Cross-reactivity of a commercial chemiluminescence immunoassay for human chorionic gonadotropin with the free beta-subunit.
An enhanced chemiluminescence immunoassay for the determination of serum human chorionic gonadotropin (HCG) in specimens from oncology patients has been assessed with respect to its cross-reactivity with the free HCG beta-subunit (HCG-beta). The assay, standardized against the First International Reference Preparation 75/537, had a cross-reactivity with the free beta-subunit of 625% (molar basis). Therefore this assay achieves high sensitivity for the detection of either intact HCG or free HCG-beta in serum of patients with seminomatous or nonseminomatous testicular cancers. Results of both assays, the in-house immunoradiometric assay (+HCG-beta) and the Amerlite HCG-60 assay, showed a close correlation (R = 0.854-0.960) when serum samples from tumour patients were analyzed. Moreover, the content of free beta-subunit determined in a specific HCG-beta assay, could be quantitatively measured in the enhanced chemiluminescence immunoassay. Thus, this assay is suitable for oncology use, but also highlights the limitations of measuring HCG in serum samples.
Luppa
P
P
Institute of Clinical Chemistry, University Hospital Grosshadern, Munich, Germany.
Spöttl
G
G
Saller
B
B
Neumeier
D
D
Mann
K
K
D000911:Antibodies, Monoclonal; D006063:Chorionic Gonadotropin / Q000097:blood*; D018997:Chorionic Gonadotropin, beta Subunit, Human; D003429:Cross Reactions; D004407:Dysgerminoma / Q000097:blood*; D006801:Humans; D007118:Immunoassay / Q000379:methods; D008163:Luminescent Measurements; D008297:Male; D010446:Peptide Fragments / Q000097:blood*; D012044:Regression Analysis; D013736:Testicular Neoplasms / Q000097:blood*
D000911:Antibodies, Monoclonal; D006063:Chorionic Gonadotropin; D018997:Chorionic Gonadotropin, beta Subunit, Human; D010446:Peptide Fragments