Screening for Iron Overload Using Transferrin Saturation

Abstract

People with parenchymal Fe overload exhibit an elevated serum Fe concentration and a raised transferrin (TIBC) saturation early in the course of the disease. They can thus be detected by simple laboratory tests before organ damage has occurred. In this study running for 2 mo., 10512 samples from .apprx. 8750 patients and blood donors were examined in a county hospital in Central Sweden. Abnormal TIBC saturation (> 70%) was found in 1.7% of the samples. This abnormality was caused by physiological fluctuations in serum Fe in 44%, liver disease in 22%, blood disorder in 10%, Fe therapy in 10.5% and parenchymal Fe overload in 11.5%. The diagnosis of Fe overload was confirmed by measuring the serum ferritin concentration and by performing the desferrioxamine test, liver biopsy, quantitative phlebotomy and family studies including HLA typing. A prevalence of Fe overload of 0.24% was found. This figure is almost certainly too low because some affected patients were probably lost because of TIBC desaturation induced by inflammatory conditions.