Long-term remission after upfront autologous hematopoietic stem cell transplant for CD5+ diffuse large-B cell lymphoma

CD5+ diffuse large B-cell lymphoma (DLBCL) is a rare subtype characterized by an inferior outcome. While dose-dense therapy shows promising activity, the optimal management remains to be determined. To evaluate the benefit of consolidative autologous hematopoietic stem cell transplantation (ASCT), we retrospectively reviewed the medical records of 47 consecutive patients with newly diagnosed de novo CD5+ DLBCL. Of 19 patients ≤ 70 of age with age-adjusted International Prognostic Index 2-3, eight underwent upfront ASCT, and nine did not, despite preserved organ function and response after induction therapy. The remaining two, ineligible for ASCT due to early progression or comorbidities, had a dismal clinical course. Among younger 17 high-risk patients eligible for ASCT, ASCT was associated with better overall (p = 0.0327) and progression-free survival (p = 0.0184). Younger patients without ASCT demonstrated similar outcomes to older patients with similar risk profiles. ASCT could be considered for high-risk CD5+ DLBCL with a response after induction therapy.

Isolated massive pleural effusion as a manifestation of chronic graft versus host disease successfully treated with corticosteroid

Isolated pleural effusion is a rare manifestation of chronic graft versus host disease (cGVHD) after hematopoietic stem cell transplantation (HSCT). We herein report a 58-year-old woman presenting with massive pleural effusion approximately 1 year after allogeneic HSCT, who was successfully treated with corticosteroid. She had discontinued tacrolimus approximately 1 month before she presented with pleural effusion, which was attributed to cGVHD after a thorough exclusion process. This case illustrates a unique manifestation of atypical cGVHD and highlights the need for prompt therapy initiation.

AKT2 inhibition accelerates the acquisition of phagocytic ability in induced pluripotent stem cell-derived neutrophils

Neutrophils are key components of the immune system that inhibit bacterial infections. Systemic bacterial infections can cause lethal conditions, especially in patients with neutropenia associated with chemotherapy or other systemic illnesses; hence, early detection of the symptoms and prompt management are crucial in such cases. Previously, we established expandable engineered neutrophil-primed progenitors (NeuPs-XL) using human-induced pluripotent stem cells (iPSCs), which can produce neutrophil-like cells at a clinically suitable scale within 4 days of inducing myeloid differentiation. In this study, using small-molecule compound-based screening, we detected that MK-2206, a selective pan-AKT inhibitor, can accelerate this differentiation process, promote phagocytic ability in neutrophils, and enhance cytokine and chemokine expression in response to lipopolysaccharides. The inhibition of AKT2 has been identified as the key mechanism underlying this acceleration. These results can make a substantial contribution to the development of strategies for the prompt production of clinically applicable iPSC-derived neutrophils, which can potentially lead to the management of severe infections associated with life-threatening neutropenia and the effective treatment of related health conditions in the future.

Acalabrutinib and steroid for autoimmune thrombocytopenia due to relapsed chronic lymphocytic leukemia with severe bone marrow infiltration

Thrombocytopenia is a frequent complication in chronic lymphocytic leukemia (CLL). Differentiating autoimmune thrombocytopenia from thrombocytopenia due to bone marrow infiltration is necessary for appropriate treatment, but sometimes difficult. Here we report a 60-year-old male patient with CLL who had achieved complete response after treatment with fludarabine, cyclophosphamide, and rituximab two years prior to presentation. He was admitted with severe thrombocytopenia that was unresponsive to intravenous immunoglobulin. Imaging studies revealed systemic enlarged lymph nodes and bone marrow aspiration was hypercellular with > 95% lymphocytes and scant megakaryocytes. Acalabrutinib 200 mg/day was administered for the treatment of CLL exacerbation. A gradual decrease in CLL cells and recovery of megakaryocytes in bone marrow were observed, but platelet counts remained low. Systemic administration of prednisolone 0.5 mg/kg, in addition to acalabrutinib, was started, considering the contribution of autoimmune thrombocytopenia; platelet recovery was rapid and sustained for more than a year. Even if bone marrow examination suggested thrombocytopenia due to direct leukemic infiltration, it is difficult to exclude the possibility of concomitant immunogenic thrombocytopenia. We conclude that for CLL patients with severe thrombocytopenia, repeating bone marrow examination and concurrent immunosuppressive therapies and treatment of the underlying CLL may be beneficial.

Prompt Initiation of Conventional Chemotherapy to Avoid Early Death in Patients with Newly Diagnosed Acute Promyelocytic Leukemia

Objective Compared to prospective trials, the early death rate of newly diagnosed acute promyelocytic leukemia (APL) in the real-world clinical setting is higher. However, the early death rate was heterogeneous according to the reported institutes. Thus, the therapeutic approach at each institute may be important for preventing early death. This study evaluated the management strategy for untreated APL in our institute to avoid early death. Methods We identified consecutive 21 patients with untreated APL who received induction therapy including all-trans retinoic acid (ATRA) between July 2007 and December 2021 at the University of Tokyo Hospital. Results As therapeutic approaches, 16 patients (76%) received ATRA administration on the day of admission, and the remaining 5 received ATRA within 4 days from admission. Notably, all patients received conventional chemotherapy added to ATRA at a median of 1 day from admission (range: 0-9 days). As clinical outcomes, no patient died during induction therapy for untreated APL, and all achieved complete molecular remission. Conclusion Compared to the previous nationwide survey, a higher proportion of patients at our institute received conventional chemotherapy in addition to ATRA, and it was initiated more promptly, which may have helped prevent early death.

