Higher Incidence Of Graft-versus-host Disease Research Articles

Efficacy of Triple Prophylaxis for Prevention of Graft-Versus-Host Disease in Matched Sibling Allogeneic Peripheral Blood Hematopoietic Stem Cell Transplantation in Pediatric Patients

BACKGROUND: Graft-versus-host disease (GVHD) continues to compromise the overall success of allogenic hematopoietic stem cell transplantation. It is the most important cause of morbidity and non-relapse mortality after allogeneic hematopoietic stem cell transplantation for malignant disease. In adults, post-transplant cyclophosphamide (Cy-PT) has been shown to be a feasible, economically accessible, and effective strategy to reduce the incidence of GVHD in matched sibling hematopoietic stem cell transplantation in combination with a calcineurin inhibitor plus mycophenolate mofetil (MMF). AIM: Demonstrate the clinical benefit of Cy-PT plus a calcineurin inhibitor combined with MMF for GVHD prophylaxis in HLA-matched, related peripheral blood stem cell transplants in pediatric patients with malignant hematologic neoplasms compared to standard therapy in historical controls. METHODS: A retrospective study was conducted on 22 pediatric patients with malignant hematologic neoplasms who underwent HLA-matched related peripheral blood allogenic stem cell transplantation (alloSCT) between July 2012 and December 2022. A comparison was made between two groups, one with triple prophylaxis using Cy-PT, cyclosporine (CsA), and MMF, and a historical cohort that received standard GVHD prophylaxis based on CsA and methotrexate (MTX). Patients were identified from a hospital registry. Descriptive and inferential statistics will be reported, using SPSS version 25 for analysis. RESULTS: Twenty-two patients received HLA-matched alloSCT from first-degree relatives genotypically identical in HLA-A, HLA-B, and HLA-DRB1 alleles. The demographic characteristics of both groups are summarized in the table. No patient experienced primary graft failure, sinusoidal obstructive syndrome, or hemorrhagic cystitis. Acute GVHD grade II-IV did not develop in patients who received Cy-PT, whereas in the CsA/MTX prophylaxis group, 1 (9%) grade IV patient was observed who died due to this cause before day 100. Two patients (18%) developed Moderate/Severe GVHD in the CsA/MTX group, and 1 (9%) had moderate GVHD in the Cy-PT group. Two-year overall survival was similar between the two groups (Cy-PT 53% and CsA/MTX 67%), as was event-free survival (PTCy 48% vs. CsA/MTX 61%). CONCLUSION: Peripheral blood represents a feasible option in our setting due to rapid graft engraftment, short hospital stays, and low incidence of primary graft failure, but with a higher incidence of GVHD as reported in the literature. We explored the efficacy and safety of triple prophylaxis for HLA-matched alloSCTs from peripheral blood using Cy-PT + CsA + MMF in a small group of patients, with outcomes slightly better than standard prophylaxis. These preliminary results motivate us to continue with this new regimen.

Pre-Transplant Total Lymphocyte Count Determines Anti-Thymocyte Globulin Exposure, Modifying Graft-versus-Host Disease Incidence and Post-Transplant Thymic Restoration: A Single-Center Retrospective Study.

The use of anti-thymocyte globulin (ATG) as part of conditioning to prevent graft-versus-host disease (GVHD) may severely impair immune reconstitution (IR). We analyzed relationships between ATG exposure, the recipient lymphocyte count, IR, and transplant outcome. We retrospectively reviewed patients aged ≤ 18 years who underwent allogeneic HSCT between April 2005 and April 2020. The outcomes of interest included the incidence of GVHD, overall survival (OS), and IR. IR was analyzed through thymic magnetic resonance imaging (MRI) and by quantifying T CD4+ and recent thymic emigrants (RTEs). The ATG-exposed group was split into a low ATG/lymphocyte ratio subgroup (ratio < 0.01) and a high ATG/lymphocyte ratio subgroup (ratio > 0.01). The low ratio subgroup had a higher incidence of GVHD (29 [59%] vs. 7 [16.6%]) but a better IR in both laboratory and MRI imaging assessments (p < 0.0001). The median thymic volume in the low ratio subgroup was significantly higher (14.7 cm3 vs. 4.5 cm3, p < 0.001). This was associated with a better OS and lower transplant-related mortality (TRM) (80.4% vs. 58.0%, p = 0.031) and (13.1% vs. 33.0%, p = 0.035). An individualized approach to ATG dosing allows for the obtainment of rapid thymic reconstitution and the best transplant-related outcomes.

