[New era of GVHD prophylaxis using posttransplant cyclophosphamide].

Use of posttransplant cyclophosphamide (PTCy) for the prophylaxis of graft-versus-host disease (GVHD) has revolutionized the field of HLA-haploidentical stem cell transplantation, which was previously considered high-risk and only feasible in specialized centers. The rapid adoption of PTCy is attributed not only to its superior efficacy in suppressing GVHD but also to its affordability and the lack of need for specialized techniques or equipment to administer it. Recently, PTCy has gained attention for its potential effectiveness in GVHD prophylaxis beyond HLA-haploidentical stem cell transplantation. In a phase III trial (BMT CTN 1703 trial) in patients undergoing allogeneic HLA-matched stem cell transplantation with reduced-intensity conditioning, GVHD-free, relapse-free survival at 1 year was significantly better among those who received PTCy-tacrolimus-mycophenolate mofetil than among those who received tacrolimus-methotrexate. In Japan, a phase II clinical trial that investigated PTCy for GVHD prophylaxis following HLA-matched or 1-2 allele mismatched peripheral blood stem cell transplantation confirmed the efficacy and safety of this approach. Effective suppression of GVHD using PTCy is expected to enhance the safety of allogeneic transplantation, potentially improving transplant outcomes and offering hope for better patient care in the field of transplantation.

Current status of conditioning regimens in haploidentical hematopoietic cell transplantation.

The development of effective prophylaxis strategies against graft-versus-host disease (GVHD) has contributed to the widespread use of haploidentical related hematopoietic cell transplantation (Haplo-HCT). Currently, GVHD prophylaxis containing posttransplant cyclophosphamide (PTCY) is considered the standard of care in Haplo-HCT, and recent studies have shown comparable results for PTCY-based Haplo-HCT and HCT from other donor sources. The conditioning regimen plays an important role in eradicating tumor cells to prevent disease relapse and suppressing the recipient's immune system to facilitate engraftment. PTCY-based Haplo-HCT was initially developed using a nonmyeloablative conditioning regimen consisting of fludarabine, cyclophosphamide and low-dose total body irradiation, but high relapse rates reinforced the need to intensify the conditioning regimen. In this respect, various myeloablative and reduced-intensity conditioning regimens have been investigated. However, the optimal conditioning regimens for PTCY-based Haplo-HCT have not yet been established, and this issue needs to be addressed based on data from patients undergoing the procedure. In this article, we review the existing literature on conditioning regimens for PTCY-based Haplo-HCT and discuss future perspectives.

Long-term follow-up of efficacy and safety in elderly patients with chronic myeloid leukemia treated with intermittent low dose dasatinib therapy.

Intermittent low dose dasatinib therapy brought about a beneficial effect in elderly patients with chronic-phase chronic myeloid leukemia (CML-CP) without inducing severe adverse events (AEs). An 85-year-old male patient, who received twice-weekly, thrice-weekly, or four-times-weekly administration of 20 mg/day dasatinib after once-weekly administration, achieved a major molecular response two years after the start of dasatinib treatment and later sometimes achieved a deep molecular response, maintaining the efficacy for 11 years. The mean daily dose ranged from 5.7 mg to 11.4 mg. Furthermore, a 79-year-old male patient, who received thrice-weekly or every other day administration of 20 mg/day dasatinib after once-weekly administration, achieved a deep molecular response at four and half years after the start of dasatinib treatment. The mean daily dose is 8.6 mg. Intermittent low dose dasatinib therapy appears to be feasible in elderly patients with CML-CP. The goal of treatment in elderly patients with CML-CP appears to be different from that in younger patients, since they often suffer from serious AEs in the case of standard dose tyrosine kinase inhibitor therapy, followed by the dose reduction or cessation of treatment.

Development of progressive multifocal leukoencephalopathy after cord blood transplantation in a patient with refractory angioimmunoblastic T-cell lymphoma.

