Thymidine sensitivity of cultured leukaemic lymphocytes.

Cultured leukaemic lymphocytes from patients with T, null, or pre-B acute lymphoblastic leukaemia are shown to be highly sensitive to growth inhibition by thymidine. Thymidine sensitivity was correlated with reduced activity of the catabolic enzyme thymidine phosphorylase and sustained elevation of the deoxythymidine triphosphate pool after exposure to thymidine. It is suggested that thymidine may have a role in the management of certain acute lymphoblastic leukaemias of lymphomas.