Immunohistochemistry of HSP105 expression in normal and neoplastic lymph nodes. (A) HSP105 expression levels measured by IHC using the defined CS in B-NHLs (97 cases) and nonmalignant lymph nodes (26 cases) plotted against tumor aggressiveness based on lymphoma histologic grade (i) or Ki-67 expression levels (ii). HSP105 CS in tumor biopsies from vaccinated patients is highlighted (white represents responders; and gray, nonresponders). The lines indicate the median values. Significant differences of HSP105 expression between groups were calculated with the unpaired 2-tailed Student t test: **P ≤ .01; ***P ≤ .001. Correlation between HSP105 expression and lymphoma aggressiveness was determined with the Spearman rank correlation test. LN indicates lymph nodes; HG, high grade; and LG, low grade. (B) Representative IHC analyses of low- and high-grade B-NHLs, using streptavidin-biotin-HRP complex method with 3-3′ diaminobenzidine as a chromogen (brown signal). Hematoxylin and eosin (left), Ki-67 (middle), and HSP105 (right) staining in one case of FL (i) and lymphoplasmocytic lymphoma (ii) before (top) and after progression (bottom) toward a DLBCL. Arrows indicate HSP105 expression on lymphoma cell surface. Digital images were acquired with Nikon DN100 digital net camera and the Nikon Eclipse E400 microscope, and processed using Photoshop CS4 software version for Macintosh Pro personal computer. Original magnifications: Bi, ×10; and Bii, ×20.