Expression of CD62L on Donor CD4+ T Cells in Allografts: Correlation with Graft-Versus-Host Disease after Unmanipulated Allogeneic Blood and Marrow Transplantation

The aim of this study was to investigate the association of donor CD4(+) T cells expressing CD62L with transplant outcomes. We report a prospective analysis of 31 patients who were treated with a Bu/Cy regimen, followed by unmanipulated blood and marrow transplantation. Median number (range) of CD4(+)CD62L(+), CD4(+)CD45RA(+)CD62L(+), and CD4(+)CD45RO(+)CD62L(+) cells infused were 0.31(0.05-1.10)x10(8)/kg, 0.22(0.03-0.95)x 10(8)/kg, and 0.17(0.01-0.81)x10(8)/kg, respectively. The incidence of grades II to IV aGVHD was 36%. In a multivariate analysis, infusion of > 0.22 x 10(8) CD4(+)CD45RA(+)CD62L(+) cells infused/kg increased the risk of grades II to IV aGVHD (HR = 4.741, 95% CI = 1.037-21.662, P = 0.045). Thirteen of 31 patients experienced cGVHD, the risk of cGVHD was increased in patients receiving > 0.45 x 10(8) CD4(+)CD45RA(+) cells infused/kg (HR = 4.614, 95% CI = 1.265-16.829, P = 0.021). Our results suggest that a high cell dose of CD4(+)CD45RA(+)CD62L(+) cells increase the incidence of grades II-IV aGVHD. A high number of CD4(+)CD45RA(+) cells infused were associated with increased risk of cGVHD in our transplant settings.