O papel do filgrastim na mobilização de células CD34 + no transplante de células tronco hematopoiéticas

Abstract

Introduction: Autologous hematopoietic stem cell transplantation (AHSCT) is essential in the treatment of oncohematological diseases such as multiple myeloma (MM), non-Hodgkin lymphoma (NHL), and Hodgkin lymphoma (HL), as well as certain solid tumors and autoimmune disorders. Effective mobilization of hematopoietic progenitor cells (HPCs) is crucial for the success of the procedure. However, between 5% and 40% of patients fail to reach the minimum required number of CD34+ cells for collection. In such cases, strategies such as increasing the dose of G-CSF, chemomobilization, or the use of CXCR4 antagonists are employed. Given the unavailability of Plerixafor for patients who do not mobilize adequately with 10 mcg/kg/day of G-CSF, this study aimed to evaluate the preemptive increase of filgrastim dose based on CD34+ cell counts on the fourth day of mobilization. Objectives: To evaluate the impact of increasing the G-CSF dose on HPC mobilization in patients undergoing AHSCT at the Hematopoietic Stem Cell Transplantation Unit of the University Hospital of the Federal University of Juiz de Fora (HU UFJF). Specific objectives included: analyzing the percentage of patients who respond to the increased dose and identifying factors associated with successful mobilization with a higher GCSF dose. Methodology: This was a retrospective observational study conducted with candidates for AHSCT at HU UFJF between October 2018 and June 2023. Participants were initially mobilized with 10 mcg/kg/day of filgrastim. On the fourth day, CD34+ cell counts were obtained by flow cytometry; for those with counts below 10 cells/µL, the dose was increased to approximately 20 mcg/kg/day, followed by a new CD34+ count on the fifth day. Data were collected from electronic medical records. Statistical analysis included the use of the T-test, Pearson’s correlation, and Poisson regression. Results: A total of 116 patients were evaluated, with a mean age of 50 years; 51.7% were male. Most patients (70%) were diagnosed with MM. On the fourth day, 27 patients (24%) did not reach an adequate CD34+ count and had their G-CSF dose increased. Among them, only 3 maintained a CD34+ count below 9 cells/µL on the fifth day. Although some patients showed an increase in CD34+ count, 6 did not achieve sufficient yield for AHSCT, resulting in a total of 9 patients who required chemomobilization due to mobilization failure. Discussion: The preemptive increase of the G-CSF dose proved effective in more than 60% of patients with initially inadequate mobilization, representing a viable and cost-effective alternative in settings with limited access to Plerixafor. These findings support the value of early CD34+ monitoring to guide therapeutic decisions. Conclusion: After adjusting the G-CSF dose, 68% of MM patients and 62.5% of lymphoma patients responded adequately to mobilization, demonstrating the effectiveness of the dose-escalation strategy based on early CD34+ cell counts.