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.

Individualized rabbit anti-thymocyte globulin dosing in adult haploidentical hematopoietic cell transplantation with high-risk hematologic malignancy: Exposure-response analysis and population pharmacokinetics simulations.

Hematopoietic cell transplantation (HCT) for hematologic malignancies with non-remission disease and/or prior post-transplant relapse have poor relapse-free survival. We previously demonstrated the efficacy of haploidentical reduced-intensity HCT regimen with glucocorticoid-based graft-versus-host disease (GVHD) prophylaxis. We recently showed a possible association between rabbit antithymocyte globulin (rATG) exposure and acute GVHD (aGVHD) risk, leading to hypothesize that optimization of rATG exposure may further improve this regimen. We retrospectively examined the exposure-response association of rATG and key clinical outcomes post haploidentical HCT. We subsequently developed an individualized rATG dosing that optimizes rATG exposure using a previously developed population pharmacokinetic model. Of the 103 patients analyzed, the median age was 47 years (range: 17-70) and majority had a non-remission disease prior to HCT (88%). rATG concentration on day 0 of HCT (Cday_0 ) was the strongest predictor of Grade 2-4 aGVHD through day +100. Patients with Cday_0 ≥ 20 µg/mL had an approximately 3-fold lower risk of Grade 2-4 aGVHD (hazard ratio [HR]: 0.32, 95% confidence interval [CI]: 0.16, 0.62) and Grade 3-4 aGVHD (HR: 0.33, 95% CI: 0.16, 0.68) as well as an approximately 2-fold lower risk of overall mortality (HR: 0.47, 95% CI: 0.28, 0.77) and relapse (HR: 0.50, 95% CI: 0.26, 0.94). In conclusion, this reduced-intensity haploidentical HCT regimen with exposure-optimized rATG may provide a promising option to patients undergoing high-risk HCT for hematologic malignancy. The developed rATG dosing warrant prospective validation.

Early evaluation of CAR-T cell therapy response in R/R DLBCL patients using 18F-FDG PET/CT.

OBJECTIVE: CD19-targeted chimeric antigen receptor T (CAR-T) cell therapy provides a durable response in patients with relapsed/refractory diffuse large B-cell lymphoma (R/R DLBCL). The role of fluorine-18-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) for early evaluation of response in patients with that immunotherapy was evaluated. SUBJECTS AND METHODS: Three separate 18F-FDG PET/CT examinations of 53 patients (29 males, 24 females; median 62 years old) with R/R DLBCL were conducted; before bridging therapy [time of decision (TD)], before CAR-T (tisagenlecleucel, n=37; lisocabtagenemaraleucel, n=16) infusion [time of CAR-T infusion (IT)], and one month (M1) after CAR-T infusion. Response was evaluated based on the Deauville 5-point scale and Lugano criteria. RESULTS: Among 21 patients (39.6%) with complete metabolic response (CMR) at IT-PET, 20 were able to continue CMR, while one showed progression at M1-PET. Among 32 patients (60.4%) with non-CMR at IT-PET, 12, 8, 4, and 8 showed CMR, partial metabolic response (PMR), (non-metabolic response (NMR), and progressive metabolic disease (PMD), respectively, at M1-PET as compared with IT-PET. Evaluations of M1-PET as compared with baseline TD-PET indicated 32, 7, 5, and 9 patients with CMR, PMR, NMR, and PMD, respectively. After a median 10.1 months, 26 patients showed progression and 13 had died from DLBCL. The 32 who achieved CMR showed significantly longer progression-free (P<0.0001) and overall survival (P<0.0001) periods as compared to the 21 non-CMR patients. CONCLUSION: Fluorine-18-FDG PET/CT findings obtained one month after CAR-T cell therapy showed accuracy for early response evaluation and prediction of progression in patients with R/R DLBCL.

Muscle oxygen extraction and lung function are related to exercise tolerance after allogeneic hematopoietic stem cell transplantation.

PURPOSE: This study aimed to investigate the relationship between exercise intolerance, muscle oxidative metabolism, and cardiopulmonary function following allogeneic hematopoietic stem cell transplantation (allo-HSCT) in a sterile isolation room setting. METHODS: This was a prospective observational cohort study conducted in a single center. Fourteen patients with hematopoietic malignancies who had undergone allo-HSCT were included in this study from June 2015 to April 2020. Patients received donor HSCT after high dose-chemotherapy and total-body irradiation. Physical activity was limited during treatments. Outcome measures included body anthropometric measurements, exercise tolerance tests using the ramp protocol, pulmonary function tests, and near-infrared spectroscopy (NIRS) measurements. Data of pre- and posttransplant measurements were compared using the paired t test or nonparametric Wilcoxon U test. Associations were assessed using the Pearson or nonparametric Spearman correlations. RESULTS: NIRS showed reduced muscle consumption and extraction of oxygen in the posttransplant period compared to the pretransplant period (ΔStO2 min pre: -18.6% vs. post: -13.0%, P = 0.04; ΔHHb max pre: 4.21µmol/l vs. post: 3.31µmol/l: P = 0.048). Exercise tolerance had reduced following allo-HSCT (Peak workload pre: 70.3 W vs. post: 58.0 W: P = 0.014). Furthermore, exercise intolerance was associated with pulmonary function, muscle oxygen consumption, and muscle oxygen extraction (all P <0.05). CONCLUSION: This analysis revealed that exercise intolerance following allo-HSCT was associated with pulmonary dysfunction and muscle oxidative dysfunction. These findings could help identify the physical function associated with impaired tissue oxygen transport leading to exercise intolerance following allo-HSCT.

