Fig. 1: Single-cell proteomic analysis of RLN, UCD and MCD lymph nodes.

A The left column displays representative full scans of RLN1 (n = 3), UCD2 (n = 5), and MCD4 (n = 4), showcasing the expression of key lineage markers. In the right column, cell segmentations and annotations for the indicated germinal center region (black box) are provided. B-cells (green) form follicles, while T cells (red) and myeloid cells (yellow) populate the interfollicular areas. UCD and MCD exhibit increased intrafollicular stromal cell proliferation (white), with MCD additionally showing interfollicular endothelial cell (blue) and plasma cell (magenta) proliferation. RLN, reactive lymph node; UCD, unicentric Castleman disease; MCD, multicentric Castleman disease; CD45negSC, CD45-negative DAPI-positive stromal cells. B Bar plots illustrate the absolute abundance of cells for the representative region shown in A. Pie charts (inset) represent the relative abundance of cell types across all imaged regions for each sample. Differential abundance against RLN was tested using a permutation test. Significantly (q < 0.01 and |log2FC | > 0.53) increased proportions are indicated with black triangles and significantly decreased proportions are indicated with blue triangles. C Increased CD21 + FDC meshworks (white) in the germinal center regions of UCD and MCD, representative of UCD (n = 5), and MCD (n = 4). D Analysis of size, area, signal intensity, image entropy of CD21, and cell diversity (Shannon index) within each follicle reveals higher expression and organization of FDC meshworks across CD, and low cell diversity in UCD. Each plotted point represents the aggregate data from a single image region (MCD, n = 11; HVCD, n = 9, RLN = 4). Box plot bounds represent the interquartile range (p25-p75) with the horizontal bar representing the median. Whiskers extend to the full range of data. Significance versus RLN1 was calculated using Tukey’s Honest Significance Difference test. *, p < 0.05; **, p < 0.01. E Twelve identified microenvironments are depicted. Sample composition (left graph) and cellular composition (right graph) of each microenvironment are shown. B cell germinal center and interfollicular CD4- and T-DC-enriched microenvironments are present in all samples. Plasma cell, macrophage, endothelial and stromal enriched microenvironments are increased in CD samples. F Voronoi diagrams of microenvironments in representative regions of cases and controls are shown. Color scheme as indicated by shading of microenvironment names in 1E. Source data are provided as a Source Data file in the supplementary dataset.