-
Annals of Hematology Mar 2024Aplastic anemia (AA) is a rare, life-threatening hematological disease, with a poorly defined incidence. As the data available on AA varies substantially worldwide, a... (Observational Study)
Observational Study
Aplastic anemia (AA) is a rare, life-threatening hematological disease, with a poorly defined incidence. As the data available on AA varies substantially worldwide, a multicenter, ambispective, observational study was carried out between 2010 and 2019 to assess the incidence, clinical management and survival of AA at seven Spanish hospitals. The incidence of AA was 2.83 per million inhabitants per year, consistent with that reported previously in Europe, with a median age at diagnosis of 61 years-old (range 12-86), and a similar number of males and females. The initial diagnosis was severe or very severe AA in 55.8% of cases and 93.7% required transfusion. The most frequent first line therapy was anti-thymocyte globulin (ATG) plus cyclosporin A (CsA, 44.2%), followed by other CsA-based regimes (46.3%), with hematopoietic stem cell transplantation an infrequent 1st line therapy. The 6-month response rate was 68.2%, which then increased over a median follow-up of 3.9 years. The 5-year overall survival (5OS) was 73.6%, similar in severe (78.6%) and very severe AA patients (74.6%) but lower in moderate AA (MAA) patients (68.4%). The 5OS was 100% in 0-25 year-old patients but dropping to 58.3% in patients ≥ 60 years-old. At the last contact, 75.8% of the patients were alive. In conclusion, the incidence, characteristics and management of AA in our study are consistent with that reported previously. In terms of survival, although the global long-term OS rate was good, there is room for improvement, particularly in older patients. Finally, what appears to be a worse long-term survival of MAA patients, as reported previously, reinforces the importance of not underestimating this condition when diagnosed as MAA.
Topics: Male; Female; Humans; Aged; Child; Adolescent; Young Adult; Adult; Middle Aged; Aged, 80 and over; Infant, Newborn; Infant; Child, Preschool; Anemia, Aplastic; Spain; Incidence; Antilymphocyte Serum; Cyclosporine; Hematopoietic Stem Cell Transplantation; Immunosuppressive Agents; Treatment Outcome
PubMed: 38175253
DOI: 10.1007/s00277-023-05602-x -
American Journal of Hematology Mar 2024Hematopoietic cell transplantation (HCT) for hematologic malignancies with non-remission disease and/or prior post-transplant relapse have poor relapse-free survival. We...
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 (C ) was the strongest predictor of Grade 2-4 aGVHD through day +100. Patients with C ≥ 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.
Topics: Adult; Humans; Middle Aged; Antilymphocyte Serum; Graft vs Host Disease; Hematologic Neoplasms; Hematopoietic Stem Cell Transplantation; Neoplasm Recurrence, Local; Recurrence; Retrospective Studies; Transplantation Conditioning; Adolescent; Young Adult; Aged
PubMed: 38165019
DOI: 10.1002/ajh.27195 -
Isatuximab Monotherapy for Desensitization in Highly Sensitized Patients Awaiting Kidney Transplant.Journal of the American Society of... Mar 2024There is no standardized desensitization regimen for kidney transplant candidates. CD38, expressed by plasma cells, could be targeted for desensitization to deplete...
SIGNIFICANCE STATEMENT
There is no standardized desensitization regimen for kidney transplant candidates. CD38, expressed by plasma cells, could be targeted for desensitization to deplete plasma cells producing alloantibodies and donor-specific antibodies. Few studies and case reports are available regarding the use of CD38 antibodies for desensitization in patients awaiting kidney transplant. This study shows that isatuximab, a CD38-targeting therapy, was well tolerated in kidney transplant candidates, with a durable decrease in anti-HLA antibodies and partial desensitization activity. The short treatment period and long follow-up of this study allowed for the understanding of the mechanism and timing for any antibody rebound. Isatuximab could be further investigated as an option for adjunct therapy to existing desensitization for patients on the kidney transplant waitlist.
