Delayed cutaneous hypersensitivity reaction to crude and semi-purified tumor extracts in cancer patients

Summary

A positive delayed cutaneous hypersensitivity reaction (DCHR) was observed to only one of five KCl soluble extracts from as many different tumoral kidneys in nine of 11 patients with kidney cancer. None of the autologous normal renal tissue extracts gave a positive reaction. SDS-PAGE analysis showed a predominant component with a molecular weight corresponding to that of serum albumin in all the four negative cancer extracts. Lipoproteins and serum albumin were removed by ultracentrifugal flotation on KBr and by affinity chromatography on antiserum albumin (α-HSA), respectively, from one of the negative crude extracts. KCl extract, F₂ fraction of KBr, and unbound material from the α-HSA column were injected simultaneously into nine patients with renal cancer. Positive DCHRs were seen to the three extracts in no patients, in three, and in eight, respectively. The α-HSA unbound fraction was positive in three of 13 patients with tumor at a site other than the kidney. The same extraction procedure was applied to normal autologous kidney tissue, and positive reactivity was observed in one of eight and three of nine patients with kidney cancer to the F₂ and α-HSA unbound fractions, respectively. An aliquot of KCl tumor extract was passed through the α-HSA column without the preliminary flotation on KBr, and the unbound fraction was positive in eight of nine patients with kidney cancer and in eight of twelve patients with other types of tumor. Three different melanomas were extracted in the same way and an increased percentage of DCHRs was found after removal of lipoproteins and HSA in melanoma patients. This reactivity, however, was not histologically related since patients with tumors other than melanoma reacted as well as melanoma patients. These data indicate that the removal of lipoproteins and HSA from crude tumor extracts may unmask or increase an existing antigenicity. The tumor-type-related experiments, however, suggest that these biochemical procedures are useful for kidney tumors but not for melanomas.