The Usefulness of Serum Transferrin Receptor in Anemia with Rheumatoid Arthritis: Comparison with Bone Marrow Iron Store / 대한류마티스학회지

ABSTRACT

OBJECTIVE: This study was aimed at investigating the usefulness of serum transferrin receptor (sTfR) in anemic patients with rheumatoid arthritis (RA) compared with bone marrow storage iron and other tests for anemia. METHODS: Fifty-five anemic RA patients were undergone anemia study including hematologic indices, iron panel, and sTfR. Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were also measured. Eighteen patients performed marrow iron stain. The sTfR and serum ferritin levels were compared with bone marrow iron store, hematologic values, iron batteries, and markers of the disease activity. RESULTS: 1) Mean sTfR concentration was 2.68+/-1.29mg/L in all patients. 2) sTfR correlated significantly with hemoglobin concentration (r=-0.491; p<0.001), hematocrit (r=-0.348; p=0.009), MCV (r=-0.597; p<0.001), RDW (r=0.696; p<0.001), serum iron (r=-0.389; p=0.003), and transferrin saturation (r=-0.451; p=0.001) 3) Ferritin did not correlated significantly with hemoglobin, hematocrit, serum iron/TIBC, MCV and RDW, except reticulocyte count (r=0.295; p=0.032) and total iron binding capacity (TIBC) (r=-0.503; p<0.001). 4) sTfR showed no significant correlation with ESR and CRP, whereas ferritin correlated with CRP (r=0.342; p=0.019). 5) Among the patients who performed iron staining from bone marrow, sTfR was higher in ?ron-depleted? group compared with ?ron replete? group (p=0.040). CONCLUSION: This study suggests that measurement of sTfR may be useful assay for anemia and the possible substitute for invasive bone marrow study in differentiating iron deficiency anemia from anemia of chronic diseases in patients with RA.