Recurrent bilateral adrenal infarction with myelodysplastic/myeloproliferative neoplasm-unclassifiable (MDS/MPN-U): a case report

BACKGROUND

Bilateral adrenal infarction is rare and only a small number of cases have been reported so far. Adrenal infarction is usually caused by thrombophilia or a hypercoagulable state, such as antiphospholipid antibody syndrome, pregnancy, and coronavirus disease 2019. However, adrenal infarction with myelodysplastic/myeloproliferative neoplasm (MDS/MPN) has not been reported.

CASE PRESENTATION

An 81-year-old man with a sudden severe bilateral backache presented to our hospital. Contrast-enhanced computed tomography (CT) led to the diagnosis of bilateral adrenal infarction. Previously reported causes of adrenal infarction were all excluded and a diagnosis of MDS/MPN-unclassifiable (MDS/MPN-U) was reached, which was considered to be attributed to adrenal infarction. He developed a relapse of bilateral adrenal infarction, and aspirin administration was initiated. Partial primary adrenal insufficiency was suspected as the serum adrenocorticotropic hormone level was persistently high after the second bilateral adrenal infarction.

CONCLUSION

This is the first case of bilateral adrenal infarction with MDS/MPN-U encountered. MDS/MPN has the clinical characteristics of MPN. It is reasonable to assume that MDS/MPN-U may have influenced bilateral adrenal infarction development, considering the absence of thrombosis history and a current comorbid hypercoagulable disease. This is also the first case of recurrent bilateral adrenal infarction. It is important to carefully investigate the underlying cause of adrenal infarction once adrenal infarction is diagnosed, as well as to assess adrenocortical function.

Aortitis Associated with Prophylactic Short-acting Granulocyte Colony-stimulating Factor Administration: A Case Report and Review of the Literature

We herein report an 83-year-old woman with filgrastim-associated aortitis during chemotherapy for relapsed diffuse large B-cell lymphoma. She had been treated with filgrastim as a prophylaxis for neutropenia during the fourth cycle of chemotherapy from day 9 to 18. On day 21, she developed a fever. Contrast-enhanced computed tomography revealed aortitis of the descending aorta. The fever abated with non-steroidal anti-inflammatory drug treatment. A literature review identified a small number of aortitis cases all caused by prophylactic use of granulocyte colony-stimulating factors (G-CSFs), among which short-acting filgrastim was rarely encountered. The present and previous findings imply a possible relationship between aortitis and prophylactic G-CSF usage.

Toxic shock like syndrome caused by Streptococcus agalactiae bacteremia during treatment for multiple myeloma

Toxic shock-like syndrome (TSLS) is a life-threatening hyperinflammatory complication caused by Streptococcus species infections. We reported the first case of TSLS caused by primary bacteremia of Streptococcus agalactiae during chemotherapy for multiple myeloma. A 74-year-old woman, who received combination chemotherapy of elotuzumab, pomalidomide, and dexamethasone for treatment-refractory multiple myeloma, was transported to our hospital under comatose and septic shock. Her blood culture detected Streptococcus agalactiae, and considering the progressive multiorgan failure, she was diagnosed with TSLS. Empiric antibiotic treatment with meropenem and respiratory and circulatory support were quickly initiated, resulting in an almost complete recovery of organ functions. It should be noted that with the advances of chemotherapy, the risk of infection is becoming more diverse.

Verification study on the catheterization of an upper arm vein using the new long peripheral intravenous catheter to reduce catheter failure incidence: A randomized controlled trial

Intravenous infusion using a peripheral intravenous catheter (PIVC) is often complicated by catheter failure (CF). We hypothesized that catheterization of an upper arm vein instead of a forearm vein may help prevent CF. This study was designed to compare the incidence of CF in patients receiving hyper-stimulant drugs when catheters are placed in the forearm using short PIVCs (SPCs) with that when catheters are placed in the upper arm using the new long PIVCs. Patients admitted to a university hospital in Tokyo, Japan were enrolled in this study and were assigned to the SPC or the new long PIVC group. The primary outcome was the incidence of CF until 7 days. The secondary outcomes were the number of CFs per 1,000 days, the duration of the indwelling catheter, and the presence of thrombi and subcutaneous edema. Forty-seven patients were analyzed (median age, 67.0 years). The incidence of CF was 0% in the new long PIVCs and 32.0% (8 catheters) in the SPCs (p = 0.007), and the number of CF per 1,000 days was 0/1,000 and 81.7/1,000 days, respectively (p = 0.001). A significant difference in the duration of the indwelling catheter until CF occurrence was observed between the two groups (p = 0.004). Thrombi and subcutaneous edema were observed more frequently in the SPC group (p < 0.001). Catheterization of an upper arm vein using the new long PIVC to administer a hyper-stimulant drug might reduce CF compared with catheterization of a forearm vein using SPC.

Daratumumab plus lenalidomide and dexamethasone for relapsed POEMS syndrome with bone plasmacytoma harboring 17p deletion

The standard therapies for polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and skin changes (POEMS) syndrome are radiation therapy, high-dose chemotherapy followed by autologous stem cell transplantation, and lenalidomide combined with dexamethasone. Daratumumab was reported to be effective for treatment-naive and relapsed POEMS syndrome, but treatment options for relapsed POEMS syndrome with poor prognostic factors or cytogenetic abnormalities have not been established due to a lack of studies in these patients. Here, we describe a case of relapsed POEMS syndrome with bone plasmacytoma harboring a newly detected 17p deletion after high-dose chemotherapy followed by autologous stem cell transplantation and radiation therapy in a male patient. He was successfully treated with daratumumab plus lenalidomide and dexamethasone (Dara-Rd). Dara-Rd could be effective in relapsed POEMS syndrome with 17p deletion, which is known as a poor cytogenetic abnormality in multiple myeloma. This report may broaden the application of Dara-Rd for POEMS syndrome.

