Differentiating Between Epstein-Barr Virus-positive Lymphoid Neoplasm Relapse and Post-transplant Lymphoproliferative Disorder After Sex-mismatched Hematopoietic Stem Cell Transplantation

After allogeneic hematopoietic stem cell transplantation (HSCT), accurate differentiation between donor-derived post-transplant lymphoproliferative disorder (PTLD) and relapse of recipient-derived lymphoproliferative disorder (LPD) is crucial for determining treatment. Conventional diagnostic approaches for PTLD include histopathological examination, flow cytometry, and chimerism analysis of bulk tumor tissue. However, these methods are inconclusive in cases in which the primary disease is an Epstein-Barr virus (EBV)-positive LPD and is of the same lineage as that of the post-HSCT LPD tumor cells. Particularly, in cases where the number of tumor cells in the tissue is low, it is difficult to determine the origin of tumor cells. In this study, we developed a new method to simultaneously detect signals using sex chromosome fluorescence in situ hybridization, immunofluorescence staining, and EBV-encoded small RNA in situ hybridization on a single section of formalin-fixed paraffin-embedded histopathological specimen. The utility of the method was validated using specimens from 6 cases of EBV-positive LPD after sex-mismatched HSCT that were previously difficult to diagnose, including Hodgkin lymphoma-like PTLD that developed after HSCT for Hodgkin lymphoma and recurrence of chronic active EBV infection. This method successfully preserved the histologic structure after staining and allowed accurate determination of tumor cell origin and lineage at the single-cell level, providing a definitive diagnosis in all cases. This method provides a powerful tool for the diagnosis of LPDs after sex-mismatched HSCT.

A single-institution pre-post comparison of subcutaneous immunoglobulin replacement therapy in allogeneic haematopoietic cell transplantation recipients

Immunoglobulin replacement therapy (IgRT) reduces the risk of infection in hypogammaglobulinaemia secondary to chronic lymphocytic leukaemia and multiple myeloma. However, the benefit of IgRT, especially subcutaneous IgRT (ScIgRT), has not been assessed in hypogammaglobulinaemia after allogeneic haematopoietic cell transplantation (allo-HCT). We performed a pre-post comparison of the clinical impact of ScIgRT after allo-HCT in a retrospective analysis of 209 patients who underwent allogeneic HCT at our institution from 2011 to 2019. Since ScIgRT became available at our institution in April 2017, we categorized patients treated from January 2011 to March 2017 as the Pre-ScIgRT group (n = 118) and those treated from April 2017 to December 2019 as the Post-ScIgRT group (n = 91). The 2-year overall survival rate was 65% in the Pre-ScIgRT group and 81% in the Post-ScIgRT group (p = 0.02). The cumulative incidence (CI) of non-relapse mortality at 2 years was 18% and 7% (p = 0.02). There were 78 infectious events in 44 patients in the Pre-ScIgRT group and 28 such events in 19 patients in the Post-ScIgRT group. The CI of the documented infection during the observation period was between 38% and 21% (p = 0.01). Our study suggests that ScIgRT may reduce infection rates and improve prognosis after allo-HCT.

Relationship between muscle thickness measured by ultrasound and physical functions: A 2-year follow-up study of allogeneic hematopoietic stem cell transplantation recipients

BACKGROUND

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially curative treatment for hematological malignancies. Several complications following allo-HSCT, such as graft-versus-host disease, infection, and malnutrition, often cause physical dysfunction, and the assessment of physical function and evaluation of muscle mass are incompletely performed. Use of ultrasound (US) allows muscle mass measurement in patients with poor general conditions. In allo-HSCT recipients, the correlation between physical function and muscle thickness, as measured by US, remains unclear.

OBJECTIVE

To clarify whether muscle thickness measured by US correlated with physical function in allo-HSCT recipients.

DESIGN

A single-center prospective cohort study.

SETTING

Hospital.

PATIENTS

Ninety-two patients underwent allo-HSCT at our hospital from April 2017 to March 2019.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE(S)

Biceps and quadriceps muscle thickness measured by US, grip strength, isometric muscle strength (elbow flexion and knee extension), and 6-minute walking test (6MWT) before allo-HSCT and on days 30, 90, 180, 1 year, and 2 years after allo-HSCT. The implementation rates of these assessments were also investigated.

RESULTS

Correlations were observed between biceps thickness and elbow flexion muscle strength/grip strength before allo-HSCT, on days 30, 90, 180, 1 year, and 2 years after allo-HSCT (r = 0.71/0.74, 0.73/0.72, 0.70/0.79, 0.67/0.75, 0.72/0.75, and 0.85/0.79, respectively, all p < .001). At the same time points, quadriceps thickness moderately correlated with knee extensor strength (r = 0.49, 0.50, 0.45, 0.64, 0.61, and 0.58, all p < .001). However, biceps and quadriceps thicknesses did not correlate with the 6MWT. The percentages of patients measured with US and 6MWT were 93.4% and 82.4% (p = .01) on day 30 and 97.5% and 87.8% (p = .02) on day 90, respectively.

CONCLUSIONS

US assessment may be a useful alternative method for estimating muscle strength in fragile allo-HSCT recipients, particularly when physical function assessment is difficult to quantify.

Gilteritinib in peritransplant period for relapsed or refractory FLT3-mutated acute myeloid leukemia: A case report of three patients

Patients with relapsed or refractory acute myeloid leukemia (RR-AML) with mutations of FMS-like tyrosine kinase 3 (FLT3) have a poor prognosis even after allogeneic hematopoietic cell transplantation (allo-HCT). Multiple FLT3 inhibitors, including gilteritinib, have been developed and serve as treatment options for RR-AML. Here, we describe three cases of FLT3 mutated RR-AML that were successfully treated with gilteritinib administration before and after allo-HCT. Gilteritinib treatment before HCT was helpful in achieving remission. However, HCT often resulted in mild liver damage, and careful introduction of gilteritinib after HCT at a lower dose may be helpful for its safe usage. The three cases discussed had a successful clinical outcome in terms of disease control as well as the management of side effects associated with gilteritinib treatment.

A case of severe oral mucosal GVHD induced by heterologous SARS-CoV-2 vaccination after cord blood transplantation

Patients who have undergone hematopoietic cell transplantation (HCT) are at a higher risk of severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) infection than the general population. Therefore, early vaccination is recommended for post-transplant patients. Although exacerbation of chronic graft-versus-host disease (cGVHD) after the initial vaccination has been reported, it is unknown whether severe cGVHD occurs when different RNA vaccines are combined. We treated a patient who developed severe oral mucosal cGVHD after receiving two different RNA vaccines. Visual inspection showed that the patient presented with typical mucocutaneous cGVHD, and cGVHD in this case responded well to low-dose steroids compared to common oral GVHD exacerbations. Histopathological findings revealed T cell, B cell, and conspicuous neutrophil infiltration. Multiple doses of SARS-Cov2 vaccination are required in post-transplant recipients. In conclusion, it is essential to obtain the vaccination history of allo-HSCT recipients with cGVHD exacerbation. Furthermore, reviewing the pathological findings may help treat patients with lower doses of steroids.