BACKGROUND
Patients with calculated panel reactive antibody (cPRA) ≥80.00%, particularly those with cPRA ≥99.90%, are considered highly sensitized and underserved by the Kidney Allocation System. Desensitization removes circulating reactive antibodies and/or suppresses antibody production to increase the chances of a negative crossmatch. CD38 is expressed highly on plasma cells, thus is a potential target for desensitization.
METHODS
This was an open-label single-arm phase 1/2 study investigating the safety, pharmacokinetics, and preliminary efficacy of isatuximab in patients awaiting kidney transplantation. There were two cohorts, cohorts A and B, which enrolled cPRA ≥99.90% and 80.00% to <99.90%, respectively.
RESULTS
Twenty-three patients (12 cohort A, 11 cohort B) received isatuximab 10 mg/kg weekly for 4 weeks then every 2 weeks for 8 weeks. Isatuximab was well tolerated with pharmacokinetic and pharmacodynamic profiles that indicated similar exposure to multiple myeloma trials. It resulted in decreases in CD38 + plasmablasts, plasma cells, and NK cells and significant reductions in HLA-specific IgG-producing memory B cells. Overall response rate, on the basis of a predefined composite desensitization end point, was 83.3% and 81.8% in cohorts A and B. Most responders had decreases in anti-HLA antibodies that were maintained for 26 weeks after the last dose. Overall, cPRA values were minimally affected, however, with only 9/23 patients (39%) having cPRA decreases to target levels. By study cutoff (median follow-up of 68 weeks), six patients received transplant offers, of which four were accepted.
CONCLUSIONS
In this open-label trial, isatuximab was well tolerated and resulted in a durable decrease in anti-HLA antibodies with partial desensitization activity.
CLINICAL TRIAL REGISTRATION NUMBER
NCT04294459 .
Topics: Humans; Kidney Transplantation; Antibodies, Monoclonal, Humanized; Kidney; Isoantibodies; Antilymphocyte Serum
PubMed: 38147137
DOI: 10.1681/ASN.0000000000000287 -
American Journal of Transplantation :... May 2024High frequencies of donor-reactive memory T cells in the periphery of transplant candidates prior to transplantation are linked to the development of posttransplant...
High frequencies of donor-reactive memory T cells in the periphery of transplant candidates prior to transplantation are linked to the development of posttransplant acute rejection episodes and reduced allograft function. Rabbit antithymocyte globulin (rATG) effectively depletes naïve CD4 and CD8 T cells for >6 months posttransplant, but rATG's effects on human donor-reactive T cells have not been carefully determined. To address this, we performed T cell receptor β-chain sequencing on peripheral blood mononuclear cells aliquots collected pretransplant and serially posttransplant in 7 kidney transplant recipients who received rATG as induction therapy. We tracked the evolution of the donor-reactive CD4 and CD8 T cell repertoires and identified stimulated pretransplant, CTV-(surface dye)-labeled, peripheral blood mononuclear cells from each patient with donor cells or third-party cells. Our analyses showed that while rATG depleted CD4 T cells in all tested subjects, a subset of donor-reactive CD8 T cells that were present at high frequencies pretransplant, consistent with expanded memory cells, resisted rATG depletion, underwent posttransplant expansion and were functional. Together, our data support the conclusion that a subset of human memory CD8 T cells specifically reactive to donor antigens expand in vivo despite induction therapy with rATG and thus have the potential to mediate allograft damage.
Topics: Kidney Transplantation; Humans; Antilymphocyte Serum; CD8-Positive T-Lymphocytes; Male; Tissue Donors; Graft Rejection; Middle Aged; Female; Adult; Receptors, Antigen, T-Cell; Animals; CD4-Positive T-Lymphocytes; Prognosis; Follow-Up Studies; Kidney Failure, Chronic; Rabbits; Graft Survival; Lymphocyte Depletion
PubMed: 38141722
DOI: 10.1016/j.ajt.2023.12.016 -
Scientific Reports Dec 2023Cyclosporine-A (CsA) is used to prevent acute graft-versus-host disease (aGvHD). European Society for Blood and Marrow transplantation (EBMT) recommends a CsA target...
