","journal-title":"PloS One"},{"key":"B15","doi-asserted-by":"publisher","DOI":"10.1016\/j.ebiom.2023.104841","article-title":"The prognostic impact of SIGLEC5-induced impairment of CD8+ T cell activation in sepsis","volume":"97","author":"Lozano-Rodr\u00edguez","year":"2023","journal-title":"eBioMedicine"},{"key":"B16","doi-asserted-by":"publisher","DOI":"10.1002\/ctm2.573","article-title":"The immune checkpoints storm in COVID-19: Role as severity markers at emergency department admission","volume":"11","author":"Avenda\u00f1o-Ortiz","year":"2021","journal-title":"Clin Trans Med"},{"key":"B17","doi-asserted-by":"publisher","first-page":"e179352","DOI":"10.1172\/JCI179352","article-title":"Soluble immune-checkpoint factors: a potential immunotherapy biomarker","volume":"134","author":"Tan","year":"2024","journal-title":"J Clin Invest"},{"key":"B18","doi-asserted-by":"publisher","DOI":"10.3390\/jcm12010009","article-title":"Acute hepatitis of unknown origin in pediatric age group: recent outbreaks and approach to management","volume":"12","author":"Patel","year":"2022","journal-title":"JCM"},{"key":"B19","doi-asserted-by":"publisher","DOI":"10.1007\/s12519-022-00581-x","article-title":"Diagnosis, treatment, and prevention of severe acute hepatitis of unknown etiology in children","volume":"18","author":"Chen","year":"2022","journal-title":"World J Pediatr"},{"key":"B20","doi-asserted-by":"publisher","DOI":"10.14218\/JCTH.2022.00281","article-title":"Acute hepatitis of unknown origin in children: early observations from the 2022 outbreak","volume":"10","author":"Zhang","year":"2022","journal-title":"J Clin Transl Hepatol"},{"key":"B21","doi-asserted-by":"publisher","DOI":"10.1016\/j.jceh.2023.05.014","article-title":"Severe acute hepatitis of unknown etiology presenting as pediatric acute liver failure: analysis of likely etiology, clinical course and outcome","volume":"13","author":"Lal","year":"2023","journal-title":"J Clin Exp Hepatol"},{"key":"B22","doi-asserted-by":"publisher","first-page":"29","DOI":"10.1093\/cei\/uxad023","article-title":"Acute hepatitis of unknown aetiology in children: a clinical update on the recent outbreak with mechanistic insights","volume":"212","author":"Vimalesvaran","year":"2023","journal-title":"Clin Exp Immunol"},{"key":"B23","doi-asserted-by":"publisher","DOI":"10.1007\/s00134-022-06765-3","article-title":"Outbreak of hepatitis in children: clinical course of children with acute liver failure admitted to the intensive care unit","volume":"48","author":"Deep","year":"2022","journal-title":"Intensive Care Med"},{"key":"B24","doi-asserted-by":"publisher","DOI":"10.3389\/fped.2022.956699","article-title":"Pediatric acute liver failure: An experience of a pediatric intensive care unit from resource limited settings","volume":"10","author":"Amatya","year":"2022","journal-title":"Front Pediatr"},{"key":"B25","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":"B26","doi-asserted-by":"publisher","first-page":"83","DOI":"10.1016\/j.hlife.2023.10.008","article-title":"SARS-CoV-2: Possible role in children with acute hepatitis of unknown origin","volume":"1","author":"Yu","year":"2023","journal-title":"hLife"},{"key":"B27","doi-asserted-by":"publisher","DOI":"10.1016\/j.chom.2021.06.015","article-title":"Children and SARS-coV-2","volume":"29","author":"Bogunovic","year":"2021","journal-title":"Cell Host Microbe"},{"key":"B28","doi-asserted-by":"publisher","first-page":"12","DOI":"10.5009\/gnl220327","article-title":"SARS-coV-2 infection and liver disease: A review of pathogenesis and outcomes","volume":"17","author":"Baldelli","year":"2023","journal-title":"Gut Liver"},{"key":"B29","doi-asserted-by":"publisher","DOI":"10.1038\/s42255-022-00552-6","article-title":"Molecular consequences of SARS-CoV-2 liver tropism","volume":"4","author":"Wanner","year":"2022","journal-title":"Nat Metab"},{"key":"B30","doi-asserted-by":"publisher","first-page":"1","DOI":"10.4254\/wjh.v16.i1.1","article-title":"Molecular mechanisms underlying SARS-CoV-2 hepatotropism and liver damage","volume":"16","author":"Quarleri","year":"2024","journal-title":"World J Hepatol"}],"container-title":["Frontiers in Immunology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fimmu.2025.1599982\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,6,24]],"date-time":"2025-06-24T09:18:25Z","timestamp":1750756705000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fimmu.2025.1599982\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,6,24]]},"references-count":30,"alternative-id":["10.3389\/fimmu.2025.1599982"],"URL":"https:\/\/doi.org\/10.3389\/fimmu.2025.1599982","relation":{},"ISSN":["1664-3224"],"issn-type":[{"value":"1664-3224","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,6,24]]},"article-number":"1599982"}}