Fc gamma receptors and IgG associated with human malignant tumours

Thirteen solid tumours were tested for Fc gamma receptors (FcR) using tissue sections and sheep erythrocytes sensitized with rabbit antibodies as indicator cells. No alteration was found in FcR activity (FcRA) between untreated tissue and tissue homogenized for 2 min or less. More extensive homogenization abolished the FcRA. Tissues homogenized for 1 min were washed at 4C and eluted at 37, 45 and 56C. The FcRA was not altered after elution at 37 and 45C. However, elution at 56C abolished the activity indicating that the FcR were either eluted or destroyed. Tumours which showed a diffuse pattern of FcRA and no non-specifically bound IgG displayed an inverse relationship between the FcRA and the eluted IgG. Such relationship was not found with tumours containing non-specifically bound IgG.