Expression of oncornavirus antigens in peripheral leucocytes of patients with chronic myeloid leukaemia.

Peripheral leucocytes from 16 patients with chronic myeloid leukaemia (CML) were examined for the presence of oncornavirus p30 antigens by indirect cytoplasmic immunofluorescence. The leucocytes of 12 patients who could be kept in balance by chemotherapy proved to be negative or contained the p30 antigen of mammalian endogenous oncornaviruses as the only viral antigen. In the leucocytes of four patients being in blastoid crisis, an antigen related to the p30 antigen of mammalian leukaemia-sarcoma viruses was detected. In five of six patients decrease in sensitivity to chemotherapy, or blastoid crisis, was preceded by expression of leukaemia-sarcoma virus p30 antigen(s). Leucocytes from 15 CML patients kept in balance by chemotherapy and those from seven being in blastoid crisis, were examined by indirect membrane immunofluorescence for the presence of antigen(s) related to the gp70 antigen of the simian and murine leukaemia-sarcoma virus. All tests proved to be negative.