Anti-Thymocyte Globulin as a Therapy for Chronic Lung Allograft Dysfunction: A Single-Center Experience.

INTRODUCTION: Anti-thymocyte globulin (ATG) is a polyclonal antibody formulation which has been used as a second-line therapy for chronic lung allograft dysfunction (CLAD). Limited data exist evaluating its efficacy; however, several single-center retrospective studies have variably demonstrated either improvement or stabilization of spirometry parameters after administration of ATG. ATG has been in use at UT Southwestern for treatment of CLAD since at least 2010; here, we seek to evaluate the effectiveness of this intervention at our center.  METHODS: A retrospective chart review was conducted of a total of 136 patients who underwent lung transplantation at UT Southwestern Medical Center between 2010 and 2022. Of these, 72 patients had received ATG specifically for treatment of CLAD, and the remaining 64 had never received ATG. Two separate analyses were performed: in the first, among those who received ATG for CLAD, spirometry data from the 6 months preceding and following ATG administration were reviewed and rates of change in FEV1 were calculated for each time period. Descriptive statistics were performed to summarize the baseline clinical characteristics and outcomes after ATG, with patients classified as having either a full response (positive rate of change in FEV1) or partial response (>20% attenuation in rate of FEV1 decline) to ATG.  In the second analysis, survival was described among those who received ATG for CLAD and comparison was provided between propensity-score matched cohorts from the ATG and non-ATG groups. RESULTS: Of the 63 patients who received ATG for treatment of CLAD (and had adequate spirometry measurements available to trend FEV1), 49 (77.8%) had at least a partial response to therapy; 8 (12.7%) experienced an overall improvement in FEV1. Response to ATG was found to be associated with a more rapid rate of pre-ATG decline in FEV1; no other baseline parameters were found to be predictive of a response to ATG. Median post-CLAD graft survival was 31.7 months among those who received ATG, and only baseline absolute neutrophil count was found to be associated with worse post-CLAD graft survival among this group. CONCLUSION: Anti-thymocyte globulin therapy, when given for CLAD, was associated with at least a modest attenuation in rate of FEV1 decline in most patients but only rarely preceded an absolute improvement in FEV1. Further study is warranted to better define the role for ATG in treatment of CLAD, a challenging disease state with limited therapeutics available.

Basiliximab induction alone vs a dual ATG-basiliximab approach in first live-donor non-sensitized kidney transplant recipients with low HLA matching.

Background: Individualizing induction therapy based on immunological risk is crucial for optimizing outcomes in kidney transplantation. Methods: A retrospective analysis included 157 first live-donor non-sensitized kidney transplant recipients (KTRs). Within this cohort, 96 individuals exhibited low human leukocyte antigen (HLA) matching (5-6 HLA mismatches). The low HLA match subgroup was categorized into 52 KTRs receiving basiliximab alone and 44 recipients treated with a combined single ATG dose of 1.5 mg/kg and basiliximab. The primary endpoint was early acute cellular rejection (ACR) within 6 months post-transplant while secondary outcomes encompassed infection rates, renal allograft function, length of stay (LOS) and readmissions post-transplant. Results: The incidence of early ACR was decreased for low HLA match KTRs, who received ATG-basiliximab, when compared with low HLA-matched KTRs who received basiliximab alone (9.1% vs 23.9%, P = .067). Age was a predictor for rejection, and subgroup analysis showed consistent rejection reduction across age groups. No significant differences were observed in admission for transplant LOS or in peri-operative complications, nor in infections rate including BK and cytomegalovirus viremia, allograft function and number of readmissions post-transplant up to 6 months post-transplant. Conclusion: In non-sensitized first live-donor KTRs with low HLA matching, a dual ATG-basiliximab induction approach significantly reduced early ACR without compromising safety.

Other Immunomodulatory Treatment for Cytokine Storm Syndromes.

