Rituximab-based treatments followed by adoptive cellular immunotherapy for biopsy-proven EBV-associated post-transplant lymphoproliferative disease in recipients of allogeneic hematopoietic stem cell transplantation

Abstract

To improve prognosis of post-transplant lymphoproliferative disease (PTLD), a sequential therapeutic strategy that rituximab-based treatments followed by donor lymphocyte infusion (DLI) or autologous EBV-specific cytotoxic T lymphocytes (EBV-CTL) for biopsy-proven EBV-associated PTLD in recipients of allogeneic hematopoietic stem cell transplantation was designed. 84 patients with EBV-PTLD were enrolled in this prospective study. After two cycles of the rituximab-based treatments, 68 of 84 patients (81% [95% CI 71-88]) responded and 52 (62% [51-72]) had CRs. This increased to 73 of 77 patients (95% [87-98]) with completion of sequential cell infusions, and 70 of 77 (91% [82-96]) achieved CRs after DLI or autologous EBV-CTL infusion. 22 patients experienced acute GVHD (aGVHD) (grade I in 5 and grade II in 13, grade III in 4) and 13 chronic GVHD (limited cGVHD in 7 and extensive cGVHD in 6) in 62 patients undergoing a median of three doses of DLI. The incidences of GVHD were similar between DLI and EBV-CTL group (aGVHD 35% vs. 33%, p = 0.876; cGVHD 21% vs. 13%; p = 0.503). EBV-CTL activity after the rituximab-based treatments did not change, while increased after cell infusions and reached its maximum in the 3rd or 6th month after EBV-CTL or DLI treatment, respectively. The 5-y cumulative incidence of PTLD relapse was 4.5% ± 3.3%. The 5-y overall survival (OS) and progression-free survival (PFS) after PTLD were 70.7% ± 5.2% and 68.9% ± 5.3%, respectively. Rituximab-based treatments combined with adoptive cellular immunotherapy might elevate CR rates and reduce relapse of PTLD after allo-HSCT.

Keywords: Adoptive cellular immunotherapy; EBV; EBV-CTL; PTLD; donor lymphocyte infusion; hematopoietic stem cell transplantation; relapse; rituximab.

Figure 1.

Study profile. DLI, Granulocyte colony-stimulating factor-mobilized donor lymphocyte infusion; EBV-CTL, Epstein-Barr virus-specific cytotoxic T lymphocytes; PD, progression of disease; CR, complete remission; MODS, multiple-organ disfunction syndrome; PFS, progression-free survival; OS, overall survival. *: included two CR patients not receiving DLI or EBV-CTL.

Figure 2.

Lymphocyte percentages in circulation and EBV-specific cytotoxic lymphocyte activity of patients who received DLI and EBV-CTL infusion. No significant difference was observed between patients received DLI and EBV-CTL in lymphocytes (CD3⁺ T cells, p = 0.552; CD16⁺CD56⁺ NK cells, p = 0.549; CD19⁺ B cells, p = 0.704). (A), (B) and (C): The percentages of CD3⁺ T cells, and CD16⁺CD56⁺ NK cells before cellular immunotherapies were not different from those before rituximab-based treatment (p = 0.471 and p = 0.603, respectively), while the CD19⁺ B cells before the cell infusions were less than those before the rituximab-based treatments (p < 0 .001). The percentages of CD3⁺ T cells, CD16⁺CD56⁺ NK cells, CD19⁺ B cells were increased in the 1st month after cellular immunotherapies than those before cell infusions (p = 0.001, p = 0.01, p < 0 .001, respectively), higher in the 3rd month than those in the 1st month after DLI or EBV-CTL (p < 0 .001, p = 0.009, p < 0 .001, respectively), and reached their maximal in the 3rd, 6th, 6th month, respectively. The CD4⁺ T cell to CD8⁺ T cell ratio increased since the 3rd month (p < 0.001), no differences among the 6th, 9th and 12th month. (D) In the spot assay, the IFNγ spot numbers before the cell infusion were not different from those before rituximab-based treatments (p = 0.296), while more in the 1st month than those before cell infusion (p < 0 .001), more in the 3rd month than those in the 1st month after cellular immunotherapies (p < 0 .001) and more in the 6th month than those in the 3rd month (p < 0 .001), no differences among the 6th, 9th and 12th month after cellular immunotherapies. The EBV-CTL activity in EBV-CTL treatment group was higher than that in the DLI group (p = 0.001). Notes: Arrows denote the time of rituximab-based treatments.

Figure 3.

Lymphocyte subsets in a relapsed PTLD patient.

Figure 4.

Response duration, time to progression, progression-free survival and overall survival.