{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,7]],"date-time":"2026-08-07T15:14:16Z","timestamp":1786115656335,"version":"build-2736575974"},"reference-count":33,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,8,6]],"date-time":"2026-08-06T00:00:00Z","timestamp":1785974400000},"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>\n                    <jats:title>Introduction<\/jats:title>\n                    <jats:p>\n                      Anti-thymocyte globulin (ATG) and post-transplantation cyclophosphamide (PTCy) are both used as\n                      <jats:italic>in-vivo<\/jats:italic>\n                      lymphodepleting treatment in allogeneic hematopoietic stem cell transplantation (HSCT), particularly in the matched unrelated donor (MUD) setting.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>In this retrospective study, we compared the incidences of infections and viral reactivations and evaluated immune cell reconstitution in the first-year post-transplant between ATG- and PTCy-based conditioning regimens in nonmyeloablative MUD transplantations. Infection incidence was evaluated for the periods 0-100 vs. 101-365 days post-transplant.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>A total of 185 patients (ATG=95, PTCy=90), transplanted between 2014 and 2021, were included. In the first 100 days after transplantation, the cumulative incidence of bacterial infections was higher in the PTCy group (ATG 17% vs. PTCy 32%, p=0.01) while CMV reactivations were more frequent in the ATG group (36% vs. 16%, p&amp;lt;0.001). Beyond 100-days post-transplant, incidence of bacterial infections was higher in the ATG group (18% vs. 1%, p&amp;lt;0.001). Fungal infection incidence was similar in both groups\/periods. The 1-year densities of viral infections (3.54 vs. 1.89, p&amp;lt;0.01) and CMV reactivations (2.21 vs. 0.68, p&amp;lt;0.01) were higher in the ATG compared to the PTCy group. After 1-year, circulating CD4+ T-cell counts were significantly lower in the ATG than in the PTCy group (p&amp;lt;0.001).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Discussion<\/jats:title>\n                    <jats:p>In conclusion, this study shows that overall PTCy is associated with better immune reconstitution and reduced rate of viral infections\/CMV reactivations compared to ATG-based conditioning. Together with our previous findings of a lower risk of acute GvHD following PTCy compared to ATG-based conditioning, these data may favor PTCy over ATG as GvHD prophylaxis.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fimmu.2026.1739320","type":"journal-article","created":{"date-parts":[[2026,8,6]],"date-time":"2026-08-06T04:25:33Z","timestamp":1785990333000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Immune reconstitution and infections with ATG versus post-transplant cyclophosphamide as GvHD prophylaxis after nonmyeloablative matched unrelated donor hematopoietic stem cell transplantation"],"prefix":"10.3389","volume":"17","author":[{"given":"Mesire","family":"Aydin","sequence":"first","affiliation":[{"name":"Department of Hematology, Amsterdam UMC, University of Amsterdam","place":["Amsterdam, Netherlands"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"David C.","family":"de Leeuw","sequence":"additional","affiliation":[{"name":"Department of Hematology, Amsterdam UMC, Free University","place":["Amsterdam, Netherlands"]},{"name":"Cancer Center Amsterdam, Amsterdam University Medical Center","place":["Amsterdam, Netherlands"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Man Wai","family":"Tang","sequence":"additional","affiliation":[{"name":"Department of Hematology, Amsterdam UMC, University of Amsterdam","place":["Amsterdam, Netherlands"]},{"name":"Cancer Center Amsterdam, Amsterdam University Medical Center","place":["Amsterdam, Netherlands"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Caroline E.","family":"Rutten","sequence":"additional","affiliation":[{"name":"Department of Hematology, Amsterdam UMC, University of Amsterdam","place":["Amsterdam, Netherlands"]},{"name":"Cancer Center Amsterdam, Amsterdam University Medical Center","place":["Amsterdam, Netherlands"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Otto J.","family":"Visser","sequence":"additional","affiliation":[{"name":"Department of Hematology, Isala Hospital","place":["Zwolle, Netherlands"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cinthy","family":"van Roessel","sequence":"additional","affiliation":[{"name":"Department of Hematology, Amsterdam UMC, Free University","place":["Amsterdam, Netherlands"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jeroen J.W.","family":"Janssen","sequence":"additional","affiliation":[{"name":"Department of Hematology, Amsterdam UMC, Free University","place":["Amsterdam, Netherlands"]},{"name":"Department of Hematology, Radboud University Medical Center","place":["Nijmegen, Netherlands"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bart J.","family":"Biemond","sequence":"additional","affiliation":[{"name":"Department of Hematology, Amsterdam UMC, University of Amsterdam","place":["Amsterdam, Netherlands"]},{"name":"Cancer Center Amsterdam, Amsterdam University Medical Center","place":["Amsterdam, Netherlands"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Arjan A.","family":"van de Loosdrecht","sequence":"additional","affiliation":[{"name":"Department of Hematology, Amsterdam UMC, Free University","place":["Amsterdam, Netherlands"]},{"name":"Cancer Center Amsterdam, Amsterdam University Medical Center","place":["Amsterdam, Netherlands"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mette D.","family":"Hazenberg","sequence":"additional","affiliation":[{"name":"Department of Hematology, Amsterdam UMC, University of Amsterdam","place":["Amsterdam, Netherlands"]},{"name":"Cancer Center Amsterdam, Amsterdam University Medical Center","place":["Amsterdam, Netherlands"]},{"name":"Department of Hematopoiesis, Sanquin Research and Landsteiner Laboratory","place":["Amsterdam, Netherlands"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Erfan","family":"Nur","sequence":"additional","affiliation":[{"name":"Department of Hematology, Amsterdam UMC, University of Amsterdam","place":["Amsterdam, Netherlands"]},{"name":"Cancer Center Amsterdam, Amsterdam University Medical Center","place":["Amsterdam, Netherlands"]},{"name":"Department of Molecular Hematology, Sanquin Research and Landsteiner Laboratory, Sanquin Research","place":["Amsterdam, Netherlands"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,8,6]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1016\/j.bbmt.2009.07.004","article-title":"Defining the intensity of conditioning regimens: working definitions","volume":"15","author":"Bacigalupo","year":"2009","journal-title":"Biol Blood Marrow Transplant"},{"key":"B2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1399-3062.2004.00075.x","article-title":"Low 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