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.

Relationship Between Corticosteroid Dose and Muscle Oxygen Consumption in Recipients of Hematopoietic Stem-Cell Transplantation.

INTRODUCTION: After hematopoietic stem-cell transplantation (HSCT), patients exhibit decreased muscle strength and muscle oxygen consumption. Furthermore, total corticosteroid dose affects the reduction in muscle strength after HSCT. However, to date, no studies have investigated the relationship between corticosteroid dose and muscle oxygen consumption and saturation in these patients. The purpose of this study was to investigate the relationship between steroid dose and deoxyhemoglobin (ΔHHb) and muscle oxyhemoglobin saturation (ΔSmO2) in patients undergoing HSCT. METHODS: This study included 17 men with hematologic disease who underwent allogeneic HSCT. We evaluated ankle dorsiflexor muscle force, ΔHHb, and ΔSmO2 in skeletal muscles by near-infrared spectroscopy (NIRS) in patients before and after HSCT. RESULTS: Peak ankle dorsiflexion, ΔHHb, and ΔSmO2 decreased significantly after transplantation as compared to measurements taken before transplantation (p < 0.01). The change in peak ankle dorsiflexion from before to after HSCT was not significantly correlated with total steroid dose. However, ΔHHb and ΔSmO2 from before to after HSCT were significantly correlated with total steroid dose (p < 0.01). CONCLUSION: This study showed that higher corticosteroid doses are associated with diminished skeletal muscle O2 consumption and skeletal muscle O2 demand relative to supply. Therefore, rehabilitation staff, nurses, and physicians should take note of these findings in patients undergoing HSCT. Moreover, physiotherapists should be carefully measuring muscle oxidative metabolism on skeletal muscle when planning physical exercise in such patients.

Tacrolimus Concentration after Letermovir Initiation in Hematopoietic Stem Cell Transplantation Recipients Receiving Voriconazole: A Retrospective, Observational Study.

Letermovir (LMV) is a new antiviral drug used to prevent cytomegalovirus infection in hematopoietic stem cell transplantation (HSCT) recipients. It has been reported to increase tacrolimus (TAC) exposure and decrease voriconazole (VRCZ) exposure in healthy participants. However, VRCZ inhibits the metabolism of TAC. Thus, the effects of LMV on TAC exposure in patients receiving VRCZ are unknown. This retrospective, observational, single-center study was conducted between May 2018 and April 2019. The TAC concentration/dose (C/D) ratio, VRCZ concentration, and VRCZ C/D ratio for 7 days before and for the first and second 7-day periods after the initiation of LMV administration were evaluated. Fourteen HSCT recipients receiving VRCZ were enrolled. There was no significant difference in the TAC C/D ratio for 7 days before and for the first and second 7-day periods after initiating LMV administration (median: 866 [IQR: 653-953], 842 [IQR: 636-1031], and 906 [IQR: 824-1210] [ng/mL]/[mg/kg], respectively). In contrast, the VRCZ C/D ratio and concentration for the first and second 7-day periods after LMV initiation were significantly lower than those before initiating LMV administration (mean 1.11 ± 0.07, 0.12 ± 0.08, and 0.22 ± 0.12 [µg/mL]/[mg/kg] and 0.7 ± 0.5, 0.8 ± 0.5, and 1.3 ± 0.7 µg/mL, respectively; n = 12). This can be explained by the increase in TAC concentration caused by CYP3A4 inhibition due to LMV and by the decrease in TAC concentration ascribed to the decrease in VRCZ concentration by CYP2C19 induction due to LMV. These results suggest that it is unnecessary to adjust the dose of TAC based on LMV initiation; however, it is necessary to adjust the dose of TAC based on conventional TAC concentration measurements.

Relationship Between Exercise Capacity and Muscle O2Hb Saturation in Patients Before Hematopoietic Stem-Cell Transplantation.

