[Antiviral activity in the serum of patients with acute myelocytic leukemia: prognostic significance. Preliminary report].

In view of suggestions that acute myeloblastic leukemia (AML) may be of viral etiology, sera of 31 patients suffering from AML were investigated for antiviral activity. Fowl plague virus (FPV), vesicular stomatitis virus (VSV), BT 20 mammary carcinoma cells and chicken embryo fibroblasts (CEF) were used as assay systems. In the FPV-BT20 system, 19 of 20 patients whose blood sample was taken when they were in complete remission showed antiviral activity in their sera. These patients stayed in complete remission for at least three months after the blood sample was taken. In the sera of 11 patients no antiviral activity could be found with the FPV-BT20 assay system. 3 of the 11 were in relapse, 5 had a relapse within 3 months and 3 stayed in remission more than 3 months after the blood sample was taken. In the FPV-CEF and in the VSV-BT20 system antiviral activity was also found. The activity in the FPV-CEF system corresponded well with the FPV-BT20 assay and the disease status, whereas the activity detected by the VSV-BT20 system did not. The nature of the antiviral activities in the sera of AML patients against FPV and VSV is not yet clear. Interferon and specific antiviral antibodies can probably be ruled out. The antiviral activity against FPV appears to be a biological index of the activity of the disease and might eventually be used to determine intensity and length of treatment.