Essential Roles of the Transcription Factor NR4A1 in Regulatory T Cell Differentiation under the Influence of Immunosuppressants.

Calcineurin inhibitors (CNIs), used as immunosuppressants, have revolutionized transplantation medicine with their strong suppressive activity on alloreactive T lymphocytes; however, they may also cause various adverse effects, including an increased risk for infection and nephrotoxicity. Regulatory T (Treg) cells can complement the deleterious side effects of CNIs with their effective Ag-specific suppressive activities. However, several studies have shown that CNIs suppress Treg cell differentiation. Therefore, an understanding of the mechanisms by which CNIs suppress Treg cell differentiation, as well as an approach for promoting the differentiation of Treg cells in the presence of CNIs, has significant clinical value. In this article, we report that the nuclear orphan receptor Nr4a1 plays a pivotal role in Treg cell differentiation in the presence of CNIs. Unlike that of its family members, Nr4a2 and Nr4a3, the expression of Nr4a1 was not suppressed by CNI treatment, thereby mediating Treg cell differentiation in the presence of CNIs. In a mouse allogeneic graft-versus-host disease model, Nr4a1 mediated tolerance by promoting Treg cell differentiation in mice administered cyclosporine A, prolonging the survival of recipients. Furthermore, activation of Nr4a1 via its agonist partially restored Treg cell differentiation, which was suppressed by cyclosporine A treatment. Finally, we found that the rs2701129 single-nucleotide polymorphism, which was shown to downregulate NR4A1 expression, showed a trend toward a higher incidence of chronic graft-versus-host disease in patients undergoing hematopoietic stem cell transplantation. Therefore, our study will be of clinical significance because we demonstrated the role of Nr4a1 in Treg cell differentiation in the presence of CNIs.

Real-world efficacy of letermovir prophylaxis for cytomegalovirus infection after allogeneic hematopoietic stem cell transplantation: A single-center retrospective analysis.

INTRODUCTION: Cytomegalovirus (CMV) infection is a common complication following allogeneic hematopoietic stem cell transplantation (aHSCT) and is associated with increased mortality. Letermovir (LET) is a novel antiviral drug used to prevent CMV infection. METHODS: We analyzed 111 consecutive patients who underwent aHSCT, retrospectively, to evaluate the efficacy of LET prophylaxis for clinically significant CMV infection (csCMVi) in real-world situations. In addition, we analyzed the influence of LET on transplant outcomes. Thirty-eight patients who were administered LET prophylactically were compared with 73 patients without LET prophylaxis after aHSCT. RESULTS: On day 180, the cumulative incidence of csCMVi in patients who received LET prophylaxis was significantly lower than that in patients without LET prophylaxis (29.7% vs. 56.2%, P < 0.001). Among the patients who developed csCMVi, the interval from aHSCT to the initiation of preemptive therapy was significantly longer in patients who received LET prophylaxis than in those who did not (129.5 days vs. 42 days, P < 0.001). The six-month overall survival was 86.1% in patients who received LET prophylaxis and 66.8% in the non-LET group (P = 0.035). CONCLUSION: LET prophylaxis was highly effective in preventing csCMVi and could potentially improve transplant outcomes, particularly when initiated early after transplantations.

Radiometric Calibration for a Multispectral Sensor Onboard RISESAT Microsatellite Based on Lunar Observations.

Radiometric calibration utilizing the Moon as a reference source is termed as lunar calibration. It is a useful method for evaluating the performance of optical sensors onboard satellites orbiting the Earth. Lunar calibration provides sufficient radiometric calibration opportunities without requiring any special equipment, and is suitable for nano/microsatellites. This study applies lunar calibration to a multispectral sensor, Ocean Observation Camera (OOC), on board a microsatellite named Rapid International Scientific Experiment Satellite. Simulating the brightness of the Moon based on the RObotic Lunar Observatory and SELENE/Spectrum Profiler models, sensitivity degradation was proven to be negligible in any of the four spectral bands of the OOC with the sensor temperature correction. A bluing trend in the OOC's sensor sensitivity was revealed, indicating a shorter observation wavelength shows larger irradiance. Comparing the top-of-atmosphere reflectance of Railroad Valley Playa with the Radiometric Calibration Network dataset revealed that the derived calibration parameter from the lunar calibration was valid for correcting the bluing trend in the visible range. Although the lunar and vicarious calibration parameters for the infrared band were unexpectedly inconsistent, lunar calibration could potentially contribute toward estimating the contaminated background radiance in the Earth observation images.

Clinical efficacy of mogamulizumab for relapsed/refractory aggressive adult T-cell leukemia/lymphoma: A retrospective analysis.