Isolated relapse of plasma cell leukemia in the central nervous systems: a case report and literature review

Plasma cell leukemia is a rare yet aggressive form of multiple myeloma characterized by high levels of plasma cells circulating in the peripheral blood. We recently experienced a case of plasma cell leukemia that had been in stringent complete remission for nine years after autologous stem cell transplantations with subsequent courses of lenalidomide maintenance therapy, and then relapsed as an extramedullary plasmacytoma in the central nervous system. Assessment of the bone marrow did not prove proliferation of plasma cells at relapse, but imbalanced elevation of serum levels of free light chains was observed without changes in other clinical biomarkers including immunoglobulin levels. Salvage chemotherapy with isatuximab, pomalidomide, and dexamethasone (IsaPD) was promptly initiated. After two courses of IsaPD, significant remission was achieved and the neuronal symptoms completely resolved. When excessive serum levels of clonotypic free light chains are noted, their significance should be carefully assessed even when plasma cell propagation in the bone marrow is not observed. In such cases, hematologists should search for extramedullary proliferation of plasma cells, including in the immune-privileged central nervous system.

Clinical characteristics of steroid-responsive but dependent chronic graft-versus-host disease: a multicenter retrospective analysis

Chronic graft-versus-host disease (cGVHD) is a long-term complication of allogeneic hematopoietic stem cell transplantation. The clinical importance of long-term corticosteroid dependency in steroid-responsive cGVHD is undetermined. We retrospectively reviewed the data of 120 consecutive patients who received systemic steroid therapy for cGVHD between January 2007 and December 2018 at three institutions. Among patients with steroid-responsive cGVHD, those who successfully tapered off corticosteroids within 1 year were defined as the early withdrawal group (EW-cGVHD) and others were defined as the dependent group (Dp-cGVHD). Twenty-six patients were classified as EW-cGVHD and 55 as Dp-cGVHD. The proportion of men was significantly higher and performance status was significantly better in EW-cGVHD. The 5-year overall survival and cGVHD recurrence-free survival rates were significantly higher in EW-cGVHD than Dp-cGVHD (96% vs. 68%, p = 0.017 and 84% vs. 41%, p = 0.002, respectively). While the relapse-free survival rate did not differ significantly (84% vs. 65%, p = 0.15), the proportion of patients requiring readmission, mainly due to cGVHD recurrence or infection, was significantly increased in Dp-cGVHD (38% vs. 84%, p < 0.001). In summary, steroid dependency in cGVHD for more than 1 year was significantly associated with poor transplant outcomes.

A culture platform to study quiescent hematopoietic stem cells following genome editing

Other than genetically engineered mice, few reliable platforms are available for the study of hematopoietic stem cell (HSC) quiescence. Here we present a platform to analyze HSC cell cycle quiescence by combining culture conditions that maintain quiescence with a CRISPR-Cas9 genome editing system optimized for HSCs. We demonstrate that preculture of HSCs enhances editing efficiency by facilitating nuclear transport of ribonucleoprotein complexes. For post-editing culture, mouse and human HSCs edited based on non-homologous end joining and cultured under low-cytokine, low-oxygen, and high-albumin conditions retain their phenotypes and quiescence better than those cultured under the proliferative conditions. Using this approach, HSCs regain quiescence even after editing by homology-directed repair. Our results show that low-cytokine culture conditions for gene-edited HSCs are a useful approach for investigating HSC quiescence ex vivo.

Bing-Neel Syndrome Successfully Treated with Tirabrutinib

Bing-Neel syndrome (BNS) is a rare central nervous system manifestation of lymphoplasmacytic lymphoma/Waldenström macroglobulinemia (LPL/WM). We herein report a 62-year-old man with LPL/WM after multiple chemotherapies. He had weakness of lower extremities and elevated serum IgM levels. A bone marrow examination showed lymphoplasmacytic cells infiltration. Contrast-enhanced magnetic resonance imaging suggested enhancing lesions in the cauda equina roots. He was diagnosed with BNS and started on treatment with tirabrutinib 480 mg daily. Within three months, he showed clinical and radiologic improvement. Tirabrutinib may have utility as an effective treatment for BNS.

Severe autoimmune pancytopenia after autologous hematopoietic stem cell transplantation for Hodgkin lymphoma

Autoimmune pancytopenia is rarely seen with Hodgkin lymphoma, and only one pediatric case of pancytopenia after autologous hematopoietic stem cell transplantation (HSCT) has been reported. We herein report a case of autoimmune pancytopenia that developed after autologous HSCT for nodular lymphocyte predominant Hodgkin lymphoma (NLPHL). A 56-year-old Japanese woman underwent autologous HSCT for NLPHL. She developed autoimmune pancytopenia seven months after autologous HSCT. In this case, PSL was effective, and the blood cell counts normalized completely. However, the patient suffered from a fatal infection, probably because of immunosuppression caused by prolonged administration of PSL, as well as a history of several chemotherapies and autologous HSCT. To our knowledge, this is the first adult case of autoimmune pancytopenia after autologous HSCT for Hodgkin lymphoma. To further validate the optimal treatment strategy for autoimmune cytopenia after autologous HSCT, more cases are necessary.

