Fig. 1

Spatial profiling of bone marrow (BM) niche and extramedullary disease (EMD) in multiple myeloma (MM). Fluorescence was optimized for better visualization of cells of interest. Markers selected for this aim were CD138, CD38 and plasma cell marker for plasma cells (PCs), while CD3, CD68, CD11b, CD31 were selected for the tumor microenvironment (TME) component. A: Region of interest (ROI) of a BM section showing fluorescence of both PCs and TME. Scale bar = 100 μm. B-C: Hematoxylin and eosin (H&E) staining of a selected area of BM from a representative patient (BM#5). Original magnifications ×20. (B). Matched area showing markers fluorescence of both PCs and the TME component. Original magnifications ×20, scale bar = 100 μm (C). D: Spatial distribution of annotated cell types in BM sample of the representative patient BM#5. E: ROI of an EMD section showing PCs and TME component. Scale bar = 100 μm. F-G: H&E staining of the selected ROI of the EMD representative sample (EMD#5). Original magnifications ×20 (F). Matched area showing markers fluorescence of both the PCs and the TME component. Original magnifications ×20, scale bar = 100 μm (G). H: Spatial distribution of annotated cell types in EMD sample of the representative patient EMD#5. I-M: BM#5 ROI at different magnifications: visualization of all selected markers (I), only selected PCs markers (L), only selected TME markers (M) in the selected ROI. Scale bar = 100 μm. N: UMAP visualization of cell populations in BM#5 (legend on side). O: Stacked bar plots showing the cell type composition of all BM samples. Color indicates cell type annotation (legend on side). P-R: EMD#5 ROI at different magnifications: visualization of all selected markers (P), only selected PCs markers (Q), only selected TME markers (R). Scale bar = 100 μm. S: UMAP visualization of cell population in EMD#5. Colors indicate cell type annotation (legend on side). T: Stacked bar plots showing the cell type composition of all EMD samples. Color indicates cell type annotation (legend on side)