Patients with hematological malignancy might already have decreased muscle oxygen saturation at rest and exercise capacity before undergoing hematopoietic stem cell transplantation (HSCT). However, to date, no studies have investigated the relationship between exercise capacity and muscle oxygen saturation at rest in these patients. Therefore, purpose of this study was to investigate the relationship between exercise capacity and muscle oxygen-hemoglobin (O2Hb) saturation (SmO2) at rest and patients' hemoglobin level before undergoing HSCT. METHODS: This study included 60 men with hematologic disease who underwent allo-HSCT. Patients performed a 6-minute walk test (6MWT) to determine exercise capacity, and muscle O2Hb saturation at rest was evaluatabed using near-infrared spectroscopy (BOM-L1TRW, Omegawave Inc., Japan); hemoglobin levels in hematological malignancy patients before undergoing HSCT were also evaluated. RESULTS: There was a significant correlation between the 6MWT and muscle O2Hb saturation at rest in hematological malignancy patients (p < 0.05). Additionally, the 6MWT was significantly correlated to the hemoglobin level (p < 0.05). Furthermore, muscle O2Hb saturation at rest was significantly related to hemoglobin level (p < 0.05). CONCLUSION: In patients with hematological malignancy, a relationship exists between exercise capacity, muscle O2Hb saturation, and hemoglobin level before they undergo HSCT. Therefore, rehabilitation staff, nurses, and physicians should recognize these relationships in patients who undergo allo-HSCT. Moreover, physiotherapists may need to promote muscle oxidative metabolism through exercise to increase exercise capacity in these patients.

Relationship Between Muscle Oxygen Saturation and Exercise Load in Patients with Malignant Hematopoietic Disease.

Our previous research confirmed that patients with malignant hematopoietic disease already had a low hemoglobin level before allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, no study has determined whether a correlation exists between exercise load, hemoglobin level, and muscle oxygen saturation (SmO2), during exercise. Therefore, the purpose of this study was to investigate whether near-infrared spectroscopy (NIRS)-derived SmO2 is associated with exercise load, as determined by a dynamometer, before allo-HSCT. This study included 19 male patients who received allo-HSCT in Hyogo College of Medicine Hospital (Japan) between November 2009 and October 2012. Patients performed isometric repeated dorsiflexion at 50% maximum voluntary contraction for 180 s to determine exercise load, and SmO2 was evaluated during exercise at the same time using NIRS (BOM-L1TRW, Omega Wave, Inc., Japan). The hemoglobin level was also evaluated before allo-HSCT. Patients with hematopoietic disease before allo-HSCT already had a low hemoglobin level. There was a significant correlation between exercise load and ∆SmO2; however, the hemoglobin level was not correlated with exercise load. In these patients, exercise load might be affected by muscle oxygen consumption rather than by the hemoglobin level. This finding shows that NIRS can used to assess fatigue in patients with malignant hematopoietic disease.

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.

Impaired skeletal muscle oxygenation following allogeneic hematopoietic stem cell transplantation is associated with exercise capacity.

INTRODUCTION: Impaired skeletal muscle oxygenation potentially contributes to reduced exercise capacity in allogeneic hematopoietic stem cell transplantation (allo-HSCT) patients during early recovery and may explain altered hemoglobin responses to exercise following allo-HSCT. We investigated whether skeletal muscle oxygenation parameters and hemoglobin parameters in the tibialis anterior decreased following allo-HSCT, and whether these results were associated with declines in exercise capacity. METHODS: We used near-infrared spectroscopy during and following a repeated isometric contraction task at 50% of maximal voluntary contraction in 18 patients before and after allo-HSCT. RESULTS: The rate of decrease in the muscle oxy-hemoglobin saturation (SmO2; an index of skeletal muscle oxygenation) was significantly lower after allo-HSCT (P < 0.01). In contrast, total hemoglobin (an index of hemoglobin) was not different after allo-HSCT. Furthermore, SmO2 during and following exercise was associated with exercise capacity (r = 0.648; P = 0.004 vs. r = 0.632; P = 0.005). CONCLUSION: The results of this study reveal that although the peripheral hemoglobin response was not altered by allo-HSCT, skeletal muscle oxygenation was decreased following allo-HSCT. Furthermore, the decrease in skeletal muscle oxygenation was associated with a reduction in exercise capacity.

Changes in Borg scale for resistance training and test of exercise tolerance in patients undergoing allogeneic hematopoietic stem cell transplantation.

