The number of CD34 cells employed in autologous hematopoietic stem cell transplantation in persons with multiple sclerosis is unrelated to the neurological outcome of the procedure. experience in 1417 patients.

Abstract Background: Autologous hematopoietic stem cell transplantation (aHSCT) is widely employed in the treatment of persons with multiple sclerosis (MS). aHSCT in MS is not a stem cell treatment, since HSCTs are only used to support the delivery of high-dose chemotherapy. Objective: To analyze the relationship between the number of CD34 cells administered during aHSCT to persons with MS and the neurological outcome. These procedures were conducted in a single institution after 2015. Methods: The number of CD34+ cells in aliquots of the apheresis products for aHSCT in persons with MS was determined by flow cytometry using anti-CD45 and CD34 antibodies. The neurological response rate (RR) was determined by assessing the patients' EDSS scores: a positive response was either a decrease or stabilization of the EDSS score; other responses were recorded as negative. MS patients included relapsing remitting (RR), secondary progressive (SP), and primary progressive (PP) forms. The aHSCT protocol included high-dose cyclophosphamide (200 mg/kg) and high-dose rituximab (1000 mg). Results: 1,417 persons were analyzed. The median number of CD34 cells per aHSCT procedure was 8.27 × 10^12 CD34 cells per Kg of body weight (IQR:4.4-12.9). A positive response to aHSCT was observed in 460/564 patients (81%). The RR rate was 81.3%, 82.5% and 83% in the RR, PP, and SP variants of the disease, respectively. The time to recovery of >0.5 x 10e9/L granulocytes was 8 days (IQR: 8.0-9.0), whereas the time to recover > 20 x 10e9/L platelets was 10 days (IQR: 8.0-10). The correlation between the number of CD34 cells and the time needed to recover >0.5 x 10e9/L granulocytes was -0.169, whereas the correlation time to recover > 20 x 10e9/L platelets was -0.012. The correlation of the number of CD34 cells in the aHSCT was 0.016, -0.23 in RR, 0.076 in PP, and 0.038 in SP. Conclusion: aHSCT induced positive responses in 81% of persons with MS. This figure further supports our previous findings using the Mexican method. As expected, there was no correlation between the neurological response and the number of CD34 cells used to restore hematopoiesis after high doses Cy. We detected a trend between shorter periods of post-aHSCT recovery and the number of CD34 cells.