|Downtime form:||A-1a Doctor/Provider Orders - Pathology Core and Specialty Care Nursery|
|Red top tube 5 mL (Clot Activator)|
Absolute Minimum: 0.65 mL serum in red top tube (Note: This volume does not allow for repeat testing.)
To avoid delays in turnaround time when requesting multiple tests, please submit separate frozen specimens for each test requested.
Quantitation Limit: <1.0 ug/mL
Results of 1 ug/mL or higher indicate detection of certolizumab
Quantitation Limit: <40 ng/mL
Results of 40 ng/mL or higher indicate detection of anti-certolizumab pegol antibodies.
As with other biologics, the optimal certolizumab concentration depends upon patient-specific factors including co-morbidities, disease, and desired therapeutic endpoint.
Trough blood collection (just before the next dose) is suitable because target ranges and therapeutic cut-offs are established by clinical studies that typically evaluate trough concentrations.
Therefore, the timing of specimen collection should be considered when interpreting drug concentrations. Drug half-life should be factored in when evaluating non-trough concentrations.
Adequate drug trough levels do not guarantee clinical efficacy since primary non-response can be due to mechanistic failure.
Lack of clinical response may be due to inadequate drug exposure, immunogenicity or mechanistic mismatch. Positive anti-certolizumab antibodies should be interpreted in the context of the concomitant free certolizumab drug level.