Successful Bridging to Allogeneic Hematopoietic Stem Cell Transplantation by Azacitidine and Venetoclax in a Case of Acute Myeloid Leukemia With t(3;3)(q21.3;q26.2) Developed Early After Orthotopic Heart Transplantation

A 48-year-old male patient developed acute myeloid leukemia (AML) with t(3;3)(q21.3;q26.2) chromosomal mutation 8 months after orthotopic heart transplantation from a human leukocyte antigen-unmatched brain-dead donor for cardiac sarcoidosis. He had sequelae of stroke and chronic renal failure at the time of AML diagnosis. He received 3 cycles of azacitidine and venetoclax induction therapy and achieved complete hematological remission with incomplete count recovery without causing severe complications, including infection. He sequentially underwent allogeneic peripheral blood stem cell transplantation from a HLA-8/8 matched, ABO-blood matched, unrelated female donor and successfully achieved donor cell engraftment. His transplanted heart was viable, and the coronary vessels were not damaged even after allogeneic peripheral blood stem cell transplantation. Although AML relapsed afterward, azacytidine/venetoclax was a tolerable bridging therapy even for early-onset AML after heart transplantation.

[Acquired hemophilia A following BNT162b2 mRNA COVID-19 vaccination]

Acquired hemophilia A (AHA) is a rare disease characteized by bleeding symptoms caused by decreased factor VIII activity due to the appearance of inhibitors to factor VIII triggered by malignancy or collagen disease. An 86-year-old woman developed purpura on her extremities after the first dose of the BNT162b2 mRNA COVID-19 vaccine. This symptom subsided after a few days. After the second dose of the BNT162b2 mRNA COVID-19 vaccine, purpura appeared again, and the patient was referred to our hospital Her APTT was remarkably prolonged to 110 seconds, and a cross-mixing test revealed an inhibitor pattern. Since FVIII activity was <1% and FVIII inhibitor was 51.6 BU, she was diagnosed with AHA. Prednisolone therapy was started, and coagulative complete remission was achieved. Because acquired hemophilia can develop after mRNA COVID-19 vaccination, as in this case, it is critical to monitor the appearance of bleeding symptom.

Entrapment partly participates in the longitudinal progression of neuropathy with anti-MAG antibodies

Neuropathy with anti-myelin-associated glycoprotein (MAG) antibodies commonly demonstrates distal-dominant prolongation of nerve conduction. However, recent electrophysiological studies have shown that distal motor demyelination is not always a distinct feature. We aimed to elucidate whether the longitudinal progression of nerve impairment occurs in a distal-dominant manner. Seven patients with neuropathy with anti-MAG antibodies were enrolled. Sequential nerve conduction studies revealed nerve conduction reduction only at the wrist segment in the median nerve of the patients, but not in the ulnar nerve. Median nerve entrapment at the wrist may play a role in longitudinal disease progression in neuropathy with anti-MAG antibodies.

Prolonged gut microbial alterations in post-transplant survivors of allogeneic haematopoietic stem cell transplantation

Dysbiosis of the gut microbiota has been reported to increase early complications after allogeneic haematopoietic stem cell transplantation (allo-HSCT). However, it remains unclear whether gut microbial alterations persist during late complications, such as chronic graft-versus-host disease (cGVHD) or secondary cancers. Here, we analysed the gut microbiota of 59 patients who survived for 1-21.7 years (median, 6.4 years) after allo-HSCT. Long-term survivors showed lower gut microbial diversity than the age- and sex-matched healthy controls. This decreased diversity was reflected in the reduced abundance of the butyrate-producing bacteria. Patients with a history of grade 3 acute graft-versus-host disease (aGVHD) exhibited higher Veillonella abundance than patients with a history of grade 1-2 or non-aGVHD cases. The abundance of Faecalibacterium showed no decrease only in limited cGVHD cases. Additionally, the microbial structure in the secondary cancer group was significantly different (p < 0.05) from that in the non-secondary cancer group. This study is the first to show that microbial dysbiosis is present over a 10-year lifetime after discharge following allo-HSCT. Our results suggest that these prolonged gut microbial alterations may be associated with the development and exacerbation of late complications in post-transplant survivors.

Asciminib vs bosutinib in CML patients pretreated with ≥2 tyrosine kinase inhibitors: Results from the Japanese subgroup analysis of ASCEMBL study

Asciminib, a first-in-class, allosteric inhibitor of BCR-ABL1 that acts by STAMP (Specifically Targeting the ABL Myristoyl Pocket), is a novel therapeutic option for patients with chronic myeloid leukemia (CML). In the global, phase 3, open-label ASCEMBL study in patients with CML in chronic phase (CML-CP) pretreated with ≥2 tyrosine kinase inhibitors (TKIs) (NCT03106779), asciminib (40 mg twice-daily) demonstrated significant superiority over the ATP-competitive TKI bosutinib (500 mg once daily) for the primary endpoint of major molecular response (MMR; BCR::ABL1 transcript levels on the international scale [BCR::ABL1^IS ] ≤0.1%) at week 24. Here, we report results from a descriptive subgroup analysis of Japanese patients enrolled in ASCEMBL study (data cut-off: May 25, 2020). Overall, 16 Japanese patients were randomized (asciminib, n = 13; bosutinib, n = 3). At week 24, the MMR rate with asciminib was 30.8% (4/13; 95% confidence interval [CI], 9.09-61.43). BCR::ABL1^IS ≤1% and complete cytogenic response (CCyR) at week 24 were 61.5% (8/13 patients) and 50.0% (4/8 patients), respectively. In the bosutinib group, no patient achieved MMR, CCyR, or BCR::ABL1^IS ≤1%, but results were limited by the low number of patients. The safety profile of asciminib was comparable to that previously observed in the overall study population. Findings from this Japanese subgroup analysis of the ASCEMBL study support the use of asciminib for the treatment of Japanese patients with CML-CP previously treated with ≥2 TKIs. ClinicalTrials.gov Identifier: NCT03106779.

Nivolumab-induced systemic lymphadenopathy occurring during treatment of malignant melanoma: a case report

Nivolumab is an anti-programmed cell death protein 1 monoclonal antibody that exhibits significant efficacy in treating melanoma and other malignancies. However, various nivolumab-induced immune-related adverse events (irAEs) have been reported, and differentiating irAEs from tumor progression is sometimes difficult. Here, we report a case of reactive lymphadenopathy occurring after treatment with nivolumab. A 56-year-old man with stage IIIC melanoma received adjuvant therapy with nivolumab after wide local excision. He developed systemic lymphadenopathy and autoimmune hemolytic anemia 1 month after receiving seven cycles of nivolumab. Pathological analysis of a cervical lymph node biopsy specimen revealed no metastatic lesion or any other malignancy, including lymphoma. Thus, the patient was diagnosed with nivolumab-induced reactive lymphadenopathy. Systemic corticosteroids were administered to reduce hemolysis, which led to the resolution of lymphadenopathy. When progressive lymphadenopathy is observed in a patient who received immune checkpoint inhibitor therapy, reactive lymphadenopathy should be carefully distinguished from progression to lymphoid metastasis, and biopsy should be performed if needed.