Higher cyclosporine-A concentration increases the risk of relapse in AML following allogeneic stem cell transplantation from unrelated donors using anti-thymocyte globulin.
Cyclosporine-A (CsA) is used to prevent acute graft-versus-host disease (aGvHD). European Society for Blood and Marrow transplantation (EBMT) recommends a CsA target serum concentration of 200-300 µg/L during the first month after allogeneic hematopoietic stem cell transplantation (HSCT). With this study, we investigated whether a median CsA concentration > 200 µg/L (CsA) the first month after HSCT, compared to ≤ 200 µg/L (CsA), increased the relapse risk of acute myloid leukemia (AML), using unrelated donors (URD) and antithymocyte globulin (ATG). Data was collected from 157 patients with AML, transplanted 2010-2016. The cumulative incidence of relapse (CIR) at 60 months was 50% in the CsA versus 32% in the CsA group (p = 0.016). In univariate analysis, CsA versus CsA (p = 0.028), 10-unit increase of CsA as a continuous variable (p = 0.017) and high risk disease (p = 0.003) were associated with higher CIR. The results remained after adjusting for disease risk. Death following relapse occurred more frequently in the CsA group (p = 0.0076). There were no significant differences in rates of aGvHD, chronic GvHD (cGvHD), EBV/CMV-infections or overall survival (OS) between the two groups. In conclusion, we found that a median CsA concentration > 200 µg/L, the first month after HSCT, results in higher CIR of AML when combined with ATG.
Topics: Humans; Cyclosporine; Antilymphocyte Serum; Unrelated Donors; Hematopoietic Stem Cell Transplantation; Leukemia, Myeloid, Acute; Graft vs Host Disease; Acute Disease; Recurrence; Retrospective Studies; Transplantation Conditioning
PubMed: 38123675
DOI: 10.1038/s41598-023-50105-4 -
Diabetes Care Feb 2024Low-dose antithymocyte globulin (ATG) (2.5 mg/kg) preserves C-peptide and reduces HbA1c in new-onset stage 3 type 1 diabetes, yet efficacy in delaying progression from...
OBJECTIVE
Low-dose antithymocyte globulin (ATG) (2.5 mg/kg) preserves C-peptide and reduces HbA1c in new-onset stage 3 type 1 diabetes, yet efficacy in delaying progression from stage 2 to stage 3 has not been evaluated.
RESEARCH DESIGN AND METHODS
Children (n = 6) aged 5-14 years with stage 2 type 1 diabetes received off-label, low-dose ATG. HbA1c, C-peptide, continuous glucose monitoring, insulin requirements, and side effects were followed for 18-48 months.
RESULTS
Three subjects (50%) remained diabetes free after 1.5, 3, and 4 years of follow-up, while three developed stage 3 within 1-2 months after therapy. Eighteen months posttreatment, even disease progressors demonstrated near-normal HbA1c (5.1% [32 mmol/mol], 5.6% [38 mmol/mol], and 5.3% [34 mmol/mol]), time in range (93%, 88%, and 98%), low insulin requirements (0.17, 0.18, and 0.34 units/kg/day), and robust C-peptide 90 min after mixed meal (1.3 ng/dL, 2.3 ng/dL, and 1.4 ng/dL).
CONCLUSIONS
These observations support additional prospective studies evaluating ATG in stage 2 type 1 diabetes.
Topics: Child; Humans; Antilymphocyte Serum; Blood Glucose; Blood Glucose Self-Monitoring; C-Peptide; Diabetes Mellitus, Type 1; Glycated Hemoglobin; Hypoglycemic Agents; Insulin; Prospective Studies
PubMed: 38117469
DOI: 10.2337/dc23-1750 -
Frontiers in Immunology 2023Idiopathic acquired aplastic anemia (AA) is considered an immune-mediated syndrome of bone marrow failure since approximately 70% of patients respond to...
