Pretransplantation predictors of survival in nonremission acute myeloid leukemia treated with haploidentical transplantation using steroid-based GVHD prophylaxis.

Haploidentical hematopoietic cell transplantation (HCT) using glucocorticoids for acute graft-versus-host disease prophylaxis (GC-haplo) may become a curative treatment option for nonremission acute myeloid leukemia (AML). This retrospective study aimed to identify pre-HCT predictors of survival in a cohort of 97 nonremission AML treated with GC-haplo in Hyogo Medical University Hospital between 2010 and 2020. Relapse and primary induction failure included in 70 (72%) and 27 (28%) patients, respectively. Sixty-one patients (63%) had undergone previous HCT. Multivariate analysis revealed that ≤ 6 months' duration between first complete remission (CR1) and first relapse (Rel1) (CR1-Rel1 interval) (hazard ratio 2.11, 95% confidence interval [CI] 1.15-3.89, P = 0.016) and serum albumin before starting the conditioning treatment of ≤ 3.5 g/dL (hazard ratio 1.80, 95%CI 1.09-2.96, P = 0.022) as risk factors for overall survival. Among three groups categorized according to serum albumin and CR1-Rel1 interval, the best 3-year overall survival was observed in patients with albumin > 3.5 g/dL and CR1-Rel1 interval > 6 months or primary induction failure (50.2%, 95%CI 28.9%-68.3%, P < 0.001), revealing that survival could be predicted using albumin and past CR duration in patients with very high-risk AML not in remission before GC-haplo.

Real-world data from yttrium-90 ibritumomab tiuxetan treatment of relapsed or refractory indolent B-cell non-Hodgkin's lymphoma: J3Zi Study.

Yttrium-90 ibritumomab tiuxetan (90YIT) is a radioimmunotherapy agent in which the radioisotope yttrium-90 is bound to ibritumomab via tiuxetan as a chelating agent, and is used for relapsed or refractory low-grade B-cell non-Hodgkin's lymphoma (rr-B-NHL). We conducted a joint study to evaluate the clinical outcome of 90YIT. The J3Zi study is composed of data from patients receiving 90YIT for rr-B-NHL from the top three institutions with 10 years of 90YIT treatment experience from October 2008 to May 2018 in Japan. The efficacy, prognostic factors and safety of 90YIT were retrospectively evaluated. Data from 316 patients were analyzed; the mean age was 64.6 years and the median number of prior treatments was 2. The median PFS was 3.0 years, the final OS rate was over 60%, and the median OS was not reached during the study period. Significant factors influencing PFS were sIL-2R ≤ 500 (U/mL) and no disease progression within 24 months of first treatment. Significant factors influencing OS were number of prior treatments ≤ 2 and sIL-2R ≤ 500 (U/mL). The PFS and OS rates were found to be significantly higher in the late half era (2013 to 2018) than in the early half era (2008 to 2013) during the study period. Prognosis following 90YIT treatment was improved in the late half era compared to the early half era. As treatment using 90YIT increased, administration of 90YIT shifted to the earlier treatment line. This may have contributed to the improvement of prognosis found in the late era. (UMIN000037105).

Hematopoietic stem cell transplantation for diffuse large B-cell lymphoma having 8q24/MYC rearrangement in Japan.

The prognosis of diffuse large B-cell lymphoma (DLBCL) having MYC rearrangement (MYC-R), including double hit lymphoma (DHL), is poor by standard immunochemotherapy. To evaluate the significance of hematopoietic stem cell transplantation (SCT) for DLBCL with MYC-R, we retrospectively analyzed Japanese SCT registry data. In total, 54 patients with DLBCL with MYC-R were identified from 4336 registered adult DLBCL patients. Detailed clinical and cytogenetic information was obtained for 48 patients. The median age at diagnosis of the 48 patients was 54.5 (range 21-67) years. Twenty-six (54%) patients had MYC-R only (single hit), and 22 (46%) had MYC-R and BCL2, and/or BCL6 rearrangement (double/triple hit). In 12 patients who received auto-SCT during the first complete response (CR), both the 2-year overall survival (OS) and progression-free survival (PFS) rates were 75.0% (95% confidence interval [CI], 40.8%-91.2%). In 20 patients who received auto-SCT after relapsed or refractory state, the 2-year OS and PFS rates were 68.2% (95% CI, 41.9%-84.5%) and 59.6% (95% CI, 35.1%-77.4%), respectively. In 17 patients who received allo-SCT, only 4 patients underwent SCT in CR. The 2-year OS and PFS rates were 29.4% (95% CI, 10.7%-51.1%) and 17.6% (95% CI, 4.3%-38.3%), respectively. The rate of non-relapse mortality at 1 year was 41.2% (95% CI, 17.1%-64.0%) in this group. The outcomes of single hit and double or triple hit were not different. These findings suggest that auto-SCT may be effective for MYC-R DLBCL, including DHL patients of chemosensitive relapsed or refractory state. Since most patients received allo-SCT not in CR, the outcome of allo-SCT was unsatisfactory due to high non-relapse mortality and early relapse. To clarify the role of allo-SCT for MYC-R DLBCL, further accumulation of patients is necessary.

