Objective:To evaluate the efficacy of allogeneic hematopoietic cell transplantation(allo-HSCT) using unrelated cord blood or haploidentical donors in the treatment of children with primary immunodeficiency diseases (PID).Methods:The clinical data of 60 children with PID admitted to Chinese People′s Liberation Army General Hospital-Sixth Medical Center from April 2014 to October 2019 were retrospectively analyzed, including 56 cases of chronic granulomatous disease, 2 cases of severe combined immunodeficiency disease, 1 case of high-IgM syndrome and 1 case of severe congenital neutropenia.All patients underwent allo-HSCT, including 12 cases receiving the transplantation from unrelated cord blood (UCB group) and 48 cases from haploidentical donors combined with a third party unrelated cord blood (haploid group). Among these patients, there were 59 males and 1 female, with a median age of 3.4 years.All patients received a myeloablative conditioning regimen based on Busulfan.The prophylaxis of acute graft versus host disease (aGVHD) was performed based on Cyclosporine.In the UCB group, the median dose of mononuclear cells and CD 34+ cells was 0.67×10 8/kg and 0.51×10 6/kg recipient body weight, respectively; In the haploid group, bone marrow and peripheral stem cells from haploid donors were infused on day 01 and day 02, respectively.The third party cord blood was infused 4 hours before bone marrow infusion.The median dose of mononuclear cells and CD 34+ cells of bone marrow and peripheral stem cells from haploid donors was 9.97×10 8/kg and 5.12×10 6/kg recipient body weight, respectively.Kaplan-Meier method was used to analyze the overall survival rate. Results:The median day to neutrophil and platelet engraftment was 13.0 days and 23.5 days, respectively.The rate of complete donor chime-rism was shown 30.0 days after transplantation.There was no case with primary engraftment failure, and 1 case with secondary engraftment failure.The incidence of grade Ⅰ-Ⅱ and grade Ⅲ-Ⅳ aGVHD was 43.3% and 15.5%, respectively.The incidence of chronic graft versus host disease with limited skin type was 6.7%, while that with extensive type was 1.1%.The median follow-up period was 818 days.There were 6 death cases, among which, 5 cases died from infection and 1 case died from heart failure.The total mortality related to transplantation was 11.9%.A total of 53 cases survived without diseases.The estimated 5-year failure free survival and overall survival rate was 83.9% and 88.1%, respectively.Conclusion:The efficacy of allo-HSCT in the treatment of children with PID using unrelated cord blood and haploidentical donors is favorable.

OX40 is a costimulatory receptor that is expressed primarily on activated CD4⁺, CD8⁺, and regulatory T cells. The ligation of OX40 to its sole ligand OX40L potentiates T cell expansion, differentiation, and activation and also promotes dendritic cells to mature to enhance their cytokine production. Therefore, the use of agonistic anti-OX40 antibodies for cancer immunotherapy has gained great interest. However, most of the agonistic anti-OX40 antibodies in the clinic are OX40L-competitive and show limited efficacy. Here, we discovered that BGB-A445, a non-ligand-competitive agonistic anti-OX40 antibody currently under clinical investigation, induced optimal T cell activation without impairing dendritic cell function. In addition, BGB-A445 dose-dependently and significantly depleted regulatory T cells in vitro and in vivo via antibody-dependent cellular cytotoxicity. In the MC38 syngeneic model established in humanized OX40 knock-in mice, BGB-A445 demonstrated robust and dose-dependent antitumor efficacy, whereas the ligand-competitive anti-OX40 antibody showed antitumor efficacy characterized by a hook effect. Furthermore, BGB-A445 demonstrated a strong combination antitumor effect with an anti-PD-1 antibody. Taken together, our findings show that BGB-A445, which does not block OX40-OX40L interaction in contrast to clinical-stage anti-OX40 antibodies, shows superior immune-stimulating effects and antitumor efficacy and thus warrants further clinical investigation.
Mice ; Animals ; Receptors, Tumor Necrosis Factor/physiology* ; Receptors, OX40 ; Membrane Glycoproteins ; Ligands ; Antibodies, Monoclonal/pharmacology* ; Antineoplastic Agents/pharmacology*