Table 1_Clusterin expression and germinal center morphometry help distinguish idiopathic multicentric castleman disease from select lymphadenopathies.xlsx

The targeted gene expression analysis revealed shared differentially expressed genes (DEGs) across all three iMCD clinical subtypes, including SPP1, XBP1, PRDM1, and CLU. We identified unique DEGs in each iMCD clinical subtype, including PLA2G2A, MSR1, IL8 (iMCD-TAFRO), IL9, KIR3DL1, IL18RAP (iMCD-IPL), and IL7, TLR8, and CX3CR1 (iMCD-NOS). Since Clusterin (CLU) was significantly upregulated in iMCD but not in related conditions, we performed immunohistochemistry and observed that Clusterin is elevated in the germinal center and mantle zone regions of iMCD patient lymph nodes.

A composite model incorporating CLU expression in these lymph node compartments with germinal center features demonstrated strong performance in differentiating iMCD from selected lymphadenopathies. Together, this work identified pathways dysregulated in iMCD lymph nodes and suggests that Clusterin, particularly when integrated with germinal center features, could be a novel biomarker.</p>