Albertine Donker

Chapter 8 278 bi-allelic and mono-allelic IRIDA patients, and between mono-allelic IRIDA patients and their phenotypically unaffected relatives with the same heterozygous TMPRSS6 defect, even after parenteral iron therapy had been given. 11 In this study, we assessed the ability of the TSAT/hepcidin ratio to discriminate between genotypically and phenotypically affected IRIDA patients and patients with IDA due to other reasons than IRIDA (e.g. menstrual blood loss, gastro-intestinal hemorrhage or malabsorption). Applying standardized hepcidin values, we aimed to establish a cut-off point for the TSAT/hepcidin ratio to distinguish bi-allelic and mono- allelic affected IRIDA patients from a control group with IDA, provided moderate or severe inflammation (defined as CRP >10 mg/L) was absent and no recent iron therapy had been provided, as these factors have been described to increase hepcidin production. 8,15-19 We observed that IRIDA cases had significantly lower TSAT/hepcidin ratios compared to IDA controls, making this ratio a specific tool for discriminating TMPRSS6- related IRIDA in a broad iron-deficient population