{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,4]],"date-time":"2026-05-04T14:17:54Z","timestamp":1777904274137,"version":"3.51.4"},"reference-count":39,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2025,2,2]],"date-time":"2025-02-02T00:00:00Z","timestamp":1738454400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Microorganisms"],"abstract":"<jats:p>Monitoring immune function in post-transplant patients is crucial to reduce the risk of viral infections (e.g., cytomegalovirus [CMV] or Epstein\u2013Barr virus [EBV]), which can lead to serious complications such as post-transplant lymphoproliferative disorder (PTLD). Recently, Torque Teno virus (TTV) has attracted interest as a marker of immune function. Thus, we studied the kinetics of common post-transplant viral infections (TTV, EBV, CMV, human herpesvirus-6 [HHV-6], and adenovirus [AdV]) and their association with clinical parameters in 23 HSCT recipients who developed PTLD (PTLD-HSCT) and 25 post-HSCT patients without PTLD (Non-PTLD-HSCT) at three different timepoints: at the time of the transplant (T0), 3 months (T1), and 6 months (T2) post-HSCT. Additionally, 25 healthy donors (HD) were used as the control. EBV, CMV, HHV-6, or AdV infections were found in a few samples, while TTV was found in all of our samples. The highest TTV levels (4.61 [T0], 6.24 [T1] and 6.70 [T2] log10 copies\/mL) were seen in PTLD-HSCT patients compared to Non-PTLD-HSCT (3.39 [T0], 4.86 [T1], and 3.75 [T2] log10 copies\/mL) and HD (2.25 log10 copies\/mL) at all timepoints. Higher TTV levels were also seen in patients with a destructive type of PTLD and in surviving PTLD-HSCT patients compared to deceased ones. TTV kinetics in PTLD patients post-HSCT showed that TTV levels increase with the fall in the host immunocompetence and that by monitoring TTV kinetics, the immune status of the patient can be monitored.<\/jats:p>","DOI":"10.3390\/microorganisms13020326","type":"journal-article","created":{"date-parts":[[2025,2,3]],"date-time":"2025-02-03T08:47:57Z","timestamp":1738572477000},"page":"326","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Viral Infections in HSCT Recipients with Post-Transplant Lymphoproliferative Disorder: The Role of Torque Teno Virus as a Marker of Immune Functions"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0633-3116","authenticated-orcid":false,"given":"Martyna","family":"Pociupany","sequence":"first","affiliation":[{"name":"Molecular Structural and Translational Virology Research Group, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, 3000 Leuven, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0002-5357-6276","authenticated-orcid":false,"given":"Carolina","family":"Tarabella","sequence":"additional","affiliation":[{"name":"Centre for Molecular and Vascular Biology, Department of Cardiovascular Sciences, KU Leuven, 3000 Leuven, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Robert","family":"Snoeck","sequence":"additional","affiliation":[{"name":"Molecular Structural and Translational Virology Research Group, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, 3000 Leuven, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8917-022X","authenticated-orcid":false,"given":"Daan","family":"Dierickx","sequence":"additional","affiliation":[{"name":"Department of Hematology, University Hospitals Leuven, 3000 Leuven, Belgium"},{"name":"Laboratory of Experimental Hematology, Department of Oncology, KU Leuven, 3000 Leuven, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2609-4896","authenticated-orcid":false,"given":"Graciela","family":"Andrei","sequence":"additional","affiliation":[{"name":"Molecular Structural and Translational Virology Research Group, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, 3000 Leuven, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,2,2]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1128\/CMR.00027-20","article-title":"Beyond Cytomegalovirus and Epstein-Barr Virus: A Review of Viruses Composing the Blood Virome of Solid Organ Transplant and Hematopoietic Stem Cell Transplant Recipients","volume":"33","author":"Zanella","year":"2020","journal-title":"Clin. 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