A multicenter phase II study of intrabone single-unit cord blood transplantation without antithymocyte globulin.

To overcome the delayed or failed engraftment after unrelated cord blood transplantation (CBT), we conducted a multicenter phase II study of intrabone single-unit CBT without antithymocyte globulin (ATG) for adult patients with hematological malignancies (UMIN-CTR, UMIN000020997). Sixty-four patients received an intrabone injection of unwashed (n = 61) or washed (n = 3) cord blood after local anesthesia. All injection-related adverse events were mild and resolved spontaneously. Sixty-two patients were evaluable for the efficacy of intrabone CBT of serological HLA-A, -B, and -DR ≥ 4/6 matched cord blood with a median number of 2.57 × 107/kg cryopreserved total nucleated cells. The probability of survival with neutrophil engraftment on day 28 was 77.4% (95% confidence interval, 67.0-85.8%), which exceeded the threshold value. The cumulative incidences of neutrophils ≥ 0.5 × 109/L on day 60 was 80.6% (68.2-88.6%), with a median time to recovery of 21 days after transplantation. The cumulative incidences of platelets ≥ 20 × 109/L and platelets ≥ 50 × 109/L on day 100 were 75.8% (62.6-84.9%) and 72.6% (59.4-82.1%), respectively, with median time to platelets ≥ 20 × 109/L and platelets ≥ 50 × 109/L of 38 and 45 days after transplantation, respectively. The cumulative incidences of grade II-IV and III-IV acute graft-versus-host disease were 29.0% and 6.5%, respectively. All responded to steroid therapy, and secondary treatments were not required. The present study suggests the efficacy of intrabone single-unit CBT without ATG in terms of early engraftment and controllable acute graft-versus-host disease.

Impact of the use of hydroxyethyl starch in granulocyte apheresis using Spectra Optia.

OBJECTIVES: To determine the impact of the use of hydroxyethyl starch (HES) in granulocyte apheresis using Spectra Optia. BACKGROUND: Granulocyte transfusion (GT) is a therapeutic option for neutropenic patients with severe bacterial or fungal infections. Recent studies in emergency medicine have shown the potential risk of using HES, which is routinely used in granulocyte apheresis to increase yield by sedimenting red blood cells. We hypothesized that the use of a newer device (Spectra Optia) would spare the need for HES. METHODS: We retrospectively compared granulocyte apheresis with HES (HES group, n = 89) and without HES (non-HES group, n = 36) using Spectra Optia. RESULTS: The granulocyte yield was significantly higher in the HES group (7.3 × 1010 vs. 2.0 × 10, p < 0.01) and was attributed to the difference in collection efficiency (36% vs. 7.7%, p < 0.01). The absolute neutrophil count on the following morning of GT was significantly higher in the HES group than in the non-HES group (2460/µl vs. 505/µl, p < 0.01). There were no significant differences in the occurrence of adverse events between the HES and non-HES groups. The renal function was unchanged in both groups after apheresis. CONCLUSIONS: We demonstrated that the advantage of using HES remained unchanged in granulocyte apheresis using Spectra Optia.

Early evaluation of tumor response to 90Y-ibritumomab radioimmunotherapy in relapsed/refractory B cell non-Hodgkin lymphoma: what is the optimal timing for FDG-PET/CT?

