Objective:To identify the characteristics of the bone marrow immune microenvironment associated with long-term survival in multiple myeloma (MM) patients.Methods:In the follow-up cohort of patients with newly diagnosed MM and who received “novel agent induction therapy and subsequent autologous stem cell transplantation and immunomodulator maintenance therapy” in the First Affiliated Hospital of Sun Yat-sen University, a cross-sectional study was carried out between August 2019 and May 2020. Using NanoString technology, the RNA expression of 770 bone marrow immune-related markers was compared between 16 patients who had progression-free survival ≥5 years and 5 patients with progressive disease. Among the 16 patients who achieved long-term survival, 9 achieved persistent minimal residual disease (MRD) negative while the other 7 had persistent positive MRD. The functional scores of each kind of immune cells were calculated based on the expression level of characteristic genes, so as to indirectly obtained the proportion of each immune cell subset. The Mann-Whitney U test and the Kruskal Wallis test were used for statistical analysis. Results:The proportion of neutrophils was significantly higher in long-surviving MM patients than in patients with progressive disease [functional scores, 13.61 (13.33, 14.25) vs. 12.93 (12.58, 13.38); Z=2.31, P=0.021]. Among long-surviving patients, those who were MRD-positive had a significantly greater number of mast cells compared with those who were MRD-negative [functional scores, 7.09 (6.49, 8.57) vs. 6.03 (5.18, 6.69); H=2.18, P=0.029]. Compared with patients with progressive disease, four genes (CTSG, IFIT2, S100B, and CHIT1) were significantly downregulated and six (C4B, TNFRSF17, CD70, IRF4, C2, and GAGE1) were upregulated in long-surviving patients. Among long-surviving patients, only gene CMA1 was significantly upgraded, 10 genes (ISG15, OAS3, MX1, IFIT2, DDX58, SIGLEC1, CXCL10, IL1RN, SERPING and TNFSF10) were significantly downregulated in the MRD-positive group compared with that in the MRD-negative group, the first 5 of which are related to the interferon response pathway. Conclusions:The increased neutrophil and mast cell numbers may be related to long-term survival in MM. Interferon signaling activation may be a key bone marrow immune profiling feature for MRD-negative, long-surviving patients with MM.

Objective: To study the efficacy, safety and long-term outcomes of integrated strategy of bortezomib-based induction regimens followed by autologous hematopoietic stem cell (ASCT) and maintenance therapy in Chinese multiple myeloma (MM) patients. Methods: 200 MM patients receiving integrated strategy of bortezomib--based induction regimens followed by ASCT and maintenance therapy were retrospectively and prospectively analyzed from December 1. 2006 to April 30. 2018. Results: The complete remission rates (CR) and better than very good partial remission rates (VGPR) after induction therapy, transplantation and maintenance therapy were respectively 31% and 75.5%, 51.8% and 87.7%,73.6% and 93.4%. There was no difference between 4 cycles and more than 5 cycles induction chemotherapy. The negative rate of MRD detection by flow cytometry was 17.6% and 38.2% respectively after induction and 3 months after transplantation. The negative rate of MRD gradually increased during the maintenance therapy. The success rate of high dose CTX combined with G-CSF mobilization was 95.5% and transplantation related mortality (TRM) was zero. The median time to progress (TTP) was 75.3 months and the median overall survival (OS) was 99.5 months. TTP of patients obtaining CR and negative MRD after induction were longer that those of no CR and positive MRD. TTP and OS of patients receiving triple-drug induction and ASCT in early stage were longer than those of double-drug induction and ASCT in late stage. LDH≥240 U/L, high risk cytogenetics, ISS II+III stage and HBsAg positive were prognostic factors at diagnosis. However, only MRD and high risk cytogenetics were independent prognostic factors after transplantation and maintenance therapy. The clinical characteristics of patients of TTP ≥6 years were listed below: light-chain type M protein, ISS I stage, normal level of hemoglobin and platelet, normal LDH, HBsAg negative, chromosome 17p-negative, good response and sustained good response. Conclusions Integrated strategy of bortezomib-based induction regimens followed by ASCT and maintenance therapy can significantly improve the short-term and long-term efficacy. The prognostic factors of TTP in different disease stages were different. Response to treatment, especially MRD, played a more important role in prognostic factors.