{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,20]],"date-time":"2026-10-20T19:57:19Z","timestamp":1792526239579,"version":"4.5.0"},"reference-count":18,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,5,7]],"date-time":"2026-05-07T00:00:00Z","timestamp":1778112000000},"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. Pediatr."],"abstract":"<jats:p>\n                    BK virus reactivation is frequently observed in patients following allogeneic stem cell transplantation and can cause nephropathy and hemorrhagic cystitis. Current treatments are mainly supportive, and antiviral therapy with cidofovir lacks clear evidence of efficacy. Therefore, novel therapeutic strategies are needed. Since adoptive transfer of virus-specific T cells has proven effective for other viral infections, this case series with four cases of post-transplant severe BKV infections evaluated the feasibility, safety, and efficacy of BKV-specific T cells in patients with refractory BKV infection using the CliniMACS Prodigy system. Three of the four patients demonstrated a reduction in BKV viral load following adoptive T-cell transfer, with detectable\n                    <jats:italic>in vivo<\/jats:italic>\n                    expansion of BKV-specific T cells in these individuals. However, complete viral clearance was not achieved in all cases. One patient with extensive immunosuppression showed minimal viral response and no detectable BKV-specific T cells after infusion. Treatment was well tolerated, with no infusion-related toxicities and no severe\n                    <jats:italic>de novo<\/jats:italic>\n                    graft-versus-host disease observed. Overall, this case series suggests that rapidly manufactured BKV-specific T cells produced via the CliniMACS Prodigy system represent a feasible, safe, and potentially effective treatment option for refractory BKV viremia after stem cell transplantation. Early administration and limited concurrent immunosuppression may improve therapeutic outcomes. Further studies are needed to confirm these findings.\n                  <\/jats:p>","DOI":"10.3389\/fped.2026.1732453","type":"journal-article","created":{"date-parts":[[2026,5,7]],"date-time":"2026-05-07T04:55:54Z","timestamp":1778129754000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":1,"title":["Case Report: BKV-specific T cells: a fast, safe and potentially effective treatment option for refractory BKV infections in pediatric patients after allogeneic stem cell transplantation"],"prefix":"10.3389","volume":"14","author":[{"given":"Sven","family":"Oberwegner","sequence":"first","affiliation":[{"name":"Department of Pediatrics I, Hematology and Oncology, University Hospital T\u00fcbingen","place":["T\u00fcbingen, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Steffen A.","family":"Hettler","sequence":"additional","affiliation":[{"name":"Department of Pediatrics I, Hematology and Oncology, University Hospital T\u00fcbingen","place":["T\u00fcbingen, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Luca","family":"Hensen","sequence":"additional","affiliation":[{"name":"Department of Internal Medicine II, Hematology, Oncology, Clinical Immunology, and Rheumatology, University Hospital T\u00fcbingen","place":["T\u00fcbingen, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Amadeus T.","family":"Heinz","sequence":"additional","affiliation":[{"name":"Department of Pediatrics I, Hematology and Oncology, University Hospital T\u00fcbingen","place":["T\u00fcbingen, Germany"]},{"name":"Stuttgart Cancer Center, Zentrum f\u00fcr Kinder-, Jugend- und Frauenmedizin (Olgahospital), P\u00e4diatrie 5 (P\u00e4diatrische Onkologie, H\u00e4matologie, Immunologie), Klinikum der Landeshauptstadt Stuttgart","place":["Stuttgart, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Christiane","family":"Braun","sequence":"additional","affiliation":[{"name":"Department of Pediatrics I, Hematology and Oncology, University Hospital T\u00fcbingen","place":["T\u00fcbingen, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michaela","family":"D\u00f6ring","sequence":"additional","affiliation":[{"name":"Department of Pediatrics I, Hematology and Oncology, University Hospital T\u00fcbingen","place":["T\u00fcbingen, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Peter","family":"Lang","sequence":"additional","affiliation":[{"name":"Department of Pediatrics I, Hematology and Oncology, University Hospital T\u00fcbingen","place":["T\u00fcbingen, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,5,7]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"115","DOI":"10.1002\/jmv.10450","article-title":"Population-based study of antibody to the human polyomaviruses BKV and JCV and the simian polyomavirus SV40","volume":"71","author":"Knowles","year":"2003","journal-title":"J Med Virol"},{"key":"B2","doi-asserted-by":"publisher","first-page":"600","DOI":"10.1002\/jmv.10436","article-title":"Prevalence of BK virus and JC virus in peripheral blood leukocytes and normal arterial walls in healthy individuals in China","volume":"70","author":"Gu","year":"2003","journal-title":"J Med Virol"},{"key":"B3","doi-asserted-by":"publisher","first-page":"143","DOI":"10.1002\/jmv.1890080208","article-title":"The persistence of papovavirus BK DNA sequences in normal human renal tissue","volume":"8","author":"Heritage","year":"1981","journal-title":"J Med Virol"},{"key":"B4","doi-asserted-by":"publisher","first-page":"662","DOI":"10.1016\/j.bbmt.2009.12.009","article-title":"Late-onset