Identification of Recurrent Mutations in the microRNA-Binding Sites of B-Cell Lymphoma-Associated Genes in Follicular Lymphoma.

Follicular lymphoma (FL) is a common indolent B-cell lymphoma that can transform into the more aggressive transformed FL (tFL). However, the molecular process driving this transformation is uncertain. In this work, we aimed to identify microRNA (miRNA)-binding sites recurrently mutated in follicular lymphoma patients, as well as in transformed FL patients. Using whole-genome sequencing data from FL tumors, we discovered 544 mutations located in bioinformatically predicted microRNA-binding sites. We then studied these specific regions using targeted sequencing in a cohort of 55 FL patients, found 16 recurrent mutations, and identified a further 69 variants. After filtering for QC, we identified 21 genes with mutated miRNA-binding sites that were also enriched for B-cell-associated genes by Gene Ontology. Over 40% of mutations identified in these genes were present exclusively in tFL patients. We validated the predicted miRNA-binding sites of five of the genes by luciferase assay and demonstrated that the identified mutations in BCL2 and EZH2 genes impaired the binding efficiency of miR-5008 and miR-144 and regulated the endogenous levels of messenger RNA (mRNA).

Ex Vivo T Cell-Depleted Hematopoietic Stem Cell Transplantation for Adult Patients with Acute Myelogenous Leukemia in First and Second Remission: Long-Term Disease-Free Survival with a Significantly Reduced Risk of Graft-versus-Host Disease.

Large series of patients with acute myelogenous leukemia (AML) after ex vivo T cell-depleted (TCD) allogeneic hematopoietic stem cell transplantation (allo-HSCT) have not been reported previously. We retrospectively analyzed the outcomes of 266 patients (median age, 54 years) with AML who received CD34-selected TCD allo-HSCTs while in first (75%) or second (25%) complete remission (CR1/CR2) at a single institution. The conditioning regimens were all myeloablative, and no additional graft-versus-host disease (GVHD) prophylaxis was given. The cumulative incidences of grade II-IV and grade III-IV acute GVHD at 180 days were 14% (95% confidence interval [CI], 10% to 18%) and 3% (95% CI, 1% to 5%), respectively. The cumulative incidence of chronic GVHD at 3 years was 3% (95% CI, 1% to 6%). The 3-year cumulative incidence of nonrelapse mortality was 21% (95% CI, 16% to 26%) and that of relapse was 21% (95% CI, 17% to 27%). Overall survival (OS) and disease-free survival (DFS) at 1, 3, and 5 years were 75%, 61%, and 56% and 68%, 57%, and 53%, respectively. There were no significant differences in OS, DFS, and relapse rates for patients who underwent transplantation in CR1 and those who did so in CR2. However, patients with high-risk cytogenetics at diagnosis had significantly poorer outcomes. The OS and DFS rates compare favorably with those for unmodified allo-HSCT, but with considerably lower rates of GVHD.

Hematopoietic Cell Transplantation Comorbidity Index Predicts Outcomes in Patients with Acute Myeloid Leukemia and Myelodysplastic Syndromes Receiving CD34+ Selected Grafts for Allogeneic Hematopoietic Cell Transplantation.

To evaluate the association between the hematopoietic cell transplantation-comorbidity index (HCT-CI) and the recently developed age-adjusted HCT-CI (HCT-CI/age) and transplant outcomes in the setting of CD34-selected allogeneic HCT, we analyzed a homogeneous population of patients undergoing allogeneic HCT with CD34-selected grafts for acute myeloid leukemia and myelodysplastic syndrome (n = 346). Median HCT-CI and HCT-CI/age scores were 2 (percentile 25 to 75, 1 to 4) and 3 (percentile 25 to 75, 1 to 5), respectively. Higher HCT-CI and HCT-CI/age scores were associated with higher nonrelapse mortality (NRM) and lower overall survival (OS). The HCT-CI distinguished 2 risk groups (0 to 2 versus ≥3), whereas, with the HCT-CI/age, there was a progressive increase in NRM and decrease in OS with increasing scores in all 4 groups (0 versus 1 to 2 versus 3 to 4 versus ≥5). Higher scores in both models were associated with lower chronic graft-versus-host disease relapse-free survival but not with higher relapse. Both models showed a promising predictive accuracy for NRM (c- = .616 for HCT-CI and c- = .647 for HCT-CI/age). In conclusion, the HCT-CI and HCT-CI/age predict transplant outcomes in CD34-selected allo-HCT, including NRM, OS, and chronic graft-versus-host disease relapse-free survival and may be used to select appropriate patients for this approach.

Role of cytotoxic therapy with hematopoietic cell transplantation in the treatment of Hodgkin lymphoma: guidelines from the American Society for Blood and Marrow Transplantation.

The role of hematopoietic cell transplantation (HCT) in the therapy of Hodgkin lymphoma (HL) in pediatric and adult patients is reviewed and critically evaluated in this systematic evidence-based review. Specific criteria were used for searching the published literature and for grading the quality and strength of the evidence and the strength of the treatment recommendations. Treatment recommendations based on the evidence are included and were reached unanimously by a panel of HL experts. Both autologous and allogeneic HCT offer a survival benefit in selected patients with advanced or relapsed HL and are currently part of standard clinical care. Relapse remains a significant cause of failure after both transplant approaches, and strategies to decrease the risk of relapse remain an important area of investigation.