Effect of nutritional status on outcomes in children receiving umbilical cord blood stem cell transplantation.

The impacts of nutritional status on clinical outcomes in children receiving umbilical cord blood stem cell transplantation (UCBT) are not fully described. We evaluated the risk for malnutrition before transplantation admission and influence of weight loss during hospitalization on short-term clinical outcomes in children with UCBT. We conducted a retrospective study of pediatric patients up to age 18 years who received UCBT and were treated at the Children's Hospital of Fudan University between January 2019 and December 2020. The mean age of the 91 patients was 1.3 years, with 78 (85.7%) men and 13 (14.3%) women (p<0.001). UCBT was performed mostly for primary immunodeficiency disease (PID) (83, 91.2%). The weight loss differences among children with different primary diseases were statistically significant (p=0.003). Children with a large amount of weight loss during hospitalization (n = 24) had higher risks of skin graft-versus-host disease (GVHD) (multivariate OR=5.01, 95% CI: 1.35-18.65), intestinal GVHD (multivariate OR=7.27, 95% CI: 1.74-30.45), a longer median hospital stay (p=0.004), higher antibiotic costs (p=0.008) and higher total hospitalization costs (p=0.004). Malnutrition on admission was significantly positively correlated with longer parenteral nutrition (PN) time (p=0.008). Early nutritional intervention effects on clinical outcomes need further assessment. Underweight recipient child and excessive weight loss during transplantation increases the length and cost of hospital stay, and is associated with a high incidence of GVHD, which affects the prognosis of transplantation and medical resources consumption.

CT-132 Outcome of Sex-Mismatched Allogeneic Hemopoietic Stem Cell Transplantation from Human Leukocyte Antigen–Identical Sibling Donors in Patients With Hematologic Diseases

Hematopoietic stem cell transplantation is a procedure aiming to cure hematologic diseases. However, graft-versus-host disease (GVHD) and disease relapse/failure are common side effects of this treatment. Sex-mismatched transplantation, particularly with female donors and male patients, is known to be associated with higher incidence of GVHD or lower incidence of survival. This is caused by the antibodies against minor histocompatibility antigens found on the Y chromosome of the male recipient, which were found to be associated with increased risk of chronic GVHD and non-relapse mortality. The study aimed to determine the incidence of acute and chronic GVHD, overall survival, and non-relapse mortality when male patients received stem cells from female matched sibling donors in allogeneic hematopoietic stem cell transplantation. Retrospective study over 8 years. Nasser Institute Hospital. In this study, patients were divided into 2 groups. Group 1: female donors to male patients (245 patients). Group 2: male donors to female patients (186 patients) and same-sex donors and patients (506 patients). The median age was 20 years (7 months-60 years). The outcome of transplants in the female-to-male group was compared with that of the male-to-female and same-sex group. Overall survival, incidence of acute and chronic GVHD, non-relapse mortality, and relapse/failure rate. Overall survival was 68.6% in group 1 compared to 69.5% in group 2 (P=0.5). Acute GVHD was 24% in group 1 compared to 19.6% in group 2 (P=0.1). Chronic GVHD was 15.1% in group 1 compared to 9.6% in group 2 (P=0.02). Non-relapse mortality was 27.7% in group 1 compared to 25.7% in group 2 (P=0.5). Relapse/failure rate was 4.9% in group 1 compared to 6.5% in group 2 (P=0.3). Allogeneic stem cell transplantation for male patients from female donors can be associated with a significantly higher rate of chronic GVHD but a lower incidence of relapse/failure.

Comparison of T Cell Subsets and Cytokines between Steady-State and G-CSF-Primed Bone Marrow and Its Association with Graft-Versus-Host-Disease

