Initial Results with a Commercial Luminescence Enhanced Enzyme Immunoassay for the Determination of Carcinoembryonic Antigen (CEA) in Body Fluids

A commercially available luminescence enhanced enzyme immunoassay (Amerlite--Amersham International) for carcinoembryonic antigen (CEA) was compared with an established enzyme immunoassay (Monoclonal 1-step Assay--Abbott Laboratories). A reference range for healthy blood donors (n = 272) was established for both kits. The blood donors were not separated into smokers and non-smokers, but were excluded from the reference group if they showed abnormal aminotransferase or gamma-glutamyltranspeptidase serum values. Twenty eight donors were excluded in this way. The test group consisted of 130 known tumour patients, and included pre- and post-operative serum samples. Normal and elevated CEA values were present. All sera were negative for HBsAg, anti-HBsAg and anti-HIV as determined with commercial enzyme immunoassays used routinely in the blood bank. The luminescence enhanced immunoassay gave rise to a reference range (95% confidence limits) of less than 3.91 micrograms/l in comparison with the enzyme immunoassay, which had a reference range of less than 4.12 micrograms/l. The proportion of elevated values in the tumour patient group was 37/130 for the luminescence enhanced enzyme immunoassay and 28/130 for the enzyme immunoassay. The correlation of values from both methods in the blood donor group was good (r = 0.771, n = 272). The CEA levels found in the tumour patient group differed significantly when measured in both kits (Wilcoxon matched-pair signed rank test--c-alpha = -6.52, p less than 0.01, n = 130), the Amersham kit giving the higher results (median values--Abbott 2.35 micrograms/l, Amersham 2.50 micrograms/l).(ABSTRACT TRUNCATED AT 250 WORDS)