Evidence for non-specifically bound IgG in human tumours.

Heat eluates of homogenized human malignant and normal tissues were prepared using the continuous flow elution technique. IgG antibodies to rabbit erythrocytes served as marker antibodies for non-specifically bound IgG. Eluates of all of the 13 malignant tumours tested contained IgG. Most were eluted at 56C, but considerable amounts also at 37C and 45C. Marker antibodies were present in eluates of 4 of the tumours, indicating that at least parts of the IgG associated with malignant human tumours are non-specifically bound. Eight tumours contained too little IgG to detect marker antibodies, and one contained high amounts of IgG without marker antibodies. Eluates of normal organs contained either no or only small amounts of IgG, although apparently normal kidneys from older individuals contained some more IgG. Marker antibodies were detected in some of the eluates indicating non-specific binding.