Sinus histiocytes in axillary lymph nodes from patients with breast cancer: macrophage characteristics and activation level.

Cell suspensions from 16 tumour-free axillary lymph nodes from breast cancer patients were prepared, using collagenase digestion to free the sinus histiocytes from the fibrous stroma of the nodes. The histiocytic cells so obtained were then characterized using four surface markers: Fc(IgG) receptors, C3 receptors, DR antigen and a macrophage-associated antigen (defined by the monoclonal antibody VEP-7). In addition phagocytosis was assessed using IgG-coated red cells, and both lysozyme and alpha-1-antitrypsin were localized by means of immunoperoxidase staining. The results demonstrated that the majority of sinus histiocytes carried surface macrophage markers, but that a minority displayed phagocytosis and the presence of lysozyme or alpha-1-antitrypsin.