title: Radioimmunoassay of human cardiac acidic isoferritin: a new index for hepatic cancer.
abstract: OBJECTIVE
  To investigate human cardiac acidic isoferritin as a specific index of hepatic cancer.
  
  
  METHODS
  Acidic isoferritin was isolated and purified from human heart muscle. A radioimmunoassay for the acidic isoferritin in human serum has been developed, on the equilibrium method. The antiserum was obtained from rabbits immunized with purified acidic isoferritin. The 125I-acidic isoferritin was prepared by the chloramine-T method. The data were processed using the automated smoothed spline function data processing program.
  
  
  RESULTS
  The intra- and inter-assay CV of acidic isoferritin RIA were 1.65% and 9.71%, respectively, and the recovery rate was 102%. The antiserum provided a linear response from 7.0 to 369.6 micrograms/L with ED50 of 27.50 micrograms/L. The cross reactivity with AFP, CEA, lactoferrin and transferrin was negligible, and that with ferritin was 1.74%. The serum acidic isoferritin concentration showed a considerable variation in different sex and age groups. The serum acidic isoferritin was measured in liver diseases including hepatic cancer, hepatic cirrhosis and acute and chronic hepatitis. Its sensitivity for diagnosis of hepatic cancer was 73.05%, independent from the severity of hepatic injury. In 8 malignant tumors studied, acidic isoferritin appeared the most valuable in the diagnosis of hepatic cancer, with its positive, negative, false positive and false negative rates all being ideal.
  
  
  CONCLUSIONS
  Acidic isoferritin may turn to be a rather specific index of hepatic cancer. Combination of monitoring both acidic isoferritin and AFP would raise the positive detection and specificity in the diagnosis of hepatic cancer.
authors.affiliation: State Key Laboratory of Nuclear Medicine, China.
authors.forename: J
authors.initials: J
authors.lastname: Jin
authors.forename: M
authors.initials: M
authors.lastname: Zhang
authors.forename: B
authors.initials: B
authors.lastname: Wang
authors.forename: H
authors.initials: H
authors.lastname: Xiao
authors.forename: J
authors.initials: J
authors.lastname: Sun
mesh_terms: D014408:Biomarkers, Tumor; D006528:Carcinoma, Hepatocellular / Q000097:blood*; D004938:Esophageal Neoplasms / Q000097:blood; D005293:Ferritins / Q000097:blood*; D006801:Humans; D008113:Liver Neoplasms / Q000097:blood*; D008175:Lung Neoplasms / Q000097:blood; D011863:Radioimmunoassay; D000509:alpha-Fetoproteins / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; C020391:acidic isoferritin; D000509:alpha-Fetoproteins; D005293:Ferritins