Measurements of serum ferritin used to predict concentrations of iron in bone marrow in anemia of chronic disease

We determined serum ferritin, C-reactive protein (CRP), fibrinogen, and the erythrocyte sedimentation rate (ESR) in 73 patients with anemia of chronic disease. Nomograms of CRP, ESR, or fibrinogen vs ferritin concentrations were constructed and used to estimate the iron store in bone marrow. Iron stores estimated from the nomograms were compared with the results of staining cytological bone marrow smears for iron, the reference method for evaluating iron in bone marrow. In contrast to the results of Witte et al. (Clin Chem 1985;31:1011; Am J Clin Pathol 1986;85:202-6 and 1988;90:85-7), we observed that nomograms of CRP, fibrinogen, or ESR (i.e., acute-phase reactants not influenced by changes in iron metabolism) vs ferritin are not suitable to correct for the acute-phase component of changes in ferritin concentrations. For ferritin concentrations less than 70 micrograms/L, we found that iron deficiency, as judged from bone marrow iron stain, apparently was always present.