{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,15]],"date-time":"2026-09-15T10:43:41Z","timestamp":1789469021900,"version":"build-2803163510"},"reference-count":28,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2026,9,10]],"date-time":"2026-09-10T00:00:00Z","timestamp":1788998400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Medicina"],"abstract":"<jats:p>Background and Objectives: FOXP3+ (Forkhead box P3) regulatory T cells contribute to immune tolerance after kidney transplantation, but their role in T cell-mediated rejection (TCMR) remains controversial. This study investigated the association between intragraft FOXP3+ cells and the recently introduced Banff-derived activity (AI) and chronicity index (CI) in biopsy-proven TCMR. Materials and Methods: This retrospective cross-sectional study included 119 kidney allograft biopsies diagnosed as acute or chronic active TCMR according to the Banff classification. FOXP3+ cells were assessed by immunohistochemistry and expressed as cortical cell density (cells\/mm2). Associations between FOXP3+ cell density, Banff-derived indices, inflammatory cell densities, and clinical parameters were analyzed using non-parametric statistical methods. Results: FOXP3+ cells were detected in 17.6% of biopsies. FOXP3+ cell density was univariately associated with higher CI values (\u03c1 = 0.228, p = 0.013) and chronic lesions interstitial fibrosis (ci) (\u03c1 = 0.284, p = 0.002) and tubular atrophy (ct) (\u03c1 = 0.246, p = 0.008). No association was observed with AI or activity lesions, except for a weak negative correlation with interstitial inflammation (i) (\u03c1 = \u22120.209, p = 0.025). In multivariable analysis, FOXP3 positivity was not significantly associated with CI after adjustment for transplantation\u2013biopsy interval (B = 0.568, 95% CI \u22120.741\u20131.876, p = 0.391). FOXP3+ cell density positively correlated with cluster of diferentiation (CD)4+ (\u03c1 = 0.350, p &lt; 0.001), CD8+ (\u03c1 = 0.229, p = 0.018), and CD163+ (\u03c1 = 0.207, p = 0.047) cell densities. No association with short-term graft outcome was observed. Conclusions: FOXP3+ cell infiltration was associated with chronic histological changes in unadjusted analyses, but this association did not remain statistically significant after adjustment for transplantation-to-biopsy interval. These preliminary findings suggest that FOXP3+ cell accumulation and chronic histological changes may represent parallel time-dependent phenomena and require confirmation in larger cohorts.<\/jats:p>","DOI":"10.3390\/medicina62091746","type":"journal-article","created":{"date-parts":[[2026,9,10]],"date-time":"2026-09-10T14:11:22Z","timestamp":1789049482000},"page":"1746","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Intragraft FOXP3+ Cells and Continuous Banff Indices in T Cell-Mediated Kidney Allograft Rejection"],"prefix":"10.3390","volume":"62","author":[{"ORCID":"https:\/\/orcid.org\/0009-0001-5342-4363","authenticated-orcid":false,"given":"Petar","family":"\u0110olonga","sequence":"first","affiliation":[{"name":"Department of Pathology, Judicial Medicine, and Cytology, University Hospital of Split, Spin\u010di\u0107eva 1, 21000 Split, Croatia"},{"name":"Department of Pathology, University of Split School of Medicine, \u0160oltanska 2, 21000 Split, Croatia"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"software","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3032-6952","authenticated-orcid":false,"given":"Petar","family":"\u0160enjug","sequence":"additional","affiliation":[{"name":"Department of Nephropathology and Electron Microscopy, Dubrava University Hospital, Avenija Gojka \u0160uska 6, 10000 Zagreb, Croatia"},{"name":"Institute of Pathology, School of Medicine, University of Zagreb, \u0160alata 10, 10000 Zagreb, Croatia"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"methodology","vocabulary":"credit"},{"role":"software","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"}]},{"given":"Anja","family":"Stadnik","sequence":"additional","affiliation":[{"name":"Department of Nephropathology and Electron Microscopy, Dubrava University Hospital, Avenija Gojka \u0160uska 6, 10000 Zagreb, Croatia"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"visualization","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"}]},{"given":"Ana","family":"Dunatov Huljev","sequence":"additional","affiliation":[{"name":"Department of Pathology, Judicial Medicine, and Cytology, University Hospital of Split, Spin\u010di\u0107eva 1, 21000 Split, Croatia"},{"name":"Department of Pathology, University of Split School of Medicine, \u0160oltanska 2, 21000 Split, Croatia"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"validation","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5454-2353","authenticated-orcid":false,"given":"Lada","family":"Zibar","sequence":"additional","affiliation":[{"name":"Department of Nephrology, Clinical Hospital Merkur, Zaj\u010deva 19, 10000 Zagreb, Croatia"},{"name":"Department of Pathophysiology, Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, Huttlerova 4, 31000 Osijek, Croatia"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"software","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"given":"Sandra","family":"Zeki\u0107 Toma\u0161","sequence":"additional","affiliation":[{"name":"Department of Pathology, Judicial Medicine, and Cytology, University Hospital of Split, Spin\u010di\u0107eva 1, 21000 Split, Croatia"},{"name":"Department of Pathology, University of Split School of Medicine, \u0160oltanska 2, 21000 Split, Croatia"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"validation","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"supervision","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2850-6316","authenticated-orcid":false,"given":"Danica","family":"Gale\u0161i\u0107 Ljubanovi\u0107","sequence":"additional","affiliation":[{"name":"Department of Nephropathology and Electron Microscopy, Dubrava University Hospital, Avenija Gojka \u0160uska 6, 10000 Zagreb, Croatia"},{"name":"Institute of Pathology, School of Medicine, University of Zagreb, \u0160alata 10, 10000 Zagreb, Croatia"},{"name":"Faculty of Farmacy and Biochemistry, University of Zagreb, Ante Kova\u010di\u0107a 1, 10000 Zagreb, Croatia"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"validation","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8292-9854","authenticated-orcid":false,"given":"Merica","family":"Glavina Durdov","sequence":"additional","affiliation":[{"name":"Department of Pathology, Judicial Medicine, and Cytology, University Hospital of Split, Spin\u010di\u0107eva 1, 21000 Split, Croatia"},{"name":"Department of Pathology, University of Split School of Medicine, \u0160oltanska 2, 21000 Split, Croatia"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"validation","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"supervision","vocabulary":"credit"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,10]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"325","DOI":"10.1097\/MOT.0000000000000189","article-title":"T-Cell-Mediated Rejection of the Kidney in the Era of Donor-Specific Antibodies","volume":"20","author":"Randhawa","year":"2015","journal-title":"Curr. 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