Transferrin in disease II: defects in the regulation of transferrin saturation with iron contribute to susceptibility to infection.

Patients with leukemia were found to have a high percentage of saturation of their serum transferrin with iron to an extent only rarely observed with other malignancies. This was associated with a reduced ability of their serum to inhibit the growth of a test strain of Pseudomonas aeruginosa. Serum iron, transferrin, and related parameters were measured serially in patients undergoing bone marrow transplantation for leukemia or aplastic anemia. It was found that a high proportion of these patients also have a high saturation of their transferrin with iron. This was related to three distinct physiologic deficits: a low level of serum transferrin; a high level of iron; and an inability to reduce the level of serum iron during infection. Three of six patients who were unable to reduce their serum during fever and infection subsequently died of sepsis. These data support the hypothesis that derangements in nonspecific serologic defense mechanisms involving iron contribute to susceptibility to infection in patients with leukemia undergoing bone marrow transplantation.