Immune recovery after in vivo T-cell depletion myeloablative conditioning hematopoietic stem cell transplantation in severe beta-thalassemia children

Eur J Haematol. 2019 Oct;103(4):342-350. doi: 10.1111/ejh.13289. Epub 2019 Aug 6.

Abstract

Background: The clinical outcome of hematopoietic stem cell transplantation (HSCT) in those with severe beta-thalassemia (β-TM) is closely related to post-transplantation immune reconstitution (IR). However, the data on the IR in these settings are scarce.

Methods: A prospective analysis of the clinical outcome and IR in 47 children with severe β-TM who underwent in vivo T-cell depletion myeloablative conditioning and matched sibling donor HSCT was performed. Immune reconstitution, including immune cell subset counts, as well as the generation of new T and B cells assays after HSCT, was measured.

Results: In the first year after HSCT, bacterial infections and cytomegalovirus (CMV) reactivation were observed in 70.2% and 36.2% of the patients, respectively. In the same period, poor CD4+ T-cell recovery was observed. The B cells recovered within 6 months. Natural killer (NK) cells recovered as early as 1 month, but their function was defective. Cord blood and bone marrow (CB + BM) group had slower T-cell recovery, and higher B cells and NK cells in comparison with peripheral blood and bone marrow (PB + BM) group.

Conclusions: The high incidence of infection within 1 year after in vivo T-cell depletion myeloablative conditioning HSCT in severe β-TM was consistent with poor IR.

Keywords: KRECs; TRECs; hematopoietic stem cell transplantation; immune reconstitution; β-thalassemia major.

MeSH terms

  • B-Lymphocytes / immunology
  • Bone Marrow / immunology
  • Bone Marrow / metabolism
  • Bone Marrow / pathology
  • Child
  • Child, Preschool
  • Female
  • Graft vs Host Disease / etiology
  • Graft vs Host Disease / prevention & control
  • Hematopoietic Stem Cell Transplantation* / adverse effects
  • Hematopoietic Stem Cell Transplantation* / methods
  • Humans
  • Immune Reconstitution*
  • Immunophenotyping
  • Killer Cells, Natural / immunology
  • Lymphocyte Count
  • Lymphocyte Depletion* / methods
  • Male
  • T-Lymphocytes / immunology*
  • T-Lymphocytes / metabolism
  • Transplantation Conditioning* / methods
  • beta-Thalassemia / immunology*
  • beta-Thalassemia / therapy*