Abstract: BACKGROUND: At present, there are many clinical reports of rituximab combined with autologous peripheral blood stem cell transplantation in the treatment of diffuse large B-cell lymphoma, but its mechanism is not very clear.  
OBJECTIVE: To compare and analyze the effects of rituximab combined with autologous peripheral blood stem cell transplantation and rituximab in the treatment of diffuse large B-cell lymphoma and changes in the levels of related factors.
METHODS:  96 patients with diffuse large B-cell lymphoma were selected, including 62 males and 34 females, aged 20-75 years. Among them, 48 cases were treated with rituximab combined chemotherapy (control group), and the other 48 cases were treated with rituximab combined chemotherapy and autologous peripheral blood hematopoietic stem cell transplantation (trial group). The clinical efficacy and adverse reactions of the two groups were compared. The survival time of the patients was followed up and recorded. Before treatment, after 6 cycles of chemotherapy and 6 months after transplantation, the serum vascular endothelial growth factor and basic fibroblast growth factor and interleukin-17 levels were detected in both groups.  
RESULTS AND CONCLUSION: (1) Adequate peripheral blood hematopoietic stem cells were collected in the experimental group. The number of CD34+cells transfused back was (3.6±0.6)×106/kg. After transfusion, the time of neutrophil implantation was (11.1±1.2) days, and the time of platelet implantation was (12.3±2.4) days. (2) The effective rate of treatment in the experimental group was significantly higher than that in the control group (81%, 56%, P < 0.05). (3) From the beginning of definite diagnosis to the end of follow-up, the survival rate was 79% and the progression-free survival rate was 50% in the trial group. The survival rate was 56% and the progression-free survival rate was 31% in the control group. The difference in survival rate and progression-free survival rate between the two groups was significant (P < 0.05). (4) There was no significant difference in the incidence of adverse reactions between the two groups (P > 0.05). (5) There was no significant difference in the levels of three kinds of cytokines between the two groups before treatment and after 6 cycles of chemotherapy. Compared with before treatment, the levels of interleukin-17 increased (P < 0.05), and the levels of vascular endothelial growth factor and basic fibroblast growth factor decreased after 6 cycles of chemotherapy (P < 0.05). Compared with that after 6 cycles of chemotherapy, the level of interleukin-17 in the trial group increased 6 months after transplantation (P < 0.05), and the levels of vascular endothelial growth factor and basic fibroblast growth factor decreased (P < 0.05), and there was no significant change in the levels of three kinds of cytokines in the control group (P < 0.05). (6) It is concluded that rituximab combined with autologous peripheral blood stem cell transplantation can improve the survival of patients with diffuse large B-cell lymphoma, and its mechanism may be related to the regulation of interleukin 17, vascular endothelial growth factor and basic fibroblast growth factor levels.

Key words: diffuse large B-cell lymphoma, rituximab, autologous peripheral blood stem cell, transplantation, interleukin 17, vascular endothelial growth factor, basic fibroblast growth factor