PURPOSE: To determine the earliest optimal timing for assessment of early response following radioimmunotherapy in non-Hodgkin lymphoma patients using FDG-PET/CT. METHODS: FDG-PET/CT was performed prior to treatment (PET1), at 2 (PET2) weeks, and at 6 (PET3) weeks after 90Y-ibritumomab radioimmunotherapy in 55 patients. Response was evaluated based on the Deauville 5-point scale and Lugano criteria as well as semiquantitative analysis and compared with progression-free survival (PFS). RESULTS: PET 2 showed complete metabolic response (CMR), partial metabolic response (PMR), stable metabolic disease (SMD), and progressive metabolic disease (PMD) in 33, 13, 6, and 3 patients, respectively, while PET 3 in 41, 8, 3, and 3 patients, respectively. Mean SUVmax of 168 target lesions decreased over time (PET1, 2, 3; 5.58 ± 2.58, 1.87 ± 1.78, 1.75 ± 2.25, respectively). Progression or recurrence after a median of 12.6 months (range 2.6-72.0 months) was seen in 44 patients. Patients with CMR or metabolic response (CMR + PMR) on PET2 showed significantly longer PFS as compared to those who did not (p = 0.00028 and p = 0.029, respectively). A similar significant difference was observed based on PET3 (p = 0.00013 and p = 0.017, respectively). The same trend was observed when analyzing only the subgroup of patients with follicular lymphoma (N = 43/55) (p < 0.0001). CONCLUSION: Use of FDG-PET/CT findings with Lugano criteria for assessing early response to radioimmunotherapy after 6 weeks allowed for accurate evaluation and prognostic stratification, though scanning after 2 weeks was too soon to precisely evaluate response. KEY POINTS: • The optimal timing of FDG-PET/CT to obtain a suitable tool for assessment of response after 90 Y-ibritumomab radioimmunotherapy of lymphoma has not yet been defined. • Assessment after 6 weeks by FDG-PET/CT using the Lugano criteria accurately evaluates treatment response and prognosis. • FDG-PET/CT performed 2 weeks after radioimmunotherapy is too early as it significantly misses objective responses.

Low incidence of HHV-6 reactivation in haploidentical hematopoietic stem cell transplantation with corticosteroid as graft-vs-host disease prophylaxis compared with cord blood transplantation.

BACKGROUND: Human leukocyte antigen (HLA) mismatch and the administration of immunosuppressive agents are considered risks for human herpesvirus 6 (HHV-6) reactivation after stem cell transplantation (SCT). However, the incidence of HHV-6 reactivation in HLA-mismatched related SCT remains unknown. METHODS: We monitored plasma HHV-6 DNA loads weekly using real-time quantitative polymerase chain reaction for 5 weeks after SCT and compared serum IL-6 levels in HLA-mismatched SCT groups. RESULTS: Compared with detection in all 11 umbilical cord blood transplantation (CBT) patients (100%), plasma HHV-6 DNA was detected in only 3 of 42 haplo-SCT patients (7.1%) despite the use of methylprednisolone and antithymocyte globulin as graft-vs-host disease prophylaxis and a reduced-intensity conditioning regimen, respectively. Correspondingly, serum IL-6 levels in haplo-SCT patients were significantly lower than those in CBT patients. No HHV-6-associated encephalitis developed in either groups. CONCLUSIONS: Neither HLA disparity nor the use of methylprednisolone and antithymocyte globulin were risk factors for HHV-6 reactivation in our haplo-SCT patients. Rather than increasing risk, the administration of immunosuppressive agents potentially prevented HHV-6 reactivation after haplo-SCT by suppressing IL-6 production.

A prospective multicenter phase II study of intrabone marrow transplantation of unwashed cord blood using reduced-intensity conditioning.

Cord blood transplantation (CBT) is associated with delayed hematopoietic recovery and graft failure. To overcome these problems, we conducted a prospective, multicenter phase II study of intrabone marrow transplantation in which patients received reduced-intensity conditioning without anti-thymocyte globulin (ATG). The primary endpoint was the probability of full donor engraftment. Forty patients with hematologic malignancies were enrolled. Cord blood (CB) cells were injected without washing into 4 iliac bone sites (2 at each hemipelvis), at which approximately 6 mL of CB was administered at one site with local anesthesia. Full donor engraftment rate was 86.8%. The cumulative incidence of neutrophil and platelet engraftment was 86.4% and 85.5%, respectively. The median time to neutrophil (>0.5 × 109 /L) and platelet (2.0 × 109 /L) recovery was 17.5 and 44 days, respectively. The probability of severe acute graft-vs-host disease (GVHD) was 47.5%. The cumulative incidence of extensive chronic GVHD was 3.0%. The probability of relapse and non-relapse mortality was 30.4% and 28.0%, respectively. The survival rate at 3 years was 45.6%, although most patients were at an advanced stage. These results suggest that our intrabone marrow-CBT procedure without using ATG improves hematopoietic recovery and decreases the incidence of chronic GVHD, but does not decrease the incidence of acute GVHD.