OBJECTIVES: Although phase 2 studies have confirmed the efficacy of mogamulizumab for adult T-cell leukemia/lymphoma (ATL), real-world data on its benefits are limited. We assessed the benefits of mogamulizumab for relapsed/refractory ATL in clinical practice. METHODS: We retrospectively analyzed patients with acute- and lymphoma-type ATL. Among 57 patients diagnosed with ATL between January 2008 and August 2018, 42 who received salvage therapy were eligible, including 24 who received mogamulizumab. RESULTS: The overall response rate to mogamulizumab was 54.2%. Median survival time (MST) and 1-year overall survival (OS) rate from mogamulizumab initiation were 7.7 months and 42.0%, respectively. Patients with acute-type ATL showed longer MST (15.1 months) and higher 1-year OS (63.6%). MST without skin rash was 5.0 months, and 1-year OS was 34.3%; however, MST with skin rash was not reached and 1-year OS was 66.7%. Among patients who received the salvage therapy, longer MST and higher 1-year OS were observed with mogamulizumab than without mogamulizumab (P = .078; 9.2 vs. 3.9 months; 47.9% vs. 17.6%, respectively). Mogamulizumab administration improved prognosis in patients with acute-type ATL and skin rash. CONCLUSIONS: In clinical practice, mogamulizumab improved OS in patients with relapsed/refractory ATL, especially those with acute-type ATL and skin rash.

Human Herpesvirus 6 Reactivation Evaluated by Digital Polymerase Chain Reaction and Its Association With Dynamics of CD134-Positive T Cells After Allogeneic Hematopoietic Stem Cell Transplantation.

BACKGROUND: Human herpesvirus 6 (HHV-6) causes life-threatening central nervous system disorders after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Recent studies implicated CD134 as a specific receptor of HHV-6B and demonstrated that its expression levels in CD4-positive T cells after allo-HSCT could be related to the reactivation of HHV-6. We prospectively evaluated the relationship between HHV-6 reactivation and CD134+ T cells in the recipients of allo-HSCT. METHODS: HHV-6 viral load in plasma was quantitatively measured weekly after allo-HSCT by digital polymerase chain reaction in 34 patients. The ratio of CD134 in CD4+ T cells (CD134/CD4 ratio) was serially measured by flow cytometry before and after transplantation. RESULTS: HHV-6 reactivation was detected in 23 patients (68%). The CD134/CD4 ratio before conditioning was significantly higher in patients with HHV-6 reactivation than in those without (median, 3.8% vs 1.5%, P < .01). In multivariate analysis, a higher CD134/CD4 ratio before conditioning was significantly associated with the incidence of HHV-6 reactivation (odds ratio, 10.5 [95% confidence interval, 1.3-85.1], P = .03). CONCLUSIONS: A higher CD134/CD4 ratio before conditioning was associated with a higher risk of HHV-6 reactivation, suggesting that the rate may be a promising marker for predicting HHV-6 reactivation after allo-HSCT.

Efficacy and safety of anagrelide as a first-line drug in cytoreductive treatment-naïve essential thrombocythemia patients in a real-world setting.

OBJECTIVE: This study aimed to retrospectively assess the efficacy and safety of anagrelide in cytoreduction therapy-naïve essential thrombocythemia (ET) patients in a real-world setting. METHOD: Data from 53 ET patients who received anagrelide as a first-line therapy were reviewed for patient characteristics, antiplatelet status, cytoreduction status, therapeutic effects, adverse events, thrombohemorrhagic event development, progression to myelofibrosis or acute leukemia, and cause of death. RESULTS: The rate of achieving a platelet count of <600 × 109 /L during anagrelide monotherapy was 83.0%. Adverse events occurred in 32 of 53 patients, and tended to be slightly more severe in patients with cardiac failure; however, they were mostly tolerable. The therapeutic effect of anagrelide was consistent, regardless of genetic mutation profiles. The incidence of anemia as an adverse event was significantly higher in the CALR mutation-positive group. Favorable platelet counts were also achieved in patients for whom hydroxyurea was introduced as a replacement for anagrelide or in addition to anagrelide because of unresponsiveness or intolerance to treatment. CONCLUSION: In Japanese cytoreduction therapy-naïve ET patients, anagrelide administration as a first-line therapy demonstrated favorable effects in reducing platelet counts, and its safety profile that was generally consistent with those in previous reports.

[Occurrence of acquired factor V inhibitor during antibiotic therapy for a surgical wound infection].

