ADVIA Centaur Cytokeratin Fragment 21-1

The ADVIA Centaur Cytokeratin Fragment 21-1 (CYFRA) assay is an in vitro diagnostic test that quantitatively measures cytokeratin 19 fragments in human serum and plasma using the ADVIA Centaur XPT analyzer. It is used as an aid in monitoring disease progression during treatment in lung cancer patients, with serial testing recommended in conjunction with other clinical information.

The proposed device is a fully automated sandwich immunoassay using acridinium ester chemiluminescent technology with a measuring interval of 0.49-100.00 ng/mL. The predicate uses electrochemiluminescence (ECLIA) with a measuring interval of 0.1-500 ng/mL. The proposed device accepts serum, EDTA plasma, and lithium heparin plasma; the predicate accepts serum and plasma. Both employ two monoclonal antibodies targeting CYFRA 21-1.

CLSI EP05-A3 (precision), CLSI EP06-ed2 (linearity), CLSI EP17-A2 (detection limit), CLSI EP07-ed3 and EP37-ed1 (interference), CLSI EP09c-ed3 (method comparison), CLSI EP28-A3c (reference interval), and multiple other CLSI EP documents for analytical validation.

Both devices measure the same analyte (CYFRA 21-1) with the same intended use (monitoring lung cancer progression). Despite differences in platform (ADVIA Centaur vs. Cobas e) and detection chemistry (acridinium ester vs. electrochemiluminescence), the proposed device demonstrates comparable analytical performance with acceptable precision, linearity, and specificity. Method comparison shows strong correlation (r=0.975) with a commercial CYFRA assay, and clinical data supports the device's effectiveness in distinguishing disease progression from stable disease with 89.3% specificity and 30.8% sensitivity.