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Biomedical subjects

H J Roth

Publications and source records attributed to H J Roth.

165 records · Page 10Linked to original sources
PubMedDate not supplied

Technical performance of the Elecsys CA 72-4 test--development and field study.

Tumor-associated glycoprotein (TAG) 72 is a mucin-like protein of high molecular weight (220-400 kd). Elevated serum levels of TAG72 are preferentially observed in patients suffering from gastric cancer. Additionally the determination of TAG72 may be a helpful tool in the management of patients suffering from mucinous ovarian cancer, in whom the clinical sensitivity of CA125 is low. The new Elecsys CA72-4 assay-available as Elecsys 2010 and 1010--was evaluated in a first field study. The test has a wide measuring range (300 U/ml) and low detection limit (0.5 U/ml) which favours its routine use. Typical precision values are 2% for intra-assay, 4% for inter-assay and 6% for inter-instrument-precision. Method comparisons to Enzymun-Test CA72-4 showed a correlation between 0.91 and 0.96. The correlation to a commercially available RIA was 0.8. With human ascites material no Hook-effect was observed up to 20,000 U/ml. No Hama-interference with clinically relevant HAMA-samples was detected.

Antigens, Neoplasm↗
PubMedDate not supplied

Human anti-mouse antibodies: pitfalls in tumor marker measurement and strategies for enhanced assay robustness; including results with Elecsys CEA.

Therapies using monoclonal antibodies may have undesirable consequences for the diagnostic use of tumor markers. These effects can be minimised by employing chimeric antibodies as well as special interference eliminating reagents. Human Anti-Mouse Antibodies (HAMA) are produced as a result of the immune response of a patient to treatment with murine monoclonal antibodies. The interaction of HAMA with the murine monoclonal antibodies of a tumor marker assay can simulate (false) positive or negative results leading to misdiagnosis and to inadequate disease management of a patient. To avoid HAMA-interferences "Roche Diagnostics" established a three-component-system: The use of chimeric antibodies, the interference elimination, which is realised in the parameters most frequently used like CEA and TSH. By employing such a chimeric antibody, Elecsys CEA proved to be extremely robust against HAMA-interferences. With 20 clinical relevant samples from different Mab-approaches, no HAMA-interference was observed. By fragmentation of the antibodies, i.e., elimination of the constant region and using monovalent fab-fragments (antigen binding fragment) combined with the addition of special blocking reagents all not-chimerized, Elecsys assays showed comparable results to chimerisation. This could also be shown with 20 clinical relevant samples.

Animals↗