Sirolimus, tacrolimus and low-dose methotrexate based graft-versus-host disease prophylaxis after non-ablative or reduced intensity conditioning in related and unrelated donor allogeneic hematopoietic cell transplant.

Encouraging results have been reported with sirolimus, tacrolimus and low-dose methotrexate after non-myeloablative allogeneic hematopoietic cell transplant. We conducted a retrospective analysis of 71 patients with lymphoid malignancies treated with this prophylaxis regimen after non-myeloablative or reduced intensity allogeneic hematopoietic cell transplant. Grafts were human leukocyte antigen (HLA)-matched related in 29 (41%), matched unrelated in 36 (51%) and 9/10 HLA-matched unrelated in six (8%) patients. The regimen was well tolerated and over 90% of patients completed the planned treatment. The cumulative incidences of 1-year grade B-D and C-D acute graft-versus-host disease (GVHD) were 0.28 (95% confidence interval [CI], 0.18-0.39) and 0.07 (95% CI, 0.03-0.15), respectively, and of 1- and 2-year chronic GVHD (National Institutes of Health criteria) in 70 evaluable patients were 0.15 (95% CI, 0.08-0.24) and 0.33 (95% CI, 0.22-0.44), respectively. The median day of onset of acute GVHD was 123 days (range, 17-268 days). Peri-transplant rituximab or anti-thymocyte globulin did not affect GVHD. The cumulative incidence of 1-year non-relapse mortality and relapse were 4% and 20%, respectively. With a median follow-up of 3.5 (range: 0.18-5.1) years, overall survival and progression-free survival at 2 years were 82% and 66%, respectively. This GVHD regimen results in a low incidence and severity of acute and chronic GVHD after reduced intensity and non-myeloablative allogeneic hematopoietic cell transplant for lymphoid malignancies. The study also highlights the incidence of late onset acute GVHD in non-myeloablative/reduced intensity conditioning, and the contribution of the new GVHD staging system that more accurately reflects clinical outcomes.

A phase II study of a nonmyeloablative allogeneic stem cell transplant with peritransplant rituximab in patients with B cell lymphoid malignancies: favorably durable event-free survival in chemosensitive patients.

The aim of this prospective phase II trial was to determine the safety and efficacy of a nonmyeloablative conditioning program incorporating peritransplant rituximab in patients with CD20+ B cell non-Hodgkin lymphoma (B-NHL) receiving an allogeneic stem cell transplant (allo-SCT). Fifty-one adult B-NHL patients, with a median age of 54 years, were treated with cyclophosphamide, fludarabine, and 200 cGy of total body irradiation. Rituximab 375 mg/m(2) was given on day -8 and in 4 weekly doses beginning day +21. Equine antithymocyte globulin was given to recipients of volunteer unrelated donor grafts. Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine and mycophenolate mofetil and tacrolimus, sirolimus, and methotrexate in 8 and 43 patients, respectively. Thirty-three patients received grafts from unrelated donors, and 18 received grafts from matched related donors. All patients engrafted. Full donor chimerism in bone marrow and peripheral T cells was seen in 92% and 89% of patients, respectively, at 3 months after allo-SCT. The cumulative incidence of grades II to IV acute GVHD at 6 months was 25% (95% confidence interval [CI], 13% to 38%) and grades III to IV was 11% (95% CI, 2% to 20%). The 2-year cumulative incidence of chronic GVHD was 29% (95% CI, 15% to 44%). The 2-year event-free and overall survival for all patients was 72% (95% CI, 59% to 85%) and 78% (95% CI, 66% to 90%), respectively. The 2-year event-free survival for chemosensitive patients was 84% (95% CI, 72% to 96%) compared with 30% (95% CI, 2% to 58%) for chemorefractory patients before allo-SCT (P < .001). This nonmyeloablative regimen, with peritransplant rituximab, is safe and effective in patients with B-NHL.

Quantitative assessment of T cell repertoire recovery after hematopoietic stem cell transplantation.

Delayed T cell recovery and restricted T cell receptor (TCR) diversity after allogeneic hematopoietic stem cell transplantation (allo-HSCT) are associated with increased risks of infection and cancer relapse. Technical challenges have limited faithful measurement of TCR diversity after allo-HSCT. Here we combined 5' rapid amplification of complementary DNA ends PCR with deep sequencing to quantify TCR diversity in 28 recipients of allo-HSCT using a single oligonucleotide pair. Analysis of duplicate blood samples confirmed that we accurately determined the frequency of individual TCRs. After 6 months, cord blood-graft recipients approximated the TCR diversity of healthy individuals, whereas recipients of T cell-depleted peripheral-blood stem cell grafts had 28-fold and 14-fold lower CD4(+) and CD8(+) T cell diversities, respectively. After 12 months, these deficiencies had improved for the CD4(+) but not the CD8(+) T cell compartment. Overall, this method provides unprecedented views of T cell repertoire recovery after allo-HSCT and may identify patients at high risk of infection or relapse.