Hyperferritinemia after adult allogeneic hematopoietic cell transplantation: quantification of iron burden by determining non-transferrin-bound iron.

Iron overload is a common complication in allogeneic hematopoietic cell transplantation (HCT). We studied the prevalence of iron overload using serum ferritin from 122 allogeneic HCT survivors who had survived a median of 1259 (range 134-4261) days. We also quantified iron overload by determining non-transferrin-bound iron (NTBI), which reflects iron overload more directly than ferritin, and compared the results with those of the ferritin assay. Fifty-two patients (43 %) showed hyperferritinemia (HF) (serum ferritin >1000 ng/mL), and there was a moderate correlation between serum ferritin and the number of transfused red blood cell units (ρ = 0.71). In multivariate analyses, HF was a significant risk factor for liver dysfunction (P = 0.0001) and diabetes (P = 0.02), and was related to a lesser extent with performance status (P = 0.08). There was a significant correlation between serum ferritin and NTBI (ρ = 0.59); however, the association of NTBI with these outcomes was weaker than that of serum ferritin. In conclusion, serum ferritin is a good surrogate marker of iron overload after allogeneic HCT, and reflects organ damage more accurately than NTBI.