[Clinical significance of erythrocyte ferritin]

Quantitative and qualitative evaluations of erythrocyte ferritin in 161 patients with RA and RAEB in MDS, AML, CML, PV, PA, HS, IDA, chronic liver disease and alcoholic liver disease were carried out. Mean erythrocyte ferritin levels of patients with RA, AML, PA, HS and alcoholic liver disease were increased compared with normal subjects. On isoelectric focusing analyses (IEF), erythrocyte ferritin in normal subjects were detected between pI 5.1 and 5.7. In the cases of RA, pI ranges of erythrocyte ferritin may be divided into three groups, acidic, neutral, basic shift on IEF respectively. In these groups, the more acidic the ferritin shift, the higher the proportion of morphological abnormalities of the erythroid precursors in the bone marrow was observed. In patients with AML (M2, M3, M4), little difference was found among these three subtypes, and all of the cases showed similar pattern with normal subjects on IEF. The ferritin from IDA showed low levels and slight basic shift compared with normal subjects on IEF, and these features were also found in patients with CML (chronic phase) and PV. After iron supplementation, marked increase of acidic ferritin was detected on IEF indicating an intermediate store for iron destined for haem synthesis. It was clear that the stainable iron in liver parenchymal cells were found at erythrocyte ferritin concentration 20 ag/cell or over in patients with chronic liver disease. Measurement of erythrocyte ferritin concentration is a helpful method for evaluating iron deposition in hepatocyte non-invasively. From these results it is considered that quantitative and qualitative analyses of erythrocyte ferritin are very useful for evaluating erythropoiesis as well as iron metabolism.