Relationship between donor-specific HPA-15 antibodies and poor graft function in HPA-15 mismatched cord blood transplantation

Poor graft function (PGF) is a fatal complication following hematopoietic stem cell transplantation and is influenced by multiple factors, such as donor-specific anti-HLA antibodies, a poor infused CD34⁺ cell count, and the donor source. Alloantibodies against human platelet antigen 15 (HPA-15) recognize platelet membrane glycoprotein CD109, which is expressed not only on platelets, but also on megakaryocytes and specific hematopoietic stem cells. HPA-15 antibodies are known to induce platelet transfusion refractoriness and neonatal alloimmune thrombocytopenia, but their effects on graft function following hematopoietic stem cell transplantation remain unknown. We encountered a case of HPA-15 mismatched cord blood transplantation with a high HPA-15b antibody titer. Prolonged PGF and megakaryocyte aplasia with sustained high-titer HPA-15b antibodies were attenuated by rituximab therapy, and rapid recovery of hematopoiesis was achieved. HPA-15-compatible platelet transfusions were highly effective for platelet recovery. Methylcellulose assays and megakaryocyte cultures revealed that patient serum inhibited in vitro hematopoietic development from patient bone marrow cells. These results suggest that HPA-15 antibodies might be a cause of PGF and that reducing the HPA-15 antibody titer might improve graft function in HPA-15 mismatched transplantation.

Special AT-Rich Sequence-Binding Protein 1 Supports Survival and Maturation of Naive B Cells Stimulated by B Cell Receptors

Epigenetic mechanisms underpin the elaborate activities of essential transcription factors in lymphocyte development. Special AT-rich sequence-binding protein 1 (SATB1) is a chromatin remodeler that orchestrates the spatial and temporal actions of transcription factors. Previous studies have revealed the significance of SATB1 in T cell lineage. However, whether and how SATB1 controls B cell lineage development is yet to be clarified. In this study, we show that SATB1 is an important factor during splenic B cell maturation. By analyzing SATB1/Tomato reporter mice, we determined the dynamic fluctuation of SATB1 expression in the B cell lineage. Although SATB1 expression decreased to minimal levels during B cell differentiation in the bone marrow, it resurged markedly in naive B cells in the spleen. The expression was dramatically downregulated upon Ag-induced activation. Splenic naive B cells were subdivided into two categories, namely SATB1^high and SATB1^-/low, according to their SATB1 expression levels. SATB1^high naive B cells were less susceptible to death and greater proliferative than were SATB1^-/low cells during incubation with an anti-IgM Ab. Additionally, SATB1^high cells tended to induce the expression of MHC class II, CD86, and CD83. Accordingly, naive B cells from B lineage-specific SATB1 conditional knockout mice were more susceptible to apoptosis than that in the control group upon anti-IgM Ab stimulation in vitro. Furthermore, conditional knockout mice were less capable of producing Ag-specific B cells after immunization. Collectively, our findings suggest that SATB1 expression increases in naive B cells and plays an important role in their survival and maturation.

Clinical implications of combination therapy with quizartinib and craniospinal irradiation for refractory acute myeloid leukemia positive for FMS‐like tyrosine kinase 3‐internal tandem duplication with central nervous system involvement

FMS‐like tyrosine kinase 3‐internal tandem duplication (FLT3‐ITD) mutation‐positive acute myeloid leukemia (AML) has a poor prognosis. We report the first case of successful bridge therapy of novel FLT3 inhibitor, quizartinib, to umbilical cord blood stem cell transplantation for FLT3‐ITD‐positive AML‐primary induction failure patients with central nervous system involvement.

Autoimmune-mediated thrombocytopenia after allogeneic hematopoietic stem cell transplantation: significance of detecting reticulated platelets and glycoprotein-specific platelet autoantibodies

Autoimmune hematological disorders are rare complications after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Diagnosis of immune thrombocytopenia (ITP) is challenging, especially after allo-HSCT, because various complications such as graft-versus-host disease, disease relapse, viral infection, thrombotic microangiopathy, and drug side effects can also cause thrombocytopenia. Assessment of reticulated platelets (RP) and plasma thrombopoietin (TPO) levels may be useful to distinguish between ITP and hypoplastic thrombocytopenia. ITP is generally characterized by an increased percentage of RP, and a normal or slightly increased plasma TPO level. We now report three cases of thrombocytopenia after allo-HSCT. RP% was elevated in these patients, as it is in primary ITP. However, in contrast to primary ITP, plasma TPO levels were high in two of three patients. Anti-αIIbβ3 and anti-GPIb/IX-specific direct IgG antibodies were detected as well, suggesting occurrence of immune-mediated platelet destruction in addition to bone marrow suppression in two patients. All three patients were successfully treated with corticosteroids and/or thrombopoietin receptor agonists (TPO-RAs). These results suggest that increased RP% and detection of glycoprotein-specific platelet autoantibodies are useful for the diagnosis of ITP after HSCT.

[Exploring new molecules that regulate hematopoietic stem cells and early stages of lymphoid hematopoiesis: the functional significance of ESAM and SATB1]

Hematopoietic stem cells (HSCs) possess multilineage differentiation capability, which sustains the production of blood and immune cells throughout life. However, the precise mechanisms by which HSCs initiate differentiation toward a particular lineage and the factors that attenuate their lymphopoietic potential with aging are yet to be elucidated. Our group has investigated this issue for over two decades. We initially developed a method for segregating early lymphoid progenitors from HSCs and identified two molecules: endothelial cell-selective adhesion molecule (ESAM), highly expressed in HSCs, and special AT-rich sequence binding protein 1 (SATB1), expressed in early lymphoid progenitors. ESAM marks HSCs across species, including humans. In addition to its significance in stress-induced hematopoiesis, ESAM is also useful in identifying features of human acute myeloid leukemia stem cells. Further, we determined the role of SATB1 in the early HSC differentiation processes toward the lymphoid lineage. Remarkably, SATB1 expression in HSCs significantly decreased with aging, whereas its exogenous induction in aged HSCs rejuvenated their lymphopoietic potential. Furthermore, SATB1-expressing HSCs demonstrated robust lymphopoietic and long-term reconstituting capability, whereas HSCs without SATB1 skewed toward the myeloid lineage. Thus, our continuing research has revealed the significance of ESAM and SATB1 in the fundamental biology of HSCs.

Casimersen for Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is a genetic disorder affecting 1 in 5,000 males which causes progressive muscle deterioration, loss of mobility and eventual death, with an average lifespan of around 25 years. While no cure currently exists for DMD, a novel treatment known as antisense-mediated exon skipping therapy has shown great promise. Exon skipping therapy induces the skipping of mutated exons, restoring the reading frame in dystrophin transcripts and resulting in a truncated but partially functional protein product. In February 2021, Sarepta Therapeutics received accelerated Food and Drug Administration (FDA) approval for their new antisense oligonucleotide, casimersen (brand name Amondys 45). Casimersen targets exon 45 of the dystrophin gene and is expected to treat ~8% of the DMD patient population. The continued approval of this drug will be dependent on satisfactory clinical results from an ongoing phase III trial. This article summarizes the preclinical and clinical data currently available for casimersen, emphasizing pharmacokinetics and safety.

Empagliflozin improves prognosis and energetic properties through modulating mitochondrial function in failing murine hearts

Background/Introduction

Sodium-glucose cotransporter 2 (SGLT2) inhibitors have been reported to have beneficial effects on heart failure in large clinical trials; however, the underlying mechanism is still unclear.

Purpose

The purpose of this study is to elucidate the mechanism of cardioprotective effect of empagliflozin in heart failure.

Methods

Eight-week-old mice deficient in cardiac and skeletal muscle-specific manganese superoxide dismutase, a mouse model of dilated cardiomyopathy (MnSOD-cKO mice), were given food mixed with or without 10 mg/kg empagliflozin for seven weeks and evaluated. Mitochondrial function in the cardiac muscle were measured by a high-resolution respirometer, Oxygraph-2K. Respiratory gas analysis were performed by indirect calorimetry (ARCO 2000) to estimate the energy consumption and energetic substrates.