Host Foxp3+CD4+ Regulatory T Cells Act as a Negative Regulator of Dendritic Cells in the Peritransplantation Period.

Host Foxp3+CD4+ regulatory T cells (Tregs) have been shown to suppress graft-versus-host disease (GVHD) in experimental bone marrow transplantation (BMT) models; however, the detailed mechanism is unknown. To address this issue, we established a murine MHC-haploidentical BMT model (BDF1 (H-2b/d) → B6C3F1 (H-2b/k)), in which transplantation following conditioning with high-dose (13 Gy) or low-dose (5 Gy) total body irradiation corresponds to myeloablative stem cell transplantation (MAST) or reduced-intensity stem cell transplantation (RIST) BMT. All MAST recipients died of GVHD within 70 d, whereas RIST recipients developed almost no GVHD and survived for at least 3 mo. In this BMT model, we investigated the kinetics of immune cells in the mesenteric lymph nodes because GVHD was most prominent in the intestines. Host Tregs that survived after total body irradiation could proliferate transiently by day 4. Comparing the kinetics of immune cells among MAST, RIST, and anti-CD25 mAb-treated RIST, we found that the transiently surviving host Tregs were fully functional, closely contacted with host dendritic cells (DCs), and significantly restrained the maturation (CD80 and CD86 expression) of DCs in a dose-dependent manner. There was a positive correlation between the ratio of DCs to host Tregs and the extent of maturation of DCs. Host Tregs suppressed alloresponse mainly by contact inhibition. Host Tregs are already active in lymph nodes before transplantation and restrain the maturation of host DCs, thereby dampening the ability of DCs to activate allogeneic donor T cells and consequently reducing the magnitude of graft-versus-host reaction. Thus, host Tregs are negative regulators of host DCs that act in the peritransplantation period.

Differences in Esterase Activity to Aspirin and p-Nitrophenyl Acetate among Human Serum Albumin Preparations.

Human serum albumin (HSA) has two major ligand-binding sites, sites I and II, and also hydrolyzes some compounds at both sites. In the present study, we investigated differences in esterase activity among HSA preparations, and also the effects of warfarin, indomethacin, and naproxen on the hydrolytic activities of HSA to aspirin and p-nitrophenyl acetate. The esterase activities of HSA to aspirin or p-nitrophenyl acetate were measured from the pseudo-first-order formation rate constant (kobs) of salicylic acid or p-nitrophenol by HSA. Inter-lot variations were observed in the esterase activities of HSA to aspirin and p-nitrophenyl acetate; however, the esterase activity of HSA to aspirin did not correlate with that to p-nitrophenyl acetate. The inhibitory effects of warfarin and indomethacin on the esterase activity of HSA to aspirin were stronger than that of naproxen. In contrast, the inhibitory effect of naproxen on the esterase activity of HSA to p-nitrophenyl acetate was stronger than those of warfarin and indomethacin. These results suggest that the administration of different commercial HSA preparations and the co-administration with site I or II high-affinity binding drugs may change the pharmacokinetic profiles of drugs that are hydrolyzed by HSA.

Unmanipulated Haploidentical Reduced-Intensity Stem Cell Transplantation Using Fludarabine, Busulfan, Low-Dose Antithymocyte Globulin, and Steroids for Patients in Non-Complete Remission or at High Risk of Relapse: A Prospective Multicenter Phase I/II Study in Japan.