BackgroundThe widespread use and success of allogeneic hematopoietic stem cell transplantation (allo-HSCT) can be affected by graft-versus-host-disease (GVHD), an immunological syndrome that involves tissue damage mediated by donor lymphocytes. Both, acute and chronic GVHD, result from an imbalance between the effector and regulatory arms of the immune system. On the other hand, worldwide, the main source of stem cells is peripheral blood (PBSC). However, its use has been associated with higher incidence of GVHD when compared with bone marrow. Although the fast engraftment using PBSC as a source of stem cells compares to that seen with G-CSF-primed bone marrow (G-BM), the latter, also associates with a decreased incidence of GVHD. At our institution, patients transplanted with G-BM, have a lower incidence of GVHD when compared to those transplanted with PBSC and steady state bone marrow (SS-BM). Some microenvironment characteristics of these sources of hematopoietic stem cells (HSCS) remain unknown, including differences between Tregs, Th17 cells, and cytokines, and its association with GVHD.AimThe aim of this study was to analyze lymphocyte subsets and associated cytokines in donor G-BM and SS-BM, comparing patients who developed GVHD and those who did not.Material and MethodsA prospective analysis was performed in 48 donors SS-BM and G-BM collected from March 2002 to April 2017. Twenty two samples collected since March 2002 were thawed; since 2014, samples (20 mL) were immediately processed and analyzed. A 24 hour resting with RPMI, and posterior activation with PMA (50 ng/ml) for 48 hours was performed. Cells were harvested and cytokines were evaluated by flow cytometry (CBA assay).From each sample, one million mononuclear cells were permeabilized, fixed, and stained with CD4-FITC, IL17A-PE, IFN -γ APC, and IL-4 PECy7, for their posterior phenotipication by flow cytometry. The samples were obtained in a BD LSR Fortessa cytometry, and analyzed with the Flow-Jo software. Comparison between variables was made by means of Student's t test using SPSS v.21.ResultsWe found increased Tregs (1.46% ± 0.69 vs 1.01% ± 0.49, p=0.01) and Th2 (1.55% ± 0.36 vs 1.28% ± 0.39, p=0.02) subsets in G-BM compared to SS-BM. Nonetheless, although differences in cytokine production were observed, we did not find any statistical significance. Acute GVHD was diagnosed in 9% (n=3) and 20% (n=3) of patients receiving G-BM and SS-BM, respectively. Chronic GVHD was seen in 33% of patients in both groups (receiving SS-BM or G-BM). Thirty one patients did not present either GVHD. In all the cohort, indistinctively from the HSCs used, acute GVHD was characterized by a predominant pro-inflammatory profile, with increased TNFα (59.28 ± 56.6 vs 14.21 ± 36.2 pg/mL, p=0.011), and a higher percentage of Th1 (22.55% ± 4.8 vs 20.71% ± 4.8, p=0.04) and Th17 (0.87% ± 0.33 vs 0.57% ± 0.24, p=0.009) cells. Furthermore, a deficient suppressor response, with decreased IL-10 production (1.17 ± 1.26 vs 33.55 ± 49.3 pg/mL, p<0.0001) as well as lower Tregs percentage (0.76% ± 0.12 vs 1.40% ± 0.68, p<0.0001) was found. Likewise, chronic GVHD showed the same profile, but with more striking differences in pro-inflammatory cytokine production. The T cell subset profile in chronic GVHD also showed an imbalance between pro-inflammatory and suppressor subsets percentage (figure 1 ).ConclusionsThis is the first study exploring the differences in T cells and cytokine profile between G-BM and SS-BM. Our results showed that G-BM has an enhanced suppressive phenotype compared to SS-BM. Also, patients who developed GVHD were characterized by an imbalance in pro-inflammatory and suppressor responses, with enhanced Th17 cells, as well as increased TNF-α, IL-6 and IL-17A production in contrast to a dampened Tregs frequency and IL-10 production which can explain the low frequency of GVHD in our transplanted patients using G-BM. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

The safety and effctiveness of donor memory T lymphocyte infusions after hematopoietic stem cell transplantation with ab T cell depletion platform in children with acute leukemia

T-cell ab depletion prevents “graft-versus-host” disease (GVHD), does not impair engraftment, and improves the outcomes of hematopoietic stem cell transplantation (HSCT) from a haploidentical donor. Memory T lymphocyte infusions (CD45RA-depleted) can transfer functional immunity to common pathogens to recipients. In a randomized study, we explored the safety and effctiveness of donor memory T lymphocyte infusions (DLI) in children with leukemia after HSCT with ab T cell depletion platform. The study was approved by the Independent Ethics Committee and the Scientifi Council of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology of the Ministry of Healthcare of the Russian Federation. A total of 149 patients were enrolled in the study; 76 patients were randomly assigned to the DLI group and 73 patients were allocated to the control group. Donors were haploidentical related in 91% of cases. The myeloablative conditioning regimen included treosulfan and total body irradiation. Anti-thymocyte globulin (ATG) was excluded from the conditioning regimen, instead, we used a combination of abatacept and tocilizumab. Graft processing involved TCRab-/CD19-depletion. The main parameters of assessment included the cumulative risk of detection of cytomegalovirus (CMV) DNA and the cumulative risk of grade II–IV GVHD. The additional parameters of assessment were the cumulative risk of transplant-related mortality, the cumulative risk of relapse, the overall and event-free survival rates, and the parameters of immune recovery. A historical control group was used to compare the primary outcomes of HSCT with ATG and an alternative immunomodulatory regimen (abatacept and tocilizumab). The cumulative risk of grade II–IV GVHD was 14% in the experimental group and 12% in the control group (p = 0.8). The cumulative risk of CMV viremia was 45% and 55% in the experimental and control groups, respectively (p = 0.4). In the prospective cohort, the rates of transplant-related mortality, the cumulative risk of relapse, and the overall survival were 2%, 25%, and 80%, respectively, without statistical diffrence between the arms. In the experimental group, we noticed a tendency toward an increase in the proportion of patients who developed an immune response to CMV in the early post-HSCT period. The substitution of ATG with tocilizumab and abatacept was not accompanied by a higher incidence of GVHD or graft failure; it was associated with signifiantly lower transplant-related mortality rates (2% vs 13%, p = 0.002) and improved immune recovery in the early post-HSCT period. Prophylactic infusions of donor memory lymphocytes are safe and may be used for further improvement in. the results of HSCT with ab T cell depletion platform.