Results

The survival rate (P=0.015) and cardiac fibrosis (P=0.036) were significantly improved in the empagliflozin group. The capacity of oxidative phosphorylation in cardiac mitochondria was significantly improved by empagliflozin. Blood lactate levels were decreased in the empagliflozin group, indicating that energy such as ATP could be produced without resorting to anaerobic metabolism.

Respiratory gas analysis revealed significant improvement in energy expenditure along with increase in food intake. Respiratory quotient was not different between the two groups, showing the consumption of the carbohydrate to fat rate was not changed by empagliflozin in this study. Ketone levels in blood and HbA1c were neither significantly different between the two groups. Although a moderate amount glucose was excreted in urine in the empagliflozin group (128.3±20.4 mg/day, 0.51±0.08 kcal/day), the available energy substrates in the whole body nonetheless expanded because of the increased caloric intake (10.58±0.72 in control group vs. 13.55±0.08 kcal/day in empagliflozin group, P=0.018).

Conclusion(s)

We have shown that empagliflozin improved myocardial mitochondrial function and increased energy metabolism, which was accompanied by adequate energy intake and uptake, even in heart failure. Empagliflozin decreased myocardial fibrosis and improved prognosis in failing murine hearts through positive energetical properties including mitochondrial function. The finding that empagliflozin modulates cardiac metabolism in a positive way provides a novel mechanism for the cardioprotective effect of SGLT2 inhibitors in heart failure.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Boehringer Ingelheim Empa improved prognosis in HFEmpa improved mitochondrial function

A Japanese Multicenter Study on PET and Other Biomarkers for Subjects with Potential Preclinical and Prodromal Alzheimer's Disease

BACKGROUND

PET (positron emission tomography) and CSF (cerebrospinal fluid) provide the "ATN" (Amyloid, Tau, Neurodegeneration) classification and play an essential role in early and differential diagnosis of Alzheimer's disease (AD).

OBJECTIVE

Biomarkers were evaluated in a Japanese multicenter study on cognitively unimpaired subjects (CU) and early (E) and late (L) mild cognitive impairment (MCI) patients.

MEASUREMENTS

A total of 38 (26 CU, 7 EMCI, 5 LMCI) subjects with the age of 65-84 were enrolled. Amyloid-PET and FDG-PET as well as structural MRI were acquired on all of them, with an additional tau-PET with 18F-flortaucipir on 15 and CSF measurement of Aβ1-42, P-tau, and T-tau on 18 subjects. Positivity of amyloid and tau was determined based on the positive result of either PET or CSF.

RESULTS

The amyloid positivity was 13/38, with discordance between PET and CSF in 6/18. Cortical tau deposition quantified with PET was significantly correlated with CSF P-tau, in spite of discordance in the binary positivity between visual PET interpretation and CSF P-tau in 5/8 (PET-/CSF+). Tau was positive in 7/9 amyloid positive and 8/16 amyloid negative subjects who underwent tau measurement, respectively. Overall, a large number of subjects presented quantitative measures and/or visual read that are close to the borderline of binary positivity, which caused, at least partly, the discordance between PET and CSF in amyloid and/or tau. Nine subjects presented either tau or FDG-PET positive while amyloid was negative, suggesting the possibility of non-AD disorders.

CONCLUSION

Positivity rate of amyloid and tau, together with their relationship, was consistent with previous reports. Multicenter study on subjects with very mild or no cognitive impairment may need refining the positivity criteria and cutoff level as well as strict quality control of the measurements.

High numbers of programmed cell death-1-positive tumor infiltrating lymphocytes correlate with early onset of post-transplant lymphoproliferative disorder

Post-transplant lymphoproliferative disorder (PTLD) is a life-threatening complication of transplantation. In addition to reactivation of Epstein-Barr virus in immunocompromised patients, impaired tumor immunity is suggested to be a risk factor for PTLD. However, it remains unclear whether immune suppressive tumor-infiltrating lymphocytes (TILs) correlate with the occurrence or prognosis of PTLD. We analyzed TILs in 26 patients with PTLD to elucidate the clinicopathological significance of the expression of PD-1 and FoxP3, which are associated with exhausted T-cells and regulatory T-cells (Tregs), respectively. Numbers of PD-1⁺ TILs in the PTLD specimens were significantly higher in patients who developed PTLD early after transplantation (P = 0.0040), while numbers of FoxP3⁺ TILs were not (P = 0.184). There was no difference in overall response rate regardless of the expression of PD-1 or FoxP3. FoxP3^high patients tended to have a shorter time to progression compared with FoxP3^low patients, especially in the case of FoxP3^high patients with diffuse large B-cell lymphoma-subtype PTLD (P = 0.011), while PD-1^high patients did not. These results suggest that T-cell exhaustion may be mainly associated with PTLD development, while immune suppression by Tregs may be dominant in enhanced progression of PTLD following disease occurrence.

POS0824 THE LONG-TERM CLINICAL COURSE OF MUSCULAR VASCULITIS DEPENDING ON THE ANTI-NEUTROPHIL CYTOPLASMIC ANTIBODY STATUS: A RETROSPECTIVE OBSERVATIONAL STUDY

Background:

Skeletal muscle is known as one of the organ involvements of primary systemic vasculitis.1,2 Muscle inflammation is detected by magnetic resonance imaging, and necrotizing vasculitis is proved by muscle biopsy.3 As with systemic vasculitis or single organ vasculitis, glucocorticoid (GC) and immunosuppressants are used in its treatment.4 There are not many reports about muscular vasculitis, and its long-term clinical course after initial treatment, including the rates of relapse and mortality, remains unclear.

Objectives:

To identify the predictors of relapse and mortality in patients with muscular vasculitis, especially focusing on the status of anti-neutrophil cytoplasmic antibody (ANCA).

Methods:

We retrospectively reviewed patients diagnosed with necrotizing vasculitis with muscle involvements in our hospital between 2004 and 2020. In all cases, muscular vasculitis was identified by muscle biopsy or magnetic resonance imaging. To focus on the clinical features of muscular vasculitis, we excluded patients with such severe organ involvements as cardiovascular, abdominal, cerebral, severe renal, and severe pulmonary involvements. We compared the 5-year cumulative incidence of relapse, the overall survival rate, and the dose of GC over 5 years between the ANCA-positive and ANCA-negative groups. A relapse was defined as any new or worsened state of disease activity requiring an escalation of GC dose. Gray’s method was used for assessing the cumulative incidence of relapse. The log-rank test was used for assessing overall survival. The Mann-Whitney U test was used for assessing the dose of GC. The possible factors for relapse in 5 years in a univariate analysis were selected for a multivariate analysis using the Cox proportional hazards model.

