Sequential cellular and humoral responses after repetitive COVID-19 vaccination in patients treated with anti-CD20 antibodies.

Patients treated with anti-CD20 antibodies for haematological disorders have insufficient immune responses to mRNA COVID-19 vaccines; however, relevant sequential data are lacking. We sequentially evaluated the humoral and cellular immune responses in 22 patients who had received anti-CD20 antibodies within 12 months before the first vaccination, before and after the third and fourth vaccinations. Humoral responses improved gradually, along with the resolution of B-cell depletion. A steady increase was noted in cellular responses, regardless of the B-cell status. Our findings suggest the potential benefit of repeated vaccinations in these patients until B-cell recovery is confirmed while enhancing cellular responses.

Japanese phase Ib study of the oral PI3K-δ and -γ inhibitor duvelisib in patients with relapsed or refractory chronic lymphocytic leukemia or small lymphocytic lymphoma.

This phase Ib, open-label, single-arm, multicenter study assessed the efficacy and safety of duvelisib, an oral dual inhibitor of phosphatidylinositol 3-kinase-δ and -γ, in Japanese patients with relapsed or refractory (r/r) chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). Duvelisib was administered orally at 25 mg twice a day (BID) until disease progression or unacceptable toxicity. The primary endpoint was objective response rate (ORR) and all responses were assessed by an independent review committee. Nine CLL patients and 1 SLL patient were enrolled. ORR was 80% (95% confidence interval 44.4, 97.5) for all 10 patients. All 6 patients previously treated with a Bruton's tyrosine kinase (BTK) or BCL2 inhibitor achieved a partial response. The most common adverse events were neutropenia (50%), diarrhea (40%), anemia, hypokalemia, constipation and rash (30% each). The most common grade ≥ 3 adverse events were neutropenia (50%), anemia (30%) and thrombocytopenia (20%). Duvelisib 25 mg BID showed favorable efficacy and a manageable safety profile in selected Japanese patients with r/r CLL/SLL, including patients previously treated with BTK or BCL2 inhibitors (Clinical trial registration: jRCTs2080224791).

Haploidentical Stem Cell Transplantation Using Post-Transplant Cyclophosphamide for T-Cell Prolymphocytic Leukemia after Alemtuzumab Induction Therapy: A Case Report.

T-cell prolymphocytic leukemia (T-PLL) is a rare aggressive disease with a poor prognosis. Allogeneic stem cell transplantation (allo-SCT) followed by alemtuzumab administration is the most promising treatment for T-PLL but is associated with a high risk of infections as alemtuzumab strongly suppresses cellular immunity, leading to high transplant-related mortality and unsatisfactory survival rates. In addition, for patients without human leukocyte antigen-matched donors, haploidentical stem cell transplantation (haplo-SCT) using post-transplant cyclophosphamide (PTCy) has been used because of the ready availability of donors and achievement of results comparable to those of transplantation with human leukocyte antigen-matched donors. However, there are no reports on the efficacy and safety, including infectious complications, of haplo-SCT with PTCy after alemtuzumab therapy in patients with. Here, we describe a 66-year-old Japanese male patient with T-PLL treated successfully with haplo-SCT after induction therapy of alemtuzumab for T-PLL. Approximately 3 months after the achievement of complete remission with alemtuzumab for T-PLL, haplo-SCT with reduced-intensity conditioning and PTCy was performed. Infectious complications were improved by early therapeutic interventions, and peripheral T cell counts gradually recovered. The patient was alive for more than 16 months after allo-SCT with no signs of relapse. Thus, haplo-SCT using PTCy should be considered as an option after alemtuzumab treatment for T-PLL.

Comparison of Haploidentical Stem Cell Transplantation with Post-Transplantation Cyclophosphamide versus Umbilical Cord Blood Transplantation in Adult Patients with Aplastic Anemia.

