Suppressed hetergeneous antinuclear antibody response in lymphomabearing NZB/NZW mice.

A long-term study of cyclophophamide-induced suppression of auto-immune disease in NZB/NZW mice demonstrated the oncogenic potential of this alkylating agent. In seven of ten mice dying with lymphomas, retrospective examination of serial tests for heterogeneous ANA showed terminal decreases of titres or reversion of tests to negative. Suppressed titres were found in one of seven mice dying with other tumours and in four of twenty-nine mice succumbing to renal disease-vasculitis. Transplantation studies confirmed the association between growing lymphoma tissue and decreasing ANA titres. In the immunosuppressed host with connective tissue disease, the loss of certain auto-antibodies may signal development of a lymphoreticular neoplasm. Tumour-induced impairment of auto-immune responsiveness may reflect the loss of specific ANA that fulfil a protective role and inhibit neoplastic growth.