Donor selection in a pediatric stem cell transplantation cohort using PIRCHE and HLA-DPB1 typing.

New strategies to optimize donor selection for hematopoietic stem cell transplantation (HSCT) have mainly been evaluated in adults, but the disease spectrum requiring HSCT differs significantly in children and has consequences for the risk of complications, such as graft-versus-host disease (GvHD). Here we evaluated whether HLA-DPB1 and Predicted Indirectly ReCognizable HLA-Epitope (PIRCHE) matching can improve donor selection and minimize risks specific for a pediatric cohort undergoing HSCT in Berlin between 2014 and 2016. The percentage of HLA-DPB1-mismatched HSCT in the pediatric cohort was in line with the general distribution among matched unrelated donor HSCT. Nonpermissive HLA-DPB1 mismatches were not associated with a higher incidence of GvHD, but the incidence of relapse was higher in patients undergoing HSCT from HLA-DPB1-matched transplantations. High PIRCHE-I scores were associated with a significantly higher risk for developing GvHD in patients undergoing HSCT from nine of ten matched unrelated donors. This finding persisted after including HLA-DPB1 into the PIRCHE analysis. Implementing PIRCHE typing in the donor selection process for HSCT in children could particularly benefit children with nonmalignant diseases and support further validation of PIRCHE-based donor selection in a larger number of children treated at different sites.

Efficacy of High-Dose Cytarabine Added to Cyclophosphamide/Total-Body Irradiation in the Conditioning Regimen of Allogeneic Hematopoietic Cell Transplantation for Myeloid Malignancy

