First 100 days outcomes of cryopreserved vs non-cryopreserved stem cells autologous bone marrow transplant in multiple myeloma - a single center experience

Objective: To compare the first 100 days' outcomes of autologous stem cell transplantation (Auto-BMT) using cryopreserved versus non-cryopreserved grafts in multiple myeloma (MM) patients. Methods: This prospective cohort study was conducted at a bone marrow transplant center in Rawalpindi, Pakistan, from March 2023 to March 2024. MM patients in stringent complete remission or complete remission per International Myeloma Working Group criteria were included. Patients were divided into two groups: those receiving non-cryopreserved stem cells and those receiving cryopreserved stem cells. Stem cell mobilization, collection, and preservation followed standardized protocols, with CD34+ counts and viability assessed pre-infusion. Data on patient demographics, disease characteristics, engraftment times, transplant-related complications, hospital stay duration, and outcomes at Day+100 post-transplant were collected and analyzed using SPSS 23.0. Results: The non-cryopreserved group had a higher mean CD34 dose (5.22 × 10⁶/l vs. 4.78 × 10⁶/l), superior cell viability (93% vs. 84%, p<0.01), faster neutrophil engraftment (12 vs. 14 days, p<0.01), and shorter hospital stays (15 vs. 16 days, p=0.03). Febrile neutropenia was universal in the cryopreserved group but affected 78.6% in the cryopreserved group. Gut toxicity was more frequent in the cryopreserved group (78.6% vs. 66.7%; p>0.05). Mucositis incidence was higher in the cryopreserved group (64% vs. 17%,). Both groups achieved complete remission by Day+100, with no mortality or relapse. Conclusion: NC stem cell grafts offer comparable efficacy to CryoP grafts while reducing costs and enhancing outcomes, particularly for engraftment speed and hospital stay duration. These findings support the adoption of NC protocols in resource-limited settings.