New monoclonal antibody enzymoassay for the specific measurement of placental ferritin isotype in hematologic malignancies

: A new enzymoimmunoassay, specific for the measurement of placental ferritin (PLF) isotype, has been described. Two monoclonal antibodies (McAbs) with different binding specificities to placental ferritin have been used in this assay. One antibody (CM-G-8) binds to all ferritins, whereas the second (CM-H-9) binds to placental ferritin only. In addition, a second enzymoassay was developed for the measurement of total common serum ferritin using CM-G-8 McAb. Serum levels of total ferritin and PLF were measured in healthy individuals and in patients with lymphoproliferative diseases and multiple myeloma. The majority of normal subjects were deficient in PLF in the serum. Increased serum levels of PLF were observed in patients with Hodgkin's lymphoma and non-Hodgkin's lymphoma of low and intermediate grades, as well as in patients with acute lymphocytic leukemia (ALL). Total ferritin was also elevated in these patients. Chronic lymphocytic leukemia (CLL) and multiple myeloma patients exhibited normal levels of common serum ferritin, whereas PLF in the serum was lacking.