Cytokine storm syndromes (CSS) include different entities such as macrophage activation syndrome, primary and secondary hemophagocytic lymphohistiocytosis (HLH), and multisystem inflammatory syndrome in children (MIS-C) associated with COVID-19. An effective management strategy is critical in CSS. While biologics have become an essential part of CSS treatment, hematopoietic stem cell transplantation (HSCT) has changed the fate of primary HLH patients. This chapter will focus on the available alternative immunomodulatory therapies in CSS, which include corticosteroids, cyclosporine A, intravenous immunoglobulin, interleukin 18 binding protein, therapeutic plasmapheresis, HSCT, and mesenchymal stromal cell-based therapies.

Corrigendum: Therapeutic drug monitoring of anti-thymocyte globulin in allogeneic stem cell transplantation: proof of concept.

[This corrects the article DOI: 10.3389/fphar.2022.828094.].

Outcomes with low dose anti-thymocyte globulin based graft versus host disease prophylaxis after mismatched unrelated donor allogeneic hematopoietic cell transplantation.

BACKGROUND: Anti-thymocyte globulin (ATG) based graft versus host disease (GVHD) prophylaxis is widely used for mismatched unrelated donor allogeneic hematopoietic cell transplantation (HCT) although optimal dose remains unclear. Although recent literature suggested improved outcomes with PTCy-based regimens when compared to ATG-based regimens these studies used doses of ATG ≥5 mg/kg. Thus, we analyzed outcomes of HLA 9/10 MMUD allogeneic HCTs using lower-dose ATG-based regimens at our center. METHODS: We retrospectively analyzed outcomes of HLA 9/10 MMUD allogeneic HCTs using lower dose ATG-based regimens for all adults undergoing allogeneic HCT at The Ottawa Hospital from 2015 to 2022. Data regarding demographics, conditioning regimen, dose of ATG, rates of GVHD, duration of remission, and survival, were collected and analyzed. RESULTS: Seventy-seven (n = 77) patients (males 62.3%; median age 50 years) underwent allogeneic HCT from MMUD. Majority(81%; n = 63) received 2.5 mg/kg of rabbit ATG and remaining 18.2% (n = 14) received 4.5 mg/kg. Grade II-IV acute GVHD occurred in 24.7% (n = 19) while any chronic GVHD occurred in 32.5% (n = 25) patients. After a median follow-up of 21 months, relapse occurred in 28.6% of patients. Two-year OS, GRFS, CIR, and NRM were 60.6%, 45.3%, 16.9%, and 18.2% respectively. Dose of ATG (2.5 mg/kg vs. 4.5 mg/kg) was not associated with outcomes in either univariate or multivariate analyses. CONCLUSIONS: When compared to published studies using ATG doses ≥5 mg/kg, GVHD prophylaxis using lower dose ATG may potentially lead to improved outcomes in patients undergoing MMUD allogeneic HCT. Further studies are needed to directly compare lower dose ATG to PTCy-based regimens to determine ideal GVHD prophylaxis for these patients.

Low-dose anti-thymocyte globulin plus low-dose posttransplant cyclophosphamide-based regimen for prevention of graft-versus-host disease in haploidentical peripheral blood stem cell transplantation for pediatric patients with hematologic malignancies.

