Soluble Transferrin Receptor and Its Ratio to Erythroblasts in Bone Marrow May Be a New Diagnostic Tool to Distinguish between Aplastic and Refractory Anemia

Abstract

Myelodysplastic syndromes (MDS), especially refractory anemia (RA) are very heterogeneous diseases regarding their morphological, biological and clinical features. One important clinical problem is the difficulty of diagnosis. Soluble transferrin receptors (sTfRs) reflect the erythropoietic activity in the bone marrow (BM). To establish whether determination of serum sTfR could be useful for the differential diagnosis between RA and aplastic anemia (AA), we measured the serum sTfR concentrations, BM cellularity and BM erythroblast percentages in 14 untreated AA and 7 untreated RA patients. The serum sTfR levels of the RA patients (820.1 ± 402.8 ng/ml) were significantly higher than those of the AA patients (491.1 ± 195.2 ng/ml; p = 0.0207). However, the serum sTfR values of RA and AA patients also overlapped. A new index, the ‘sTfR-E index’ [the ratio of serum sTfR level (ng/ml) to BM cellularity (%) × BM erythroblasts (%)] is proposed, which is expected to reflect the number of transferrin receptors (TfR) on the cell membrane per BM erythroblast. The sTfR-E index values of the 7 RA patients (0.395 ± 0.234) were significantly lower than those of the 14 AA patients (2.669 ± 1.633; p = 0.0003). The sTfR-E index values of AA and RA patients overlapped only marginally. In conclusion, the sTfR-E index may be a useful new diagnostic tool to distinguish between AA and RA patients.

The soluble transferrin receptor in dysplastic erythropoiesis in myelodysplastic syndrome

“…Matsuda et al. confirmed the low TfR numbers on the MDS erythroblasts and proposed a new parameter, the ‘sTfR‐E index’ to distinguish between aplastic anemia and MDS patients (15). The sTfR‐E index depends on the sTfR levels, marrow cellularity and the amount of marrow erythroblasts and is supposed to reflect the number of transferring receptors on the cell membrane per bone marrow erythroblast.…”

“…Most of the patients show normal or slightly elevated sTfR concentrations, while the values are markedly elevated in another cases (9–14). The sTfR heterogeneity observed in MDS reflects its enormous variability regarding the morphological, biological and clinical features (10,15,16). The common denominator of MDS is dysplasia and ineffective hematopoiesis in one or more of the major myeloid cell lines.…”