Macrophage phenotype within simple ganglia

Immunohistological staining of the connective tissue stroma of simple ganglia using monoclonal antibodies demonstrated infiltrating mononuclear phagocytes. These cells were characterised by positive staining for the leukocyte common antigen, the monocyte associated CD14 phenotype and HLA-class II antigens. There was only occasional expression of an epitope associated with macrophage maturity, and of the iC3b receptor. No expression of the C3b receptor, the high affinity Fc receptor, the p150.95 adhesion molecule or the p8.14 molecule was observed. Polymorphonuclear leukocytes and lymphocytes were absent. The restricted epitope expression by the mononuclear phagocyte population of simple ganglia may be a reflection of the absence of other inflammatory cells and indicates that the micro-environment within inflammatory lesions such as subcutaneous rheumatoid nodules is very different to that present in ganglia.