Copy Number Alterations Suggest a Functional Switch from Innate Immunity to DNA Repair and Drive Clinical Heterogeneity in Plasma Cell Dyscrasias

Background/Objectives: Multiple myeloma (MM) is a genetically complex hematological neoplasm driven by accumulating genomic events. Despite therapeutic advances, MM remains an incurable disease with a complex molecular picture. Characterizing copy number alterations (CNAs) represents a promising strategy to identify dysregulated biological pathways and reveal novel therapeutic targets. This study aimed to characterize the CNA profile across pre-malignant gammopathies, MM, and plasma cell leukemia, identifying the key molecular pathways involved in disease progression. Methods: Genomic analysis via array comparative genomic hybridization (aCGH) was performed on bone marrow samples from 21 patients representing all disease stages. Data were analyzed in CytoGenomics software version 5.3.0.14 utilizing the GRCh38/hg38 human genome. CNAs were identified with the ADM-2 algorithm, followed by functional enrichment analysis to determine significantly overrepresented pathways. Results: Pre-malignant evaluation suggested a potential functional switch from innate immunity and olfactory signaling in Monoclonal Gammopathy of Undetermined Significance (MGUS) to DNA repair mechanisms in Smoldering Multiple Myeloma (SMM), marking early genomic instability. In active MM, 280 CNAs were detected. Low-risk (ISS-I) patients retained cell adhesion signatures, whereas high-risk (ISS-III) profiles exhibited extensive genomic instability affecting tissue remodeling and cytokine signaling. Conclusions: In summary, our descriptive findings suggest that early alterations in immune response and olfactory signaling pathways may emerge as potential triggers driving pre-malignant dyscrasias and active MM development.