A patient undergoing cord blood transplantation for refractory angioimmunoblastic T-cell lymphoma was subsequently managed with long-term immunosuppressants for chronic graft-versus-host disease (GVHD). On day 591 post-transplant, she exhibited disorientation and cognitive dysfunction. Magnetic resonance imaging (MRI) of the brain revealed two hyperintense foci in the white matter, suggestive of progressive multifocal leukoencephalopathy (PML). However, we did not include PML in the differential diagnosis at that time. Unfortunately, she developed progressive cognitive impairment, and repeated brain MRIs showed a progression in lesion size. She was still taking immunosuppressants to control her GVHD, therefore we suspected PML. The diagnosis of PML was confirmed through the detection of a John Cunningham (JC) virus in the cerebrospinal fluid on day 640 post-transplant. This report highlights the critical need to consider PML in differential diagnoses for post-allogeneic transplant patients, especially those who exhibit progressive neurological symptoms while on prolonged immunosuppressant therapy.

Donor Lymphocyte Infusion for Relapsed Acute Leukemia or Myelodysplastic Syndrome after Hematopoietic Stem Cell Transplantation: A Single-Institute Retrospective Analysis.

Objective The prognosis of the patients who relapsed after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is poor, and therapeutic options are limited. In the present study, we investigated the efficacy and factors associated with the survival in patients with acute leukemia or myelodysplastic syndrome (MDS) who relapsed following allo-HSCT and were treated with donor lymphocyte infusion (DLI) in real-world practice. Patients Twenty-nine patients with acute myeloid leukemia21, acute lymphoid leukemia4 or MDS4 were enrolled. Eleven patients were diagnosed with hematological relapse, and 18 were diagnosed with molecular or cytogenetic relapse. Results The median injection number and median total number of infused CD3+ T cells were 2 and 5.0×107/kg, respectively. The cumulative incidence of acute graft-versus-host disease (aGVHD) of grade ≥II at 4 months after the initiation of DLI was 31.0%. Extensive chronic graft-versus-host disease (cGVHD) occurred in 3 (10.3%) patients. The overall response rate was 51.7%, including 3 cases of hematological complete remission (CR) and 12 cases of molecular/cytogenetic CR. Cumulative relapse rates at 24 and 60 months following DLI in patients who achieved CR were 21.4% and 30.0%, respectively. The overall survival rates at 1, 2 and 3 years after DLI were 41.4%, 37.9% and 30.3%, respectively. Molecular/cytogenetic relapse, a longer interval from HSCT to relapse, and concomitant chemotherapy with 5-azacytidine (Aza) were significantly associated with a relatively long survival following DLI. Conclusion These results indicated that DLI was beneficial for patients with acute leukemia or MDS who relapsed after allo-HSCT and suggested that DLI in combination with Aza for molecular or cytogenetic relapse might result in favorable outcomes.

Low- versus standard-dose post-transplant cyclophosphamide as GVHD prophylaxis for haploidentical transplantation.

Haploidentical haematopoietic cell transplantation (haplo-HCT) using post-transplant cyclophosphamide (PTCY) as graft-versus-host disease (GVHD) prophylaxis is the standard of care for various haematological malignancies. The original PTCY dose after haplo-HCT was 100 mg/kg, but no dose-finding studies have been performed to identify the optimal dose. We performed a retrospective analysis to compare standard-dose PTCY (100 mg/kg) with reduced-dose PTCY (80 mg/kg): 969 in the standard-dose group and 538 in the reduced-dose group. As there was a significant difference between the two groups regarding patient and transplant characteristics, we performed propensity score (PS) matching. After PS matching, 425 patients in each group were included. The probabilities of 2-year OS were 55.9% in the standard-dose group and 47.0% in the reduced-dose group (p = 0.36). The cumulative incidences of 2-year non-relapse mortality were 21.3% in the standard-dose group and 20.5% in the reduced-dose group (p = 0.55). There was no significant difference in the incidence of acute (grade II-IV 29.2% [95% CI, 24.9-33.6] vs. 25.3% [95% CI, 21.3-29.6]; grade III-IV 7.3% [95% CI, 5.1-10.0] vs. 6.6% [95% CI, 4.5-9.3]) or chronic GVHD. In conclusion, reduced- and standard-dose PTCY were comparable in terms of major clinical outcomes.

Efficacy and Safety of Single-dose Pegfilgrastim for CD34 + Cell Mobilization in Healthy Volunteers: A Phase 2 Study.

