Haploidentical Stem Cell Transplantation With TCR αβ(+)/CD19(+) Depletion in Children With Nonmalignant Hematologic Disorders: Outcomes From a Referral Center in Peru.

Haploidentical hematopoietic stem cell transplantation (haplo-HSCT) with TCR αβ+/CD19+ cell depletion is a promising therapeutic alternative for children with nonmalignant hematologic disorders, especially in low-income countries where finding a compatible donor is challenging. The use of this transplantation approach for nonmalignant hematologic disorders has not been previously described in the Peruvian pediatric population. We present the outcomes of children under 19 with nonmalignant hematologic disorders who underwent haplo-HSCT with TCR αβ+/CD19+ cell depletion between 2018-2022 at a referral center in Lima, Peru. Survival probabilities and cumulative incidence functions were calculated using the Kaplan-Meier method. A total of 17 children aged between 1 to 18.6 years (median = 9.7 years) were included. The follow-up period ranged from 10 days to 66.20 months, with a median of 4.34 months. The probability of overall survival, event-free survival, and failure-free survival was 33.70%, 31.40%, and 68.8%, respectively. The incidence rate of graft failure was 49.80%, while the mortality rate not associated with graft failure was 18.8%. The incidence rate of acute graft-versus-host disease (GvHD) was 25.60%, and the incidence rate of viral infections was 59.40%. The high incidence rates of graft failure and viral infections suggest that these factors may negatively impact the survival of children with nonmalignant hematologic disorders who undergo haplo-HSCT with TCR αβ+/CD19+ cell depletion. Therefore, optimizing the current conditioning regimens and ensuring timely access to first, second, and third-line antivirals is crucial to improve the survival of these patients.

Rodríguez-Torres JC ，Pando-Caciano A ，Mamaní-Cajachagua PE ，Murillo-Vizcarra SA ... -  《-》

Haploidentical Stem Cell Transplantation After TCR-αβ(+) and CD19(+) Cells Depletion In Children With Congenital Non-Malignant Disease.

Haploidentical hematopoietic stem cell transplantation (haplo-HSCT) represents a valuable alternative for children with nonmalignant disease and ex vivo negative selection of TCR-αβ+ cells is an emerging graft manipulation option that carries several potential advantages in terms of reduced risk of graft-versus-host disease (GvHD) and improved immune reconstitution. We report all consecutive patients with a diagnosis of nonmalignant disease who received a TCR-αβ+ and CD19+depleted haplo-HSCT at "IRCCS Istituto Giannina Gaslini" from 2013 to 2019; the conditioning regimen was myeloablative or non-myeloablative, depending on underlying disease; all patients received antithymocyte globulin and rituximab. No post-transplantation GvHD prophylaxis was given in presence of a TCR-αβ+ cell dose in the graft lower than the threshold of 1 × 105/kg of the recipient's weight. Among 20 HSCTs, engraftment occurred in 17 (85%) after a median of 14 and 12 days from graft infusion for neutrophils and platelets, respectively. Primary graft failure was diagnosed in 3 (15%) patients, and 2 (10%) experienced secondary rejection; all of these patients underwent a second HSCT. The cumulative incidence of a-GvHD and c-GvHD was 15% (2 = grade 1, 1 = grade 4) at 90 days and 5% (1 = grade 1) at 7 months, respectively. Cytomegalovirus reactivation requiring pre-emptive treatment was observed in 9 patients (45%). One patient developed a JC virus-related progressive multifocal leukoencephalopathy, successfully managed with donor-derived virus-specific T-cell infusions. A complete immunological recovery was reached in most patients within 6 months. After a median follow-up of 4 years, 18 patients are alive, with a cumulative survival probability of 90%. Haplo-HSCT after ex vivo TCR-αβ+/CD19+ negative selection may be considered a good option for children with nonmalignant diseases because it ensures a high engraftment rate with an acceptable risk of graft failure, very low incidence of significant GvHD, and good immune reconstitution with low frequency of severe virus-related disease. However, the control of viral infection/reactivation should be kept high to promptly provide pre-emptive treatments and approaches of antiviral adoptive immunotherapy.