Aplastic anemia patients who are refractory to immunosuppressive therapy or with very low neutrophil counts require allogeneic hematopoietic stem cell transplantation (HSCT). Umbilical cord blood transplantation (UCBT) has been a treatment option when an HLA-matched donor is not available, and HSCT from a related haploidentical donor using post-transplantation cyclophosphamide (PTCy) for graft-versus-host disease (GVHD) prophylaxis (PTCy-haplo) recently became another important approach. We aimed to compare the outcomes of PTCy-haplo and UCBT in adult patients with aplastic anemia to identify more effective and safer approaches for alternative donor transplantation. Data in a nationwide registry were analyzed retrospectively to assess the outcomes of aplastic anemia patients age ≥16 years who underwent PTCy-haplo or UCBT as their first HSCT between 2016 and 2020. The primary endpoint was 1-year overall survival (OS) after HSCT. Secondary endpoints included 1-year failure-free survival (FFS), neutrophil and platelet engraftment, and acute and chronic GVHD. Eighty-three patients who underwent PTCy-haplo (n = 24) or UCBT (n = 59) were eligible. The 1-year OS rate was 78.5% (95% confidence interval [CI], 55.7% to 90.5%) in the PTCy-haplo group and 77.5% (95% CI, 64.5% to 86.3%; P = .895) in the UCBT group. The 1-year FFS rate was 78.7% (95% CI, 56.1% to 90.6%) in the PTCy-haplo group and 62.2% (95% CI, 48.5% to 73.3%; P = .212) in the UCBT group. Among patients age <40 years, the PTCy-haplo group had a significantly higher FFS rate (92.9% [95% CI, 59.1% to 99.0%]) vs 63.9% [95% CI, 43.2% to 78.7%]; P = .047). Neutrophil engraftment and platelet engraftment rates were significantly higher in the PTCy-haplo group compared with the UCBT group: 95.8% (95% CI, 73.9% to 99.4%) vs 78.0% (95% CI, 65.1% to 86.6%, P < .001) and 83.3% (95% CI, 61.5% to 93.4%) vs 72.9% (95% CI, 59.6% to 82.4%; P = .025). No significant difference was observed in the cumulative incidence of grade II-IV acute GVHD and chronic GVHD between the 2 groups. Aplastic anemia patients achieved significantly higher neutrophil and platelet engraftment rates with PTCy-haplo than with UCBT. OS and the incidences of acute and chronic GVHD were similar between the 2 groups. In patients age <40 years, the FFS rate was higher in the PTCy-haplo group. PTCy-haplo is promising for alternative donor transplantation in adult patients with aplastic anemia.

Efficacy of letermovir in HLA-haploidentical hematopoietic transplantation with posttransplant cyclophosphamide.

BACKGROUND: Cytomegalovirus reactivation (CMV-R) is a significant complication of allogeneic hematopoietic stem cell transplantation (allo-HCT), especially in human leukocyte antigen-haploidentical transplantation (haplo-HCT) with posttransplant cyclophosphamide (PTCy). Prophylactic letermovir (LTV) prevents CMV-R in patients undergoing allo-HCT. However, evidence regarding its use in haplo-HCTs with PTCy is limited. Therefore, we aimed to investigate the efficacy of prophylactic LTV in haplo-HCT with PTCy. METHODS: We retrospectively analyzed 52 patients seropositive for CMV who underwent haplo-HCT with PTCy at our institution between January 2015 and June 2021 and compared patients who received LTV prophylaxis (LTV group: n = 29) with those who did not receive prophylaxis for CMV (control group: n = 23). The primary endpoint was the 100-day cumulative CMV-R incidence. We used Gray's test and the Fine and Gray test to compare the two groups. RESULTS: The 100-day cumulative CMV-R incidence was lower in the LTV group than in the control group (17.2% vs 81.8%, p < 0.001). Multivariate analysis revealed that prophylactic LTV reduced the 100-day cumulative CMV-R incidence (hazard ratio: 0.17, 95% confidence interval: 0.06-0.44, p < 0.001). CONCLUSIONS: Prophylactic LTV effectively prevents CMV-R in patients undergoing haplo-HCT for PTCy.

Trajectories of the SARS-CoV-2 RNA load in patients with hematological malignancy.

OBJECTIVES: The higher risk of prolonged viral shedding in coronavirus disease (COVID-19) patients with hematological malignancies (HM) necessitates test-based de-isolation strategies. However, evidence to establish their appropriate isolation period is insufficient. This study investigated the factors affecting prolonged viral shedding and the requisite isolation period in these patients. METHODS: We retrospectively reviewed 14 COVID-19 patients with HM between January and April 2022, who were subjected to our test-based de-isolation strategy, followed by analysis of the viral load trajectory. The viral loads of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were evaluated using the cycle threshold (Ct ) of the reverse-transcription quantitative polymerase chain reaction. The trajectories were classified according to the time-interval from COVID-19 onset to the attainment of Ct values >30. RESULTS: The median interval between onset and attainment of a Ct value >30 was 22 days. Five patients with mild or moderate COVID-19 without intense treatment histories achieved Ct values >30 within 20 days. The other nine patients needed more than 20 days, including three patients who did not meet this criterion during the observation period. CONCLUSIONS: The SARS-CoV-2 viral load trajectories in patients with HM can be stratified by treatment history for the underlying HM and severity of COVID-19.

