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Prediction of T-cell reconstitution by assessment of T-cell receptor excision circle before allogeneic hematopoietic stem cell transplantation in pediatric patients

2004; Elsevier BV; Volume: 105; Issue: 2 Linguagem: Inglês

10.1182/blood-2004-04-1405

1528-0020

Xiaohua Chen, Raymond Barfield, Ely Benaim, Wing Leung, James Knowles, Dawn Lawrence, Mario Otto, Sheila Shurtleff, Geoffrey Neale, Frederick G. Behm, Victoria Turner, Rupert Handgretinger,

Immune Cell Function and Interaction

Abstract The extent and rapidity with which T cells are regenerated from graft-derived precursor cells directly influences the incidence of infection and the T-cell–based graft-versus-tumor effect. Measurement of T-cell receptor excision circles (TRECs) in peripheral blood is a means of quantifying recent thymic T-cell production and has been used after transplantation in many studies to estimate thymus-dependent T-cell reconstitution. We hypothesized that the quality of thymic function before transplantation affects thymus-dependent T-cell reconstitution after transplantation. We used real-time polymerase chain reaction (PCR) to quantify signal-joint TRECs (sjTRECs) before and after transplantation. T-cell reconstitution was evaluated by T-cell receptor β (TCRβ) CDR3 size spectratyping. We tested 77 healthy sibling donors and 244 samples from 26 pediatric recipients of allogeneic hematopoietic stem cell transplantation (AHSCT). Blood from the healthy donors contained 1200 to 155 000 sjTREC copies/mL blood. Patients who had greater than 1200 copies/mL blood before transplantation showed early recovery of sjTREC numbers and TCRβ repertoire diversity. In contrast, patients who had fewer than 1200 copies/mL blood before transplantation demonstrated significantly slower restoration of thymus-dependent T cells. We conclude that the rate of reconstitution of thymus-dependent T cells is dependent on the competence of thymic function in the recipients before transplantation. Therefore, pretransplantation measurement of sjTREC may provide an important tool for predicting thymus-dependent T-cell reconstitution after transplantation.