The low-dose anti-thymocyte globulin (ATG) plus low-dose post transplantation cyclophosphamide (PTCy) -based (low-dose ATG/PTCy-based) regimen had a promising activity in preventing of graft-versus-host disease (GVHD) in adult patients. However, its efficacy in pediatric patients remain to be defined. Here, we presented the findings from 35 pediatric patients undergoing haploidentical peripheral blood stem cell transplantation (haplo-PBSCT) with the new regimen for GVHD prophylaxis. The cumulative incidences (CIs) of grades II-III and III-IV acute GVHD (aGVHD) were 34% (95% CI, 17-48%) and 11% (95% CI, 0-21%) within 180 days post-transplantation, respectively. The CIs of chronic GVHD (cGVHD) and moderate-to-severe cGVHD within 2 years were 26% (95% CI, 7-41%) and 12% (95% CI, 0-25%), respectively. The 2-year probabilities of overall survival, relapse-free survival, and graft-versus-host disease and relapse-free survival were 89% (95% CI, 78-100%), 82% (95% CI, 68-98%) and 59% (95% CI, 43-80%), respectively. The CIs of cytomegalovirus (CMV) and Epstein-Barr virus (EBV) reactivation by day 180 were 37% (95% CI, 19-51%) and 20% (95% CI, 6-32%) respectively. These results strongly advocate for the efficacy of the low-dose ATG/PTCy-based regimen as a robust strategy for GVHD prevention in haplo-PBSCT for pediatric patients.

Combination of Anti-thymocyte Globulin with Post-transplant Cyclophosphamide for GVHD Prophylaxis in Patients Undergoing Haploidentical Hematopoietic Stem Cell Transplantation: Systematic Review and Meta-analysis.

A new strategy combining anti-thymocyte globulin with post-transplant cyclophosphamide (ATG/PTCy) for graft-versus-host disease (GVHD) prevention was developed. This study aims to perform a systematic review and meta-analysis of studies comparing ATG/PTCy with ATG or PTCy in patients with hematological malignancies undergoing haploidentical hematopoietic stem cell transplantation. Meta-analysis was conducted with Review Manager version 5.4; pooled risk ratios (RRs) and hazard ratios (HRs) were calculated for dichotomous data and time-to-event data, respectively. A fixed-effects model was used if there was no significant heterogeneity. Literature search and study selection identified 14 eligible studies, including both randomized controlled trial and retrospective comparative studies. Different dosage adjustment strategies were applied; the total dose was 2.5-10 mg/kg for ATG and 29-100 mg/kg for PTCy. Meta-analysis results suggest that ATG/PTCy is associated with significantly lower risk of grades II-IV acute GVHD compared with ATG (RR 0.52; 95% CI: 0.41-0.65; P < .00001) and PTCy (RR 0.53; 95% CI: 0.34-0.83; P = .005) without increasing risk of disease relapse. In addition, ATG/PTCy is associated with significantly better overall survival and GVHD-free/relapse-free survival than ATG and PTCy. Future research is required to further establish the benefits of ATG/PTCy and determine the optimal dosage adjustment strategies. BACKGROUND: Haploidentical stem cell transplantation (haplo-HSCT) is associated with higher incidences of graft-versus-host disease (GVHD). A new strategy combining anti-thymocyte globulin with post-transplant cyclophosphamide (ATG/PTCy) for GVHD prevention has been developed, but its benefits and risks remain unclear. OBJECTIVE: This study aims to performs a systematic review and meta-analysis of studies comparing ATG/PTCy with ATG or PTCy in patients with hematological malignancies undergoing haplo-HSCT. STUDY DESIGN: Literature search was performed in databases including Ovid Medline, Embase, Cochrane Library and China Biology Medicine (CBM). Two investigators independently screened eligible studies and extracted data. Meta-analysis was conducted with Review Manager version 5.4; pooled hazard ratios (HRs) for time-to-event outcomes were obtained using a generic inverse-variance method, and pooled risk ratios (RRs) for dichotomous data were obtained using the Mantel-Haenszel method. A fixed-effects model was adopted if there was no significant heterogeneity. The primary outcome is incidence of acute GVHD. RESULTS: Literature search and study selection identified 14 eligible studies, including both 1 randomized controlled trial and 13 retrospective comparative studies. Different dosage adjustment strategies were applied; the total dose was 2.5-10 mg/kg for ATG and 29-100 mg/kg for PTCy. Meta-analysis results suggest that ATG/PTCy is associated with significantly lower risk of grades II-IV acute GVHD compared with ATG (RR 0.52; 95% CI: 0.41-0.65; P < .00001) and PTCy (RR 0.53; 95% CI: 0.34-0.83; P = .005) without increasing risk of disease relapse. In addition, ATG/PTCy is associated with significantly lower risk of grades III-IV acute GVHD (RR 0.33; 95% CI: 0.23-0.49; P < .00001) and chronic GVHD (RR 0.65; 95% CI: 0.51-0.81; P = .0002) in comparison with ATG. Further analyses suggest that ATG/PTCy is associated with significantly better overall survival and GVHD-free/relapse-free survival than ATG and PTCy, but the risks of cytomegalovirus (RR 1.42; 95% CI: 1.03-1.95; P = .03) and Epstein Barr Virus (RR 3.17; 95% CI: 1.61-6.23; P = .0008) reactivation are higher when compared with PTCy. CONCLUSIONS: Our results suggest that the combination of ATG with PTCy for GVHD prevention in haplo-HSCT is associated with improved efficacy but higher risk of infection. Future research is required to further establish the benefits and risks of ATG/PTCy and determine the optimal dosage adjustment strategies.