INTRODUCTIONAllogeneic hematopoietic cell transplantation (HCT) is an effective therapeutic option for adults with acute myelogenous leukemia (AML) and myelodysplastic syndrome (MDS) after the conventional cyclophosphamide and total-body irradiation (CY/TBI) regimen, but post-transplant relapse is still of high importance. High-dose cytarabine (HDCA) can be added to CY/TBI for an intensified regimen; however, its additional effects have not yet been completely elucidated.METHODSWe conducted a cohort study to compare the prognosis of HDCA/CY/TBI and CY/TBI in HCT for AML/MDS, using a Japanese transplant registry database. Inclusion criteria are adult patients (aged 16 years or older) who underwent a single-unit cord blood transplantation (CBT) or bone marrow or peripheral blood stem cell transplantation (BMT/PBSCT) as a first HCT after CY/TBI (CY, 60 mg/kg for 2 days; TBI, 10-12 Gy divided into 4-6 fractions) or CY/TBI plus HDCA (HDCA/CY/TBI) between January 2000 and December 2012. HDCA was defined as cytarabine administration of 2 to 3 g/m2 twice a day for 2 to 3 days (total dose, 6-12 g/m2) before HCT.Overall survival (OS) was calculated with the Kaplan-Meier method and compared using log-rank tests for each covariant related to pre-transplant patient characteristics. Factors with significance or borderline significance (p < 0.1) in the univariate analysis were subjected to a multivariate analysis using the Cox proportional hazards model. The Fine-Gray proportional hazards model was used in multivariate analyses for tumor-related mortality and non-relapse mortality (NRM).Our protocol complied with the Declaration of Helsinki, and it was approved by the Registry Data Management Committee and by the Ethics Committee of Kyoto University, where the study was performed. Written informed consent was obtained from each patient at each institution.RESULTSWe analyzed data on 3,031 patients in total, composed of the HDCA/CY/TBI group (n = 1,052) and the CY/TBI group (n = 1,979) after CBT (n = 929) and BMT/PBSCT (n= 2,102). The median age was 38 years, and 86.1% of the patients had AML; high-risk disease was observed in 55.5% of the patients. In BMT/PBSCT, unrelated donors comprised 54.6%, and 63.9% of donors were HLA-matched. The median follow-up period after HCT was approximately 3.2 years. In CBT, OS was significantly superior in the HDCA/CY/TBI group compared to the CY/TBI group (adjusted hazard ratio [HR], 0.56; 95% confidence interval [CI], 0.45-0.69; p < 0.01), while in BMT/PBSCT improvement of OS was not observed in the HDCA/CY/TBI group (HR, 1.14; p = 0.13) (refer to Figure). Tumor-related mortality was lower in HDCA/CY/TBI than CY/TBI after CBT (HR, 0.50; p < 0.01); in BMT/PBSCT, however, post-transplant relapse and tumor-related mortality were not suppressed by the addition of HDCA (HR, 0.89 and 0.90; p = 0.58 and 0.34, respectively). The incidence of grade II to IV acute graft-versus-host disease (GVHD) and chronic GVHD was significantly higher in the HDCA/CY/TBI group than the CY/TBI group after CBT (HR, 1.33 and 2.30; p = 0.02 and < 0.01, respectively), whereas there were no differences in BMT/PBSCT (HR, 0.95 and 1.04; p = 0.54 and 0.64, respectively). Incidence of infectious episodes (bacterial, viral, and fungal) showed no significant differences between regimens in both donor sources. Hemorrhagic cystitis and thrombotic microangiopathy increased in HDCA/CY/TBI compared to CY/TBI after BMT/PBSCT (HR, 1.47 and 1.60; p = 0.06 and 0.04, respectively), leading to significantly higher NRM in this group (HR, 1.48, p < 0.01). On the other hand, NRM was not increased by the addition of HDCA after CBT (HR, 0.94; p = 0.73).CONCLUSIONThis study is the first to show the differences between HDCA/CY/TBI and CY/TBI after HCT for AML/MDS using a large cohort. Superiority of HDCA/CY/TBI to CY/TBI in CBT was clearly indicated, while these merits were not applied to BMT/PBSCT. The higher incidence of GVHD and stronger graft-versus-leukemia (GVL) effects may be involved in these differences between donor sources (BMT/PBSCT compared to CBT). A large-scale prospective study is warranted to validate these results and to establish the suitable conditioning regimens including HDCA administration. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Prophylactic Donor Lymphocyte Infusion to Prevent Relapse after Allogeneic Stem Cell Transplantation

Donor lymphocyte infusion (DLI) has been used to treat disease relapse after stem cell transplantation, but high incidence of graftversus-host disease (GVHD) after traditional DLI, and low response rates with robust relapse in acute leukemia have limited its wide application. Nonetheless, the promising graft versus leukemia effect elicited by DLI makes it a viable option, especially in the state of minimal residual disease after stem cell transplantation. Prophylactic donor lymphocyte infusion has been explored as a more tolerable, less toxic and efficacious option to prevent relapse. This review will summarize the results of the latest prophylactic DLI studies, and discuss our ongoing prophylactic DLI clinical trial after T cell depleted stem cell transplantation in patients with high risk hematologic malignancies.

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Aim The goal of the study was to evaluate a correlation of an HLA restricted minor histocompatibility antigen (mHAg) with the development of graft versus host disease (GVHD). The objective was to assess whether testing for mHAgs should be done on a prospective basis, to guide donor selection and reduce the high incidence of GVHD in post-transplant allografts when treating hematologic malignancies. Methods A cohort of 45 patient/unrelated donor pairs, 10/10 HLA match, in the NCI protocol 07-C-0195 were typed for 18 mHAgs using an SSP-PCR typing kit (Minor Histocompatibility Antigen Typing Kit; Life Technologies, Carlsbad, CA). GVHD data was obtained from the clinical protocol database. Patients were determined not evaluable if they relapsed or had residual disease requiring a donor lymphocyte infusion or additional chemotherapy. Due to clinical status, one patient could not be evaluated for acute or chronic GVHD. In addition, 4 patients could not be evaluated for chronic GVHD. Therefore, 44 out of 45 patients were evaluated for acute GVHD and 40 out of 45 patients for chronic GVHD. Statistical analysis was performed using the Fisher exact test. Results Patients with mHAg mismatches were analyzed for both acute and chronic GVHD. Preliminary analysis demonstrates that out of the 45 patient/donor pairs, 30 pairs had mHAgs mismatched in the GVHD direction. 19 of the 30 patients (63%) with mismatches developed acute GVHD (P = 0.062) and 15 of the 30 patients (50%) with mismatches developed chronic GVHD (P = 0.061). Nine of these patients developed both acute and chronic GVHD. Conclusions Data suggests some correlation regarding mHAg mismatches and the development of GVHD. Further study and a larger cohort may allow a gauge for the efficacy of testing for the mHAgs on a prospective basis. Testing on a prospective basis could give clinicians more knowledge to select donors with a favorable mHAg constellation to reduce the risk of their transplant patients developing GVHD.