Results:

Forty-nine patients were enrolled. The median age of onset was 77 (69-82) years and 71.4% were women. There were 30 ANCA-positive patients (90.0% with anti-myeloperoxidase) and 19 ANCA-negative patients. The median age and the number of patients with renal involvements were higher in the ANCA-positive group than in the ANCA-negative group (73.0 ± 9.29 years vs. 79.5 ± 20.28 years, p=0.0062 and 7/30 [23.3%] vs. 0/19 [0.0%], p=0.034, respectively). The Birmingham Vasculitis Activity Score (ver. 3), the induction dose of GC, and the rate of immunosuppressants use were not significantly different between the two groups. During the observational period, 24 patients relapsed. The 5-year cumulative incidence of relapse was significantly higher in the ANCA-positive group than in the ANCA-negative group (p=0.026) (Figure 1). The Cox proportional hazards model revealed that the presence of ANCA was an independent risk factor for relapse (hazard ratio: 3.15; 95% confidence interval 1.06–9.38; p=0.040). During the observational period, 9 patients died (3 died from cancer, 1 from interstitial pneumonia, 1 from cerebral hemorrhage, 1 from infection, and 3 from unknown reasons). The ANCA-positive group exhibited a higher mortality rate than the ANCA-negative group without a statistical significance (p=0.12). The 5-year cumulative dose of GC was larger in the ANCA-positive group than in the ANCA-negative group without a statistical significance (14786 [11246–19138] mg vs. 10088 [7129–12634] mg, p=0.12).

Conclusion:

In muscular vasculitis, the presence of ANCA is an independent risk factor for long-term relapse. Stratified treatment depending on the ANCA status may reduce the relapse rate and the occurrence of side effects of GC in patients with muscular vasculitis.

References:

[1]Kitching AR et al. Nat Rev Dis Primers 2020; 6(1): 71.

[2]Hernández-Rodríguez J et al. J Autoimmun 2014; 48-49: 84-9.

[3]Ushiyama S et al. Rheumatol Int 2020; 40(10): 1667-74.

[4]Ganeshanandan LR et al. Semin Arthritis Rheum 2020; 50(3): 503-8.

Disclosure of Interests:

None declared

Group 2 innate lymphoid cells support hematopoietic recovery under stress conditions

The cell-cycle status of hematopoietic stem and progenitor cells (HSPCs) becomes activated following chemotherapy-induced stress, promoting bone marrow (BM) regeneration; however, the underlying molecular mechanism remains elusive. Here we show that BM-resident group 2 innate lymphoid cells (ILC2s) support the recovery of HSPCs from 5-fluorouracil (5-FU)-induced stress by secreting granulocyte-macrophage colony-stimulating factor (GM-CSF). Mechanistically, IL-33 released from chemo-sensitive B cell progenitors activates MyD88-mediated secretion of GM-CSF in ILC2, suggesting the existence of a B cell-ILC2 axis for maintaining hematopoietic homeostasis. GM-CSF knockout mice treated with 5-FU showed severe loss of myeloid lineage cells, causing lethality, which was rescued by transferring BM ILC2s from wild-type mice. Further, the adoptive transfer of ILC2s to 5-FU-treated mice accelerates hematopoietic recovery, while the reduction of ILC2s results in the opposite effect. Thus, ILC2s may function by "sensing" the damaged BM spaces and subsequently support hematopoietic recovery under stress conditions.

Autonomous TGFβ signaling induces phenotypic variation in human acute myeloid leukemia

Heterogeneity of leukemia stem cells (LSCs) is involved in their collective chemoresistance. To eradicate LSCs, it is necessary to understand the mechanisms underlying their heterogeneity. Here, we aimed to identify signals responsible for heterogeneity and variation of LSCs in human acute myeloid leukemia (AML). Monitoring expression levels of endothelial cell-selective adhesion molecule (ESAM), a hematopoietic stem cell-related marker, was useful to detect the plasticity of AML cells. While healthy human hematopoietic stem/progenitor cells robustly expressed ESAM, AML cells exhibited heterogeneous ESAM expression. Interestingly, ESAM^- and ESAM⁺ leukemia cells obtained from AML patients were mutually interconvertible in culture. KG1a and CMK, human AML clones, also represented the heterogeneity in terms of ESAM expression. Single cell culture with ESAM^- or ESAM⁺ AML clones recapitulated the phenotypic interconversion. The phenotypic alteration was regulated at the gene expression level, and RNA sequencing revealed activation of TGFβ signaling in these cells. AML cells secreted TGFβ1, which autonomously activated TGFβ pathway and induced their phenotypic variation. Surprisingly, TGFβ signaling blockade inhibited not only the variation but also the proliferation of AML cells. Therefore, autonomous activation of TGFβ signaling underlies the LSC heterogeneity, which may be a promising therapeutic target for AML.

[Processes regulating early lymphocyte differentiation]

Lymphocytes play pivotal roles in innate and adaptive immunity. The differentiation process by which hematopoietic stem cells (HSCs) acquire specific functions has been extensively investigated and is considered the paradigm of cell differentiation. It has been widely accepted that highly enriched HSCs are heterogeneous with respect to their lymphopoietic potential, and aged or stressed HSCs are skewed to the myeloid lineage. Several transcription factors and cytokine signaling pathways have been reported as essential to lymphocyte differentiation. However, the molecular mechanism that modulates the earliest stage remains unclear. Furthermore, the origin and characteristics of early T-lymphoid progenitors that migrate from the bone marrow to the thymus are still unknown in this field. Epigenetic mechanisms likely influence early lineage specification through the regulation of mitochondrial function and modification of nuclear chromatin structure. This review summarizes previous and recent findings on the processes involved in early lymphocyte differentiation. Thus, it provides a foundation for the understanding of the physiology of HSC aging and the pathology of intractable acute lymphocytic leukemia.

Whole-exome sequencing identified mutational profile of a case with T-cell chronic lymphocytic leukemia

We believe that our report and further case reports on T-cell chronic lymphocytic leukemia with genetic profile will contribute to the molecular classification of this rare but distinct disease.

Activation of invariant natural killer T cells ameliorates doxorubicin-induced cardiotoxicity in mice

Objective

Doxorubicin (DOX) is one of the most important anticancer agents and widely used to treat cancers but clinical utility of DOX is limited for its dose-dependent cardiotoxicity. The precise mechanism of DOX-induced cardiotoxicity is still not fully understood but it has been reported that cardiac inflammation is involved in the cardiotoxicity. Invariant natural killer T (iNKT) cells, a unique subset of T lymphocytes that recognize glycolipid antigens and secrete a large amount of both Th1 and Th2 cytokines on activation, have been shown to play crucial roles in the regulation of immune responses. However, it remains unclear whether iNKT cells are involved in DOX-induced cardiotoxicity.

Methods and results

Male C57BL/6J mice were administered DOX (20mg/kg body weight; n=28) or vehicle (Vehicle; n=6). DOX-administered mice were further divided into 2 groups; those treated with α-galactosylceramide (αGC, 0.1μg/g body weight; DOX-αGC; n=14), which specifically activates iNKT cells, or those treated with PBS (DOX-PBS; n=14) by intraperitoneal injections (twice; 4 days before and 3 days after DOX administration).An echocardiography conducted at 14 days after DOX/Vehicle administration revealed that LV fractional shortening was significantly reduced in the DOX-PBS compared to the Vehicle (49.3±0.8% vs. 59.2±1.7%, P&lt;0.05), and this decrease was completely attenuated in the DOX-αGC (57.7±1.3%, P&lt;0.05 vs. DOX-PBS)without affecting LV end-diastolic diameter. Flow cytometric analysis revealed that the ratio of iNKT cells to mononuclear cells infiltrated into the heart tissue was significantly increased in the DOX+αGC compared to the Vehicle and the DOX+PBS (1.00±0.09% vs. 0.54±0.09% and 0.71±0.07%, P&lt;0.05). Immuno-histochemistry revealed that the infiltration number of Iba1+macrophages in the heart tissue was significantly elevated in the DOX+αGC compared to the Vehicle and the DOX+PBS (55.4±3.2 cells/mm2 vs. 21.7±2.0 cells/mm2 and 37.5±5.9 cells/mm2, P&lt;0.05) The ratio of fibrosis area to the heart tissue was markedly higher in the DOX-PBS than in Vehicle (4.3±0.5% vs. 2.2±0.1%, P&lt;0.05), and this increase was completely attenuated in the DOX-αGC (2.8±0.1%, P&lt;0.05 vs.DOX-PBS).Real-time PCR analysis revealed that mRNA expressions of M2 macrophage markers (Arginase 1 and Retnla) and IL-4 were significantly enhanced in the DOX+αGC compared to the DOX+PBS (Arginase 1: 2.5±0.4 vs. 1.6±0.3 [relative ratio to the Vehicle], P=0.08; Retnla: 2.4±0.5 vs. 1.1±0.2 [relative ratio to the Vehicle], P&lt;0.05; IL-4: 1.0±0.3 vs. 8.94±2.8 [relative ratio to the DOX+PBS], P&lt;0.05), while those of M1 macrophage markers (iNOS and MCP-1) did not change among all groups.