A Mentee's perspective on Dr. Anthony Monaco: the quiet giant of transplantation.

A mentee's perspective of an academic journey on a path paved by a pioneering transplant surgeon-scientist.

Anti-thymocyte globulin combined with post-transplantation cyclophosphamide reduce graft-versus-host disease in hematopoietic stem cell transplantation for pediatric leukemia.

This retrospective analysis evaluated the use of anti-thymocyte globulin (ATG) with or without post-transplantation cyclophosphamide (PTCy) for graft-versus-host disease (GvHD) prophylaxis in children with acute leukemia undergoing hematopoietic stem cell transplantation (HSCT). The study included 57 children, with 35 in the ATG-PTCy group and 22 in the ATG group. While overall incidence of acute and chronic GvHD did not differ significantly between groups, the ATG-PTCy group had lower rates of grade II-IV acute GvHD (p = 0.013) and moderate-to-severe chronic GvHD (p = 0.001) compared to the ATG group. Importantly, ATG-PTCy significantly improved GvHD/relapse-free survival (GRFS) compared to ATG (65.71% vs. 36.63%; p = 0.003). There were no differences in engraftment, infection rates, immune reconstitution, overall survival, leukemia-free survival, relapse rate, or non-relapse mortality between the two groups. Combining ATG with PTCy may reduce moderate-to-severe GvHD and improve GRFS in children undergoing HSCT for acute leukemia.

Dual T-cell depletion with individually tailored anti-thymocyte globulin and attenuated dose of post-transplant cyclophosphamide in haploidentical peripheral stem cell transplantation.

This study aimed to assess the efficacy of dual T-cell suppression using individually tailored doses of antithymocyte globulin (ATG) and attenuated dose of post-transplant cyclophosphamide (PTCy) in haploidentical hematopoietic stem cell transplantation (haplo-HSCT). We conducted a retrospective analysis of 78 adults with acute leukemia or myelodysplastic syndrome who underwent haplo-HSCT using intravenous busulfan and fludarabine conditioning. Thirty-two patients received attenuated ATG/PTCy, while 46 patients received ATG (7.5 mg/kg) as GVHD prophylaxis. The 100-day cumulative incidence of grade III-IV (9.7% vs. 32.4%, P = 0.018) acute GVHD, as well as 2-year moderate-severe chronic GVHD (13.9% vs. 43.9%, P = 0.018) in the ATG/PTCy group were significantly lower than those in the ATG group. The 2-year overall survival was comparable between the two groups. However, 2-year GVHD-free, relapse-free survival in the ATG/PTCy group was significantly higher compared to that in the ATG group (38.9% vs. 21.7%, P = 0.021). Moreover, during post-engraftment period, the ATG/PTCy group exhibited lower incidences of life-threatening bacterial (12.5% vs. 37%, P = 0.033) and viral infection (0% vs. 17.4%, P = 0.035) than the ATG group. In conclusion, the combination of individually tailored ATG and low-dose PTCy appears to be a promising strategy in haplo-HSCT.

