Plasma transferrin and the relation to iron status in patients with chronic uremia

The relations between plasma transferrin, iron status and plasma albumin were studied in 76 patients with chronic uremia (23 non-dialyzed, 18 peritoneal dialyzed and 35 hemodialyzed). Patients with reduced (grade O) hemosiderin marrow iron had higher plasma transferrin (P less than 0.001), lower serum iron (P less than 0.01), transferrin saturation (P less tha 0.001) and serum ferritin (P less than 0.001), and higher iron absorption (P less than 0.001) than patients with "normal" (grade 1+) marrow iron. There were no significant differences between transferrin levels in the three groups of uremic subjects, when patients with identical marrow iron grade were compared. Plasma transferrin was correlated both to serum ferritin (r = -0.59, P less than 0.001) and iron absorption (r = 0.56, P less than 0.001). Patients with grade O marrow iron had normal transferrin levels compared with a healthy control group of 75 subjects, while levels in patients with grade 1+ marrow iron were lower than in controls (P less than 0.001). Plasma albumin displayed significant variations between the groups, being almost normal in non-dialyzed, slightly lower in hemodialyzed and lowest in peritoneal dialyzed patients. There was no correlation between plasma transferrin and plasma albumin. Due to its close association with iron metabolism, plasma transferrin is unsuitable as a marker of protein depletion, whereas plasma albumin seems to be a better indicator of protein status in uremic subjects.