This prospective, multicenter phase I/II study of unmanipulated HLA-haploidentical reduced-intensity stem cell transplantation using a low dose of anti-T lymphocyte globulin (ATG) and steroid was conducted in 5 institutions in Japan. Thirty-four patients with hematologic malignancies who were in an advanced stage or at a high risk of relapse at the time of transplantation were enrolled. Among them, 7 patients underwent transplantation as a second transplantation because of relapse after the previous allogeneic stem cell transplantation. The conditioning regimen consisted of fludarabine, busulfan, and ATG (Fresenius, 8 mg/kg), and graft-versus-host disease (GVHD) prophylaxis consisted of tacrolimus and methylprednisolone (1 mg/kg). All patients except 1 (97.1%) achieved donor-type engraftment. Rapid hematopoietic engraftment was achieved, with neutrophils > .5 × 10(9)/L on day 11 and platelets > 20 × 10(9)/L on day 17.5. Treatment was started for ≥grade I GVHD, and the cumulative incidences of acute grade I and grade II to IV GVHD were 27.5% and 30.7%, respectively. The incidence of chronic GVHD (extensive type) was 20%. Fourteen patients (41.2%) had a relapse. The cumulative incidence of transplantation-related mortality at 1 year after transplantation was 26.5%. The survival rate at day 100 was 88.2%. The survival rates at 1 year for patients with complete remission (CR)/chronic phase (n = 8) and non-CR (n = 26) status before transplantation were 62.5% and 42.3%, respectively. In the multivariate analysis, non-CR status before transplantation was the only factor significant prognostic factor of increased relapse (P = .0424), which tended to be associated with a lower survival rate (P = .0524). This transplantation protocol is safe and feasible, if a suitable donor is not available in a timely manner. As the main cause of death was relapse and not GVHD, more intensified conditioning or attenuation of GVHD prophylaxis and/or donor lymphocyte infusion may be desirable for patients with non-CR status.

Early detection of cytomegalovirus-specific cytotoxic T lymphocytes against cytomegalovirus antigenemia in human leukocyte antigen haploidentical hematopoietic stem cell transplantation.

Human leukocyte antigen (HLA)-haploidentical stem cell transplantation (haplo-SCT) is associated with a high incidence of cytomegalovirus (CMV) infection, probably originating from the delayed reconstitution of CMV-specific T cell immunity. There have been few reports on the presence of CMV-specific cytotoxic T lymphocytes (CMV-CTLs) after haplo-SCT. We have studied CMV-specific immune reconstitution by measuring the absolute number of CMV-CTLs using a flow cytometry method with HLA-A2-restricted NLVPMVATV peptide dextramers. We examined the association between reconstitution patterns of CMV-CTLs and the duration of CMV antigenemia in 15 patients who underwent first allogeneic SCT from HLA-haploidentical-related donors with HLA-A2. In seven and eight patients, CMV antigenemia consecutively resolved for more than 4 weeks (the CMV antigenemia 'resolved' group) and intermittently persisted (the CMV antigenemia 'persistent' group) during a 100-day observation period, respectively. The group of the seven patients, in whom levels of CMV antigenemia were reduced to zero, had a significantly lower maximum level of CMV antigenemia than the CMV antigenemia persistent group. In contrast, the CMV antigenemia persistent group had a significantly higher maximum level of CMV-CTLs, but the levels took longer to peak. Despite no difference in general lymphocyte recovery between the two groups, the CMV antigenemia resolved group had significantly higher median CMV-CTL counts than the CMV antigenemia persistent group at 6 weeks after onset of CMV infection. Flow cytometry analysis of CMV-CTLs is a convenient method of monitoring reconstitution of CMV-specific lymphocyte immunity following haplo-SCT.

Fatal reactivation of hepatitis B virus infection in a patient with adult T-cell leukemia-lymphoma receiving the anti-CC chemokine receptor 4 antibody mogamulizumab.

We report an adult T-cell leukemia-lymphoma (ATL) patient suffering from fatal reactivation of hepatitis B virus (HBV) infection after treatment with the anti-CC chemokine receptor 4 (CCR4) monoclonal antibody, mogamulizumab. HBV reactivation occurred without liver damage in this hepatitis B surface antigen (HBsAg) negative patient, who was seropositive for antibodies against the viral core and surface antigens at baseline, after two cycles of CHOP regimen (cyclophosphamide, doxorubicin, vincristine and prednisolone) followed by six cycles of THP-COP regimen (cyclophosphamide, pirarubicin, vincristine and prednisolone). Unexpectedly, mogamulizumab monotherapy for relapsed CCR4 positive ATL induced sudden and fatal liver failure due to HBV reactivation, despite antiviral prophylaxis with entecavir. This clinical course may not only offer important suggestions to prevent critical HBV reactivation in HBsAg positive cancer patients who receive immune-enhancing drugs such as anti-CCR4 antibody, but also provide a clue to understanding the pathogenesis of HBV reactivation following systemic chemotherapy.