Posttransplant cyclophosphamide versus anti-thymocyte globulin versus combination for graft-versus-host disease prevention in haploidentical transplantation for adult acute myeloid leukemia: A report from the European Society for Blood and Marrow Transplantation Acute Leukemia Working Party.

BACKGROUND: The optimal choice for graft-versus-host disease (GVHD) prophylaxis in haploidentical stem cell transplantation (haplo-SCT) remains debatable. Posttransplant cyclophosphamide (PTCy) and anti-thymocyte globulin (ATG) are two common strategies, but little is known about their combination. METHODS: Using the European Society for Blood and Marrow Transplantation (EBMT) registry, the authors identified 3649 adult patients with acute myeloid leukemia (AML) who underwent haplo-SCT in complete remission between 2007 and 2021 at 260 EBMT-participating centers who received either PTCy (n = 2999), ATG (n = 358), or combination prophylaxis (n = 292). Cord blood transplants, combined bone marrow and peripheral grafts, and transplants with ex vivo graft manipulation were excluded. Median follow-up was 31.8 months. RESULTS: On multivariate analysis, adjusting for patient age and performance status, disease status at transplant, cytogenetic risk, conditioning intensity, stem cell source, female-to-male graft, and donor and patient CMV status, we present the following. Compared to PTCy, ATG had a higher risk of nonrelapse mortality (hazard ratio [HR], 1.6; p = .003), worse leukemia-free survival (HR, 1.4; p = .002), overall survival (HR, 1.49; p = .0009), and GVHD-free and relapse-free survival (HR, 1.29; p = .012). The combination of PTCy and ATG, however, led to significantly reduced rates of grade 2-4 (HR, 0.51; p = .0003) and grade 3-4 (HR, 0.5; p = .018) acute GVHD and did not affect any transplant outcomes compared to PTCy without ATG. CONCLUSION: The authors conclude that ATG alone is a less effective prophylaxis strategy compared to PTCy, however, the combination of PTCy and ATG is superior to either monotherapy. They propose that this combination could be considered a potential new standard of care for GVHD prophylaxis in haplo-SCT for AML.

Reduced-toxicity conditioning regimen with low dose post-transplantation cyclophosphamide and low-dose anti-thymocyte globulin as graft-versus-host disease prophylaxis for haploidentical stem cell transplantation in older patients.

Reduced-toxicity conditioning (RIC) regimens are used for allogeneic hematopoietic stem cell transplantation in older patients. However, successful outcomes are hindered by graft-versus-host disease (GVHD), treatment-related mortality, and relapse, particularly after haploidentical donor hematopoietic stem cell transplantation (HID-HSCT). The aim of this study was to evaluate the effectiveness of an RIC conditioning regimen that included a combination of cyclosporin A, methotrexate (on day + 1), mycophenolate, lower doses of post-transplantation PTCy (40 mg/kg on day + 3), and ATG (7.5 mg/kg) as GVHD prophylaxis prior to haplo-stem cell transplantation (haplo-SCT) in older patients. METHODS: We retrospectively analyzed outcomes in 55 patients ≥ 55 years of age with hematologic malignancies treated with fludarabine, cytarabine, busulfan, and low-dose cyclophosphamide as the conditioning regimen between January 1, 2019, and November 30, 2023. RESULTS: Neutrophil engraftment was successful in all patients within 28 days, with 54 patients (98.2%) achieving complete donor chimerism. The cumulative incidence of non-relapse mortality was 0% at 30 days, 7.5% at 100 days, and 19% at 1 year. The cumulative incidence of grade II-IV acute graft-versus-host disease (aGVHD) was 25% (95%CI, 15-38%), whereas that of grade III-IV aGVHD was 9.1% (95% CI, 3.3-19%). The cumulative incidence of extensive chronic graft-versus-host disease at 1 year was 3.6% (95%CI, 0.66-11%). The cumulative incidences of relapse, overall survival, and GVHD-free/relapse-free survival at 1 year were 9.0%, 71.6%, and 67.1%, respectively. CONCLUSIONS: An RIC conditioning regimen, including a combination of lower PTCy/ATG as GVHD prophylaxis, followed by haplo-SCT, might be a promising option for appropriately selected older patients.

