nm23-H1 expression in non-Hodgkin and Hodgkin lymphomas

We assessed for nm23-H1 expression in 262 lymphoid neoplasms including 191 B-cell non-Hodgkin lymphoma (NHL), 54 T-cell NHL, and 17 Hodgkin lymphoma (HL). We used a monoclonal anti-nm23-H1 antibody, routinely processed tissue, and immunohistochemical methods. We semiquantified the percentage of positive cells (0%, <25%, 25% to 75%, and >75%) and also estimated staining intensity (1 to 3+). Some percentage of nm23-H1 positive cells was detected in almost all types of NHL and HL, but T-cell NHL (87%) and HL (94.1%) more frequently had >75% positive cells than B-cell NHL (47.6%) (T- NHL vs. B-NHL, P<0.0001; HL vs. B-NHL, P=0.0011). High-intensity (3+) nm23-H1 staining was also more frequently observed in T-cell NHL (61.1%) and HL (76.5%) compared with B-cell NHL (43.5%) (T- NHL vs. B-NHL, P=0.013; HL vs. B-NHL, P=0.007). In most types of NHL and HL the nm23-H1 immunoreactivity was predominantly cytoplasmic. However, in plasma cell myeloma (PCM) nm23-H1 immunoreactivity was predominantly nuclear. In B-cell NHL, the percentage of nm23-H1-positive cells and the intensity of staining was not significantly different between various lymphoma types with the exception of PCM. We conclude that nm23-H1 is expressed in most types of B-cell and T-cell NHLs and HL, with a greater number of positive cells and higher staining intensity in T-cell NHL and HL, and PCM often being negative. The abundant intracellular expression of nm23-H1 suggests that serum levels of nm23-H1 are a reflection of tumor content. Unlike the conclusions of earlier studies, nm23-H1 expression in B-cell NHL was not significantly increased in clinically aggressive versus indolent neoplasms.