False positive results in an enzyme immunometric assay for the ovarian cancer associated antigen CA 125.
A commercially available two-site, solid phase enzyme immunoassay was used for measuring CA 125. Samples from six healthy subjects with known false positive CA 125 results (range 42-895 U/ml) were retested after addition of murine serum. A decrease ranging from 45 to 81% in the CA 125 levels was seen after addition of 63 ml/l murine serum. After addition of 500 ml/l three out of six samples had antigen levels below 35 U/ml. It is concluded that in the present study false positive CA 125 results could be diminished by addition of murine serum to the sample and may be due to human antibodies against murine immunoglobulins. Addition of murine serum to samples from persons with no evidence of disease and increased CA 125 levels is recommended.
Mogensen
O
O
Department of Oncology, Aarhus University Hospital, Denmark.
Møller
J
J
D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000276:immunology; D015295:Antigens, Tumor-Associated, Carbohydrate / Q000032:analysis*; D004797:Enzyme-Linked Immunosorbent Assay; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008722:Methods; D051379:Mice; D010051:Ovarian Neoplasms / Q000276:immunology*
D000888:Antibodies, Anti-Idiotypic; D015295:Antigens, Tumor-Associated, Carbohydrate