Safety verification of a new peripheral intravenous catheter placed in the upper arm vein for administration of drugs with high irritant potential

Despite the widespread use of peripheral intravenous catheters, unscheduled catheter failure before completion of treatment occurs frequently. If a large vein is selected, catheter failures may be prevented despite administering a highly irritant drug. In this study, we attempted to use a catheter that can be placed in a large upper arm vein. The new catheter was 88 mm long but had no guidewire to reduce contamination risk. This study aimed to evaluate the safety of the first-in-human trial for the new catheter with the administration of highly irritant drugs. This study was conducted at a university hospital in Tokyo, Japan. Eight Japanese adults were hospitalized adults with planned administration of non-cancer drugs with high irritant potential using a peripheral catheter. A trained nurse catheterized with the new catheter in the upper arm using ultrasonography. The catheterization site was monitored by staff and a research nurse once every 24 hours for up to 7 days. No adverse events or catheter failure occurred and the catheter placement success rate was 100%. In two patients, a temporary occlusion alarm of the infusion pump occurred, possibly due to the flexion of the catheter base. The new peripheral intravenous catheter did not interrupt medical treatments as is common after placement, but safety administered the irritant drugs. However, because this catheter may be easily affected by the contraction of the muscle at the fixation position, the position and method of catheter fixation in the upper arm need to be carefully considered.

Severe infections and renal dysfunction during immunosuppressive therapy with cyclosporine A for aplastic anemia

Although immunosuppressive therapy (IST) with cyclosporine A (CyA) has been widely used in patients with aplastic anemia (AA), little attention has been given to its safety. This study aimed to clarify the adverse events of IST in patients with AA. We retrospectively identified 42 patients with AA treated with IST. Seventeen of the 42 patients (40%) experienced severe infection at a median of 142 days from the start of IST, and 18 (49%) experienced renal dysfunction at a median of 73 days. A large proportion of infected patients had severe AA (90 vs. 14%, p = 0.056). Notably, all patients with severe infection showed poor response to IST at the time of infection onset. Analysis regarding risk factors for renal dysfunction showed that median age at the initiation of IST was significantly higher in patients with renal dysfunction than those without renal dysfunction (65 years vs. 44 years, p = 0.020). Only 2 of 18 patients showed improvement in serum creatinine levels despite reduction or discontinuation of CyA. Our results suggest that poor responders to IST and elderly patients are at higher risk of severe infection and renal dysfunction, respectively.

Discordant lymphomas of classic Hodgkin lymphoma and peripheral T-cell lymphoma following dupilumab treatment for atopic dermatitis

There have recently been a few case reports of cutaneous T-cell lymphomas following treatment of atopic dermatitis with dupilumab, which works binding to the interleukin (IL)-4 receptor and inhibiting the JAK/ STAT cascade located downstream of both IL-4 and IL-13. Here, we report the first case of Hodgkin lymphoma (HL) in a patient treated with dupilumab for one year. Based on multiple biopsies, this case was diagnosed as a rare combination of discordant lymphomas of HL and peripheral T-cell lymphoma. As both lymphomas are known to overexpress IL-13, future studies should carefully evaluate the effect of anti-IL-13 therapy. A literature review showed that dermatitis persisted or worsened in all reported lymphoma cases following dupilumab and cutaneous T-cell lymphoma was diagnosed within 2 years of the start of treatment with dupilumab. In these cases, with the addition of our own, the median interval was 12 months, and 31% needed multiple biopsies for diagnosis of lymphomas. Our results demonstrate a need to be alert to potential development of lymphomas associated with the IL-13 and IL-4 pathways in patients with poorly responsive atopic dermatitis receiving dupilumab, and to consider the possibility of composite or discordant lymphomas in diagnosis and treatment of lymphomas.

Heterozygous Dnmt3a R878C Induces Expansion of Quiescent Hematopoietic Stem Cell Pool

Somatic mutation of DNMT3A (DNA methyltransferase 3 alpha) is implicated in the development of a wide range of hematological disorders, including clonal hematopoiesis indeterminant potential. To elucidate the functional roles of endogenous levels of a DNMT3A R882 mutant, we generated a novel Dnmt3a R878C conditional knock-in mouse model. In contrast to viable heterozygotes, mice homozygous for the Dnmt3a R878C mutation in the hematopoietic system were not viable (Dnmt3a R878C is homologous to human DNMT3A R882C). Hematopoietic cell-specific heterozygous expression of Dnmt3a R878C led to significant expansion of adult quiescent hematopoietic stem cells (HSCs); however, these mice had no incidence of hematological malignancies. The expanding HSC population in heterozygous Dnmt3a R878C knock-in mice showed an accumulation of G0 phase cells. In contrast to aberrantly enhanced self-renewal capacity in vitro, heterozygous Dnmt3a R878C knock-in HSCs had no competitive repopulating advantage in vivo over wild-type HSCs. Considering the capacity of the heterozygous Dnmt3a R878C mutant for HSC pool expansion, our Dnmt3a R878C knock-in mouse line is a useful platform to dissect the pathophysiology of clonal hematopoiesis. This mouse line can also help to elucidate the biological and molecular actions of DNMT3A mutations in the malignant transformation of normal HSCs.

