The effect of tumors on antibody levels in mice.

As a result of immunization with various antigens, mice with certain transplanted tumors, namely, Sarcoma 37, Sarcoma 180, Earle's sarcoma L, a methylcholanthrene-induced fibrosarcoma, and Barrett's Transplantable mammary adenocarcinoma, yielded antisera of a lower titer than those from similarly treated normal mice. Antisera from tumor-bearing mice had one-half, or less than one-half, of the agglutinin titer of antisera from normal mice. In terms of precipitin N, immunized Swiss mice bearing Sarcoma 37 yielded as little as 40 per cent as much antibody as did similarly treated normal mice. Spontaneous mammary tumors did not elicit this effect, but a transplanted mammary tumor, TMC-1, acquired the property of doing so after thirteen transplantations. Mice in which tumors had regressed yielded amounts of antibody equal to those of normal mice. It was concluded that rapidly growing transplanted tumors lower antibody titers, but that slowly growing, or regressed, tumors do not do so. The phenomenon was also demonstrable by passive transfer of mouse antisera into tumor-bearing and normal mice and was found to be specific, inasmuch as rabbit antisera passively transferred in mice failed to show this difference. This indicated that an abnormally high destruction of antibody occurred in tumor-bearing mice. The effect did not appear to be due to inhibitors or to changes in other serum components.