Acute Graft Versus Host Disease in Hematopoietic Stem Cell Alotransplant Recipients

The transplantation of hematopoietic stem cells (HSCT) is a therapeutic intervention where the hematopoietic stem cells and the cells originating from them are being removed and replaced by the normal stem cells of donor or the patient him/her-self. HSCT today represent standardized biological manipulation for treating malignant, genetic and autoimmune diseases. The application of allogeneic hematopoietic stem cell transplantation (HSCT) is limited by life-threatening complications such as severe or acute graft-versus-host disease (GVHD). Despite intensive prophylaxis with immunosuppressive agents, the incidence of GVHD occurs in 9-50% of patients undergoing transplant with an identical HLA sibling matched donor and 75% of patients undergoing unrelated HLA donors. To evaluate our experiences in GVHD prophylaxis and treatment after alloHSCT, GVHD incidence and prognostic factors and administration of new immunosuppressive regiments. Can we recognize clinical parameters which are associated with occurrence and severity of graft-versus-host disease? Starting from September 2000 till September 2010, 63 patients (36 males and 27 females) at the age of 16-56 (median range 33 years) with hematological malignancies were treated with alloHSCT on Department of Hematology, Clinical Centre, Skopje. In 10 patients bone marrow was used as source of stem cells and in 53 patients stem cells were obtained from peripheral blood. From the group of 63 patients, 26 patients had active disease at the time of transplantation. GVHD prophylaxis was accomplished with combination of cyclosporine and methotrexate (Seattle regimen) or more intensive immunosuppression regiments. GVHD was noticed in 30 patients (47.6%) and in 33 patients (52.4%) a manifestation of GVHD was noticed. Acute GVHD was noticed in 24 patients (38%) and chronic GVHD in 20 patients (31.7%) The remaining 32 patients (45%) achieved complete clinical and hematological remission. Lethal outcome was confirmed in 31(49%) patients (9 from chrGVHD, 6 from acute GVHD, 16 from disease relapse). The incidence of acute GVHD in our study was 38% and 31% for chronic GVHD. The most common GVHD reaction was registered in female donors and male recipients, with higher GVHD incidence in elderly patients. In all patients stem cells were obtained from peripheral blood. Active disease, sex, source of hematopoietic cells, age and conditional regiments are the most significant predictive factors with the high incidence of GVHD.

Impact of prophylactic donor leukocyte infusions on mixed chimerism, graft-versus-host disease, and antitumor response in patients with advanced hematologic malignancies treated with nonmyeloablative conditioning and allogeneic bone marrow transplantation

In an attempt to capture graft-versus-tumor effects without graft-versus-host disease (GVHD), the authors initiated a trial of nonmyeloablative allogeneic bone marrow transplantation (BMT) in patients with advanced hematologic malignancies, with the majority of patients having chemotherapy-refractory disease. Forty-two patients received an HLA-matched related donor BMT after a cyclophosphamide and antithymocyte globulin-based conditioning that also included thymic irradiation for patients who had not received prior mediastinal radiotherapy. Prophylactic donor leukocyte infusion (pDLI) at a dose of 1 × 10 7 CD3 + cells per kilogram were given beginning 5 weeks post-BMT to 16 patients with mixed chimerism (MC) but without GVHD, whereas 26 patients did not receive pDLI, either because of GVHD or early relapse. Twelve of 16 patients (75%) receiving pDLI had T cell chimerism at the time of pDLI ≥40%. These patients, by day 100 post-BMT, either converted to full donor chimerism (FDC) (n = 10) or had an increase in or stable donor chimerism (n = 2) after pDLI. Four of 4 patients whose T cell chimerism was ≤20% at the time of pDLI, lost the graft. In contrast, only 5 of 18 evaluable patients (28%) not receiving a pDLI converted to FDC by day 100 post-BMT, 7 maintained MC, and 10 of an evaluable 22 lost the graft. Patients who had undergone a previous autologous stem cell transplant had a higher rate of conversion to FDC (69% v 31%) and higher incidence of GVHD (69% v 34%) compared with those who did not have a previous autologous SCT. Eleven of 16 patients (69%) who received a pDLI achieved a remission with 50% 1-year progression-free survival rate and 44% 3-year overall survival rate. Nineteen of 42 patients (45%) had ≥grade II acute GVHD, including 12 after BMT and 7 after pDLI. Approximately one third of patients, after having initial MC, eventually lost their donor graft. The authors conclude that (1) pDLI has the potential to convert MC to FDC; (2) sustained remissions can be achieved in patients with chemorefractory hematologic malignancies who receive a pDLI, albeit with a significant risk of acute GVHD; and (3) the degree of donor T cell chimerism at the time of pDLI is predictive of the fate of MC, ie, donor T cell chimerism ≥40% or ≤20% at the time of pDLI correlates with conversion of MC or loss of the graft, respectively.