High D-index during mobilization predicts poor mobilization of CD34+ cells after anti-lymphoma salvage chemotherapy

BACKGROUND

Performing stem cell collection after mobilization chemotherapy was a well-balanced strategy between anti-tumor effect and efficient collection of CD34+ cells, but deep and prolonged nadir exposed patients to risk of febrile neutropenia. Febrile neutropenia was known to be associated with lower yields of CD34+ cells, but quantitative data referring to association between yields of CD34+ cells and severity of neutropenia was lacking. We hypothesized that D-index, which was developed for quantitative evaluation of severity of neutropenia especially in the field of hematologic malignancies, could predict yields of CD34+ cells.

METHODS

We performed a single center, retrospective analysis of patients with relapsed or refractory aggressive lymphoma who were mobilized with ESHAP or modified ESHAP. We evaluated the association between yields of CD34+ cells at first apheresis and D-index.

RESULTS

Thirty-six patients were included, and we demonstrated that yields of CD34+ cells from patients with higher D-index were significantly lower than those from patients with lower D-index. Multivariate linear regression analysis and logistic regression analysis also demonstrated the significant predictive power of D-index. Further, D-index was significantly correlated to platelet count before starting mobilization chemotherapy. Platelet count was known to predict yields of CD34+ cells, and combination of platelet count and D-index could identify patients with lowest CD34+ yields.

CONCLUSION

D-index could predict yields of CD34+ cells and it seemed that its predictive power was not less than that of platelet count. Prospective studies including more heterogeneous patients were needed to validate our study.

[Role of FDG-PET/CT in diffuse large B-cell lymphoma]

FDG-PET/CT has been widely used not only at the time of diagnosis of non-Hodgkin's lymphoma but also during and after treatment. With the help of large amount of data on Hodgkin's lymphoma, for which FDG-PET is extraordinarily useful, evidence is also rapidly accumulating for non-Hodgkin's lymphoma. Currently, there is a consensus that FDG-PET/CT is effective in stratifying the prognosis of non-Hodgkin's lymphoma in a PET-avid disease, especially diffuse large B-cell lymphoma (DLBCL). However, in the enormous evidence accumulated till date, the variability in the clinical conditions of the patients, timing, and the FDG-PET/CT assessment method makes it difficult to overlook and understand the complete picture. In this article, we will review the position of FDG-PET/CT in the response assessment of DLBCL, evolution of evaluation methods, and evidence for determining therapeutic efficacy using FDG-PET/CT and for modifying treatment based on the FDG-PET/CT results.

Cerebral toxoplasmosis complicating lymphoplasmacytic lymphoma in partial remission

Toxoplasma gondii can develop toxoplasmic encephalitis (TE) in immunodeficient conditions such as AIDS and after organ transplantation. While some cases of TE with malignant lymphoma were reported, these cases occurred immediately after chemotherapy or when their diseases were active. Here we report the first Case of TE that occurred in patient who was in partial remission (PR) of lymphoplasmacytic lymphoma (LPL) for two years. A 76-year-old man was referred to our institute because of disturbance of consciousness, right arm weakness and paresthesia. A computed tomography (CT) scan detected multiple nodules in his brain. Magnetic resonance imaging (MRI) of the head detected multiple gadolinium-enhancing parenchymal lesions with hyperintense signals on T2-and diffusion-weighted images, located in both cerebral and cerebellar hemispheres. Blood test and cerebrospinal fluid (CSF) findings were unremarkable. His rapidly deteriorating consciousness precluded a chance of brain biopsy. Considering the limited efficacy of antimicrobials and the imaging findings that could be compatible with the diagnosis of malignant lymphoma, we suspected central nerve system (CNS) recurrence of LPL. Although chemotherapy was initiated, he died of respiratory failure just after chemotherapy. A pathological autopsy showed his cause of death was TE. To our knowledge, this is the first case of TE in long-term PR of malignant lymphoma. TE should be suspected when patients with malignant lymphoma present unexplained neurologic symptoms regardless of their treatment efficacy of lymphoma. (226/250 words).

Evi1 upregulates Fbp1 and supports progression of acute myeloid leukemia through pentose phosphate pathway activation

Evi1 is a transcription factor essential for the development as well as progression of acute myeloid leukemia (AML) and high Evi1 AML is associated with extremely poor clinical outcome. Since targeting metabolic vulnerability is the emerging therapeutic strategy of cancer, we herein investigated a novel therapeutic target of Evi1 by analyzing transcriptomic, epigenetic, and metabolomic profiling of mouse high Evi1 leukemia cells. We revealed that Evi1 overexpression and Evi1‐driven leukemic transformation upregulate transcription of gluconeogenesis enzyme Fbp1 and other pentose phosphate enzymes with interaction between Evi1 and the enhancer region of these genes. Metabolome analysis using Evi1‐overexpressing leukemia cells uncovered pentose phosphate pathway upregulation by Evi1 overexpression. Suppression of Fbp1 as well as pentose phosphate pathway enzymes by shRNA‐mediated knockdown selectively decreased Evi1‐driven leukemogenesis in vitro. Moreover, pharmacological or shRNA‐mediated Fbp1 inhibition in secondarily transplanted Evi1‐overexpressing leukemia mouse significantly decreased leukemia cell burden. Collectively, targeting FBP1 is a promising therapeutic strategy of high Evi1 AML.

