[Clinical characteristics of cytokine release syndrome after haploidentical hematopoietic stem cell transplantation for thalassemia major].

Objectives: To investigate the clinical characteristics of cytokine release syndrome (CRS) in children with thalassemia major (TM) after haploidentical hematopoietic stem cell transplantation (haplo-HSCT) and their prognosis.

Methods: A retrospective analysis was performed for the clinical data of 280 children with TM who underwent haplo-HSCT in the Department of Hematology and Oncology, Shenzhen Children's Hospital, from January 2019 to December 2021. According to the CRS criteria, they were divided into two groups: CRS grade <3 (260 children) and CRS grade ≥3 (20 children). The children with TM were analyzed in terms of clinical characteristics of CRS after haplo-HSCT and their prognosis.

Results: There were significant differences between the two groups in neutrophil engraftment time, clinical manifestations of CRS, and the rate of use of glucocorticoids within 4 days after haplo-HSCT (=0.012, 0.040, and <0.001 respectively). For the CRS grade <3 group, the incidence rate of acute graft-versus-host disease (aGVHD) was 9.6% within 3 months after transplantation, while no aGVHD was observed in the CRS grade ≥3 group within 3 months after transplantation, but there was no significant difference in the incidence of aGVHD between the two groups within 3 months after transplantation (=0.146). No transplantation-related death was observed in either group within 3 months after haplo-HSCT.

Conclusions: The children with CRS grade≥3 have an early neutrophil engraftment time, severe and diverse clinical manifestations of CRS, and a high rate of use of glucocorticoids within 4 days after haplo-HSCT. For these children, early use of low-dose glucocorticoids after transplantation may alleviate CRS response and reduce the incidence of aGVHD, thereby bringing more benefits to the children. CRS after haplo-HSCT has no significant impact on the prognosis of the children.