Bendamustine Plus Rituximab as Salvage Treatment for Patients with Relapsed or Refractory Low-grade B-cell Lymphoma and Mantle Cell Lymphoma: A Single-Center Retrospective Study.

Bendamustine plus rituximab (B-R) is an effective therapy for relapsed or refractory (r/r) low-grade B-cell lymphoma (LGBCL) and mantle cell lymphoma (MCL); however, clinical data from Japanese patients treated with B-R therapy are limited. We retrospectively evaluated the efficacy and safety of B-R therapy in 42 patients who received B-R therapy at our hospital for r/r LGBCL and MCL. All patients received intravenous (IV) ritux-imab 375 mg/m2 on day 1 and IV bendamustine 90 mg/m2 on days 2 and 3 every 28 days for up to 6 cycles. The common histologic subtypes were follicular lymphoma (n = 29, 70%), marginal zone lymphoma (n = 6, 14%), and MCL (n = 5, 12%). The overall response rate was 93%, with 62% complete response and complete response unconfirmed. The median progression-free survival (PFS) was 38 months (95% confidence interval [CI], 24.6 to not reached [NR]), and the median overall survival (OS) was 80 months (95% CI, 60.7 to NR). Patients receiving a cumulative dose of bendamustine ≥ 720 mg/m2 showed a significantly longer PFS and OS. Grade 3/4 adverse events (≥ 10%) included neutropenia (55%), lymphopenia (69%), and nausea (24%). B-R therapy was effective and well tolerated, and the cumulative dose of bendamustine was associated with a favorable outcome.

Daratumumab therapy for relapsed or refractory multiple myeloma: a single-center retrospective study.

BACKGROUND: Significant advancements have been achieved in the quality of treatment for relapsed/refractory multiple myeloma (RRMM). Currently, daratumumab (DARA) is a highly effective drug widely used for RRMM; however, the knowledge on its efficacy and safety in Japanese patients remains limited. Accordingly, we aimed to evaluate the efficacy and safety of DARA therapy for RRMM. METHODS: We reviewed the medical records of patients who received DARA combination therapy and evaluated its efficacy and safety in our hospital. RESULTS: DARA was administered to 44 patients between October 2017 and March 2019. The median number of previous therapies was three (range 1-9). The rates of ≥ complete response and overall response were 27.3% and 61.4%, respectively. The median progression-free survival (PFS) duration was 12.3 months [95% confidence interval (CI) 5.1 to not reached (NR)] and estimated 2-year overall survival rate was 63.7% (95% CI 46.9-76.5%). In the multivariate analysis, patients with ≥ three previous lines of therapy and mass lesions showed significantly shorter PFS durations. The observed grade 3/4 adverse events (≥ 10%) included neutropenia (59.0%), thrombocytopenia (29.5%), anemia (36.4%), lymphopenia (38.6%) and febrile neutropenia (18.2%). None of the patients discontinued DARA therapy in spite of these AEs. CONCLUSION: DARA is an effective treatment option for most patients and is tolerable. However, patients with heavy treatment before DARA therapy and mass lesions are likely to show poorer outcomes. Our findings suggest the use of DARA therapy early in the course of the disease.

PD-1 modulates regulatory T-cell homeostasis during low-dose interleukin-2 therapy.

CD4+Foxp3+ regulatory T cells (Tregs) play a central role in the maintenance of immune tolerance after hematopoietic stem cell transplantation. We previously reported that low-dose interleukin-2 (IL-2) therapy increased circulating Tregs and improved clinical symptoms of chronic graft-versus-host-disease (cGVHD); however, the mechanisms that regulate Treg homeostasis during IL-2 therapy have not been well studied. To elucidate these regulatory mechanisms, we examined the role of inhibitory coreceptors on Tregs during IL-2 therapy in a murine model and in patients with cGVHD. Murine studies demonstrated that low-dose IL-2 selectively increased Tregs and simultaneously enhanced the expression of programmed cell death 1 (PD-1), especially on CD44+CD62L+ central-memory Tregs, whereas expression of other inhibitory molecules, including CTLA-4, LAG-3, and TIM-3 remained stable. PD-1-deficient Tregs showed rapid Stat5 phosphorylation and proliferation soon after IL-2 initiation, but thereafter Tregs became proapoptotic with higher Fas and lower Bcl-2 expression. As a result, the positive impact of IL-2 on Tregs was completely abolished, and Treg levels returned to baseline despite continued IL-2 administration. We also examined circulating Tregs from patients with cGVHD who were receiving low-dose IL-2 and found that IL-2-induced Treg proliferation was promptly followed by increased PD-1 expression on central-memory Tregs. Notably, clinical improvement of GVHD was associated with increased levels of PD-1 on Tregs, suggesting that the PD-1 pathway supports Treg-mediated tolerance. These studies indicate that PD-1 is a critical homeostatic regulator for Tregs by modulating proliferation and apoptosis during IL-2 therapy. Our findings will facilitate the development of therapeutic strategies that modulate Treg homeostasis to promote immune tolerance.