Primary prophylaxis with pegfilgrastim during the first cycle of R-CHOP to avoid reduction of dose intensity in elderly patients

The long-term effects of pegfilgrastim administered in the first cycle of chemotherapy in day-to-day practice remain unclear. We retrospectively identified 114 patients aged ≥ 70 years with diffuse large B-cell lymphoma who received a rituximab-cyclophosphamide-doxorubicin-vincristine-prednisolone (R-CHOP) regimen in our institution. Twenty-six patients received pegfilgrastim (pegfilgrastim group); of the 88 patients scheduled to receive conventional granulocyte-colony stimulating factor (G-CSF) when their neutrophil count decreased (neut-adjusted-G group), conventional G-CSF was ultimately administered to 57. During the first cycle of R-CHOP, the incidence of febrile neutropenia was lower in the pegfilgrastim group than in the neut-adjusted-G group (0% vs. 18%, p = 0.020). Throughout all cycles, a higher proportion of patients exhibited sustained relative dose intensity (≥ 80%) in the pegfilgrastim group than in the neut-adjusted-G group (25% vs. 4.0%, p = 0.008). A lower proportion of patients received a reduced dose in the second cycle in the pegfilgrastim group than in the neut-adjusted-G group (0% vs. 10%, p = 0.116). Although the differences were not significant, the pegfilgrastim group showed higher progression-free survival and overall survival than the neut-adjusted-G group. Adequate prevention of febrile neutropenia using pegfilgrastim during the first cycle of R-CHOP may contribute to avoidance of dose intensity reduction in all cycles.

Severe cellulitis caused by Achromobacter xylosoxidans after allogeneic hematopoietic stem cell transplantation

Achromobacter xylosoxidans (A. xylosoxidans) is an aerobic gram-negative bacillus and often isolated from aquatic environments. It is supposed to cause infections in patients with malignancy or immunodeficiency. It causes various healthcare-associated infections, but cellulitis is rare. Herein, we report the first case of sever cellulitis by A. xylosoxidans after allogeneic hematopoietic stem cell transplantation (HSCT). A 49-year-old man underwent allogeneic HSCT from 8/8 HLA-matched unrelated donor with myeloablative conditioning for relapsed acute myeloid leukemia. He developed skin chronic graft versus host disease 11 months after HSCT. During the prolonged treatment with prednisolone and cyclosporine, he developed cellulitis on his left leg and admitted to our hospital. Blood and exudate culture revealed A. xylosoxidans. Although empirical therapy with cefepime was ineffective, his symptoms were dramatically improved after administration of meropenem. To our knowledge, this is the first case of A. xylosoxidans cellulitis after allogeneic HSCT. A. xylosoxidans should be considered as a possible cause of cellulitis in post-allogeneic HSCT patients on prolonged immunosuppressive therapy.

[Successful treatment of refractory chylothorax associated with diffuse large B-cell lymphoma by multidisciplinary care]

Chylothorax is an intrathoracic leakage of chyle due to thoracic duct damage. Malignant lymphoma is the most common nontraumatic cause of chylothorax. In March 2019, a 74-year-old woman presented to our department with bilateral pleural effusion and mesenteric/retroperitoneal masses. She was diagnosed with diffuse large B-cell lymphoma upon performing a biopsy. In May 2019, she was hospitalized for dyspnea due to pleural effusion, and thoracentesis revealed abundant chyle. Although the tumor shrunk after chemotherapy, chylothorax improvement was poor; thus, she could not be discharged. For the management of refractory chylothorax, lymphangiography, thoracic duct embolization, and pleurodesis were performed, and the chylothorax improved immediately. However, in May 2020, right chylothorax recurred without a relapse of malignant lymphoma, which did not improve with conservative treatment. Lymphangiography was performed again; however, treatment via the lymphatic vessels was difficult. Thus, pleurodesis was performed four times, after which the chylothorax regressed. Chylothorax is often refractory. When chemotherapy for malignant lymphoma does not improve chylothorax, multidisciplinary treatment is effective.

Hemoglobin and C-reactive protein levels as predictive factors for long-term successful glucocorticoid treatment for multicentric Castleman's disease

Although anti-interleukin-6 therapy with tocilizumab and siltuximab is recommended for multicentric Castleman's disease (MCD), burdens caused by frequent hospital visits and high drug payments is an issue to be considered. Although glucocorticoid monotherapy might be less effective compared to these agents, substantial proportions of patients can be successfully treated for years. Therefore, we conducted a retrospective analysis of Castleman's disease patients to explore predictors of glucocorticoid responsiveness and revealed that higher hemoglobin and/or lower C-reactive protein levels before starting glucocorticoid monotherapy were associated with lower probability of requirements for second-line treatment among patients initially treated with glucocorticoid. We concluded that glucocorticoids had a potential to induce sustained disease control for indolent MCD patients with specific clinical characteristics.

Insulin- and Lipopolysaccharide-Mediated Signaling in Adipose Tissue Macrophages Regulates Postprandial Glycemia through Akt-mTOR Activation

The physiological role of immune cells in the regulation of postprandial glucose metabolism has not been fully elucidated. We have found that adipose tissue macrophages produce interleukin-10 (IL-10) upon feeding, which suppresses hepatic glucose production in cooperation with insulin. Both elevated insulin and gut-microbiome-derived lipopolysaccharide in response to feeding are required for IL-10 production via the Akt/mammalian target of rapamycin (mTOR) pathway. Indeed, myeloid-specific knockout of the insulin receptor or bone marrow transplantation of mutant TLR4 marrow cells results in increased expression of gluconeogenic genes and impaired glucose tolerance. Furthermore, myeloid-specific Akt1 and Akt2 knockout results in similar phenotypes that are rescued by additional knockout of TSC2, an inhibitor of mTOR. In obesity, IL-10 production is impaired due to insulin resistance in macrophages, whereas adenovirus-mediated expression of IL-10 ameliorates postprandial hyperglycemia. Thus, the orchestrated response of the endogenous hormone and gut environment to feeding is a key regulator of postprandial glycemia.

