This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Grant, C. K. Articles by Essex, M. Search for Related Content PubMed PubMed Citation Articles by Grant, C. K. Articles by Essex, M.

Complement and Tumor Antibody Levels in Cats, and Changes Associated with Natural Feline Leukemia Virus Infection and Malignant Disease¹

Department of Microbiology, Harvard School of Public Health, Boston, Massachusetts 02115 [C. K. G., C. R., M. E.], Department of Statistics, Harvard University Science Center, Cambridge, Massachusetts 02138 [D. K. P.], and Department of Surgery, School of Veterinary Medicine, University of California, Davis, California 95616 [B. R. M.]

Complement-dependent antibody (CDA) and complement levels were measured in sera from 314 cats. Many of the cats (65%) had received prior natural exposure to horizontally transmitted feline leukemia virus (FeLV), and some of the cats (13%) had lymphoid tumors. In CDA assays, sera were tested against ⁵¹Cr-labeled cat lymphoma cells, and normal cat serum was used as a complement source. In assays for total lytic complement activity, the lymphoma cells were presensitized with alloantiserum. CDA was frequently detected in sera from persistently viremic cats, suggesting no direct CDA-FeLV interaction, and lack of such antibody-virus interaction in sera was confirmed by contingency table analysis. CDA was infrequently detected in cats with tumors, and data analysis provided strong support for CDA-tumor interaction (p = 0.002), thereby supporting the concept that CDA has specific antitumor activity. Most individual cat complement values were distributed normally, but a reduction in mean activity was found in FeLV-infected cats with detectable CDA. Wide variations in complement activity occurred from week to week only in FeLV-infected animals, and severely depleted complement levels were sometimes associated with FeLV-related anemia or lymphoid cancers. The possibility is discussed that some lymphoid tumors of cats develop and progress in the face of a CDA-mediated (anti-feline oncornavirus-associated cell membrane antigen) tumor immune response at times when complement levels are depleted.

¹ Supported by Grant 1483-C-1 from the American Cancer Society, Massachusetts Division; a grant from Harvard Biomedical Research Funds; and National Cancer Institute Contract CA-18216.

² Special Fellow of the Leukemia Society of America and Scholar, American Cancer Society, Massachusetts Division. To whom requests for reprints should be addressed.

Received 7/24/78. Accepted 10/ 2/78.