Recombinant human soluble thrombomodulin attenuates FK506-induced endothelial dysfunction through prevention of Akt inactivation.

Thrombomodulin (TM), a transmembrane glycoprotein on vascular endothelial cells, is a naturally occurring anticoagulant. Recombinant human soluble TM (rTM), composed of the extracellular domain of TM, also shows anti-coagulant and anti-inflammatory activity, but the effects of rTM on microangiopathy remain unclear. We reported that FK506 induced endothelial dysfunction through inactivation of Akt and extracellular-regulated kinase 1/2 using a three-dimensional culture blood vessel model. In the present study, we examined the effects of rTM on FK506-induced endothelial dysfunction. We found that rTM suppressed FK506-induced endothelial cell death, but not the breakdown of capillary-like tube structures. rTM prevented FK506-induced inactivation of Akt, but not of extracellular-regulated kinase 1/2. Akt inhibition by LY294002 abrogated the preventive effect of rTM on FK506-induced Akt inactivation and the suppressive effect of rTM on FK506-induced cell death. These results suggest that rTM attenuates FK506-induced endothelial dysfunction through prevention of Akt inactivation.

Label-free Raman observation of cytochrome c dynamics during apoptosis.

We performed label-free observation of molecular dynamics in apoptotic cells by Raman microscopy. Dynamic changes in cytochrome c distribution at the Raman band of 750 cm(-1) were observed after adding an apoptosis inducer to the cells. The comparison of mitochondria fluorescence images and Raman images of cytochrome c confirmed that changes in cytochrome c distribution can be distinguished as release of cytochrome c from mitochondria. Our observation also revealed that the redox state of cytochrome c was maintained during the release from the mitochondria. Monitoring mitochondrial membrane potential with JC-1 dye confirmed that the observed cytochrome c release was associated with apoptosis.

Expression of CD56 is an unfavorable prognostic factor for acute promyelocytic leukemia with higher initial white blood cell counts.

Expression of CD56 has recently been introduced as one of the adverse prognostic factors in acute promyelocytic leukemia (APL). However, the clinical significance of CD56 antigen in APL has not been well elucidated. We assessed the clinical significance of CD56 antigen in 239 APL patients prospectively treated with all-trans retinoic acid and chemotherapy according to the Japan Adult Leukemia Study Group APL97 protocol. All patients were prospectively treated by the Japan Adult Leukemia Study Group APL97 protocol. The median follow-up period was 8.5 years. Positive CD56 expression was found in 23 APL patients (9.6%). Expression of CD56 was significantly associated with lower platelet count (P = 0.04), severe disseminated intravascular coagulation (P = 0.04), and coexpression of CD2 (P = 0.03), CD7 (P = 0.04), CD34 (P < 0.01) and/or human leukocyte antigen-DR (P < 0.01). Complete remission rate and overall survival were not different between the two groups. However, cumulative incidence of relapse and event-free survival (EFS) showed an inferior trend in CD56(+) APL (P = 0.08 and P = 0.08, respectively). Among patients with initial white blood cell counts of 3.0 × 10(9)/L or more, EFS and cumulative incidence of relapse in CD56(+) APL were significantly worse (30.8% vs 63.6%, P = 0.008, and 53.8% vs 28.9%, P = 0.03, respectively), and in multivariate analysis, CD56 expression was an unfavorable prognostic factor for EFS (P = 0.04). In conclusion, for APL with higher initial white blood cell counts, CD56 expression should be regarded as an unfavorable prognostic factor.

Donor-derived cytomegalovirus-specific CD8+ T cells restricted to shared, donor-specific, or host-specific HLA after HLA mismatched hematopoietic stem cell transplantation.

