MRI as an alternative to serum ferritin for diagnosis of iron overload in children in the context of immune response after stem cell transplantation.

Multiple blood cell transfusions may cause iron overload or even liver fibrosis, requiring early diagnosis and intervention. SF is the standard for estimating iron levels in the body, but it also increases with inflammation. We hypothesized that T2 * magnetic resonance (MR) relaxometry is a more accurate alternative for follow-up in pediatric patients before and after allogenic SCT. Twenty-three children (mean age 10.2 years, 10 female, 13 male) were evaluated prospectively before SCT as well as at least 1 year after SCT with T2 * relaxometry on a 1.5 T MR-scanner to estimate liver iron concentrations from the T2 * values ("MR-Fe"). The results were compared with SF, while also considering CRP, and correlated with the number of transfusions. Overall, 24.3 transfusions were administered in average, mainly within 100 days of SCT (mean 10.5 units). Both MR-Fe and SF increased after SCT and decreased in the absence of new transfusions 1 year later without chelate therapy. This suggests regeneration of LP and iron loss, although the original states were not reached. Additionally, simultaneous peaks of CRP and SF were observed directly after SCT. MR-Fe did neither reveal these peaks nor was it associated with CRP (P = .39). We postulate that these early CRP and SF peaks after SCT are probably related to inflammatory reactions and not to iron overload. Thus, SF is not reliable for iron overload diagnosis after SCT in every condition. Beside this interaction, SF and MR-Fe revealed similar accuracy. MRI, however, has practical and economical disadvantages in routine estimation of iron.