[The occurrence of cytokine release syndrome and its impact on the prognosis of patients with relapsed and refractory multiple myeloma following chimeric antigen receptor T-cell therapy].

To analyze the incidence of cytokine release syndrome (CRS) and its impact on the prognosis of patients with relapsed and refractory multiple myeloma (RRMM) following treatment with chimeric antigen receptor T-cell (CAR-T) therapy. A retrospective collection was conducted of the clinical data of 91 patients with RRMM who underwent CAR-T therapy at the Affiliated Hospital of Xuzhou Medical University from January 2020 to October 2022. Before CAR-T cell infusion, the patient underwent pretreatment with the fludarabine plus cyclophosphamide (FC) regimen. On day 0 (d0), the patient received a dose of 1×10 cells/kg of CAR-T. The occurrence of CRS was recorded post-treatment and graded accordingly, with grades 1 to 2 indicating mild CRS and grade≥3 indicating severe CRS. The follow-up cut-off date was February 14, 2023, with a median follow-up time [ ( )] of 14.1 (3.1, 37.7) months. Kaplan-Meier survival curve analysis assessed the progression-free survival (PFS) and overall survival (OS) of Grade 1 and Grade 2 CRS patients. Furthermore, univariate logistic regression analysis was conducted to identify factors associated with the development of severe CRS. In a cohort of 91 patients diagnosed with RRMM, there were 51 male and 40 female individuals, with a median age [ ()] of 57 (31, 73) years. All 91 cases (100%) experienced CRS, with 82 cases (90%) classified as mild (grades 1-2) CRS and 9 cases (10%) classified as severe (grades 3-5) CRS. In a study involving 9 patients with severe CRS, 8 cases resulted in mortality. The Kaplan-Meier survival curve analysis revealed that among grade 1 CRS patients, neither the median PFS nor the median OS was achieved. For grade 2 CRS patients, the median PFS was 12 months (95%: 4-not achieved), and the median OS was 21 months (95%: 4-not achieved). The progression-free survival and overall survival rates of grade 2 CRS patients were both lower than those of grade 1 CRS patients (both <0.05). Single-factor logistic regression analysis revealed that a high tumor burden (=1.025, 95%: 1.002-1.049, =0.031), a prolonged duration of CRS onset (=0.809, 95%: 0.646-0.971, =0.037) and persistence (=1.758, 95%: 1.349-2.481, =0.001) were identified as significant factors associated with severe CRS in patients with RRMM. Patients with RRMM who undergoes CAR-T therapy have a high incidence of CRS, with a higher mortality rate among those experiencing severe CRS. Furthermore, patients with grade 2 CRS exhibit lower rates of progression-free survival and overall survival compared to those with grade 1 CRS. Factors associated with the development of severe CRS in RRMM patients include high tumor burden and prolonged duration and onset of CRS.