Assessment of immunosuppression induction with basiliximab compared to antithymocyte-globulin in adult heart transplant patients.

BACKGROUND: Patients undergoing heart transplants are at risk of rejection which can have significant morbidity and mortality. Induction immunosuppression at the time of transplant reduces the early risk and has additional benefits. The induction agent of choice within our program was changed from rabbit antithymocyte-globulin (rATG) to basiliximab, so it was necessary to evaluate whether this had any impact on patient outcomes. OBJECTIVES: Our primary objective was to describe rejection, infection, and other outcomes in adult heart transplant patients at the University of Alberta Hospital in Edmonton, Canada. METHODS: This study was a nonrandomized, retrospective cohort study. RESULTS: Sixty-three patients were included with median ages 50 years versus 54 years. More female patients received rATG (20% vs. 42.4%). The most common indication for transplant in both cohorts was ICM (63.3% vs. 57.6%). Patients who received rATG had significantly higher PRA (0% vs. 43%, p < .001). Acute rejection episodes were similar between basiliximab and rATG at 3 months (16.7% vs. 15.1%; p = 1.0) and 6-months (30.0% vs. 18.1%; p = .376). Infections were not statistically different with basiliximab compared to rATG at 3-months, 43.3% vs. 63.6% and at 6-months 60.0% vs. 66.7%). There were no fatalities in either group. CONCLUSIONS: Our study did not demonstrate differences in rejection with basiliximab compared to rATG. Mortality did not differ, but basiliximab-treated patients had fewer infections and infection-related hospitalizations than those treated with rATG. Larger studies with longer durations are needed to more completely describe the differences in rejection and infectious outcomes.

Comparing the Outcomes of Matched and Mismatched Unrelated Allogeneic Hematopoietic Stem Cell Transplantation with Different Anti-Thymocyte Globulin Formulations: A Retrospective, Double-Centre Experience on Behalf of the Polish Adult Leukemia Group.

Despite notable advancements in immunotherapy in the past decades, allogeneic hematopoietic stem cell transplantation (allo-HCT) remains a promising, potentially curative treatment modality. Only a limited number of studies have performed a direct comparison of two prevalent rabbit anti-thymocyte globulin (r-ATG) formulations-specifically, Thymoglobuline (ATG-T, formerly Genzyme) and Grafalon (ATG-G, formerly Fresenius). The primary objective of our retrospective analysis was to compare the outcomes of adult patients undergoing matched or mismatched unrelated donor (MUD/MMUD) allo-HCT, with a graft-versus-host disease (GvHD) prophylaxis based on either ATG-T or ATG-G. A total of 87 patients who had undergone allo-HCT between 2012 and 2022 were included. We observed no significant differences between ATG-T and ATG-G concerning the occurrence of acute graft-versus-host disease (aGvHD), regardless of its severity. Conversely, chronic graft-versus-host disease (cGvHD) occurred less frequently in the ATG-T group compared to the ATG-G group (7.5% vs. 38.3%, p = 0.001). The negative impact of ATG-G on cGvHD was confirmed by multivariate analysis (HR 8.12, 95% CI 2.06-32.0, p = 0.003). Patients treated with ATG-T manifested a higher incidence of cytomegalovirus (CMV) reactivations (70% vs. 31.9%, p < 0.001), with a shorter time between transplant and CMV (<61 days, 77.8% vs. 33.3%, p = 0.008) and a higher median CMV copy number (1000 vs. 0, p = 0.004). Notably, despite a higher occurrence of CMV reactivations in the ATG-T cohort, most patients were asymptomatic compared to ATG-G (85.7% vs. 43.8%, p = 0.005). By multivariate analysis, only aGvHD had an influence on CMV reactivations (HR 0.18, 95% CI 0.04-0.75, p = 0.019). Finally, we observed no significant differences in terms of 5-year overall survival (OS) and 3-year relapse-free survival (RFS) while comparing ATG-T and ATG-G (32.0% vs. 40.3%, p = 0.423; 66.7% vs. 60.4%, p = 0.544, respectively).

