RT journal article T1 A blood microRNA classifier for the prediction of ICU mortality in COVID-19 patients: a multicenter validation study A1 de Gonzalo Calvo, David A1 Molinero, Marta A1 Benítez, Iván D. A1 Perez Pons, Manel A1 García Mateo, Nadia A1 Ortega, Alicia A1 Postigo, Tamara A1 García Hidalgo, María C. A1 Belmonte, Thalía A1 Rodríguez Muñoz, Carlos A1 González, Jessica A1 Torres, Gerard A1 Gort Paniello, Clara A1 Moncusí Moix, Anna A1 Estella García, Ángel A1 Tamayo Lomas, Luis A1 Martínez de la Gándara, Amalia A1 Socias, Lorenzo A1 Peñasco, Yhivian A1 de la Torre, María del Carmen A1 Bustamante Munguira, Elena A1 Gallego Curto, Elena A1 Martínez Varela, Ignacio A1 Martín Delgado, María Cruz A1 Vidal Cortés, Pablo A1 López Messa, Juan A1 Pérez García, Felipe A1 Caballero, Jesús A1 Añón, José Manuel A1 Loza Vázquez, Ana A1 Carbonell, Nieves A1 Marin Corral, Judith A1 Jorge García, Ruth Noemí A1 Barberà, Carmen A1 Ceccato, Adrián A1 Fernández Barat, Laia A1 Ferrer, Ricard A1 García Gasulla, Dario A1 Lorente Balanza, Jose Ángel A1 Menéndez, Rosario A1 Motos, Ana A1 Peñuelas, Oscar A1 Riera, Jordi A1 Bermejo Martin, Jesús F. A1 Torres, Antoni A1 Barbé, Ferrán A2 Medicina K1 COVID-19 K1 Biomarker K1 ICU K1 microRNA K1 Prognosis K1 SARS-CoV-2 AB Background: The identification of critically ill COVID-19 patients at risk of fatal outcomes remains a challenge. Here, we first validated candidate microRNAs (miRNAs) as biomarkers for clinical decision-making in critically ill patients. Second, we constructed a blood miRNA classifier for the early prediction of adverse outcomes in the ICU. Methods: This was a multicenter, observational and retrospective/prospective study including 503 critically ill patients admitted to the ICU from 19 hospitals. qPCR assays were performed in plasma samples collected within the first 48 h upon admission. A 16-miRNA panel was designed based on recently published data from our group. Results: Nine miRNAs were validated as biomarkers of all-cause in-ICU mortality in the independent cohort of critically ill patients (FDR < 0.05). Cox regression analysis revealed that low expression levels of eight miRNAs were associated with a higher risk of death (HR from 1.56 to 2.61). LASSO regression for variable selection was used to construct a miRNA classifier. A 4-blood miRNA signature composed of miR-16-5p, miR-192-5p, miR-323a-3p and miR-451a predicts the risk of all-cause in-ICU mortality (HR 2.5). Kaplan‒Meier analysis confirmed these findings. The miRNA signature provides a significant increase in the prognostic capacity of conventional scores, APACHE-II (C-index 0.71, DeLong test p-value 0.055) and SOFA (C-index 0.67, DeLong test p-value 0.001), and a risk model based on clinical predictors (C-index 0.74, DeLong test-p-value 0.035). For 28-day and 90-day mortality, the classifier also improved the prognostic value of APACHE-II, SOFA and the clinical model. The association between the classifier and mortality persisted even after multivariable adjustment. The functional analysis reported biological pathways involved in SARS-CoV infection and inflammatory, fibrotic and transcriptional pathways. Conclusions: A blood miRNA classifier improves the early prediction of fatal outcomes in critically ill COVID-19 patients. PB Springer SN 1465-9921 YR 2023 FD 2023-06-17 LK http://hdl.handle.net/10498/29728 UL http://hdl.handle.net/10498/29728 LA eng DS Repositorio Institucional de la Universidad de Cádiz RD 08-nov-2026