BACKGROUND: Pegfilgrastim, a long-acting form of granulocyte-colony stimulating factor, with a convenient single-injection dosage, is being investigated for peripheral blood stem cell (PBSC) mobilization in healthy volunteers. However, data on the adequate dose of pegfilgrastim for PBSC mobilization are limited. This phase 2, single-arm study evaluated the efficacy and safety of pegfilgrastim for PBSC mobilization in healthy volunteers. METHODS: The study comprised 2 phases: pilot (steps 1-3, dose escalation, a single subcutaneous dose of 3.6, 7.2, and 10.8 mg pegfilgrastim, respectively) and evaluation (step 4, efficacy and safety assessments). The primary endpoint was the proportion of subjects who achieved mobilization of ≥20 × 10 6 /L cluster of differentiation 34 positive (CD34 + ) cells. RESULTS: Thirty-five subjects (6 each in steps 1 and 2 and 23 in step 4) were included. In the pilot phase, step 3 with a 10.8 mg dose was not conducted due to favorable outcomes in step 2 (desired CD34 + cell count), at 7.2 mg pegfilgrastim, which was identified as the optimal dose for the evaluation phase. In the evaluation phase, successful CD34 + mobilization was achieved in all 23 subjects. The mean peripheral blood CD34 + cells count peaked on day 5. Back pain, thrombocytopenia, transient elevations of alkaline phosphatase, and lactate dehydrogenase were the most common adverse events. All adverse events were mild, and none led to study discontinuation. CONCLUSIONS: A single-dose pegfilgrastim successfully mobilized an optimal number of CD34 + cells and was well tolerated. Pegfilgrastim could be an alternative option for PBSC mobilization in healthy volunteers. The trial was registered at www.clinicaltrials.gov (NCT03993639).

Posttransplant cyclophosphamide in unrelated and related peripheral blood stem cell transplantation from HLA-matched and 1 allele mismatched donor.

Posttransplant cyclophosphamide (PTCy)-based graft-versus-host disease (GVHD) prophylaxis has been increasingly used in HLA-haploidentical transplantation and recent studies also demonstrated the efficacy of PTCy in HLA-matched transplantation. We conducted a prospective multicenter phase II study to evaluate the safety and efficacy of PTCy with tacrolimus and mycophenolate mofetil in 43 patients who underwent HLA-matched (n = 21), 1 allele mismatched (n = 20), or 2 allele mismatched (n = 2) peripheral blood stem cell transplantation (PBSCT) following myeloablative (n = 28) or reduced-intensity (n = 15) conditioning. The incidence of grade III-IV acute GVHD at 100 days was 2.3%. The incidences of grades II-IV acute GVHD, all grade chronic GVHD, and moderate to severe chronic GVHD at 2 years were 16.3%, 14.0%, and 4.7%, respectively. Overall survival, disease-free survival, and non-relapse mortality at 2 years were 75.3%, 74.0%, and 7.0%, respectively. GVHD-free, relapse-free survival at 2 years was 67.0%. The rate of off-immunosuppressants in patients who survived without relapse at 2 years was 85.4%. These results indicate that PTCy is a valid option for GVHD prophylaxis in both HLA-matched and HLA 1-2 allele mismatched PBSCT.

HokUS-10 scoring system predicts the treatment outcome for sinusoidal obstruction syndrome after allogeneic hematopoietic stem cell transplantation.

Hepatic sinusoidal obstruction syndrome (SOS) is a severe and life-threatening complication after allogeneic hematopoietic stem cell transplantation (HSCT). We conducted a multi-center retrospective study to evaluate the utility of our ultrasonographic scoring system for the diagnosis of SOS (HokUS-10) in predicting SOS-related mortality (SOS-RM). We analyzed a total of 42 patients who developed SOS after HSCT. The cumulative incidences of SOS-RM, non-relapse mortality (NRM), and overall survival at day 180 after the diagnosis of SOS were 26.4%, 28.8% and 54.5%, respectively. The area under the receiver operating characteristic curve analysis showed that the optimal cut-off value of HokUS-10 total score to predict SOS-RM was 8 points after the treatment of SOS. In the individual HokUS-10 score, ascites and portal vein flow-related scores (PV mean velocity and PV flow direction) after the treatment of SOS were shown as significant risk factors for SOS-RM. Our study suggested that US findings after the treatment can predict the treatment outcomes for SOS.