Abstract 2611: Activated pentose phosphate pathway mediated by FBP1 upregulation supports progression of acute myeloid leukemia with high EVI1 expression

EVI1 (ecotropic viral integration site 1) is a transcription factor essential for the development and progression of acute myeloid leukemia (AML). Since high EVI1 expression, seen in approximately 10% of AML patients (EVI1high AML), is associated with poor clinical outcome, development of a novel therapeutic strategy is required. In this study, we investigated key molecules that are induced by aberrant EVI1 expression and modulate the metabolomics of leukemia cells. We conducted whole transcriptome analysis by RNA-sequencing in murine leukemia cells induced by retroviral transduction with EVI1 followed by transplantation into irradiated mice. We identified 45 genes with more than 10-fold expression in EVI1-transduced bone marrow cells compared to those with the mock vector at both pre-leukemic phase and leukemia phase. Intriguingly, the fructose bisphosphatase 1 gene (Fbp1), which encodes a key enzyme of gluconeogenesis was highly upregulated in EVI1-induced AML cells. We confirmed that FBP1 mRNA expression is quickly upregulated by ectopic expression of EVI1 in murine LSK (Linneg, c-Kitpos, Sca-1pos) cells. Moreover, we observed an enrichment of EVI1 in the promoter and enhancer region of Fbp1 by chromatin immunoprecipitation followed by qPCR analysis in murine hematopoietic cells, suggesting that Fbp1 expression is directly regulated by EVI1. Although high FBP1 expression suppresses glycolytic metabolism and negatively affects cellular proliferation in various types of solid tumor, its role in AML has not been investigated. In contrast to the results previously reported in other types of cancers, pharmacologic inhibition or short hairpin RNA (shRNA)-mediated knockdown of FBP1 significantly decreased colony-forming cell (CFC) capacity in EVI1-transduced murine LSK cells and significantly delayed progression of leukemia in the mice secondarily transplanted with EVI1-induced AML cells in vivo. These results suggest that aberrant expression of FBP1 is important for progression of EVI1high AML. While high FBP1 enzymatic activity negatively affects the glycolytic pathway, it in turn enhances the pentose phosphate pathway (PPP) through elevating the fructose-6-phosphate level. Activated PPP results in enhanced nucleotide synthesis essential for rapidly dividing cells. Importantly, individual knockdown of main PPP enzymes (G6pd, Pgd, Rpia) by shRNA transduction significantly decreased the CFC capacity of EVI1 transduced murine LSK cells, further confirming an important role of PPP in driving proliferation of EVI1high leukemia cells. Collectively, these results indicate that the activated PPP through transcriptional upregulation of FBP1 is crucial for progression of EVI1-driven leukemia. Since inhibition of FBP-1 did not compromise normal hematopoiesis, targeting the enzyme can be a promising therapeutic approach for the EVI1high AML.

Citation Format: Hideaki Mizuno, Yuki Kagoya, Akira Chiba, Junji Koya, Yosuke Masamoto, Mineo Kurokawa. Activated pentose phosphate pathway mediated by FBP1 upregulation supports progression of acute myeloid leukemia with high EVI1 expression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2611.

Modeling ASXL1 mutation revealed impaired hematopoiesis caused by derepression of p16Ink4a through aberrant PRC1-mediated histone modification

In spite of distinct clinical importance, the molecular mechanisms how Additional sex combs-like 1 (ASXL1) mutation contributes to the pathogenesis of premalignant conditions are largely unknown. Here, with newly generated knock-in mice, we investigated the biological effects of the mutant. Asxl1^G643fs heterozygous (Asxl1^G643fs/+) mice developed phenotypes recapitulating human low-risk myelodysplastic syndromes (MDS), and some of them developed MDS/myeloproliferative neoplasm-like disease after long latency. H2AK119ub1 level around the promoter region of p16Ink4a was significantly decreased in Asxl1^G643fs/+ hematopoietic stem cells (HSC), suggesting perturbation of Bmi1-driven H2AK119ub1 histone modification by mutated Asxl1. The mutant form of ASXL1 had no ability to interact with BMI1 as opposed to wild-type ASXL1 protein. Restoration of HSC pool and amelioration of increased apoptosis in hematopoietic stem and progenitor cells were obtained from Asxl1^G643fs/+ mice heterozygous for p16Ink4a. These results indicated that loss of protein interaction between Asxl1 mutant and Bmi1 affected the activity of PRC1, and subsequent derepression of p16Ink4a by aberrant histone ubiquitination could induce cellular senescence, resulting in low-risk MDS-like phenotypes in Asxl1^G643fs/+ mice. This model provides a useful platform to unveil the molecular basis for hematological disorders induced by ASXL1 mutation and to develop therapeutic strategies for these patients.

Targeting chronic myeloid leukemia stem cells: can transcriptional program be a druggable target for cancers?

Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm resulting from acquisition of constitutively active BCR-ABL protein tyrosine kinase in a hematopoietic stem cell (HSC). Though tyrosine kinase inhibitors (TKIs) have changed a fatal disease into manageable disease, most patients cannot discontinue TKI treatment due to persistence of TKI-resistant leukemia stem cells (LSCs). Much effort has been made to find out factors or pathways specifically operating in LSCs to selectively target LSCs, with some promising results at least in preclinical models. In this article, we briefly review the role of Wnt/β-catenin signaling and its related factors in CML LSCs, especially focusing on Tcf1/Lef1 transcription factors, major effectors of Wnt/β-catenin pathway, of which transcriptional program have recently been shown to be targetable with prostaglandin E1.