Plasma exchange eliminates residual mogamulizumab but does not warrant prompt recovery of peripheral Treg levels.

Mogamulizumab (Mog), a humanized anti-CCR4 antibody, provides an important treatment option for relapsed/refractory adult T cell leukemia/lymphoma. However, administration of Mog before allogenic hematopoietic stem cell transplantation has been reported to be a risk factor for severe acute graft-versus-host disease (GVHD). The etiological hypothesis is Mogamulizumab may eradicate CCR4-positive regulatory T cells (Tregs). Theoretically, Treg homeostasis and course of GVHD can be affected by plasma exchange (PE) with decreasing plasma Mog concentration. Here, we present a case of severe acute GVHD after pretransplantation Mog, in which PE was performed for liver failure. As a result, plasma Mog concentration was decreased but it did not lead to the prompt elevation of Treg levels in peripheral blood and clinical responses of GVHD were limited to partial remission. Our case suggests that recovery of donor-derived Treg in the acute phase after HSCT is multifactorial and the single procedure of PE-based Mog depletion does not necessarily warrant the quick restoration of Treg homeostasis.

[Diffuse large B-cell lymphoma relapsing with intravascular large B-cell lymphoma-like perivascular and intravascular lesions].

A 64-year-old woman was diagnosed with diffuse large B-cell lymphoma (DLBCL) in 2013. After eight courses of R-CHOP therapy followed by local irradiation of the remaining retroperitoneal soft tissue shadow, complete response was confirmed on 18F-2-fluoro-2-deoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT). Early in 2016, patient's serum LDH and soluble IL-2 receptor levels elevated. With suspected recurrence of DLBCL, FDG-PET/CT was performed that showed no lymphadenopathy or abnormal FDG uptake. By the end of July 2016, the patient developed fever and night sweating. Intravascular large B-cell lymphoma (IVLBCL) was suspected, and the patient underwent random skin biopsies, which revealed large atypical cells infiltrating peripheral and intravascular regions of the subcutaneous adipose tissue. Cell morphology, immunostaining, and PCR analysis of the immunoglobulin heavy chain gene suggested the recurrence of DLBCL. Despite salvage chemotherapy and autologous peripheral stem cell transplantation with high-dose chemotherapy, approximately 15 months later, DLBCL recurred and involved the lungs. The patient again received chemotherapy and achieved a second remission. Because DLBCL may recur like intravascular lymphoma, the same tests used for IVLBCL diagnosis are required in cases of suspected recurrence of DLBCL based on clinical and laboratory findings.

Angioimmunoblastic T-cell Lymphoma Presenting as a Methotrexate-associated Lymphoproliferative Disorder with Extreme Peripheral Blood Plasmacytosis.

A 74-year-old man was admitted to our hospital because of systemic lymphadenopathy, weight loss, and a fever at night that had persisted for approximately 1 month. Blood tests revealed extreme peripheral blood plasmacytosis and hypergammaglobulinemia. A lymph node biopsy showed angioimmunoblastic T-cell lymphoma (AITL). Based on the history of methotrexate (MTX) administration, the established diagnosis was MTX-associated lymphoproliferative disorder (MTX-LPD). After MTX was discontinued, the lymphadenopathy spontaneously regressed and the plasmacytosis disappeared. He had no disease progression for three years. We found that AITL as an MTX-LPD can cause plasmacytosis, and the prognosis of this disease may not be poor.

Possible prognostic impact of WT1 mRNA expression at day + 30 after haploidentical peripheral blood stem cell transplantation with posttransplant cyclophosphamide for patients with myeloid neoplasm: a multicenter study from the Okayama Hematological Study Group.

BACKGROUND: Previous studies have revealed that relapse of myeloid neoplasms after allogeneic hematopoietic stem cell transplantation (allo-HSCT) could be predicted by monitoring Wilms' tumor 1 (WT1) mRNA expression. However, only a few studies have investigated patients who received human leukocyte antigen-haploidentical stem cell transplantation with posttransplant cyclophosphamide (PTCY-haplo). In this study, we investigated the relationship between WT1 mRNA levels and clinical outcomes in the PTCY-haplo group, and compared them with those in the conventional graft-versus-host disease prophylaxis group (conventional group). METHODS: We retrospectively analyzed 130 patients who received their first allo-HSCT between April 2017 and December 2020, including 26 who received PTCY-haplo. RESULTS: The WT1 mRNA expression level at day + 30 after allo-HSCT associated with increased risk of 1-year cumulative incidence of relapse (CIR) was ≥ 78 copies/µg RNA in the conventional group (p < 0.01) and ≥ 50 copies/µg RNA in the PTCY-haplo group (p = 0.03). CONCLUSIONS: The appropriate cutoff level of WT1 mRNA at day + 30 after allo-HSCT for predicting prognosis in patients treated with PTCY-haplo may be < 50 copies/µg RNA.

