An evaluation of monoclonal antibodies for serum ferritin measurements.

Serum ferritin measurements have become an important laboratory parameter of iron status in prevalence surveys. Because the use of monoclonal antibodies may reduce variability and facilitate standardization, the present study was undertaken to determine whether their performance is comparable to conventional immunological reagents in an immunoradiometric assay for serum ferritin. When evaluated as the capture antibody for the solid phase, no differences in dose response curves were observed between monoclonal reagent and whole antiserum. When monoclonal reagent was used as the radiolabeled indicator antibody, the dose response curves were also similar to those obtained with affinity-purified polyclonal reagent although between-assay variability was somewhat higher with monoclonal antibody. In measurements of serum ferritin in patients with a wide range of iron status, no consistent differences were observed in the results from assays using monoclonal antibody and those of the conventional reagent. These preliminary studies indicate that the performance of monoclonal antibodies in a conventional ferritin assay is comparable to conventional immunological reagents.