Small number of HTLV-1-positive cells frequently remains during complete remission after allogeneic hematopoietic stem cell transplantation that are heterogeneous in origin among cases with adult T-cell leukemia/lymphoma

Stem cell therapy for HTLV-1 induced adult T-cell leukemia/lymphoma (ATLL): A comprehensive review

Adult T-cell leukemia/lymphoma (ATLL) is a rare and aggressive form of cancer associated with human T-cell lymphotropic virus type 1 (HTLV-1) infection. The emerging field of stem cell therapies for ATLL is discussed, highlighting the potential of hematopoietic stem cell transplantation (HSCT) and genetically modified stem cells. HSCT aims to eradicate malignant T-cells and restore a functional immune system through the infusion of healthy donor stem cells. Genetically modified stem cells show promise in enhancing their ability to target and eliminate ATLL cells. The article presents insights from preclinical studies and limited clinical trials, emphasizing the need for further research to establish the safety, efficacy, and long-term outcomes of stem cell therapies for ATLL and challenges associated with these innovative approaches are also explored. Overall, stem cell therapies hold significant potential in revolutionizing ATLL treatment, and ongoing clinical trials aim to determine their benefits in larger patient populations.

Allogeneic hematopoietic stem cell transplantation for adult T-cell leukemia/lymphoma with HTLV-1-associated myelopathy

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) can be curative for adult T-cell leukemia/lymphoma (ATL), but comorbidities increase transplant-related mortality. Here we report the outcome of allo-HSCT in a patient with ATL with human T-cell leukemia virus type I (HTLV-1)-associated myelopathy-tropical spastic paraparesis (HAM/TSP). A 48-year-old man was diagnosed with HAM/TSP and started prednisolone therapy. Ten years later, he developed lymphoma-type ATL. At the diagnosis of ATL, Osame's Motor Disability Score (OMDS) was 4. When prednisolone was gradually tapered and stopped following chemotherapy for ATL, HAM/TSP symptoms recurred (OMDS 7). Bone marrow transplantation from a human leukocyte antigen allele 8/8 matched unrelated donor was performed while ATL was in partial remission. Neutrophil engraftment with complete donor chimerism was achieved on day 19 after allo-HSCT. Mild gait improvement (OMDS 5) was observed on day 30. Although ATL relapsed on day 275, progression of HAM/TSP symptoms was not observed. Furthermore, there was no clear progression of HAM/TSP symptoms after donor lymphocyte infusions. The outcome of this case suggests that ATL patients with HAM/TSP tolerate allo-HSCT and donor lymphocyte infusions.

Complete remission and proviral load negativization after allogeneic-SCT in a patient with Adult T-cell lymphoma: Case report

Adult T-cell lymphoma is an aggressive and poor prognosis HTLV1-associated lymphoma. There is no standard treatment, but it is known that intensive chemotherapy regimens are necessary, with or without concomitant antiretroviral therapy, plus consolidation with allogeneic stem cell transplantation. Our case report shows a favorable outcome after 2 cycles of chemotherapy and allogeneic stem cell transplantation without antiretroviral agents, achieving complete remission, and a negative proviral load.

Progress in Allogeneic Hematopoietic Cell Transplantation in Adult T-Cell Leukemia-Lymphoma

The prognosis of aggressive adult T-cell leukemia-lymphoma (ATL) remains poor because of frequent infections and drug resistance. Dose-intensified chemotherapy followed by autologous stem cell transplantation failed to improve the prognosis of patients with ATL; however, we first revealed that allogeneic hematopoietic cell transplantation (allo-HCT) might improve their prognosis. We showed that reduced-intensity stem cell transplantation using peripheral blood was feasible for elderly patients. Further, the prognosis of patients in remission, who receive cord blood transplantation, has been recently improved and is equivalent to that of patients who receive transplants from other stem cell sources. As for the timing of HCT, the patients who underwent transplantation early showed better outcomes than those who underwent transplantation late. Based on the analysis of patients with aggressive ATL, including those who received transplants, we identified five prognostic factors for poor outcomes: acute-type ATL, poor performance status, high soluble interleukin-2 receptor levels, hypercalcemia, and high C-reactive protein level. Next, we developed a new prognostic index: the modified ATL-PI. The overall survival (OS) rates were significantly higher in patients who underwent allo-HCT than those who did not in the intermediate and high-risk groups stratified using the modified ATL-PI. Two new anti-cancer agents, mogamulizumab and lenalidomide, were recently approved for ATL patients in Japan. They are expected to induce longer survival in ATL patients when administered along with transplantation. However, a retrospective analysis that the risk of severe, acute, and corticosteroid-refractory graft-versus-host disease was higher in patients who received mogamulizumab before allo-HCT, and that mogamulizumab might increase the transplant-related mortality (TRM) rates and decrease the OS rates compared to those of patients who did not receive mogamulizumab. However, our recent study showed that administration of mogamulizumab before allo-HCT tended to improve the survival of patients with ATL. In conclusion, allo-HCT procedures for patients with aggressive ATL have considerably progressed and have helped improve the prognosis of these patients; however, many concerns still remain to be resolved. Further development of allo-HCT by using new molecular targeting agents is required for the improvement of cure rates in patients with ATL.

T-cell lymphomas, a challenging disease: types, treatments, and future

T-cell lymphomas are rare and aggressive malignancies associated with poor outcome, often because of the development of resistance in the lymphoma against chemotherapy as well as intolerance in patients to the established and toxic chemotherapy regimens. In this review article, we discuss the epidemiology, pathophysiology, current standard of care, and future treatments of common types of T-cell lymphomas, including adult T-cell leukemia/lymphoma, angioimmunoblastic T-cell lymphoma, anaplastic large-cell lymphoma, aggressive NK/T-cell lymphoma, and cutaneous T-cell lymphoma.