PURPOSE: We aimed to investigate the relationship between Borg scale and intensity of resistance training in patients who had undergone allogeneic hematopoietic stem cell transplantation (allo-HSCT). Furthermore, the relationship between Borg scale, heart rate (HR), and intensity of exercise tolerance test was also studied. METHODS: The study included 28 patients (19 men and 9 women) who had undergone allo-HSCT between June 2015 and February 2017. Their knee extension strengths and exercise tolerances were evaluated. Patients were asked to grade between 0 and 10 on Borg scale based on the level of difficulty experienced during exercising, after 10 repetitions in randomized 20, 40, and 60% resistance training for knee extension. Additionally, we evaluated Borg scale, HR, and load intensity during exercise tolerance test, every minute of the exercise for 2 weeks before and 3 weeks after HSCT. RESULTS: Knee extension strength and exercise tolerance were significantly decreased 3 weeks after HSCT from those before HSCT (p < 0.01). Additionally, rise in Borg scale with increase in load intensity during knee extension resistance training, both before and after HSCT (p < 0.01), was noted. Furthermore, Borg scale was found to be associated with HR and load intensity during exercise tolerance test in patients both before and after HSCT (p < 0.01). CONCLUSIONS: A correlation was found between Borg scale with intensity of resistance training and exercise tolerance in patients who had undergone allo-HSCT. Therefore, Borg scale could be useful to determine the intensity of physical exercise in patients who have undergone allo-HSCT.

Fatigue, Muscle Oxygen Consumption and Blood Flow to the Skeletal Muscle After Allogeneic Hematopoietic Stem Cell Transplantation.

The purpose of this study was to compare the differences in fatigue to those in muscle oxygen consumption and blood flow to the skeletal muscles before and after allogeneic hematopoietic stem cell transplantation (allo-HSCT). This study included 25 male patients who had received allo-HSCT between November 2009 and August 2012. Fatigue was assessed by using the Piper fatigue scale. Muscle oxygen consumption, shown by the change in deoxyhemoglobin (ΔHHb), and blood flow to the skeletal muscle, shown by the change in total hemoglobin (ΔtHb), were measured non-invasively in the tibialis anterior muscle during endurance exercise using near-infrared spectroscopy. ΔHHb and ΔtHb were significantly lower following allo-HSCT than before it (p < 0.05). Before allo-HSCT, no relationship was observed between fatigue and either ΔHHb or ΔtHb. However, after allo-HSCT, a significant relationship was found between fatigue and ΔHHb (p < 0.05). Patients experience decreased muscle oxygen consumption and blood flow to skeletal muscles after allo-HSCT. Furthermore, fatigue may have a relationship with decreased muscle oxygen consumption in patients after allo-HSCT. Rehabilitation staff, nurses, and physicians should recognise both decreases in muscle oxygen consumption and blood flow in patients who have undergone allo-HSCT, and physiotherapists may need to promote muscle oxidative metabolism through exercise in order to maintain muscle strength.

Hemoglobin Dynamics in the Skeletal Muscle of Patients with Malignant Hematopoietic Disease.

Impaired oxygen utilization in skeletal muscle potentially contributes to muscle weakness in patients with malignant hematopoietic disease and may explain altered hemodynamic responses to exercise in these patients. We investigated whether changes in hemoglobin parameters in the tibialis anterior muscle in patients with malignant hematopoietic diseases were different from those in age-matched healthy controls and whether these results were associated with a decline in muscle strength. Near-infrared spectroscopy was used during and after a repeated isometric contraction task at 50% of maximal voluntary contraction in 16 patients and 21 age- and sex-matched healthy controls. In the healthy control group, there was a correlation between muscle strength and hemoglobin dynamics, (ΔtHbmean: r = 0.42, p < 0.05; ΔtHbmax: r = 0.575, p < 0.01, respectively) but not in patients with malignant hematopoietic disease. The results of this study may suggest that haemoglobin dynamics during and following exercise were different between patients with malignant hematopoietic disease and healthy controls.

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.

Pharmacokinetics of 8 mg/kg anti-human T-lymphocyte rabbit immunoglobulin conditioning for hematopoietic stem cell transplantation in Japanese patients.

Anti-human T-lymphocyte immunoglobulin, rabbit (ATG, Zetbulin(®) intravenous infusion liquid), is an immunosuppressive agent that is indicated for aplastic anemia in Japan. The "prevention of graft-versus-host disease (GVHD) for allogeneic hematopoietic stem cell transplantation in adults" indication has been added to ATG in 32 countries worldwide, but has not yet been approved for GVHD prevention in Japan. The pharmacokinetics of ATG in Japanese people has not yet been assessed. In this study, to assess ATG pharmacokinetics, ATG (2 mg/kg/day from day-4 to day-1) as a pretransplant treatment was administered to six patients who had received transplantation of HLA-haploidentical stem cells. The ATG concentration was measured using an ELISA kit for rabbit IgG. The serum ATG concentration increased with administration for 4 consecutive days, peaking at a concentration of 66.0 µg/ml (±8.8 SD). Subsequently, it gradually decreased with an elimination half-life of 21.9 days (±20.4 SD) but was still detectable in serum even a few weeks after allogeneic hematopoietic stem cell transplantation. We found the pharmacokinetics of ATG in this study to be comparable to those described in previous reports from Europe.