Two case reports of fulminant giant cell myocarditis treated with rabbit anti-thymocyte globulin.

Background: Giant cell myocarditis (GCM) is an inflammatory form of acute heart failure with high rates of cardiac transplantation or death. Standard acute treatment includes multi-drug immunosuppressive regimens. There is a small but growing number of case reports utilizing rabbit anti-thymocyte globulin in severe cases. Case summary: Two cases are presented with similar presentations and clinical courses. Both are middle-aged patients with no significant past medical history, who presented with new acute decompensated heart failure that quickly progressed to cardiogenic shock requiring inotropic and mechanical circulatory support. Both underwent endomyocardial biopsies that diagnosed GCM. Both were treated with a multi-agent immunosuppressive regimen, notably including rabbit anti-thymocyte globulin, with subsequent resolution of shock and recovery of left ventricular ejection fraction. Both remain transplant-free and without ventricular arrhythmias at 7 months and 26 months, respectively. Discussion: In aggregate, these cases are typical of GCM. They add to growing observational data that upfront rabbit anti-thymocyte globulin may reduce morbidity and mortality in GCM, including potentially preventing the need for complex interventions like orthotopic heart transplantation.

Unrelated umbilical cord blood transplantation with low-dose anti-thymocyte globulin for children with severe aplastic anemia: A case series.

OBJECTIVE: This study aimed to investigate the prognosis of unrelated umbilical cord blood transplantation (UCBT) using low-dose anti-thymocyte globulin (ATG) in children diagnosed with severe aplastic anemia (SAA). METHODS: This retrospective case series study was conducted involving pediatric SAA patients treated at the Capital Institute of Pediatrics from January 2020 to February 2023. All patients underwent a reduced-intensity conditioning (RIC) regimen alongside low-dose ATG. RESULTS: The study comprised nine patients (five males) with a median age of 5 years (range: 1.7 to 7 years). The median follow-up duration was 799 days (range: 367 to 1481 days), during which all patients survived. The median time interval from diagnosis to transplantation was 3 months (range: 1 to 9 months). The median dosage of ATG administered was 5 mg/kg (range: 2.5 to 7.5 mg/kg). The median durations for granulocyte and platelet engraftment were 15 days (range: 12 to 23 days) and 26 days (range: 12 to 41 days), respectively. Three patients experienced grade 2-4 acute graft-versus-host disease (aGVHD). Epstein-Barr virus (EBV) reactivation was observed in three patients, while cytomegalovirus (CMV) reactivation occurred in seven patients, with no cases of CMV disease or post-transplant lymphoproliferative disorder (PTLD). One patient experienced recurrence 15 months after transplantation due to influenza A infection. CONCLUSION: These findings indicate that SAA patients may attain a favorable prognosis following UCBT with a RIC regimen combined with low-dose ATG.

Characteristics of Coronavirus Disease in Allogeneic Hematopoietic Stem Cell Transplantation During the Omicron Wave: A Single-Center Study.