ＨＬＡ適合造血細胞移植におけるマイナー組織適合抗原不一致の重要性

Mismatches of minor histocompatibility antigens (mHas) between HLA-identical stem cell donors and recipients are known as a major risk factor for graft-versus-host disease (GVHD). We determined alleles of 9mHas for 40 patients who had undergone stem cell transplantation from HLA-identical donors and investigated the association of their mismatches with relapse rate and GVHD. We observed a tendency toward a higher incidence of GVHD and lower relapse rate in patients with at least one or more incompatibilities of mHas than in patients without incompatibilities. In particular, relapse rate was significantly lower in a group of patients grafted from HLA-identical sibling donors with mHa-incompatibilities (p=0.05). In addition, no relapse was observed in at least one or more mHa-incompatible patients who developed GVHD. We conclude that mHas contribute to the development of the graft-versus-leukemia effect and may potentiate the graft-versus-leukemia effect in incompatible patients who develop GVHD.

The role of alphabeta- and gammadelta-T cells in allogenic donor marrow on engraftment, chimerism, and graft-versus-host disease.

We previously characterized a facilitating cell (FC) in mouse marrow that enables engraftment of allogeneic hematopoietic stem cells (HSCs) without causing graft-versus-host disease (GVHD). The FC shares some cell surface molecules with T cells (Thy1+, CD3epsilon+, CD8+, CD5+, and CD2+) but is T-cell receptor (TCR) negative. Historically, depletion of CD3+ or CD8+ cells from rat marrow was associated with an increased rate of failure of engraftment. In this study, we evaluated whether depletion of alphabeta- and gammadelta-TCR(+) T cells from donor marrow would retain engraftment potential yet avoid GVHD. Wistar-Furth rats were conditioned with 950 cGy of total body irradiation and transplanted with ACI bone marrow processed to remove either alphabeta-TCR(+), gammadelta-TCR(+), or alphabeta- plus gammadelta-TCR(+) T cells. Recipients were typed for chimerism at 28 days and monthly thereafter. Recipients of marrow depleted of alphabeta- (group A), gammadelta- (group B), or alphabeta- and gammadelta-TCR(+) T cells (group C) engrafted and had an average chimerism level of 73.0+/-8.3%, 92.3+/-9.2%, and 46.3+/-32.8%, respectively. Aggressive T-cell depletion did not remove the FC population (CD8+/CD3+/TCR(-)). Group A and group B both developed GVHD, with a higher incidence of GVHD in group B compared to group A. None of the recipients in group C developed GVHD. These data demonstrate that depletion of T cells from rat marrow does not impair engraftment of HSCs, indirectly supporting the existence of FCs in rat marrow. Moreover, donor alphabeta- and gammadelta-TCR(+) T cells contribute to GVHD in a nonredundant fashion, although alphabeta-TCR(+) T cells are more potent as the effector cells. Finally, the level of donor chimerism is influenced by the composition of the graft, because recipients of marrow that contain alphabeta-TCR(+) T cells exhibited significantly higher donor chimerism compared to recipients of marrow depleted of both alphabeta- and gammadelta-TCR(+) T cells.

Partially mismatched blood cell transplants for high-risk hematologic malignancy.