Epitope Mismatch at HLA-DRB1 Associates with Reduced Relapse Risk in Cord Blood Transplantation for Standard-Risk Hematologic Malignancy.

Cord blood transplantation (CBT) is an attractive therapeutic option for patients with hematologic malignancies. CBT tolerates HLA mismatches between donors and recipients, but the HLA mismatches that generate graft-versus-tumor (GVT) effects remain unknown. Given that HLA molecules contain epitopes comprising polymorphic amino acids that determine their immunogenicity, we investigated associations between epitope-level HLA mismatches and relapse following single-unit CBT. A total of 492 patients with hematologic malignancies who underwent single-unit, T cell-replete CBT were included in this multicenter retrospective study. HLA epitope mismatches (EMs) were quantified using HLA matchmaker software from donor and recipient HLA-A, -B, -C, and -DRB1 allele data. Patients were dichotomized by median EM value and divided into 2 groups: patients who underwent transplantation in complete/partial remission (standard stage: 62.4%) and others (advanced stage: 37.6%). The median number of EMs in the graft-versus-host direction (GVH-EM) was 3 (range, 0 to 16) at HLA class I and 1 (range, 0 to 7) at HLA-DRB1. Higher HLA class I GVH-EM was associated with increased nonrelapse mortality (NRM) in the advanced stage group (adjusted hazard ratio [HR], 2.12; P = .021), with no significant advantage for relapse in either stage. In contrast, higher HLA-DRB1 GVH-EM was associated with better disease-free survival in the standard stage group (adjusted HR, .63; P = .020), which was attributed to lower relapse risk (adjusted HR, .46; P = .014). These associations also were observed even within HLA-DRB1 allele-mismatched transplantations in the standard stage group, indicating that EM might have an impact on relapse risk independent of allele mismatch. High HLA-DRB1 GVH-EM did not increase NRM in either stage. High HLA-DRB1 GVH-EM may lead to potent GVT effects and a favorable prognosis following CBT, especially in patients who underwent transplantation at the standard stage. This approach may facilitate appropriate unit selection and improve the overall prognosis of patients with hematologic malignancies who undergo CBT.

Humoral response and safety of the BNT162b2 and mRNA-1273 COVID-19 vaccines in allogeneic hematopoietic stem cell transplant recipients: An observational study.

BACKGROUND: The effectiveness of mRNA COVID-19 vaccines and the optimal timing of vaccine administration in allogeneic hematopoietic stem cell transplantation (Allo-HSCT) recipients remains inadequately investigated. We examine the effectiveness and safety of mRNA COVID-19 vaccines in allo-HSCT recipients. METHOD: This prospective observational study included 44 allo-HSCT recipients and 38 healthy volunteers. The proportion of subjects acquiring anti-S1 IgG antibodies were considered as the primary endpoint. The occurrence of adverse events after vaccination and objective deterioration of chronic graft-versus-host disease (GVHD) were defined as secondary endpoints. In addition, we compared the geometric mean titers (GMT) of anti-S1 antibody titers in subgroups based on time interval between transplantation and vaccination. RESULTS: A humoral response to the vaccine was evident in 40 (91%) patients and all 38 healthy controls. The GMT of anti-S1 titers in patients and healthy controls were 277 (95% confidence interval [CI]: 120-643) BAU/mL and 532 (95% CI 400-708) BAU/mL, respectively. (p = 0.603). A short time interval between transplantation and vaccination (≤6 months) was associated with low anti-S1 IgG antibody titers. No serious adverse events and deterioration of chronic GVHD were observed. Only one case of new development of mild chronic GVHD was recorded. CONCLUSION: Messenger RNA COVID-19 vaccines induce humoral responses in allo-HSCT recipients and can be administered safely.