Treatment of relapsed adult T-cell leukemia/lymphoma after allogeneic hematopoietic stem cell transplantation: the Nagasaki Transplant Group experience

Adult T-cell leukemia/lymphoma (ATL) relapse is a serious therapeutic challenge after allogeneic hematopoietic stem cell transplantation (allo-SCT). In the present study, we retrospectively analyzed 35 patients who experienced progression of or relapsed persistent ATL after a first allo-SCT at 3 institutions in Nagasaki prefecture (Japan) between 1997 and 2010. Twenty-nine patients were treated by the withdrawal of immune suppressants as the initial intervention, which resulted in complete remission (CR) in 2 patients. As the second intervention, 9 patients went on to receive a combination of donor lymphocyte infusion and cytoreductive therapy and CR was achieved in 4 patients. Of 6 patients who had already had their immune suppressants discontinued before the relapse, 3 patients with local recurrence received local cytoreductive therapy as the initial treatment, which resulted in CR for more than 19 months. Donor lymphocyte infusion-induced remissions of ATL were durable, with 3 cases of long-term remission of more than 3 years and, interestingly, the emergence or progression of chronic GVHD was observed in all of these cases. For all 35 patients, overall survival after relapse was 19.3% at 3 years. The results of the present study suggest that induction of a graft-versus-ATL effect may be crucial to obtaining durable remission for ATL patients with relapse or progression after allo-SCT.

Impact of graft-versus-host disease on outcomes after allogeneic hematopoietic cell transplantation for adult T-cell leukemia: a retrospective cohort study

Allogeneic hematopoietic cell transplantation (HCT) is an effective treatment for adult T-cell leukemia (ATL), raising the question about the role of graft-versus-leukemia effect against ATL. In this study, we retrospectively analyzed the effects of acute and chronic graft-versus-host disease (GVHD) on overall survival, disease-associated mortality, and treatment-related mortality among 294 ATL patients who received allogeneic HCT and survived at least 30 days posttransplant with sustained engraftment. Multivariate analyses treating the occurrence of GVHD as a time-varying covariate demonstrated that the development of grade 1-2 acute GVHD was significantly associated with higher overall survival (hazard ratio [HR] for death, 0.65; P = .018) compared with the absence of acute GVHD. Occurrence of either grade 1-2 or grade 3-4 acute GVHD was associated with lower disease-associated mortality compared with the absence of acute GVHD, whereas grade 3-4 acute GVHD was associated with a higher risk for treatment-related mortality (HR, 3.50; P < .001). The development of extensive chronic GVHD was associated with higher treatment-related mortality (HR, 2.75; P = .006) compared with the absence of chronic GVHD. Collectively, these results indicate that the development of mild-to-moderate acute GVHD confers a lower risk of disease progression and a beneficial influence on survival of allografted patients with ATL.

Minimal residual disease detection by flow cytometry in adult T-cell leukemia/lymphoma

Little information exists regarding the detection of minimal residual disease (MRD) in adult T-cell leukemia/lymphoma (ATLL). We evaluated 75 peripheral blood samples from 17 ATLL cases using flow cytometry (FC); 50 of the samples were concurrently evaluated by polymerase chain reaction (PCR) for clonal T-cell receptor gamma chain (TRG) gene rearrangement and the presence of human T-cell lymphotropic virus-1 proviral sequences. Residual ATLL cells were identified using a multiparametric approach to identify aberrant T-cell immunophenotypes. Malignant T cells were CD4+, CD3 dim+, CD26-, CD25 bright, CD7+, and CD27+, with occasional dim expression of CD2 or CD5. FC exhibited a high sensitivity, detecting as few as 0.29% ATLL cells/WBC (4.9 cells/microL) in the peripheral blood. PCR for TRG gene rearrangement was slightly more sensitive, and FC and PCR complemented each other in detecting MRD. In 2 patients, there was complete remission; 4 patients had disease refractory to therapy, and 3 died; 11 others had persistent disease with variable numbers of ATLL cells in the peripheral blood. Higher levels of ATLL cells appeared to correlate with disease severity. FC detection of aberrant T cells permits sensitive and quantitative monitoring of MRD in ATLL.

Emerging drugs for rarer chronic lymphoid leukemias

BACKGROUND

Rarer indolent lymphoid leukemias include well defined mature B-cell and T-cell neoplasm with widely varying natural history and specific morphological, immunophenotypic and molecular characteristics. Among these are prolymphocytic leukemia (PLL), hairy cell leukemia (HCL) and its variants, large granular lymphocyte leukemia (LGLL) and adult T-cell leukemia/lymphoma (ATLL).

OBJECTIVE

To present current therapies and emerging drugs potentially useful in the treatment of rarer chronic lymphoid leukemias.

METHODS

After searching MEDLINE, PubMed and the Current Contents database, and conference proceedings from the previous 3 years of the American Society of Hematology (ASH), the European Society of Hematology (EHA) and the American Society of Clinical Oncology (ASCO) were searched manually; articles written in English and additional relevant publications were then selected.

RESULTS/CONCLUSION

New drugs including monoclonal antibodies (mAbs), new purine analogs, small molecules targeting specific molecular targets and other agents are included. Future research should focus on the novel therapeutic strategies based on the molecular pathogenic mechanisms and the development of new targeted therapies for each distinct chronic lymphoid leukemia.