Responses of regulatory and effector T-cells to low-dose interleukin-2 differ depending on the immune environment after allogeneic stem cell transplantation.

CD4+Foxp3+ regulatory T cells (Tregs) play a central role in the maintenance of immune tolerance after allogeneic hematopoietic stem cell transplantation (HSCT). Tregs promptly respond to low concentrations of IL-2 through the constitutive expression of high-affinity IL-2 receptors. It has been reported that low-dose IL-2 therapy increased circulating Tregs and improved clinical symptoms of chronic GVHD. Clinical studies of IL-2 therapy so far have mainly targeted patients in the chronic phase of transplantation when acute immune responses has subsided. However, the biological and clinical effects of exogenous IL-2 in an acute immune environment have not been well investigated. In the current study, we investigated the impact of exogenous IL-2 therapy on the post-transplant homeostasis of T cell subsets which influence the balance between GVHD and GVL in the acute phase, by setting the various immune environments early after HSCT in murine model. We initially found that 5,000 IU of IL-2 was enough to induce the active proliferation of Treg without influencing other conventional T cells (Tcons) when administered to normal mice. However, activated Tcons showed the response to the same dose of IL-2 in recipients after allogeneic HSCT. In a mild inflammatory environment within a threshold, exogenous IL-2 could effectively modulate Treg homeostasis with just limited influence to activated T cells, which resulted in an efficient GVHD suppression. In contrast, in a severely inflammatory environment, exogenous IL-2 enhanced activated T cells rather than Tregs, which resulted in the exacerbation of GVHD. Of interest, in an immune-tolerant state after transplant, exogenous IL-2 triggered effector T-cells to exert an anti-tumor effect with maintaining GVHD suppression. These data suggested that the responses of Tregs and effector T cells to exogenous IL-2 differ depending on the immune environment in the host, and the mutual balance of the response to IL-2 between T-cell subsets modulates GVHD and GVL after HSCT. Our findings may provide useful information in the optimization of IL-2 therapy, which may be personalized for each patient having different immune status.

High-dose dexamethasone therapy as the initial treatment for idiopathic thrombocytopenic purpura.

There is a controversy which short term high dose dexamethasone therapy (HDD) or standard dose prednisolone therapy as the initial treatment leads to long term efficacy in idiopathic thrombocytopenic purpura (ITP) patients. We conducted a multicenter, prospective trial to determine the efficacy and safety of short-term HDD in ITP patients aged 18-80 years with platelet counts of < 20 × 109/l, or < 50 × 109/l and bleeding symptoms. The primary endpoints are the proportion of complete response (CR) plus partial response (R) on day 180 after the completion of the 46-day HDD. Twenty-three patients were enrolled. Test for Helicobacter pylori (H. pylori) was positive for 6 patients and negative for 17 patients. In positive patients, 5 were received successful H. pylori eradication therapy. The proportion of CR + R was 60.9% (14/23) with 90% confidence interval of 41.7-77.8%. For patients with positive H. pylori and successful eradication, the proportion of CR + R was 80.0% (4/5). There was one grade 4 adverse event. Although we have enrolled relatively old, severe ITP patients with a median age of 63 years in this study, the efficacy was comparable to the reported clinical trials with HDD therapy.

Extranodal CD20-positive peripheral T-cell lymphoma presenting with adrenal and testicular masses.

We report a case of extranodal CD20-positive peripheral T-cell lymphoma (PTCL). A 59-year-old man was admitted because of a right testicular mass in April 2006. CT scan revealed bilateral adrenal masses and he underwent right orchiectomy. The enlarged testis showed diffuse infiltration of large CD20-positive lymphocytes with slight CD3-positive cells. These cells were negative for CD10 and showed a high MIB-1 index. The pathological diagnosis was diffuse large B-cell lymphoma. He received R-CHOP, but developed brain involvement. He received whole brain radiotherapy following high-dose methotrexate, but he died of disease progression in August 2007. At autopsy, lymphoma cells were definitely positive for CD3 and negative for CD20. Monoclonal TCR gamma gene rearrangement was detected in the brain specimen without IgH rearrangement by PCR. The testicular tumor also showed the same clonal bands. Immunohistochemical re-evaluation of the testis showed CD20+, CD79a-, PAX5-, MUM1-, CD3 p+, CD5 p+, CD4-, CD8-, CD7 p+, granzyme B+, and TIA1+. Based on the clinical course and immunohistology, we finally diagnosed this case as extranodal PTCL-nos (not otherwise specified) with aberrant CD20 expression, which is extremely rare. The detection of gene rearrangement, plural immunohistochemical markers and knowledge of the possibility of CD20+ PTCL-nos are necessary for such cases.