hemorrhagic cystitis in children after hematopoietic stem cell transplantation for thalassemia and sickle cell anemia: a prospective evaluation of polyoma (BK) virus infection and treatment with cidofovir","volume":"16","author":"Gaziev","year":"2010","journal-title":"Biol Blood Marrow Transplant"},{"key":"B5","doi-asserted-by":"publisher","first-page":"664","DOI":"10.1038\/bmt.2013.235","article-title":"High burden of BK virus-associated hemorrhagic cystitis in patients undergoing allogeneic hematopoietic stem cell transplantation","volume":"49","author":"Gilis","year":"2014","journal-title":"Bone Marrow Transplant"},{"key":"B6","doi-asserted-by":"publisher","first-page":"134","DOI":"10.1093\/jpids\/piu043","article-title":"A prospective study on the predictive value of plasma BK virus-DNA load for hemorrhagic cystitis in pediatric patients after stem cell transplantation","volume":"4","author":"Cesaro","year":"2015","journal-title":"J Pediatric Infect Dis Soc"},{"key":"B7","doi-asserted-by":"publisher","first-page":"34","DOI":"10.1016\/j.ijsu.2019.01.019","article-title":"BK Virus associated haemorrhagic cystitis. A systematic review of current prevention and treatment strategies","volume":"63","author":"Aldiwani","year":"2019","journal-title":"Int J Surg"},{"key":"B8","doi-asserted-by":"publisher","first-page":"632","DOI":"10.1111\/ejh.12848","article-title":"BKV-specific T cells in the treatment of severe refractory haemorrhagic cystitis after HLA-haploidentical haematopoietic cell transplantation","volume":"98","author":"Pello","year":"2017","journal-title":"Eur J Haematol"},{"key":"B9","doi-asserted-by":"publisher","first-page":"845","DOI":"10.3390\/vaccines11040845","article-title":"Long-term follow-up after adoptive transfer of BK-virus-specific T cells in hematopoietic stem cell transplant recipients","volume":"11","author":"Koldehoff","year":"2023","journal-title":"Vaccines (Basel)"},{"key":"B10","doi-asserted-by":"publisher","first-page":"13","DOI":"10.1186\/s13045-019-0701-1","article-title":"Strategies of adoptive T -cell transfer to treat refractory viral infections post allogeneic stem cell transplantation","volume":"12","author":"Kaeuferle","year":"2019","journal-title":"J Hematol Oncol"},{"key":"B11","doi-asserted-by":"publisher","first-page":"2080","DOI":"10.3324\/haematol.2022.281996","article-title":"Automated production of specific T cells for treatment of refractory viral infections after allogeneic stem cell transplantation","volume":"108","author":"Heinz","year":"2023","journal-title":"Haematologica"},{"key":"B12","doi-asserted-by":"publisher","first-page":"187.e1","DOI":"10.1016\/j.jtct.2022.11.023","article-title":"BK viremia and changes in estimated glomerular filtration rate in children and young adults after hematopoietic cell transplantation","volume":"29","author":"Wychera","year":"2023","journal-title":"Transplant Cell Ther"},{"key":"B13","doi-asserted-by":"publisher","first-page":"3044","DOI":"10.1093\/cid\/ciz1194","article-title":"The natural history of BK polyomavirus and the host immune response after stem cell transplantation","volume":"71","author":"Laskin","year":"2020","journal-title":"Clin Infect Dis"},{"key":"B14","doi-asserted-by":"publisher","first-page":"3547","DOI":"10.1200\/JCO.2017.73.0655","article-title":"Off-the-Shelf virus-specific T cells to treat BK virus, human herpesvirus 6, cytomegalovirus, epstein\u2013barr virus, and adenovirus infections after allogeneic hematopoietic stem-cell transplantation","volume":"35","author":"Tzannou","year":"2017","journal-title":"J Clin Oncol"},{"key":"B15","doi-asserted-by":"publisher","first-page":"5745","DOI":"10.1182\/bloodadvances.2020003073","article-title":"Virus-specific T-cell therapy to treat BK polyomavirus infection in bone marrow and solid organ transplant recipients","volume":"4","author":"Nelson","year":"2020","journal-title":"Blood Adv"},{"key":"B16","doi-asserted-by":"publisher","first-page":"2710","DOI":"10.1200\/JCO.20.02608","article-title":"Third-party BK virus-specific cytotoxic T lymphocyte therapy for hemorrhagic cystitis following allotransplantation","volume":"39","author":"Olson","year":"2021","journal-title":"J Clin Oncol"},{"key":"B17","doi-asserted-by":"publisher","first-page":"113375","DOI":"10.1016\/j.jim.2022.113375","article-title":"Generation of good manufacturing practice grade virus-specific T cells for the management of post-transplant CMV infections","volume":"511","author":"Arunachalam","year":"2022","journal-title":"J Immunol Methods"},{"key":"B18","doi-asserted-by":"publisher","first-page":"199","DOI":"10.1016\/j.jim.2014.01.013","article-title":"In vitro expansion of antigen-specific CD8(+) T cells distorts the T-cell repertoire","volume":"405","author":"Koning","year":"2014","journal-title":"J Immunol Methods"}],"container-title":["Frontiers in Pediatrics"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fped.2026.1732453\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,5,7]],"date-time":"2026-05-07T04:55:55Z","timestamp":1778129755000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fped.2026.1732453\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,5,7]]},"references-count":18,"alternative-id":["10.3389\/fped.2026.1732453"],"URL":"https:\/\/doi.org\/10.3389\/fped.2026.1732453","relation":{},"ISSN":["2296-2360"],"issn-type":[{"value":"2296-2360","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,5,7]]},"article-number":"1732453"}}