What Can We Expect after Performing Allogeneic Stem Cell Transplantation for Adult T Lymphoma in Patients from Romania, Europe?

Introduction: Adult T lymphoma (ATL) is a rare and aggressive disease shown to be consistently caused by the human T lymphoma virus I (HTLV-I). It generally occurs in Japan and Africa, with a low incidence in Europe. Romania is an exception to this rule, presenting an endemic representation of ATL.

Aim: The aim of this study was to present our experience with allogeneic stem cell transplantation (alloSCT) for ATL.

Methods: The current study was a retrospective analysis of the ATL cases that received alloSCT in the Fundeni Clinical Institute. The patients were included between January 2016 to April 2019.

Results: A total of 7 patients were included in the present study, out of which 2 (28%) presented the acute form, while the rest presented the lymphomatous form. Four (57%) patients presented extranodal involvement, with 3 of those (75%), showing skin involvement. Of note, all patients presenting skin involvement also had bone marrow involvement. Thus, skin involvement was associated with a more advanced disease. Graft versus host disease (GvHD) was present in 4 (57%) patients, two of which were acute GvHD and two, chronic GvHD. Interestingly, the two patients that relapsed presented either acute or chronic GvHD, showing that the graft versus lymphoma (GVL) effect that can be observed in other lymphoma types is not observed in this cohort. Another noticeable observation is the fact that 4 out of the 6 patients tested for HTLV-I at 6 months post alloSCT presented a positive HTLV-I viral load. This event occurred, although, at 30 days, all patients presented 100% donor chimerism and the donor samples were negative for HTLV-I. This shows a possible imperfect jump of the HTLV-I from the recipient to the donor T lymphocytes or the possibility of a reinfection. Three (43%) patients presented a response less than complete remission (CR) after the first line of therapy, two of which progressed to death. The two deaths occurred at 14 and 15 months from the diagnosis, with the other follow-up periods in the cohort being higher than 26 months with the exception of one patient that had a follow-up of 6.8 moths from diagnosis. These two aforementioned patients were also the only ones to relapse thus far.

Conclusion: For ATL, alloSCT represents a viable and potentially curative approach when used in chemosensitive disease. This being said, there are clear differences from other lymphomas, ATL having to be considered separately.