Conclusions

Activation of iNKT cells ameliorates DOX-induced cardiotoxicity in mice via enhanced M2 macrophage polarization with the upregulation of IL-4 and reducing cardiac fibrosis. iNKT cell activation can be a novel preventive strategy against DOX-induced cardiotoxicity.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): Japan Agency for Medical Research and Development (18lm0203001j0002) and JSPS KAKENHI (18K15834).

Characterizing genetic variants for DAG and IP3 signalling pathways in severe cases of coronary spastic angina

Background

We previously reported that the activity of phospholipase C (PLC), a key molecule for intracellular calcium signaling, was enhanced in patients with coronary spastic angina (CSA). Furthermore, we found PLC-δ1 864 G to A mutation in about 10% of the male CSA patients. However, comprehensive understanding of genetic role in the pathogenesis of CSA remains to be elucidated.

Purpose

We tested the hypothesis that variants in the genes responsible for contraction signaling, especially a Ca2+-dependent mechanism, plays an important role in the pathogenesis of CSA.

Methods and results

Exome sequencing was performed to genotype comprehensively CSA cohort, enabling investigation of 258 gene network for diacylglycerol (DAG) and inositol trisphosphate (IP3) signallings, which are responsible for contraction signaling in the vascular smooth muscle cell (VSMC) by a Ca2+-dependent mechanism.

The study population included 30 Japanese patients with severe cases of CSA (18 men and 12 women with a mean age of 62.2±10.1 years). In 23 patients, ST segment elevation was recorded on the electrocardiogram during a spontaneous attack. In other 3 patients, ventricular fibrillation occurred following CSA attacks. The rests were diagnosed by ECG changes and elevated cardiac enzymes following CSA attacks. Genetic information from these CSA patients were compared with those from 914 healthy controls.

Frequencies of 17 common, functional polymorphisms of DAG and IP3 signallings were statistically similar to those of healthy controls. By high-quality (Call Quality ≥20, Read Depth ≥10), and predicted-deleterious (CADD score ≥20) filterings, the number of the candidate genes were narrowed from 234,445 to 17,738, and by selecting genes for DAG and IP3 signallings, further narrowed to 208 genes. Compared with 914 healthy controls, DAG and IP3 signalling genes revealed 26 variants in 15 genes in CSA cases, and by further filtering for rare (914 healthy control frequency &lt;1%), 21 variants in 12 genes were found. They shared variants in G protein subunit alpha q (GNAQ), phospholipase C beta 3 (PLCB3), inositol 1,4,5-trisphosphate receptor type 3 (ITPR3), glutamate ionotropic receptor NMDA type subunit 2D (GRIN2D) in ≥5 cases. By filtering for high-quality, predicted-deleterious, and rare, genetic variants related with DAG and IP3 signalling were more found in severe CSA patients compared with healthy controls (CSA 4.33/person vs healthy controls 2.60 /person).

Conclusions

These findings indicate genetic heterogeneity in CSA susceptibility and a likely polygenic basis, giving a cumulative effect on DAG and IP3 signalling pathways in a subset of individual CSA patients. Study of larger cohorts is warranted to define genetic risk factors for CSA.

Funding Acknowledgement

Type of funding source: None

Retrospective analysis of risk factors for liposomal amphotericin B-associated nephrotoxicity

In this study, we examined patients who received liposomal amphotericin B (L-AMB) to determine the risk factors associated with nephrotoxicity before and during L-AMB treatment. In this retrospective, single-center, observational cohort study, we examined 37 patients who received L-AMB treatment between April 2018 and December 2019. Nephrotoxicity was observed in 11 (29.7%) patients. We focused on the baseline albumin level and body surface area (BSA) before L-AMB treatment. Univariate analysis showed that the BSA and baseline albumin levels in patients with nephrotoxicity were significantly higher than those in patients without nephrotoxicity. Moreover, univariate analysis showed that albumin supplementation was significantly associated with the frequency of nephrotoxicity during L-AMB treatment. Multiple logistic regression analysis revealed the following independent risk factors for nephrotoxicity before or during L-AMB treatment: baseline albumin level (odds ratio [OR] = 16.000; 95% CI 1.480-172.000; P = 0.022) and albumin supplementation (OR = 40.800; 95% CI 2.210-753.000; P = 0.013). In conclusion, we identified baseline albumin level and albumin supplementation as novel risk factors for L-AMB-induced nephrotoxicity.

Golodirsen for Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is a life-shortening X-linked genetic disorder characterized by progressive wasting and weakening of muscles in boys. Loss-of-function mutations in the DMD gene, which codes for dystrophin, lead to this disease. The majority of mutations in this gene result in the exclusion of one or more exons from the transcript, eventually causing the remaining exons not to fit together correctly (i.e., out-of-frame mutations). Antisense oligonucleotides, e.g., phosphorodiamidate morpholino oligomers (PMOs), can induce therapeutic exon skipping during pre-mRNA processing to restore the reading frame of the primary transcript of DMD. As a result, truncated but partially functional dystrophin is produced, potentially slowing down the disease progression. Golodirsen is a provisionally approved PMO-based drug for approx. 8% of all DMD patients amenable to exon 53 skipping. This article summarizes golodirsen's pharmacology, efficacy and safety information. It also discusses some controversies that golodirsen met after the approval.

Chlorpromazine eliminates acute myeloid leukemia cells by perturbing subcellular localization of FLT3-ITD and KIT-D816V

Mutated receptor tyrosine kinases (MT-RTKs) such as internal tandem duplication of FMS-like tyrosine kinase 3 (FLT3 ITD) and a point mutation KIT D816V are driver mutations for acute myeloid leukemia (AML). Clathrin assembly lymphoid myeloid leukemia protein (CALM) regulates intracellular transport of RTKs, however, the precise role for MT-RTKs remains elusive. We here show that CALM knock down leads to severely impaired FLT3 ITD- or KIT D814V-dependent cell growth compared to marginal influence on wild-type FLT3- or KIT-mediated cell growth. An antipsychotic drug chlorpromazine (CPZ) suppresses the growth of primary AML samples, and human CD34+CD38- AML cells including AML initiating cells with MT-RTKs in vitro and in vivo. Mechanistically, CPZ reduces CALM protein at post transcriptional level and perturbs the intracellular localization of MT-RTKs, thereby blocking their signaling. Our study presents a therapeutic strategy for AML with MT-RTKs by altering the intracellular localization of MT-RTKs using CPZ.

