Cell-destructive activity in the serum of a tumor patient after infusion of alkyl lysophospholipid

Sera collected from 1 tumor patient after a 12-hour infusion of 30-50 mg alkyl lysophospholipids (ALP)/kg induced a progressive destruction of human leukemia cells (HL60) in vitro. This cytotoxic serum activity correlated with the dose of ALP administered and was inhibited by the addition of a metabolizable lysophospholipid analogue. Human bone marrow cells and concanavalin A-stimulated lymphoblasts were affected to a much lesser degree, whereas cells of the erythroleukemia line K562 appeared to be relatively resistant. When cells were cultured in postinfusion sera, the cytotoxicity of ALP in vitro was enhanced as much as fifteenfold when compared with the cytotoxicity of ALP when the cells were cultured in normal sera. No change in either relative or absolute distribution of phospholipids in postinfusion sera could be detected