Acquired factor V (FV) inhibitor is a rare disorder. Herein we report a case of an 82-year-old Japanese woman with FV inhibitor exhibiting a pseudo decline in the activities of the multiple coagulation factors. After rectal cancer surgery, she received antibiotic therapy for wound infection. As prothrombin and activated partial thromboplastin time was prolonged, heparin for atrial fibrillation was discontinued without improvement. Coagulation factor activity assays revealed deficiencies in II, V, VII, VIII, IX, X, XI, and XII factor activities; in particular, the FV activity was markedly decreased to <1%. The cross-mixing test findings revealed an inhibitor pattern, and multiple coagulation factor inhibitors were positive. The FV inhibitor level was high at 62 Bethesda U/ml. The patient exhibited no bleeding tendency with the prolonged wound infection without immunosuppressive therapy. The inhibitor disappeared four months after the onset.

[Successful treatment with brentuximab vedotin maintenance therapy after autologous stem cell transplantation in high-risk Hodgkin lymphoma].

A 56-year-old woman was diagnosed with classical Hodgkin lymphoma in December 2012. She achieved complete remission (CR) with six cycles of adriamycin, bleomycin, vinblastine, and dacarbazine (ABVD). In March 2015, she experienced a relapse marked by high fever, respiratory discomfort, and pain in the left thigh owing to tumor involvement of the femur. She was treated with one cycle of brentuximab vedotin (BV), followed by irradiation of the left femoral lesion. She achieved partial remission (PR) but developed recurrence after the third cycle of BV. She achieved PR again with two cycles of standard bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone (BEACOPP) regimen; therefore, autologous stem cell transplantation (ASCT) was performed. Because the dosing interval used for BV therapy was longer than that in the recommended schedule, we could not definitively attribute her recurrence to BV resistance. Moreover, she maintained a good performance status after recurrence during subsequent cycles of BV therapy. Because of attaining PR after ASCT, she subsequently received a total of 12 BV cycles for consolidation. She achieved CR 3 months after ASCT and has remained in CR until 29 months. For patients who show relapse after initial BV therapy, retreatment with BV should be carefully considered. Patients who show relapse after achieving at least PR with initial BV therapy are potential candidates for post-ASCT BV maintenance therapy to reduce their tumor burden.

Realistic Lenalidomide Dose Adjustment Strategy for Transplant-Ineligible Elderly Patients with Relapsed/Refractory Multiple Myeloma: Japanese Real-World Experience.

Lenalidomide is an immunomodulatory drug administered orally in the treatment of multiple myeloma. Some elderly patients require a reduced lenalidomide dose because of comorbidities and/or adverse events. This study investigated the actual dose of lenalidomide in elderly patients, finding that most received reduced (5-10 mg) doses. The most common reasons for dose reduction were renal dysfunction (54% of patients), fatigue (grade ≥3; 20%), hematologic disorder (grade ≥3; 14%), and rash (grade ≥3; 9%). Their median time to progression was 11.8 months and their median overall survival was 39.2 months. The overall response rate was 73%, including 17% with a complete response, 19% with a very good partial response, and 37% with a partial response. These results showed that, contrary to western countries, most patients were treated with a reduced dose of lenalidomide in Japan. However, it is suggested that continued treatment with a tolerable dose may yield favorable outcomes.

Rapid improvement of hyperammonemic encephalopathy by bortezomib treatment in IgD-type multiple myeloma.

A 74-year-old man visited our hospital with complaints of anorexia, weight loss, and impaired activities of daily living. He presented mild consciousness disturbance at the first visit, but specific causes were identified. The IgD level was>2,000 mg/dl and bone marrow biopsy was performed after aspiration failed due to excessive density. He was diagnosed with IgD/λ multiple myeloma (MM). He lapsed into a coma with an extremely high ammonia level of 484 µg/dl on day 8 after admission. His diagnosis was established as hyperammonemic encephalopathy (HE). He was treated with dexamethasone (Dex) pulse therapy and continuous hemodiafiltration. Minor improvement of hyperammonemia was achieved. Combination therapy with bortezomib and Dex was commenced. His ammonia level rapidly decreased and his mental state improved. HE accompanied by MM is rare and further studies are needed to clarify outcomes in response to treatment using the novel agent Bor. Although HE is potentially fatal, we found Bor to be rapidly effective against HE.

[Primary Central Nervous System Post-Transplant Lymphoproliferative Disorder in a Patient with Acute Lymphocytic Leukemia].

A 27-year-old woman with acute lymphocytic leukemia, who underwent allogeneic hematopoietic stem cell transplantation, complained of nausea and blurred vision 288 days after the transplantation. Intracranial tumors were identified on brain MRI. She received whole brain radiation after open biopsy, but she died. The tumors had characteristics of diffuse large B cell lymphoma, and she was finally diagnosed with primary central nervous system post-transplant lymphoproliferative disorder. This disease is rare and has a poor outcome. Therefore, accumulation of cases and establishment of treatments for this condition are urgently needed.

