ABSTRACTObjectivesAutologous hematopoietic stem cell transplantation (ASCT) is a crucial method used in patients with multiple myeloma (MM). This study aims to evaluate the role of ASCT in immunoglobulin (Ig) reconstitution and long-term outcomes in patients aged ≥ 60 years.MethodsFrom March 2008 to May 2019, 93 patients aged ≥ 60 years who were diagnosed with MM and underwent ASCT were retrospectively analyzed. All patients underwent follow-ups and the deadline for follow-up was October 31, 2022. The Ig levels were measured using the immune turbidimetry method at 3, 6, and 12 months after transplantation. Patients who died or experienced relapse were excluded from the analysis. The prognostic value of Ig levels was estimated using the Kaplan-Meier survival curve and Cox regression method.ResultsNo patients died, and all patients with complications showed improvements after treatment. Patients in the Ig reconstitution group had a lower international staging system (ISS) stage, whereas those in the immunoparesis group had a higher ISS stage. The median duration of follow-up was 36 (range, 13–120) months. The Ig reconstitution within 12 months indicated a longer overall survival and progression-free survival outcomes. The detection of Ig levels was an independent indicator for the prognosis of MM.Discussion and conclusionThe Ig reconstitution within 12 months of ASCT could predict the overall outcomes of patients with MM aged ≥ 60 years.