Giardino S ，Bagnasco F ，Falco M ，Miano M ，Pierri F ，Risso M ，Terranova P ，Di Martino D ，Massaccesi E ，Ricci M ，Chianucci B ，Dell'Orso G ，Sabatini F ，Podestà M ，Lanino E ，Faraci M ... -  《-》

Immune Modulation Properties of Zoledronic Acid on TcRγδ T-Lymphocytes After TcRαβ/CD19-Depleted Haploidentical Stem Cell Transplantation: An analysis on 46 Pediatric Patients Affected by Acute Leukemia.

TcRαβ/CD19-cell depleted HLA-haploidentical hematopoietic stem cell transplantation (haplo-HSCT) represents a promising new platform for children affected by acute leukemia in need of an allograft and lacking a matched donor, disease recurrence being the main cause of treatment failure. The use of zoledronic acid to enhance TcRγδ+ lymphocyte function after TcRαβ/CD19-cell depleted haplo-HSCT was tested in an open-label, feasibility, proof-of-principle study. Forty-six children affected by high-risk acute leukemia underwent haplo-HSCT after removal of TcRαβ+ and CD19+ B lymphocytes. No post-transplant pharmacological graft-versus-host disease (GvHD) prophylaxis was given. Zoledronic acid was administered monthly at a dose of 0.05 mg/kg/dose (maximum dose 4 mg), starting from day +20 after transplantation. A total of 139 infusions were administered, with a mean of 3 infusions per patient. No severe adverse event was observed. Common side effects were represented by asymptomatic hypocalcemia and acute phase reactions (including fever, chills, malaise, and/or arthralgia) within 24-48 h from zoledronic acid infusion. The cumulative incidence of acute and chronic GvHD was 17.3% (all grade I-II) and 4.8% (all limited), respectively. Patients given 3 or more infusions of zoledronic acid had a lower incidence of both acute GvHD (8.8 vs. 41.6%, p = 0.015) and chronic GvHD (0 vs. 22.2%, p = 0.006). Transplant-related mortality (TRM) and relapse incidence at 3 years were 4.3 and 30.4%, respectively. Patients receiving repeated infusions of zoledronic acid had a lower TRM as compared to those receiving 1 or 2 administration of the drug (0 vs. 16.7%, p = 0.01). Five-year overall survival (OS) and disease-free survival (DFS) for the whole cohort were 67.2 and 65.2%, respectively, with a trend toward a better OS for patients receiving 3 or more infusions (73.1 vs. 50.0%, p = 0.05). The probability of GvHD/relapse-free survival was significantly worse in patients receiving 1-2 infusions of zoledonic acid than in those given ≥3 infusions (33.3 vs. 70.6%, respectively, p = 0.006). Multivariable analysis showed an independent positive effect on outcome given by repeated infusions of zoledronic acid (HR 0.27, p = 0.03). These data indicate that the use of zoledronic acid after TcRαβ/CD19-cell depleted haploHSCT is safe and may result in a lower incidence of acute GvHD, chronic GvHD, and TRM.

Merli P ，Algeri M ，Galaverna F ，Milano GM ，Bertaina V ，Biagini S ，Girolami E ，Palumbo G ，Sinibaldi M ，Becilli M ，Leone G ，Boccieri E ，Grapulin L ，Gaspari S ，Airoldi I ，Strocchio L ，Pagliara D ，Locatelli F ... -  《Frontiers in Immunology》

T-cell receptor αβ(+) and CD19(+) cell-depleted haploidentical and mismatched hematopoietic stem cell transplantation in primary immune deficiency.