Impact of a third dose of anti-SARS-CoV-2 vaccine in hematopoietic cell transplant recipients: A Japanese multicenter observational study.

This prospective observational study aimed to assess the serological response and safety after the third booster shot of SARS-CoV-2 mRNA vaccines in 292 hematopoietic cell transplant (HCT) recipients. In our patients, mild systemic reactions were present in 10-40% and GVHD aggravation in 1.1%. Overall, clinically relevant response (>250 U/mL) was observed in 93.1% of allogeneic (allo)-HCT recipients and 70.6% of autologous (auto)-HCT recipients, respectively. Of note, detectable antibody response with any titer following the first two doses was a powerful predictor for adequate response after booster shot in both cohorts. For such patients, 98.8% of allo- and 92.3% of auto-HCT recipients obtained clinically relevant response after dose 3. In addition, continued systemic steroid and/or calcineurin inhibitors at the booster shot significantly correlated with serological response. These findings highlighted that booster vaccination efficiently improved serological response without safety concerns and thus recommended for the majority of HCT recipients.

A case of Hodgkin lymphoma-type Richter syndrome presenting as small-intestinal perforation.

Hodgkin lymphoma type of Richter syndrome (HL-type RS) is a rare disease that arises in patients with chronic lymphocytic leukemia (CLL). HL-type RS lesions can manifest in various sites and are often accompanied by related symptoms. This is the first case report to describe diagnosis of HL-type RS after emergency surgery for gastrointestinal perforation caused by the development of a HL-type RS lesion. A 47-year-old man diagnosed with CLL three years prior began treatment with ibrutinib due to worsening anemia and splenomegaly two months prior to the emergency department presentation. Although splenomegaly improved, lymphocytopenia, anemia, and a newly arising mesenteric lymphadenopathy continued to worsen. He presented to the emergency department with abdominal pain, and subsequent surgery revealed small intestinal perforation and mesenteric lymphadenopathy with HL-type RS confirmed by histopathological examination of the resected small intestine. He subsequently received brentuximab vedotin, doxorubicin, vinblastine, and dacarbazine (A + AVD), which effectively managed the HL-type RS. If CLL clinical presentation deviates from the typical course, an early tissue biopsy should be considered to evaluate for HL-type RS. Given the adoption of the A + AVD regimen as the standard treatment for Hodgkin lymphoma, further research is needed to evaluate its efficacy in HL-type RS.

Assessment of hepatic veno-occlusive disease/sinusoidal obstruction syndrome using different scanning approaches for the ultrasonographic evaluation of portal vein blood flow and hepatic artery resistive index in hematopoietic stem cell transplant recipients.

PURPOSE: Sinusoidal obstruction syndrome (SOS) is a fatal complication of hematopoietic stem cell transplantation (HSCT). Previously, we established a scoring system (Hokkaido ultrasound-based scoring system-10; HokUS-10) comprising 10 ultrasound parameters for SOS diagnosis. In HokUS-10, the portal vein time-averaged flow velocity (PV TAV) and hepatic artery resistive index (HA RI) are measured using subcostal scanning. However, measurement errors and delineation difficulties occur. Therefore, we aimed to prospectively evaluate PV TAV and HA RI measurements obtained via intercostal scanning as an alternative method to subcostal scanning and determine their cutoff values. METHODS: HokUS-10 was administered before and after HSCT. PV TAV and HA RI were measured on subcostal and right intercostal scans. RESULTS: We performed 366 scans on 74 patients. The median value (range) of PV TAV in the main and right portal veins was 15.0 cm/s (2.2-49.6 cm/s) and 10.5 cm/s (1.6-22.0 cm/s), respectively. A low correlation was observed between the two values (r = 0.39, p < 0.01). The highest diagnostic value of the right portal vein was less than 8.0 cm/s. The median value (range) of HA RI in the proper and right hepatic arteries was 0.72 (0.52-1.00) and 0.70 (0.51-1.00), respectively. A strong correlation was observed between the two values (r = 0.65, p < 0.01). The highest diagnostic value of the right HA RI was 0.72 or higher. CONCLUSION: Quantitative measurement of PV TAV and HA RI using intercostal scanning can be appropriately performed as an alternative method to using subcostal scanning.

