Evaluation of a particle-enhanced turbidimetric immunoassay for the measurement of ferritin: application to patients participating in an autologous blood transfusion program

Abstract

Objectives: To evaluate a turbidimetric immunoassay for the measurement of ferritin, and to assay this method in a group of patients undergoing an autologous blood transfusion program.

Design and methods: We used an ILab 900 analyzer. This instrument automates a particle-enhanced immunoturbidimetric assay with an analysis time of 9 min. This technique was compared with a microparticle immunoassay. The turbidimetric assay was used to measure ferritin in a group of 30 patients undergoing an autologous blood transfusion program.

Results: The assay was linear in the range 3-1400 microg/L (r = 0.9999). The intra- and inter-assay imprecision (CV) at 20, 97 and 469 microg/L were <3.0 and <5.0%, respectively. Recovery was 88. 7 to 97.4%. The detection limit was 3 microg/L. Hemoglobin (</=4 g/L), mild hyperbilirubilinemia (bilirubin </=50 micromol/L), triglycerides (</=10 mmol/L) and myeloma paraproteins did not interfere with the assay. The assay showed good correlation with a microparticle enzymoimmunoassay (r = 0.994) with a mean difference between methods of -6 +/- 16 microg/L. This method was sensitive, accurate, and fast enough for an efficient follow-up of autologous blood transfusion patients.

Conclusions: The new automated serum assay for ferritin is an attractive alternative that avoids the need for dedicated instrumentation.