Control of Guest Inclusion and Chiral Recognition Ability of 6-O-Modified ß-Cyclodextrins in Organic Solvents by Aromatic Substituents at the 2-O Position.

The host-guest chemistry and applications of cyclodextrins in aqueous media is well established. However, a comprehensive study in organic solvents is lacking. Here, we report the design and synthesis of 6-O-tert-butyldimethylsilylated ß-cyclodextrin (TBDMS-ß-CD) bearing various aromatic substitutions at the 2-O position and their inclusion complex formation with aromatic guests in nonpolar organic solvents. Compared to the parent TBDMS-ß-CD, these derivatives exhibit at least a 10-fold increase in inclusion ability toward pyrene through cooperative guest binding with the CD cavity and the aromatic substituents at the 2-O position. The type of the aromatic substituent largely affects the chiral recognition ability of TBDMS-ß-CD toward 1-(1-naphthyl)ethylamine in cyclohexane. A TBDMS-ß-CD derivative with a p-tolyl substituent has a remarkable chiral selectivity for the (S)-1-(1-naphthyl)ethylamine over the corresponding (R)-isomer (KS /KR =4.1±0.5), whereas a TBDMS-ß-CD derivative with a 2-picolyl substituent shows the inverse chiral selectivity (KR /KS =8.7±0.6).

LSD1-mediated repression of GFI1 super-enhancer plays an essential role in erythroleukemia.

Super-enhancers (SEs) consist of enhancer clusters with abundant binding of transcription factors (TFs) and cofactors. LSD1 is a histone modifier that eliminates SE activity. However, whether SE suppression by LSD1 is associated with leukemogenesis remains unknown. In erythro-megakaryocyte lineage leukemia cells, activation of the SE of GFI1 (GFI1-SE) is related to induction of myeloid differentiation by LSD1 inhibitors NCD38 and NCD25 and to their antileukemia effect. Although functional TF-motifs were concentrated in an evolutionally conserved area, NCD38 barely induced additional TF recruitment. Instead, the transcription cofactors including LSD1, CoREST, HDAC1, and HDAC2 were evicted from GFI1-SE. Deletion of GFI1-SE impaired induction of myeloid differentiation by NCD38 and NCD25 in erythroleukemia cells. Gene set enrichment analysis revealed that the GFI1-SE deletion impaired NCD38-induced programs related to granulocyte differentiation and the CEBPA network, but restored NCD38-suppressed programs related to erythroid development, GATA1 targets, and acute myeloid leukemia (AML) clusters including FAB subtype M6 and AML with myelodysplastic syndrome-related chromosomal abnormalities. Ontologies of genes whose expression changes by NCD38 were canceled due to the GFI1-SE deletion showed enrichment in AML and neutropenia signatures. Collectively, our data suggest that sustainable repression of GFI1-SE by LSD1 is essential for sustenance of erythroleukemia cells.

Thymic Development of a Unique Bone Marrow-Resident Innate-like T Cell Subset with a Potent Innate Immune Function.

Mainstream CD8+ and CD4+ T cells of αß lineage are developed in the thymus through TCR-mediated selection in the context of MHC class I and MHC class II in association with self-peptides, respectively. In addition, minor αßT cells bearing invariant TCRs, NKT cells, and mucosal-associated invariant T cells are selected via MHC-like molecules, CD1d, and MR1 complexed with nonpeptide Ags, respectively, parts of which express neither CD4 nor CD8. In this study, we indicate that bone marrow (BM), but barely other lymphoid tissues, harbors CD4/CD8 double-negative αßT cells with an apparently diverse TCR repertoire at considerable proportions in healthy adult mice. The BM-resident double-negative αßT (BMDNT) cells are developed in the thymus in a Notch and IL-7-dependent manner but independently of known restriction elements, including MHC class I, MHC class II, CD1d, and MR1. These cells are sustained in BM throughout the adult stage with "homeostatic" proliferation via IL-1ß derived from normal myeloid cells dominating the BM environment. Although BMDNT cells secrete a unique set of cytokines, including IL-17, GM-CSF, IL-3, and CCL chemokines on TCR stimulation, these T cells also express a series of NK receptors and exhibit a potent NK-like cytotoxic activity. Furthermore, BMDNT cells show robustly accelerated proliferation and activation following systemic administration of TLR ligands likely through the enhanced production of IL-1ß by myeloid cells in situ. Our results suggest that αßT lineage cells that are developed in the thymus by default of TCR-mediated selection are maintained and differentiated to innate-like T cells in BM and may play a role in innate immunity in the hematopoietic environment.