[HLA-haploidentical stem cell transplantation].

HLA-haploidentical stem cell transplantations using posttransplant cyclophosphamide (PTCy-haplo) rapidly increased worldwide. In Japan, the number of HLA-haploidentical stem cell transplantation cases exceeded related HLA-matched transplants in 2020. Recent retrospective studies using Japanese registry data have reported comparable transplantation outcomes between PTCy-haplo and HLA-matched unrelated and cord blood transplantations. PTCy-haplo was initially developed in the bone marrow transplantation setting after non-myeloablative conditioning but has recently become widely used in peripheral blood stem cell transplantation and myeloablative conditioning. Peripheral blood stem cell transplantation increases the occurrence of graft-versus-host disease but may have more improved transplant outcomes compared with bone marrow transplantation. Other factors, such as the number of infused cluster of differentiation 34-positive cells, donor age, HLA class II mismatch, HLA-B leader, and reduced PTCy dosage, may also contribute to the outcome of PTCy-haplo transplantations. Furthermore, PTCy has been reportedly effective in related/unrelated HLA-matched transplantation and HLA-mismatched unrelated transplantations. A prospective phase II trial using PTCy in patients who underwent HLA-matched and 1-2 allele-mismatched transplantation is ongoing in Japan. Patient enrollment has already been completed, and the results will be revealed soon. Using PTCy to sufficiently reduce the occurrence of graft-versus-host disease will make performing allogeneic transplants with a higher safety level possible.

Clinical implications of NUP98::NSD1 fusion at diagnosis in adult FLT3-ITD positive AML.

OBJECTIVES: The cryptic fusion oncogene NUP98::NSD1 is known to be associated with FLT3-ITD mutation in acute myeloid leukemia (AML), and an independent poor prognostic factor in pediatric AML. However, there are little data regarding the clinical significance of NUP98::NSD1 in adult cohort. METHODS: We conducted a multicenter retrospective study to investigate the prevalence, clinical characteristics, and prognostic impact of NUP98::NSD1 in adult FLT3-ITD-positive AML patients. RESULTS: In a total of 97 FLT3-ITD-positive AML patients, six cases (6.2%) were found to harbor the NUP98::NSD1 fusion transcript. NUP98::NSD1 positive cases had significantly higher platelet counts and a higher frequency of FAB-M4 morphology than NUP98::NSD1 negative cases. NUP98::NSD1 was found to be mutually exclusive with NPM1 mutation, and was accompanied by the WT1 mutation in three of the six cases. The presence of NUP98::NSD1 fusion at the time of diagnosis predicted poor response to cytarabine-anthracycline-based intensive induction chemotherapy (induction failure rate: 83% vs. 36%, p = .038). Five of the six cases with NUP98::NSD1 underwent allogeneic hematopoietic stem cell transplantation (HSCT). Two of the five cases have successfully maintained remission, with one of them being rescued through a second HSCT. CONCLUSIONS: Detecting NUP98::NSD1 in adult FLT3-ITD-positive AML is crucial to recognizing chemotherapy-resistant group.

Clinical characteristics and risk factors of pneumococcal diseases in recipients of allogeneic hematopoietic stem cell transplants in the late phase: A retrospective registry study.

