Independent prognostic value of semaphorin-4D, interleukin-1β and complement activation in newly diagnosed multiple myeloma patients.

Multiple myeloma represents a systemic disease of the bone marrow (BM) niche, in which immune and skeletal pathways are tightly interconnected. However, the independent prognostic significance of bone and immune-related markers in newly diagnosed multiple myeloma (NDMM) remains incompletely understood. Semaphorin (Sema) 4D, activin-A, and periostin ELISA, LEGENDplex™ Human Bone Metabolism Panel and proteomic analysis for novel biomarker identification were conducted in 71 consecutive samples from NDMM patients. In 25 patients, genomic analysis was performed on sorted clonal plasma cells. NDMM patients had a median age at diagnosis of 65 years and a median follow-up of 2.5 years. Interleukin (IL)-1β and Sema4D levels predicted progression-free survival (PFS), highlighting their role in disease relapse. Proteomic profiling revealed a systemic signature associated with worse prognosis, enriched in complement activation components. Complement C5 significantly affected PFS and time to progression (TTP). IL-1β and C5 predicted PFS independently of the second revision of the International Staging System (R2-ISS) stage, and a similar trend was noted for Sema4D. Myeloma bone disease (MBD) did not significantly affect overall survival, PFS, or TTP, suggesting that contemporary treatments mitigate its impact. Genomic analyses identified variants associated with inferior PFS, including HLA-DRB5 (c.300_306delinsCGGG) and HLA-DQB1 (c.317_319delinsCGG). Sema4D and the IL-1β-complement cascade emerged as key drivers of disease progression, independent of R2-ISS stage, representing potential prognostic and therapeutic targets in NDMM.