First report of familial mixed phenotype acute leukemia: shared clinical characteristics, Philadelphia translocation, and germline variants.

While our understanding of the molecular basis of mixed phenotype acute leukemia (MPAL) has progressed over the decades, our knowledge is limited and the prognosis remains poor. Investigating cases of familial leukemia can provide insights into the role of genetic and environmental factors in leukemogenesis. Although familial cases and associated mutations have been identified in some leukemias, familial occurrence of MPAL has never been reported. Here, we report the first cases of MPAL in a family. A 68-year-old woman was diagnosed with MPAL and received haploidentical stem cell transplantation from her 44-year-old son. In four years, the son himself developed MPAL. Both cases exhibited similar characteristics such as biphenotypic leukemia with B/myeloid cell antigens, Philadelphia translocation (BCR-ABL1 mutation), and response to acute lymphoblastic leukemia-type chemotherapy. These similarities suggest the presence of hereditary factors contributing to the development of MPAL. Targeted sequencing identified shared germline variants in these cases; however, in silico analyses did not strongly support their pathogenicity. Intriguingly, when the son developed MPAL, the mother did not develop donor-derived leukemia and remained in remission. Our cases provide valuable insights to guide future research on familial MPAL.

Short- and long-term performance of risk calculation tools for mortality in patients with acute coronary syndrome.

Background: The mortality rate of acute coronary syndrome (ACS) remains high. Therefore, patients with ACS should undergo early risk stratification, for which various risk calculation tools are available. However, it remains uncertain whether the predictive performance varies over time between risk calculation tools for different target periods. This study aimed to compare the predictive performance of risk calculation tools in estimating short- and long-term mortality risks in patients with ACS, while considering different observation periods using time-dependent receiver operating characteristic (ROC) analysis. Methods: This study included 404 consecutive patients with ACS who underwent coronary angiography at our hospital from March 2017 to January 2021. The ACTION and GRACE scores for short-term risk stratification purposes and CRUSADE scores for long-term risk stratification purposes were calculated for all participants. The participants were followed up for 36 months to assess mortality. Using time-dependent ROC analysis, we evaluated the area under the curve (AUC) of the ACTION, CRUSADE, and GRACE scores at 1, 6, 12, 24, and 36 months. Results: Sixty-six patients died during the observation periods. The AUCs at 1, 6, 12, 24, and 36 months of the ACTION score were 0.942, 0.925, 0.889, 0.856, and 0.832; those of the CRUSADE score were 0.881, 0.883, 0.862, 0.876, and 0.862; and those of the GRACE score 0.949, 0.928, 0.888, 0.875, and 0.860, respectively. Conclusions: The ACTION and GRACE scores were excellent risk stratification tools for mortality in the short term. The prognostic performance of each risk score was almost similar in the long term, but the CRUSADE score might be a superior risk stratification tool in the longer term than 3 years.

SDHAF1 confers metabolic resilience to aging hematopoietic stem cells by promoting mitochondrial ATP production.

Aging generally predisposes stem cells to functional decline, impairing tissue homeostasis. Here, we report that hematopoietic stem cells (HSCs) acquire metabolic resilience that promotes cell survival. High-resolution real-time ATP analysis with glucose tracing and metabolic flux analysis revealed that old HSCs reprogram their metabolism to activate the pentose phosphate pathway (PPP), becoming more resistant to oxidative stress and less dependent on glycolytic ATP production at steady state. As a result, old HSCs can survive without glycolysis, adapting to the physiological cytokine environment in bone marrow. Mechanistically, old HSCs enhance mitochondrial complex II metabolism during stress to promote ATP production. Furthermore, increased succinate dehydrogenase assembly factor 1 (SDHAF1) in old HSCs, induced by physiological low-concentration thrombopoietin (TPO) exposure, enables rapid mitochondrial ATP production upon metabolic stress, thereby improving survival. This study provides insight into the acquisition of resilience through metabolic reprogramming in old HSCs and its molecular basis to ameliorate age-related hematopoietic abnormalities.

Context-dependent modification of PFKFB3 in hematopoietic stem cells promotes anaerobic glycolysis and ensures stress hematopoiesis.