Allogeneic hematopoietic stem cell transplantation (HSCT) is used as a therapeutic approach for primary immunodeficiencies (PIDs). The best outcomes have been achieved with HLA-matched donors, but when a matched donor is not available, a haploidentical or mismatched unrelated donor (mMUD) can be useful. Various strategies are used to mitigate the risk of graft-versus-host disease (GvHD) and rejection associated with such transplants. We sought to evaluate the outcomes of haploidentical or mMUD HSCT after depleting GvHD-causing T-cell receptor (TCR) αβ CD3+ cells from the graft. CD3+TCRαβ+/CD19+ depleted grafts were given in conditioned (except 3) children with PIDs. Treosulfan (busulfan in 1 patient), fludarabine, thiotepa, and anti-thymocyte globulin or alemtuzumab conditioning were used in 77% of cases, and all but 4 received GvHD prophylaxis. Twenty-five patients with 12 types of PIDs received 26 HSCTs. Three underwent transplantation for refractory GvHD that developed after the first cord transplantation. At a median follow-up of 20.8 months (range, 5 month-3.3 years), 21 of 25 patients survived and were cured of underlying immunodeficiency. Overall and event-free survival at 3 years were 83.9% and 80.4%, respectively. Cumulative incidence of grade II to IV acute GvHD was 22% ± 8.7%. No case of visceral or chronic GvHD was seen. Cumulative incidences of graft failure, cytomegalovirus, and/or adenoviral infections and transplant-related mortality at 1 year were 4.2% ± 4.1%, 58.8% ± 9.8%, and 16.1% ± 7.4%, respectively. Patients undergoing transplantation with systemic viral infections had poor survival in comparison with those with absent or resolved infections (33.3% vs 100%). CD3+TCRαβ+ and CD19+ cell-depleted haploidentical or mMUD HSCT is a practical and viable alternative for children with a range of PIDs.

Shah RM ，Elfeky R ，Nademi Z ，Qasim W ，Amrolia P ，Chiesa R ，Rao K ，Lucchini G ，Silva JMF ，Worth A ，Barge D ，Ryan D ，Conn J ，Cant AJ ，Skinner R ，Abd Hamid IJ ，Flood T ，Abinun M ，Hambleton S ，Gennery AR ，Veys P ，Slatter M ... -  《-》

Haploidentical HSCT for hemoglobinopathies: improved outcomes with TCRαβ(+)/CD19(+)-depleted grafts.

We examined outcomes of haploidentical hematopoietic cell transplantation (haplo-HCT) using T-cell receptor αβ+ (TCRαβ+)/CD19+-depleted grafts (TCR group, 14 patients) in children with hemoglobinopathies. Patients received a preparative regimen consisting of busulfan, thiotepa, cyclophosphamide, and antithymocyte globulin preceded by fludarabine, hydroxyurea, and azathioprine. The median follow-up among surviving patients was 3.9 years. The 5-year probabilities of overall survival (OS) and disease-free survival (DFS) were 84% and 69%, respectively. The incidence of graft failure was 14%. We compared outcomes to a historical group of 40 patients with hemoglobinopathies who received CD34+-selected grafts (CD34 group). The median follow-up of surviving patients for the CD34 group was 7.5 years. The 5-year probabilities of OS and DFS were 78% and 39%, respectively. The CD34 group had a significantly higher incidence of graft failure (45%) than the TCR group (14%) (P = .048). The incidences of grades 2 to 4 acute graft-versus-host disease (GVHD) in the TCR and CD34 groups were 28% and 29%, respectively, and 21% and 10% (P = .1), respectively, for extensive chronic GVHD. Viral reactivation was common in both groups. The overall incidence of posttransplant lymphoproliferative disorders for the entire group was 16%. Among all patients, 5 developed autoimmune hemolytic anemia or thrombocytopenia, with the overall cumulative incidence of 11%. The 2 groups showed suboptimal CD4+ recovery within the first 6 months of transplantation with no significant difference between groups. These data demonstrate that TCRαβ+/CD19+-depleted grafts are associated with a reduced incidence of graft failure, but delayed immune reconstitution and associated morbidity and mortality remain a significant challenge.

Gaziev J ，Isgrò A ，Sodani P ，Paciaroni K ，De Angelis G ，Marziali M ，Ribersani M ，Alfieri C ，Lanti A ，Galluccio T ，Adorno G ，Andreani M ... -  《-》