Idiopathic acquired aplastic anemia (AA) is considered an immune-mediated syndrome of bone marrow failure since approximately 70% of patients respond to immunosuppressive therapy (IST) consisting of a course of anti-thymocyte globulin (ATG) followed by long-term use of ciclosporin. However, the immune response that underlies the pathogenesis of AA remains poorly understood. In this study, we applied high-dimensional mass cytometry on bone marrow aspirates of AA patients pre-ATG, AA patients post-ATG and healthy donors to decipher which immune cells may be implicated in the pathogenesis of AA. We show that the bone marrow of AA patients features an immune cell composition distinct from healthy donors, with significant differences in the myeloid, B-cell, CD4 and CD8 T-cells lineages. Specifically, we discovered that AA pre-ATG is characterized by a disease-specific immune cell network with high frequencies of CD16 myeloid cells, CCR6 B-cells, Th17-like CCR6 memory CD4 T-cells, CD45RACCR7CD38 CD8 T-cells and KLRG1 terminally differentiated effector memory (EMRA) CD8 T-cells, compatible with a state of chronic inflammation. Successful treatment with IST strongly reduced the levels of CD16 myeloid cells and showed a trend toward normalization of the frequencies of CCR6 B-cells, CCR6 memory CD4 T-cells and KLRG1EMRA CD8 T-cells. Altogether, our study provides a unique overview of the immune landscape in bone marrow in AA at a single-cell level and proposes CCR6 as a potential new therapeutic target in AA.
Topics: Humans; Anemia, Aplastic; Bone Marrow; CD8-Positive T-Lymphocytes; Cyclosporine; Pancytopenia; Antilymphocyte Serum
PubMed: 38094307
DOI: 10.3389/fimmu.2023.1274116 -
Saudi Journal of Kidney Diseases and... Jan 2023Development of de novo donor-specific anti-HLA antibody (dnDSA) is associated with poor graft survival in adults. However, there is a paucity of data about its...
Development of de novo donor-specific anti-HLA antibody (dnDSA) is associated with poor graft survival in adults. However, there is a paucity of data about its prevalence and outcome in Indian children. We retrospectively assessed the proportion and spectrum of dnDSA and its outcome on antibody-mediated rejection (ABMR) and graft function. Children ≤18 years who were transplanted between November 2016 and October 2019 were included in this study. Pretransplant donor-specific antibody (DSA) was screened by complement-dependent cytotoxicity, flow cytometry crossmatch, and single antigen bead (SAB) class I and II by Luminex platform. Either antithymocyte globulin or basiliximab was used as induction. Tacrolimus, mycophenolate, and prednisolone were used for the maintenance of immunosuppression. SAB screening was done at 1, 3, 6 months, and yearly in seven children and at the time of acute graft dysfunction in eight. Mean fluorescence intensity ≥1000 was considered positive. Protocol biopsies were done at 3, 6, and 12 months and annually thereafter in seven children. Fifteen children, all males with a median age (interquartile range) of 13 years (11; 15.5) were analyzed. Only one child had pretransplant DSA who developed dnDSA posttransplant. Overall, 8 (53%) developed dnDSA over a median follow-up of 18 months. Seven (87%) had Class II, one Class I and 3 (37%) both Class I and II. Six had dQ and two had DR. All children with dnDSA had ABMR, of these two had subclinical rejection. DSAs persisted despite treatment, though graft function improved. Children with DSA and ABMR had lower graft function than those without DSA. The proportion of dnDSA was high in our study, majority against DQ. The detection of dnDSA prompted early diagnosis and treatment of ABMR.
Topics: Adult; Male; Humans; Child; Adolescent; Kidney Transplantation; Retrospective Studies; Graft Rejection; HLA Antigens; Antibodies; Antilymphocyte Serum; Graft Survival; Isoantibodies; Transplant Recipients
PubMed: 38092720
DOI: 10.4103/1319-2442.391006 -
Immunotherapy Feb 2024Severe aplastic anemia (SAA) and very severe aplastic anemia (vSAA) are blood diseases of the bone marrow. If a suitable donor for bone marrow transplant as initial... (Review)
Review
WHAT IS THIS SUMMARY ABOUT?
