High-affinity folate finding in chronic myelogenous leukaemia serum, relationship of binding characteristics to activity of disease and binder concentration.

High-affinity binding of [3H]folate to chronic myelogenous leukaemia serum displayed positive co-operativity. There seemed to be a relationship between the concentration level of binder in serum and the activity of the disease in the sense that the serum level of binder during remission fell to a value similar to that of normal serum. This was accompanied by a shift from positive co-operativity to the binding type of normal serum, i.e. negative co-operativity. The data support the hypothesis that the different characteristics of high-affinity folate binding in chronic myelogenous leukaemia and normal serum are related to parallel differences in the serum level of binder.