Immune reconstitution after human leukocyte antigen (HLA)-mismatched (haploidentical) hematopoietic stem cell transplantation (haplo-HCT) can significantly influence long-term outcomes. The three possible HLA haplotypes after transplantation are: one carried by both the patient and the donor (shared HLA), one by donor only (donor-specific HLA), and one by patient only (host-specific HLA), and the donor T cells remain restricted to one of these three haplotypes. Understanding the presence of donor T cells restricted to each haplotype may provide more detailed insights into post-transplant immune response and potentially provide valuable information for the development of chimeric antigen receptor T cell or T cell receptor T cell constructs. In this study, patients or donors with HLA-A24 or HLA-A2 were tested with HLA-A*24:02- and A*02:01-restricted cytomegalovirus (CMV)-specific tetramers for detecting the respective HLA-restricted T cells. Sixty-four samples from 40 patients were assayed. More than half of the patients at day 90 and all patients by day 900 had shared HLA-restricted T cells. After day 90, half of the patients had donor-specific HLA-restricted T cells, but no host-specific HLA-restricted T cells were found. In the comparative analysis of the transplant types, shared HLA-restricted T cells were positive in all three categories: haplo-HCT (50%), 2-haplo-mis-HCT (75%), and spousal HCT (67%). Furthermore, donor-specific HLA-restricted T cells demonstrated positivity in haplo-HCT at 57% and in 2-haplo-mis-HCT at 60%, with a threshold of 0.01%. Donor-specific HLA-restricted T cells for spousal HCT were not examined due to the lack of an appropriate HLA combination for the tetramers. The presence of shared HLA-restricted T cells explains the host defense after HLA-haploidentical transplantation, while the presence of donor-specific HLA-restricted T cells may account for host defense against hematotropic viruses, such as CMV. However, this study failed to detect host-specific HLA-restricted T cells, leaving the host defense against epitheliotropic viruses unresolved, thus requiring further investigation.

Ruxolitinib in steroid-refractory acute graft-vs-host disease: Japanese subgroup analysis of the randomized REACH2 trial.

Acute graft-versus-host disease (aGvHD) is a major complication after allogeneic hematopoietic stem cell transplantation in Japan and other countries. Nearly one-third of patients do not respond to standard systemic steroid therapy and no standard second-line treatment has been established in Japan. We report efficacy and safety findings of ruxolitinib versus best available therapy (BAT) from a subgroup analysis of the international, phase 3 REACH2 study in Japanese patients with steroid-refractory aGvHD. The primary endpoint was overall response rate (ORR) at day 28. Overall, 9 patients received ruxolitinib and 21 received BAT. The ORR at day 28 (88.9% vs 52.4%) and durable ORR at day 56 (66.7% vs 28.6%) were higher with ruxolitinib versus BAT. The estimated cumulative incidence of loss of response at 6 months was 12.5% with ruxolitinib and 18.2% with BAT. The median failure-free survival was longer with ruxolitinib versus BAT (2.73 vs 1.25 months). The most common adverse events up to day 28 in the ruxolitinib and BAT groups were anemia (55.6% vs 19.0%) and thrombocytopenia (44.4% vs 4.8%, respectively). Ruxolitinib showed better efficacy outcomes and a consistent safety profile compared with BAT in the Japanese subgroup, and the findings were consistent with overall study results.

C16, a PKR inhibitor, suppresses cell proliferation by regulating the cell cycle via p21 in colorectal cancer.

Double-stranded RNA-activated protein kinase R (PKR) is highly expressed in colorectal cancer (CRC). However, the role of PKR in CRC remains unclear. The aim of this study was to clarify whether C16 (a PKR inhibitor) exhibits antitumor effects and to identify its target pathway in CRC. We evaluated the effects of C16 on CRC cell lines using the MTS assay. Enrichment analysis was performed to identify the target pathway of C16. The cell cycle was analyzed using flow cytometry. Finally, we used immunohistochemistry to examine human CRC specimens. C16 suppressed the proliferation of CRC cells. Gene Ontology (GO) analysis revealed that the cell cycle-related GO category was substantially enriched in CRC cells treated with C16. C16 treatment resulted in G1 arrest and increased p21 protein and mRNA expression. Moreover, p21 expression was associated with CRC development as observed using immunohistochemical analysis of human CRC tissues. C16 upregulates p21 expression in CRC cells to regulate cell cycle and suppress tumor growth. Thus, PKR inhibitors may serve as a new treatment option for patients with CRC.