Evaluation of iron status in anemic patients with rheumatoid arthritis using an automated immunoturbidimetric assay for transferrin receptor

We have evaluated a newly introduced immunoturbidimetric transferrin recept or assay (IdeA TfR-IT, Orion Diagnostica, Finland) in healthy subjects and in a study population consisting of patients with rheumatoid arthritis and juvenile chronic arthritis. The IdeA TfR-IT assay was found to provide repr oducible results which were in good agreement with the ELISA assays from Or ion Diagnostica (IDeA-ELISA, correlation R-2=0.8, n=102) and R&D systems (Q uantikine TfR ELISA assay, correlation R-2=0.95, n=39). The analysis of the patient samples suggested that, on the basis of serum transferrin receptor and ferritin concentrations, in approximately one third of patients with r heumatoid arthritis anemia is due to the depletion of iron stores. Apparent ly, in all patients with rheumatoid arthritis iron deficiency must be consi dered as a potential cause of the anemia. Now, that assays which are suitab le for automated analyzers have become available for the measurement of ser um transferrin receptor, this analyte has the potential to become a part of the routine evaluation of iron status.