Differential Analysis of Immune Reconstitution after Allogeneic Hematopoietic Stem Cell Transplantation in Children with Wiskott-Aldrich Syndrome and Chronic Granulomatous Disease
Authors: Zhou Ya , Zhang Luying , Meng Yan , Lei Xiaoying , Jia Lanzhou , Guan Xianmin , Yu Jie , Dou Ying 
Published: March 2023

Abstract
Objective: To investigate similarities and differences in immune reconstitution after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in kids with two primary immunodeficiency diseases, Wiskott-Aldrich syndrome (WAS) and chronic granulomatous disease (CGD).
Method: We retrospectively analyzed the lymphocyte subpopulations (CD3+ T cells, CD4+ T cells, CD8+ T cells, NK cells, B cells) and various immunoglobulin counts (IgM, IgA, IgG, C3, C4) on Days 15, 30, 100, 180 and 360 after transplantation in 70 children with WAS and 48 children with CGD who underwent allo-HSCT at the Transplantation Center of the Department of Hematology-Oncology, Children's Hospital of Chongqing Medical University from January 2007 to December 2020, and we compared and analyzed the differences in the immune reconstitution process between the two groups.
Results: ① On Day 15 posttransplantation, the WAS group had significantly higher NK cell counts than the CGD group. On Days 30, 100 and 180 posttransplantation, the WAS group had notably higher CD4+ T-cell counts than the CGD group. On Days 100 and 180 posttransplantation, the WAS group had considerably higher B-cell counts than the CGD group. ② On Day 15 posttransplantation, NK cell counts in the WAS group were considerably higher than those in the CGD group among kids aged 1-3 years who underwent transplants. On Days 30 and 180 posttransplantation, the WAS group had notably higher CD4+ T-cell counts than the CGD group among kids aged 1-3 years who underwent transplants. On Day 180 posttransplantation, B-cell counts in the WAS group were consistently higher than those in the CGD group among kids aged 1-3 years who underwent transplants. On Day 360 posttransplantation, the CGD group had notably higher CD8+ T-cell counts than the WAS group among kids aged 1-3 years who underwent transplants. ③ On Days 15 and 30 posttransplantation, kids who underwent non-umbilical cord blood transplantation (non-UCBT) had significantly higher B-cell counts than kids who underwent UCBT in the WAS group. On Days 100 and 180 posttransplantation, children who underwent UCBT had apparently higher B-cell counts than children who underwent non-UCBT in the WAS group. On Day 30 posttransplantation, kids who underwent UCBT had notably higher CD3+ T-cell counts than kids who underwent non-UCBT in the WAS group. On Days 30, 100 and 180 posttransplantation, kids who underwent UCBT had obviously higher CD4+ T-cell counts than kids who underwent non-UCBT in the WAS group. On Day 360 posttransplantation, children who underwent UCBT had markedly higher NK cell counts than children who underwent non-UCBT in the WAS group. ④ On Day 15 posttransplantation, NK cell counts were probably higher in the non-cord-blood-transplanted kids with WAS compared to the non-cord-blood-transplanted kids with CGD. On Days 30 and 100 posttransplantation, CD4+ T-cell counts weresignificantly higher in the non-cord-blood-transplanted kids with WAS compared to the non-cord-blood-transplanted kids with CGD. On Day 30 posttransplantation, B-cell counts were notably higher in the non-cord-blood-transplanted kids with WAS compared to the non-cord-blood-transplanted kids with CGD. ⑤ On Day 100 after allo-HSCT, the CGD group had higher C3 levels than the WAS group. On Day 360 after allo-HSCT, the CGD group had higher IgA and C4 levels than the WAS group.
Conclusion: ① During the immune reconstitution process, the WAS group had significantly higher lymphocyte subpopulation counts than the CGD group after transplantation, indicating that the rate of immunity recovery was faster in kids within the WAS group compared to those kids within the CGD group, which may be related to the type of graft (percentage undergoing UCBT) and the different primary diseases themselves. ② During B-cell reconstitution in kids with WAS, kids who underwent non-UCBT had notably higher B-cell counts than kids who underwent UCBT at Days 15 and 30 posttransplantation, and kids who underwent UCBT had notably higher B-cell counts than kids who underwent non-UCBT at Days 100 and 180 posttransplantation, indicating that cord blood has strong B-cell reconstitution potential after allo-HSCT.