Macrophage/histiocytic antigen CD68 expression in neoplastic and reactive lymph nodes.

There are some reports, suggesting that infiltrating macrophages may promote tumour progression in non-Hodgkin's lymphoma (nHL). The aim of the study was an evaluation of macrophages, marked by antibody against CD68 in indolent and aggressive nHL. The study was performed in 65 patients: 50 with nHL and 15 with lymph nodes affected by reactive hyperplasia. Immunohistochemical analyses were performed on paraffin-embedded specimens with monoclonal anti-CD68 antibody. Scoring on the basis of the percentage of positive cells indicated CD68 expression in 34/50 (68%) of the patients with nHL and in only 5/15 (33%) of the patients with reactive hyperplasia. The expression of CD68 was statistically significantly higher in the aggressive nHL than in indolent nHL. An increased number of CD68 positive macrophages in clinically aggressive nHL may confirm their role in tumour progression.