Limited effects of long-term enzyme replacement therapy on the cardiac conduction system in Fabry disease.

The long-term effects of enzyme replacement therapy (ERT) on cardiac function and the conduction system in Fabry disease are not clearly understood. We report a case of a 48-year-old man with non-classical Fabry disease treated with ERT for 11 years. He was diagnosed with Fabry disease at age 27 years based on the presence of decreased alpha-galactosidase A activity in the peripheral leukocytes and of the causal alpha-galactosidase A mutation (Val339Gln). Subsequently, peritoneal dialysis was initiated for renal failure at age 35 years. ERT was initiated at age 39 years to halt the progression of cardiac dysfunction. Electrical conduction disturbances progressed gradually to complete atrioventricular block with atrial standstill during 9 years of ERT despite the lack of progression of ventricular hypertrophy. Although he underwent permanent pacemaker implantation to prevent sudden cardiac death, the atrioventricular junctional rhythm remained, thereby lowering the ventricular pacing rate. Based on this case, we recognize that the effects of ERT are limited for inhibiting the progression of Fabry disease and especially for inhibiting arrhythmia and conduction disturbances. Early diagnosis of Fabry disease and early initiation of ERT might be the key to further improvements in this disease and its associated conditions. .

Selective dissociation between LSD1 and GFI1B by a LSD1 inhibitor NCD38 induces the activation of ERG super-enhancer in erythroleukemia cells.

Lysine-specific demethylase 1 (LSD1) is a histone modifier for transcriptional repression involved in the regulation of hematopoiesis. We previously reported that a LSD1 inhibitor NCD38 induces transdifferentiation from erythroid lineage to granulomonocytic lineage and exerts anti-leukemia effect through de-repression of the specific super-enhancers of hematopoietic regulators including ERG in a human erythroleukemia cell line, HEL. However, the mechanistic basis for this specificity of NCD38 has remained unclear. Herein, we report major partners associated with LSD1 and clarify the mechanism in HEL cells. Proteome analysis identified 54 candidate proteins associated with LSD1, including several transcription factors such as GFI1B and RUNX1 as well as BRAF-histone deacetylase complex (BHC) components such as CoREST, HDAC1, and HDAC2. NCD38 selectively disrupted the interaction of LSD1 with GFI1B but not with RUNX1, CoREST, HDAC1 and HDAC2. Erg was downregulated in murine erythroid progenitors with prominent upregulation of Gfi1b. NCD38 induced ERG and attenuated an erythroid marker CD235a in HEL while this attenuation was mimicked by the lentiviral overexpression of ERG. The ERG super-enhancer contained the conserved binding motif of GFI1B and was actually occupied by GFI1B. NCD38 dissociated LSD1 and CoREST but not GFI1B from the ERG super-enhancer. Collectively, the selective separation of LSD1 from GFI1B by NCD38 restores the ERG super-enhancer activation and consequently upregulates ERG expression, inducing the transdifferentiation linked to the anti-leukemia effect.

Sipa1 deficiency unleashes a host-immune mechanism eradicating chronic myelogenous leukemia-initiating cells.

Chronic myelogenous leukemia (CML) caused by hematopoietic stem cells expressing the Bcr-Abl fusion gene may be controlled by Bcr-Abl tyrosine kinase inhibitors (TKIs). However, CML-initiating cells are resistant to TKIs and may persist as minimal residual disease. We demonstrate that mice deficient in Sipa1, which encodes Rap1 GTPase-activating protein, rarely develop CML upon transfer of primary hematopoietic progenitor cells (HPCs) expressing Bcr-Abl, which cause lethal CML disease in wild-type mice. Resistance requires both T cells and nonhematopoietic cells. Sipa1-/- mesenchymal stroma cells (MSCs) show enhanced activation and directed migration to Bcr-Abl+ cells in tumor tissue and preferentially produce Cxcl9, which in turn recruits Sipa1-/- memory T cells that have markedly augmented chemotactic activity. Thus, Sipa1 deficiency uncovers a host immune mechanism potentially capable of eradicating Bcr-Abl+ HPCs via coordinated interplay between MSCs and immune T cells, which may provide a clue for radical control of human CML.