THU0324 CYTOMEGALOVIRUS REACTIVATION AND HIGH INITIAL SERUM CREATININE ARE SIGNIFICANT PROGNOSTIC FACTORS FOR SUBSEQUENT SEVERE INFECTIONS IN PATIENTS WITH ANCA-ASSOCIATED VASCULITIS

Background:

There are several reports that cytomegalovirus (CMV) reactivation resulted in more co-infections affecting survival in rheumatic disease, and CMV reactivation can lead to infections in granulomatosis with polyangiitis patients by inducing CD4+CD28- T cell and depressing naïve T cell populations.1-4Despite this evidence, the prognostic value of CMV reactivation for severe infections in patients with connective tissue disease are still unknown.

Objectives:

The aim of this study was to examine prognostic factors for severe infection during the early phase of treatment, especially in CMV reactivation, in patients with antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV) who received initial high dose corticosteroid therapy (prednisolone > 0.8mg/kg/day).

Methods:

We analyzed the data of 88 consecutive hospitalized patients newly diagnosed with AAV at our hospital from January 2006 to March 2019 in this retrospective cohort study. There were 32 patients with CMV reactivation during remission induction therapy compared to 56 patients without CMV reactivation. CMV reactivation was defined by the detection of CMV pp65 antigen in blood samples, and CMV positive cells ≥ 5 per 3.0 × 105polymorphonuclear neutrophils (PMNs). The variable for severe infections within 180 days with apvalue < 0.1 in univariate analysis were selected for multivariate analysis using the Cox regression model. The positive predictive value (PPV) and positive likelihood ratio (PLR) of CMV reactivation for subsequent severe infections were also analyzed.

Results:

Patients with CMV reactivation, compared to those without, had a higher prevalence of MPO-ANCA, renal manifestation and renal impairment at diagnosis, received hemodialysis (HD), higher revised five factor score (FFS), older age, higher Birmingham Vasculitis Activity Score at diagnosis, and higher initial doses of corticosteroids (CS) at baseline. Revised FFS ≥ 2, renal involvement, high initial serum creatinine (≥ 1.5 mg/dl) at diagnosis, received HD, and CMV reactivation were associated with severe infections in the univariate analysis, although receiving cyclophosphamide or rituximab was not. Among these variables, CMV reactivation (Hazard ratio [HR] 3.50; 95% confidence interval [CI]: 1.22-10.10;p= 0.02) and high initial serum creatinine at diagnosis (HR 8.09; 95%CI: 2.00-32.73;p< 0.01) were independent risk factors for severe infections within 180 days. (Table 1) The PPV and PLR of CMV reactivation for subsequent severe infections were 35% and 1.91. When including higher initial serum creatinine, PPV and PLR for subsequent severe infections was 67% and 7.26.

Table 1.

Cox regression analysis for severe infections within 180 days.

Univariate analysisMultivariate analysisPotential prognostic factorsHR (95% CI)P valueHR (95% CI)P valueAge ≥ 651.36 (0.48-3.71)0.580Male1.23 (0.50-3.04)0.648Past history of lung disease0.39 (0.11-1.36)0.140Past history of diabetes mellitus0.64 (0.15-2.77)0.550Lung involvement1.76 (0.67-4.62)0.254Renal involvement†3.68 (1.22-11.10)0.021Serum Cr ≥ 1.5 at diagnosis9.50 (3.40-26.49)< 0.0018.09 (2.00-32.73)0.003Hemodialysis4.85 (1.73-13.54)0.0030.96 (0.31-2.97)0.950BVAS ≥ 201.50 (0.59-3.81)0.393Revised FFS ≥ 24.40 (1.28-15.13)0.0180.83 (0.16-4.27)0.818MPSL pulse therapy1.16 (0.47-2.86)0.746Received CYC or RTX1.54 (0.55-4.27)0.409CMV reactivation5.10 (1.93-13.48)0.0013.50 (1.22-10.06)0.020

† “Renal involvement” was excluded in the multivariate analysis to avoid multicollinearity.

Conclusion:

Our study shows that there should be focus on subsequent severe infections when CMV reactivation is detected during early phase of treatment, especially in renal-impaired patients with ANCA-associated vasculitis.

References:

[1]Gardiner BJ et al. Rheumatol Int. 2019;39:1229-40

[2]Hung M et al. J Microbiol Immunol Infect. 2019;52:114-21.

[3]Hanaoka R et al. Mod Rheumatol. 2012;22:438-45.

[4]Morgan MD et al. Arthritis Rheum. 2011;63:2127-37.

Disclosure of Interests:

Daisuke Waki Speakers bureau: Mitsubishi Tanabe Pharma, AbbVie Inc, eisai Co,. Ltd, ONO PHARMACEUTICAL CO., LTD,, Keisuke Nishimura Speakers bureau: Mitsubishi Tanabe Pharma Corporation. Pfizer Inc. Kyowa Kirin Co., Ltd. Chugai Pharmaceutical Co., Ltd. ONO PHARMACEUTICAL CO., LTD. Japan Blood Products Organization. Kissei Pharmaceutical Co., Ltd. Astellas Pharma Inc. AYUMI Pharmaceutical Corporation. Eisai Co., Ltd. DAIICHI SANKYO COMPANY. Norvartis AG. Bayer AG. Sanofi K.K.

, Tomohiro Yoshida: None declared, Keiichiro Kadoba: None declared, Nozomi Tanaka: None declared, Hiroyuki Murabe: None declared, Toshihiko Yokota: None declared

Soft sensors for a sensing-actuation system with high bladder voiding efficiency

Sensing-actuation systems can assist a bladder with lost sensation and weak muscle control. Here, we advance the relevant technology by integrating a soft and thin capacitive sensor with a shape memory alloy-based actuator to achieve a high-performance closed-loop configuration. In our design, sensors capable of continuous bladder volume detection and actuators with strong emptying force have been used. This integration has previously hindered performance due to large bladder volume changes. Our solution integrates sensing-actuation elements that are bladder compatible but do not interfere with one another, achieving real-time bladder management. The system attains a highly desirable voiding target of 71 to 100% of a rat's bladder with a volume sensitivity of 0.7 μF/liter. Our system represents an efficient voiding solution that avoids overfilling and represents a technological solution to bladder impairment treatment, serving as a model for similar soft sensor-actuator integration with other organs.

Ectonucleotidase CD39 is highly expressed on ATLL cells and is responsible for their immunosuppressive function

Adult T-cell leukemia/lymphoma (ATLL) patients have an extremely poor prognosis, partly due to their immunosuppressive state. The majority of ATLL patients have leukemic cells with phenotype similar to Tregs, prompting suggestions that ATLL cells themselves have immunosuppressive functions. In this study, we detected CD39 expression on ATLL cells, particularly frequent on aggressive subtypes. CD39 and CD73 convert extracellular adenosine triphosphate (ATP) into adenosine, a key player in Tregs’ immunosuppression. In vitro culture, both CD39⁺ ATLL cells and normal Tregs converted rapidly extracellular ATP to AMP, which was disturbed by CD39 inhibitors, and was negated in the CD39 knockout MJ cell line. The proliferation of cocultured CD4⁺/CD8⁺ normal T cells was suppressed by CD39⁺ MJ cells, but not by CD39 knockout MJ cells. Supplemented ATP was exhausted by an EG7-OVA T-cell line with stable CD39 induction, but not by mock. When these cell lines were subcutaneously transplanted into murine flanks, Poly(I:C) peritoneal administration reduced tumor size to 1/3 in mock-transplanted tumors, but not in CD39 induced tumors. Overall, we found that ATLL cells express CD39 at a high rate, and our results suggest that this helps ATLL cells escape antitumor immunity through the extracellular ATPDase-Adenosine cascade. These findings will guide future clinical strategies for ATLL treatment.