Pneumococcal diseases are one of the most important infectious complications in the late period following allogeneic hematopoietic stem cell transplantation (allo-HSCT). The importance of long-term follow-up care is increasing, as the number of long-term survivors following allo-HSCT increases, but there has been a dearth of research specifically focusing on pneumococcal diseases during the late post-transplant period (day >100). Using a transplant registry database between January 1, 2001 and December 31, 2011, we aimed to assess the clinical spectrum and risk factors for pneumococcal diseases in the late post-transplant period. Among the 22,514 recipients who received allo-HSCT over an 11-year period and could be followed for ≥100 days, 43 patients developed 49 episodes of pneumococcal diseases. Six of the 43 patients died from pneumococcal diseases, and four of these six patients died within a week, despite having undergone allo-HSCT two or more years ago. A history of chronic graft-versus-host disease (odds ratio [OR], 2.31; 95% confidence interval [CI], 1.15-4.66; P = 0.02), viral infection (OR, 3.38; 95% CI, 1.70-6.72; P < 0.01), and complete remission of the underlying disease at the time of transplantation (OR, 2.38; 95%CI, 1.10-5.14; P = 0.03) were identified as risk factors. Given the risk of sudden death and the high mortality rate, attention should be paid to pneumococcal diseases in providing long-term follow-up care, even several years after allo-HSCT.

Effect of Graft-versus-Host Disease on Post-Transplantation Outcomes following Single Cord Blood Transplantation Compared with Haploidentical Transplantation with Post-Transplantation Cyclophosphamide for Adult Acute Myeloid Leukemia.

The possibility that HLA mismatches could reduce relapse after alternative HLA-mismatched allogeneic hematopoietic cell transplantation (HCT) is an attractive concept for treating acute myeloid leukemia (AML). However, it remains unclear whether the prognostic effect of graft-versus-host disease (GVHD) on survival differs between recipients of single-unit cord blood transplantation (CBT) and recipients of haploidentical HCT using post-transplantation cyclophosphamide (PTCy-haplo-HCT) for AML. The objective of this retrospective study was to compare the effect of acute GVHD and chronic GVHD on post-transplantation outcomes between recipients of CBT and recipients of PTCy-haplo-HCT. We retrospectively evaluated the effect of acute and chronic GVHD on post-transplantation outcomes following CBT and PTCy-haplo-HCT in adults with AML (n = 1981) between 2014 and 2020 using a Japanese registry database. In univariate analysis, the probability of overall survival was significantly greater in patients who developed grade I-II acute GVHD (P < .001, log-rank test) and limited chronic GVHD (P < .001, log-rank test) among CBT recipients, but these effects were not significant among PTCy-haplo-HCT recipients. In multivariate analysis, in which the development of GVHD was treated as a time-dependent covariate, the effect of grade I-II acute GVHD on reducing overall mortality differed significantly between CBT and PTCy-haplo-HCT (adjusted hazard ratio [HR] for CBT, .73, 95% confidence interval [CI], .60 to .87; adjusted HR for PTCy-haplo-HCT, 1.07; 95% CI, .70 to 1.64; P for interaction = .038). Our data demonstrate that grade I-II acute GVHD was associated with a significant improvement in overall mortality in adults with AML receiving CBT but not in recipients of PTCy-haplo-HCT.

IgG4-IgE complex interferes with measurement of IgE concentration.

BACKGROUND AND AIMS: Patients with immunoglobulin G4 (IgG4)-related disease (IgG4-RD) have elevated immunoglobulin E (IgE) concentration compared to that in healthy individuals, which suggests the occurrence of IgE-mediated allergic reactions. We have previously shown that IgG4 and IgE form a complex in some patients with IgG4-RD. However, it is currently unknown whether and how the presence of the IgG4-IgE complex affects IgE concentration measurements by different assays. MATERIALS AND METHODS: Twenty patients with confirmed presence or absence of IgG4-IgE complex were evaluated. We compared IgE concentrations measured by ST AIA-PACK IgE II (AIA-PACK), Elecsys IgE II Immunoassay (Elecsys), and Iatroace IgE (Iatroace) and evaluated to what extent the IgG4-IgE complex interfered with these measurements. RESULTS: In patients with the IgG4-IgE complex, IgE concentrations measured using Iatroace were significantly lower than those measured using Elecsys and tended to be lower than those measured using AIA-PACK. IgE concentrations determined by Iatroace were significantly different in patients with and without the IgG4-IgE complex, whereas no significant differences between these groups were detected when IgE concentrations were measured by AIA-PACK or Elecsys. CONCLUSION: The formation of the IgG4-IgE complex underestimates measured IgE concentrations depending on the method used. Therefore, caution should be exercised when selecting a specific IgE assay for patients with IgG4-RD.