Del Rosal, TeresaGarcía-García, María LuzCasas Flecha, InmaculadaIglesias-Caballero, MariaPozo Sanchez, FranciscoAlcolea, SoniaBravo, BlancaRodrigo-Muñoz, José MDel Pozo, VictoriaCalvo, Cristina2023-07-182023-07-182023-03-01Pediatr Infect Dis J. 2023 Mar 1;42(3):184-188.http://hdl.handle.net/20.500.12105/16287Background: Torque teno virus (TTV) is a ubiquitous anellovirus responsible for persistent infections and is considered a marker of immune function. The role of TTV as a facilitator of respiratory infections (RIs) is unknown. Objectives: Our aim was to estimate, in a prospective study, the prevalence of TTV in the nasopharyngeal aspirate (NPA) of hospitalized children <5 years old, with RIs and correlate them with outcomes and immune response. Patients and methods: NPA was taken for testing of 16 respiratory viruses by reverse transcription-polymerase chain reaction (PCR), TTV PCR, and immunologic study. Results: Sixty hospitalized children with an RI were included. A total of 51/60 patients had positive common respiratory viral (CRV) identification. A total of 23/60 (38.3%) children were TTV+ in NPA. TTV+ patients had other CRVs in 100% of cases versus 78.3% in TTV- ( P = 0.029). The TTV+ patients tended to be older, have fever, and to need pediatric intensive care unit admission more often than TTV- patients. Abnormal chest radiograph was more frequent in the TTV+ patients, odds ratios 2.6 (95% CI: 1.3-5.2). The genetic expression of filaggrin (involved in epithelial barrier integrity) was lower in TTV+ patients; however, the levels of filaggrin in the NPA were increased. Conclusions: TTV infection is common in children with RI and could be associated with abnormal imaging in radiograph, greater severity and an alteration in filaggrin gene expression and protein release.engVoRhttp://creativecommons.org/licenses/by-nc-nd/4.0/Torque teno virusInfantsViral respiratory infectionsDNA Virus InfectionsPneumoniaRespiratory Tract InfectionsTorque teno virusVirus DiseasesChild, PreschoolHumansDNA, ViralFilaggrin ProteinsProspective StudiesViral LoadAttribution-NonCommercial-NoDerivatives 4.0 Internacional36729788423184-18810.1097/INF.00000000000037961532-0987The Pediatric infectious disease journalopen access