Adiponectin Enhances Quiescence Exit of Murine Hematopoietic Stem Cells and Hematopoietic Recovery Through mTORC1 Potentiation

Myelotoxic injury, such as chemotherapeutic agents and ionizing radiation, unlocks the vigorous power of hematopoietic stem cells (HSCs) to replenish the hematopoietic system, making quiescent HSCs enter the cell cycle. Considering that both HSC-intrinsic and -extrinsic mechanisms enforce quiescence of HSCs, the drastic change in bone marrow (BM) environment after injury, represented by massive expansion of BM adipocytes, might trigger HSC activation. BM adipocytes, the major cellular component in the ablated marrow, however, reportedly suppress proliferation of hematopoietic cells, which may indicate the BM adipocytogenesis is an irrational response of injured organism. Given that adipose tissue is an endocrine organ with pleiotropic functions, we hypothesized that adipocyte-derived factors, especially adiponectin, an anti-inflammatory adipokine involved in regulation of granulopoiesis, are implicated in HSC activation. Myeloablative intervention increased BM adiponectin by multiple mechanisms, including adipocyte expansion and increased diffusion from the blood. Adiponectin-null (Adipoq ^-/- ) mice showed delayed hematopoietic recovery after BM injury, with Adipoq^-/- HSCs more quiescent and defective in mammalian target of rapamycin complex 1 (mTORC1) activation. Recombinant adiponectin promoted not only HSC activation in vivo but cytokine-induced activation in vitro, and shortened the time for exit from quiescence in an mTORC1-dependent manner. These data illustrate a scarcely-reported example of a cell-extrinsic factor, adiponectin, enhancing quiescence exit of HSCs, and subsequent hematopoietic recovery. Our findings also highlight adipocytes as a source of adiponectin to ensure the proliferative burst of hematopoietic cells in ablated marrow. Stem Cells 2017;35:1835-1848.

Adiponectin Enhances Antibacterial Activity of Hematopoietic Cells by Suppressing Bone Marrow Inflammation

Obesity has been shown to increase the morbidity of infections, however, the underlying mechanisms remain largely unknown. Here we demonstrate that obesity caused adiponectin deficiency in the bone marrow (BM), which led to an inflamed BM characterized by increased tumor necrosis factor (TNF) production from bone marrow macrophages. Hematopoietic stem and progenitor cells (HSPCs) chronically exposed to excessive TNF in obese marrow aberrantly expressed cytokine signaling suppressor SOCS3, impairing JAK-STAT mediated signal transduction and cytokine-driven cell proliferation. Accordingly, both obese and adiponectin-deficient mice showed attenuated clearance of infected Listeria monocytogenes, indicating that obesity or loss of adiponectin is critical for exacerbation of infection. Adiponectin treatment restored the defective HSPC proliferation and bacterial clearance of obese and adiponectin-deficient mice, affirming the importance of adiponectin against infection. Taken together, our findings demonstrate that obesity impairs hematopoietic response against infections through a TNF-SOCS3-STAT3 axis, highlighting adiponectin as a legitimate target against obesity-related infections.

Adiponectin regulates psoriasiform skin inflammation by suppressing IL-17 production from γδ-T cells

Accumulating epidemiologic evidence has revealed that metabolic syndrome is an independent risk factor for psoriasis development and is associated with more severe psoriasis. Adiponectin, primarily recognized as a metabolic mediator of insulin sensitivity, has been newly drawing attention as a mediator of immune responses. Here we demonstrate that adiponectin regulates skin inflammation, especially IL-17-related psoriasiform dermatitis. Mice with adiponectin deficiency show severe psoriasiform skin inflammation with enhanced infiltration of IL-17-producing dermal Vγ4+γδ-T cells. Adiponectin directly acts on murine dermal γδ-T cells to suppress IL-17 synthesis via AdipoR1. We furthermore demonstrate here that the adiponectin level of skin tissue as well as subcutaneous fat is decreased in psoriasis patients. IL-17 production from human CD4- or CD8-positive T cells is also suppressed by adiponectin. Our data provide a regulatory role of adiponectin in skin inflammation, which would imply a mechanism underlying the relationship between psoriasis and metabolic disorders.

Moxifloxacin is more effective than tosufloxacin in reducing chemotherapy-induced febrile neutropenia in patients with hematological malignancies

Recent studies have shown the prophylactic efficacy of fluoroquinolones against infections in patients with chemotherapy-induced neutropenia. However, little is known about the differences between fluoroquinolones, and there are some concerns about the emergence of resistant bacteria. In this retrospective study, we compared the prophylactic efficacy of moxifloxacin (MFLX) and tosufloxacin (TFLX) for chemotherapy-induced febrile neutropenia. The cumulative incidences of febrile neutropenia were 74.7% (59 of 79) in the MFLX group and 81.1% (219 of 270) in the TFLX group (log-rank test p = 0.044). Subgroup analysis revealed a more prominent prophylactic advantage of MFLX in patients with acute myeloid leukemia (AML) or long duration of neutropenia (p = 0.013 and 0.008, respectively). There were no significant differences in the incidences of adverse events and fluoroquinolone resistant bacteria in both groups. This study indicates that prophylaxis with MFLX is more beneficial to reduce febrile neutropenia episodes than TFLX, especially in patients with high-risk disease.