Viltolarsen for the treatment of Duchenne muscular dystrophy

Duchenne muscular dystrophy is the most common lethal X-linked genetic disorder, characterized by progressive muscle loss, with cardiac and respiratory complications. It is caused by a lack of dystrophin protein due to mutations in the DMD gene, which can disrupt the reading frame of the dystrophin primary transcript. Antisense oligonucleotides such as phosphorodiamidate morpholino oligomers (PMOs) can induce exon skipping during pre-mRNA splicing and restore the reading frame of the DMD primary transcript. The resulting dystrophin protein is internally deleted but partially functional. Viltolarsen, also known as NS-065/NCNP-01, is a PMO developed through comprehensive sequence optimization and is designed to skip exon 53 on the DMD primary transcript. Exclusion of exon 53 from the DMD primary transcript can treat 8-10% of DMD patients worldwide. This review paper summarizes the mechanism of action, pharmacokinetics and safety of viltolarsen from preclinical and clinical trials.

Variable SATB1 Levels Regulate Hematopoietic Stem Cell Heterogeneity with Distinct Lineage Fate

Hematopoietic stem cells (HSCs) comprise a heterogeneous population exhibiting self-renewal and differentiation capabilities; however, the mechanisms involved in maintaining this heterogeneity remain unclear. Here, we show that SATB1 is involved in regulating HSC heterogeneity. Results in conditional Satb1-knockout mice revealed that SATB1 was important for the self-renewal and lymphopoiesis of adult HSCs. Additionally, HSCs from Satb1/Tomato-knockin reporter mice were classified based on SATB1/Tomato intensity, with transplantation experiments revealing stronger differentiation toward the lymphocytic lineage along with high SATB1 levels, whereas SATB1^- HSCs followed the myeloid lineage in agreement with genome-wide transcription and cell culture studies. Importantly, SATB1^- and SATB1⁺ HSC populations were interconvertible upon transplantation, with SATB1⁺ HSCs showing higher reconstituting and lymphopoietic potentials in primary recipients relative to SATB1^- HSCs, whereas both HSCs exhibited equally efficient reconstituted lympho-hematopoiesis in secondary recipients. These results suggest that SATB1 levels regulate the maintenance of HSC multipotency, with variations contributing to HSC heterogeneity.

P856Incidence and Outcomes of irregular protrusion after stent implantation in patients with acute myocardial infarction: An in in vivo optical coherence tomography study

Background

Irregular protrusion, a protrusion of material with an irregular surface into the lumen of the vessel after stent implantation, can only be identified by optical coherence tomography (OCT). A previous study demonstrated that irregular protrusion after stent implantation was an independent predictor of 1-year major adverse cardiac events (MACE) in CAD patients. However, the true incidence and prognostic significance of irregular protrusion after stenting in patients with ST-segment elevation myocardial infarction (STEMI) have not previously examined.

Aims

The aims of this study were the following: 1) to evaluate the incidence of irregular protrusion detected by OCT in STEMI patients after stenting; and 2) to compare the long-term outcomes between patients with and without irregular protrusion.

Methods and results

A total of 210 STEMI patients who had post-procedure OCT imaging after coronary stenting within 12 hours after symptom onset were studied. We divided them into two groups: those with irregular protrusion (n=159) and those without (n=51) after stenting. There were no significant differences in baseline characteristics between the 2 groups except that peak CK-MB levels were higher in patients with irregular protrusion than those without (289 (137–563) vs. 260 (63–349) U/L, p<0.05). During mean follow-up period of 298 days, the overall incidence of MACE defined as cardiac death, target vessel-related myocardial infarction, and target lesion revascularization was 15.3%. Kaplan-Meier curve showed that the incidence of MACE did not differ between patients with and without irregular protrusion (14.7% vs. 17.7%, p=0.53 by Log-rank).

Conclusions

Irregular protrusion after stent implantation was detected in three-fourth of STEMI patients. Although patients with irregular protrusion had a greater myocardial damage, it did not influence clinical outcomes.

Acknowledgement/Funding

Donation course from Abbott Japan

Pre- and post-serial metagenomic analysis of gut microbiota as a prognostic factor in patients undergoing haematopoietic stem cell transplantation

The human gut harbours diverse microorganisms, and gut dysbiosis has recently attracted attention because of its possible involvement in various diseases. In particular, the lack of diversity in the gut microbiota has been associated with complications of haematopoietic stem cell transplantation (HSCT), such as infections, acute graft-versus-host disease and relapse of primary disease, which lead to a poor prognosis. However, few studies have serially examined the composition of the intestinal microbiota after HSCT. In this study, we demonstrated, using next-generation sequencing of the bacterial 16S ribosomal RNA gene, combined with uniFrac distance analysis, that the intestinal microbiota of patients undergoing allogeneic HSCT substantially differed from that of healthy controls and recipients of autologous transplants. Faecal samples were obtained daily throughout the clinical course, before and after transplantation. Notably, the proportions of Bifidobacterium and genera categorized as butyrate-producing bacteria were significantly lower in patients with allogeneic HSCT than in healthy controls. Furthermore, among allogeneic transplant recipients, a subgroup with a preserved microbiota composition showed a benign course, whereas patients with a skewed microbiota showed a high frequency of complications and mortality after transplantation. Thus, we conclude that the stability of intestinal microbiota is critically involved in outcomes of HSCT.

Safety of tapering tacrolimus dose in patients with well-controlled anti-acetylcholine receptor antibody-positive myasthenia gravis

BACKGROUND AND PURPOSE

Tapering immunosuppressants is desirable in patients with well-controlled myasthenia gravis (MG). However, the association between tapering of calcineurin inhibitor dosage and reduction-associated exacerbation is not known. The aim of this study was to clarify the frequency of reduction-associated exacerbation when tacrolimus is tapered in stable patients with anti-acetylcholine receptor antibody-positive MG, and to determine the factors that predict exacerbations.

METHODS

We retrospectively analyzed 115 patients in whom tacrolimus dosage was tapered. The reduction-associated exacerbation was defined as the appearance or worsening of one or more MG symptoms <3 months after the reduction.

RESULTS

Tacrolimus dosage was successfully tapered in 110 patients (96%) without any exacerbation. Five patients (4%) experienced an exacerbation, but symptoms were reversed in all patients when the tacrolimus dose was increased to the previous maintenance level. No patient developed an MG crisis. The age at onset was significantly earlier (30 vs. 56 years, P = 0.025) and the reduction in dosage was significantly larger (2.0 vs. 1.0 mg/day, P = 0.002) in patients with reduction-associated exacerbation than in those without exacerbation. The cut-off values determined in a receiver-operating characteristic curve analysis were 52 years (sensitivity, 57%; specificity, 100%) for the age at onset and 1.5 mg (sensitivity, 80%; specificity, 100%) for the dose reduction.

CONCLUSION

Tapering of tacrolimus was possible in most patients with well-controlled anti-acetylcholine receptor antibody-positive MG. Early age at onset and a large reduction from maintenance dosage were associated with exacerbation. Reductions ≤1.5 mg/day from the maintenance dosage should be considered for patients with late-onset disease.