Severe aplastic anemia (SAA) and very severe aplastic anemia (vSAA) are blood diseases of the bone marrow. If a suitable donor for bone marrow transplant as initial treatment is unavailable, standard immunosuppression is used. Standard immunosuppression treatment includes horse antithymocyte globulin (hATG) and cyclosporin A (CsA). This summary investigated the results of standard immunosuppression treatment (Group A) versus standard immunosuppression treatment with a medication called eltrombopag (Group B) in participants with SAA and vSAA. Eltrombopag is a medicine that improves the blood platelet level and is taken by mouth (orally).
WHAT WERE THE RESULTS OF THE STUDY?
Compared to Group A, more participants in Group B showed increased blood cell level to a normal range without SAA or vSAA and faster treatment response. Side effects were similar in both groups even with the addition of eltrombopag for Group B. Participants in both groups reported feeling well after 6, 12 and 24 months. Differences in the participant-reported scores (overall health, physical, emotional, and social) between Group A and Group B were minimal.
WHAT DO THE RESULTS OF THE STUDY MEAN?
Immunosuppression treatment (hATG plus CsA) with eltrombopag benefited participants with SAA and vSAA and could be the new standard for SAA in persons who cannot undergo bone marrow transplant. At this time, eltrombopag is only approved in specific countries to treat the condition under study that is discussed in this summary. NCT02099747 (RACE study).
Topics: Humans; Anemia, Aplastic; Antilymphocyte Serum; Cyclosporine; Benzoates; Immunosuppressive Agents; Treatment Outcome
PubMed: 38088156
DOI: 10.2217/imt-2023-0200 -
HLA Jan 2024Hematopoietic stem cell transplantation (HSCT) offers the highest curative potential for patients with hematological malignancies. Complications including infection,...
Hematopoietic stem cell transplantation (HSCT) offers the highest curative potential for patients with hematological malignancies. Complications including infection, graft-versus-host disease (GVHD), and relapse reflect delayed or dysregulated immune reconstitution. After transplantation, NK cells rapidly reconstitute and are crucial for immune surveillance and immune tolerance. NK cell function is tightly regulated by killer immunoglobin-like receptors (KIRs). Previous studies have revealed that donor KIRs, especially some activated KIRs (aKIRs) are closely related to transplant outcomes. Here, we performed a retrospective study, including 323 patients who received haploidentical (haplo) HSCT in our center. In univariate analysis, donor KIR2DS1, KIR2DS3 and KIR3DS1 gene protected patients with lymphoid disease from Epstein-Barr virus (EBV) and cytomegalovirus (CMV) reactivation, while donor KIR2DS1, KIR2DS5 and KIR3DS1 gene conferred a higher risk of CMV reactivation for patients with myeloid disease. Multivariate analysis confirmed that donor telomeric (Tel) B/x and KIR2DS3 gene best protected patients with lymphoid disease from EBV (p = 0.017) and CMV reactivation (p = 0.004). In myeloid disease, grafts lacking Tel B/x and KIR2DS5 gene correlated with the lowest risk of CMV reactivation (p = 0.018). Besides, donor aKIR genes did not influence the rates of GVHD, relapse, non-relapse mortality (NRM) and overall survival (OS) in this study. The reactivation of EBV and CMV was associated with poor prognosis of haplo-HSCT. In conclusion, we found that donor aKIR genes might have a synergistic effect on CMV and EBV reactivation after haplo-HSCT. Whether the influence of donor aKIR genes varies with disease types remained to be studied.
Topics: Humans; Herpesvirus 4, Human; Antilymphocyte Serum; Retrospective Studies; Epstein-Barr Virus Infections; Alleles; Neoplasm Recurrence, Local; Hematopoietic Stem Cell Transplantation; Cytomegalovirus Infections; Graft vs Host Disease; Recurrence
PubMed: 38081622
DOI: 10.1111/tan.15320