Serum ferritin (SF) levels may have poor predictive value in diagnosing iron overload in patients with thalassemia major after hematopoietic stem cell transplantation (HSCT), according to findings published in the European Journal of Haematology.
Iron overload post-HSCT can cause long-term organ damage and liver dysfunction and is often diagnosed based on SF levels rather than liver iron concentration (LIC). However, SF levels can vary as a result of factors other than iron overload, such as infection or inflammation. Thus SF may have limitations as a prognostic measure.
In this multicenter retrospective study, researchers analyzed 82 measurements of iron overload from 36 patients with thalassemia major who were younger than 20 years old and who had undergone HSCT. The researchers assessed the relationship between SF and LIC in the first, second, third, fourth, and beyond the fourth year post-HSCT.
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Indication of iron overload was defined as LIC under 5 mg/g dry weight (dw) or SF greater than 1 mg/L. A measurement of LIC greater than 5 mg/g dw but SF less than 1 mg/L was defined as a false negative; a measurement of LIC less than 5 mg/g dw but SF greater than 1 mg/L was defined as a false positive. The researchers calculated the overall error rate by determining the proportion of false indications.
SF and LIC were found to have a significant correlation in the first year post-HSCT (P >.001) but did not significantly correlate beyond the second year post-HSCT (P =.217). In the first year post-HSCT, the overall error rate was found to be 10%. The overall error rate for the second, third, fourth, and beyond the fourth year after HSCT was found to be 35%, 58%, 60%, and 25%, respectively.
The authors concluded that iron overload in patients with thalassemia should be diagnosed by assessing LIC by MRI or SQUID, as using SF levels as a prognostic tool can cause patients to undergo unnecessary iron chelation therapy or phlebotomy treatment.
Reference
1. Farisch A, Salzmann-Manrique E, Cario H, et al. Serum ferritin is not a reliable predictor to determine iron overload in thalassemia major patients post hematopoietic stem cell transplantation [published online September 6, 2018]. Eur J Haematol. doi: 10.1111/ejh.13169