Metabolic pathways are plastic and rapidly change in response to stress or perturbation. Current metabolic profiling techniques require lysis of many cells, complicating the tracking of metabolic changes over time after stress in rare cells such as hematopoietic stem cells (HSCs). Here, we aimed to identify the key metabolic enzymes that define differences in glycolytic metabolism between steady-state and stress conditions in murine HSCs and elucidate their regulatory mechanisms. Through quantitative 13C metabolic flux analysis of glucose metabolism using high-sensitivity glucose tracing and mathematical modeling, we found that HSCs activate the glycolytic rate-limiting enzyme phosphofructokinase (PFK) during proliferation and oxidative phosphorylation (OXPHOS) inhibition. Real-time measurement of ATP levels in single HSCs demonstrated that proliferative stress or OXPHOS inhibition led to accelerated glycolysis via increased activity of PFKFB3, the enzyme regulating an allosteric PFK activator, within seconds to meet ATP requirements. Furthermore, varying stresses differentially activated PFKFB3 via PRMT1-dependent methylation during proliferative stress and via AMPK-dependent phosphorylation during OXPHOS inhibition. Overexpression of Pfkfb3 induced HSC proliferation and promoted differentiated cell production, whereas inhibition or loss of Pfkfb3 suppressed them. This study reveals the flexible and multilayered regulation of HSC glycolytic metabolism to sustain hematopoiesis under stress and provides techniques to better understand the physiological metabolism of rare hematopoietic cells.

Mechanism of Drug-Eluting Stent Thrombosis Diagnosed by Histopathological Evaluation of Directional Coronary Atherectomy Specimen.

An 89-year-old man with a history of percutaneous coronary intervention using a sirolimus-eluting stent presented with recurrent in-stent occlusion. Pathological assessment of the neointima resected via directional coronary atherectomy revealed a double-layered thrombus. Clopidogrel resistance and limited antithrombotic regimen owing to high bleeding risk likely resulted in the in-stent thrombotic occlusion.

The Impact of Pretransplant Use of Tyrosine Kinase Inhibitors on Allogeneic Stem Cell Transplantation in Patients with Chronic Myeloid Leukemia-A Single-institution Retrospective Study.

Objective Chronic myeloid leukemia (CML) is a malignant hematological disorder, and allogeneic stem cell transplantation (allo-SCT) was its only curative treatment until the introduction of tyrosine kinase inhibitors (TKIs). Allo-SCT is still considered for CML patients who are resistant to TKIs and in an advanced phase. Currently, second- and third-generation (2/3 G) TKIs are typically incorporated into the first-line treatment of CML. However, the impact of 2/3 G TKIs on subsequent allo-SCT remains unclear. We therefore evaluated the effect of 2/3 G TKIs on allo-SCT. Methods We retrospectively evaluated the effect of pretransplant therapy with TKIs on the outcome of allo-SCT for CML using clinical data at our institution. Patients or Materials Thirty-two CML patients who received their first allo-SCT procedure at our institute from 2001 to 2020 were included. We divided the patients into three subgroups based on TKI treatment before allo-SCT. Patients receiving no TKIs, only imatinib (IM), and 2/3 G TKIs were classified into the Non-TKI, IM, and 2/3 G TKI groups, respectively. Results In a univariate analysis, the pretransplant use of 2/3 G TKIs was significantly associated with a higher 5-year overall survival (91.7%) and relapse-free survival (75.0%) than the use of IM (37.5% and 12.5%) in patients presenting with or progressing to the advanced phase. In addition, pretransplant use of 2/3 G TKIs did not increase the incidence of graft-versus-host disease (GVHD). Conclusions We demonstrated that the pretransplant use of 2/3 G TKIs was safe and improved the outcome of CML patients who presented with or progressed to the advanced phase without increasing the frequency of GVHD.

Successful management of pregnancy-associated thrombotic thrombocytopenic purpura by monitoring ADAMTS13 activity.

Thrombotic thrombocytopenic purpura (TTP) during pregnancy is very rare and is caused by an absent or severely depleted ADAMTS13 (a disintegrin-like and metallopeptidase with thrombospondin type 1 motif, 13). A 37-year-old multigravida woman developed TTP with severe anemia and thrombocytopenia at 22 weeks' gestation. ADAMTS13 activity was markedly decreased to 3% and ADAMTS13 inhibitor was positive, leading to a definitive diagnosis of TTP. She was successfully treated by plasmapheresis six times, resulting in symptomatic relief. Close follow up with periodic ADAMTS13 measurement facilitated plasmapheresis at appropriate points at a minimum frequency during pregnancy. Because of intrauterine growth retardation from 28 weeks' gestation, an elective cesarean section was performed at 30 weeks' gestation. After delivery, the mother and child showed no appreciable problem. To our knowledge, this is the first report of successful management for pregnancy-associated TTP by monitoring ADAMTS13 activity during pregnancy and the postpartum period.