An antibody against anemia-inducing substance inhibits cation influx in red blood cells from cancer patients

Resealed ghost of red blood cells (RBCs) from advanced cancer patients incl udes proteins with antigenicities common to an anemia-inducing substance th at we separated from plasma of patients with advanced malignant neoplasms. Although cation influx in vitro in RBCs from a cancer patient is larger tha n that from a normal healthy volunteer, an antibody against anemia-inducing substance inhibited the in vitro cation influx in RBCs from the cancer pat ient. Activation of the cation influx with N-ethylmaleimide after reaction with the antibody reversed the effect to create a greater cation influx in RBCs from the patient, as compared with that from the healthy volunteer.