Objectives: This study aimed to characterize the clinical characteristics, outcomes, and risk factors for coronavirus disease 2019 (COVID-19) in 492 patients who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) during the Omicron wave. Methods: Data were retrospectively collected from patient charts and the electronic medical record systems at the First Affiliated Hospital of Zhejiang University School of Medicine between December 2022 and January 2023. Results: The median follow-up period of the entire cohort was 62 days. Myeloid malignancies (58.5%) and acute lymphocytic leukemia (30.5%) constituted the most common underlying disease. Among the 492 patients, 415, 67, and 10 exhibited mild, moderate, and severe COVID-19, respectively. The incidence of moderate-to-severe COVID-19 was 15.7%. The 60-day overall survival and complete resolution rates were 98.1% and 80.6%, respectively. The risk factors for moderate-to-severe COVID-19 included corticosteroid use within 3 months before diagnosis, <6 months interval between allo-HSCT and COVID-19 diagnosis, and antithymocyte globulin use for graft-versus-host disease prophylaxis. Conclusions: During the Omicron wave, patients with allo-HSCT demonstrated a low COVID-19-related mortality rate and high moderate-to-severe and prolonged disease incidence. Prevention in the early posttransplantation period is critical for allo-HSCT recipients receiving corticosteroids.

Comparable outcomes with low-dose and standard-dose horse anti-thymocyte globulin in the treatment of severe aplastic anemia.

BACKGROUND: The standard dose (SD) of horse anti-thymocyte globulin (hATG) ATGAM (Pfizer, USA) or its biosimilar thymogam (Bharat Serum, India) for the treatment of Aplastic Anemia (AA) is 40 mg/kg/day for 4 days in combination with cyclosporine. Data on the impact of hATG dose on long-term outcomes are limited. Here, we describe our comparative experience using 25 mg/kg/day (low-dose [LD]) hATG for 4 days with SD for the treatment of AA. METHODS: We retrospectively studied patients with AA (age > 12 years) who received two doses of hATG combined with cyclosporine. Among 93 AA patients who received hATG, 62 (66.7%) and 31 (33.3%) patients received LD and SD hATG with cyclosporine, respectively. Among these,seventeen(18.2%) patients also received eltrombopag with hATG and cyclosporine. Overall response rates [complete response (CR) and partial response (PR)] of LD and SD hATG groups at 3 months (50% vs. 48.4%; p = 0.88), 6 months (63.8% vs. 71.4%; p = 0.67), and 12 months (69.6% vs. 79.2%; p = 0.167) were comparable. The mean (Standard Deviation) 5-year Kaplan-Meier estimate of overall survival and event-free survival was 82.1 (4.6)% and 70.9 (5.5)% for the study population. The mean (standard deviation) 5-year Kaplan-Meier estimate of overall survival and event-free survival of those who received LD hATG versus SD hATG dose was 82.9 (5·3)% versus 74.8 (10·3)% (P = 0·439), and 75.2 (6.2)% versus 61.4(11.2)% (P = 0·441). CONCLUSION: Our study revealed that the response rates of patients with AA and LD were similar to those of patients with SD to hATG combined with cyclosporine in a real-world setting.

Immunosuppression in two cases of indeterminate hepatitis.

Background: Pediatric acute liver failure (PALF) is a potentially lethal and rapidly progressive clinical syndrome, with a large proportion of cases remaining indeterminate despite extensive investigations. Patients and Results: In this case report, we describe two male children with indeterminate PALF and a family history of autoimmune disease, both of whom were lymphopenic with necrosis, inflammation, and lymphocytic infiltrates on their liver biopsies. One of these patients subsequently developed hepatitis-associated aplastic anemia. Notably, in addition to receiving standard liver failure care, both patients were successfully treated off-label with anti-thymocyte globulin (ATG), as well as a more prolonged course of cyclosporine and corticosteroids. Conclusions: The fact that these medications all suppress T lymphocytes further supports the theory that T-cell activation plays a prominent role in the pathophysiology of indeterminate hepatitis. Further research should examine the short-term and long-term effects of ATG in this population, as well as the necessary duration of treatment with immune-suppressing agents.