Abstract
Iron metabolism in patients with rheumatoid arthritis was evaluated. In 42 patients, anemia was seen in 57.1%, in which normochromic anemia was 63%, hypochromic 24% and hyperchromic 13%, respectively. Serum iron concentration was lower in 66% and total iron binding capacity (TIBC) was lower or normal in 82%. Serum ferritin level was not lower in 83%. Ferrokinetic studies in 15 patients with rheumatoid arthritis revealed rapid PID T_??_, lower PIT and RIT, which were compatible with lower serum iron concentration, less in vitro erythroid colonies (CFU-E) and hypocellular erythroid bone marrow. The release of reticuloendothelial iron was evaluated after intravenous injection of 59Fe chondrotin ferrous sulfate (Radio-Colloid). Percent radioactivity 4 and 6 hours after the injection to the injected dose was 7.9% and 6.7%, respectively, in patients with rhematoid arthritis, which was significantly lower than normal. The amounts of released iron in 8 hours were also reduced. These findings might suggest a defect in the release of iron from the reticuloendothelial tissues to the plasma, resulting in hypoferremia and inadeguate supply of iron to bone marrow. On the other hand, hypocellular bone marrow in erythroid series and lower PIT would explain the primary genesis of the anemia.