Eleven patients with high-risk hematologic malignancy received cryopreserved but otherwise unmanipulated blood cell transplants (BCT) from partially mismatched family members in whom progenitor cells had been mobilized by G-CSF. Donors were mismatched by up to one antigen in the GVH direction and up to three antigens in the rejection direction. Outcomes were compared with those of 22 patients receiving BCT from fully matched donors. Two mismatched patients died without engraftment on day 21 and 32. One had rejected bone marrow from the same donor, the other was mismatched by two antigens in the rejection direction and received the lowest dose of CD34+ cells. Median time to granulocyte engraftment was 21.5 (range 16-33) days for the mismatched group compared with 16 (11-28) days for the matched group (P = 0.01). No correlation was found between CD34+ cell dose and time to granulocyte or platelet recovery. In the mismatched and matched BCT groups respectively, the risk of grade II-IV acute graft-versus-host disease (GVHD) was 73% vs 28% (P = 0.001) and of chronic GVHD 100% vs 78% at 18 months (P = 0.01). The relationship of T cell dose to acute GVHD could only be evaluated in the matched group and no correlation was found. One of 11 mismatched patients and eight of 22 matched patients had relapse or persistent disease. Disease-free survival at 1 year was similar at 55% for mismatched and 50% for matched BCT. These results indicate that allogeneic BCT from partially mismatched family members is accompanied by a high incidence of GVHD but may result in comparable survival to BCT from fully matched donors.

HLA and graft-versus-host disease: A population-based study of HLA phenotypes of Jewish and Arabic bone marrow transplanted patients in Israel

The relationship between the incidence of graft-versus-host disease (GVHD) and human leukocyte antigens (HLA) was analyzed in HLA-identical sibling bone marrow transplantation donor/recipient pairs from the two major populations in Israel: Jewish and Arabic. HLA phenotypes were significantly different, in both groups, between patients and healthy controls. Among Jews, a higher incidence of GVHD was found with A28, CW3, CW6 of class I and DR7, DQ2 of class II; a lower incidence was found with A2, A26, B14. Among Arabs, a higher incidence of GVHD was found with B41, CW7 of class I, and DR2, DR13 of class II. The development of GVHD is apparently associated with HLA phenotypes specific to each population.

HERPES-VIRUS IMMUNITY AND ACUTE GRAFT-VERSUS-HOST DISEASE

The influence of pretransplant herpes-virus antibodies in 126 marrow-graft recipients and their HLA-identical (A, B, C, DR) sibling donors on the incidence of grades II-IV acute graft-versus-host disease (GVHD) was studied in relation to previously reported risk factors for GVHD. Logistic regression procedures were used to control for confounding factors. Increasing donor age (odds ratio 3·7 per decade; p = 0·02) and donor seronegativity for Epstein-Barr virus (EBV; odds ratio 10·1; p = 0·005) were associated with a high incidence of GVHD. Total rather than selective gastrointestinal decontamination (odds ratio 0·1; p = 0·004), donor seronegativity for herpes simplex virus (HSV; odds ratio 0·1; p = 0·003), and recipient EBV-seronegativity (odds ratio 0·05; p =0·002) were associated with a low incidence of GVHD. Pretransplant EBV and HSV serology may thus contribute substantially to the estimation of the risk for GVHD.

Increased incidence of murine graft-versus-host disease after allogeneic bone marrow transplantation by previous infusion of syngeneic bone marrow cells.

Different groups of BALB/c mice received supralethal total-body irradiation (TBI; 8.5 Gy, day 0). When 30 x 10(6) allogeneic (C57B1) bone marrow (BM) cells were infused with or without 10 x 10(6) syngeneic (BALB/c) bM cells on day 1, many animals (60%) died from graft-versus-host disease (GVHD). Typing of peripheral blood leukocytes for donor antigens showed that, respectively, 22/22 and 17/21 of the mice in both groups became chimeric. When syngeneic bone marrow was given on day 1 and allogeneic bone marrow on day 2 after TBI, a similar number of animals (21/23) became chimeric, but GVHD occurred more frequently in this group (25/26 mice, P less than 0.01). When the syngeneic bone marrow cells were replaced by spleen cells, or when the transplantation of allogeneic bone marrow was delayed till days 3 or 6 after TBI, almost all mice rejected the allogeneic BM graft and became long-term survivors. BALB/c mice receiving 30 x 10(6) C57B1 BM cells after 17 daily fractions of 0.2 Gy of total lymphoid irradiation (TLI), showed a high incidence of chimerism (15/17) and in none of the latter animals was GVHD observed. Despite the high incidence of GVHD in the mice receiving allogeneic BM after TBI and syngeneic BM transplantation, as compared with mice prepared with TLI which do not develop GVHD, suppressor cells were as easily induced after TBI and syngeneic BM transplantation as after TLI.