Infliximab Activity and Neutralizing
| Label Mnemonic: | IFX NAB |
| Epic code: | LAB8272 |
| Downtime form: | A-1a Doctor/Provider Orders - Pathology Core and Specialty Care Nursery |
Commercial Mailout Laboratory
6240-8 RCP
356-8593
6240-8 RCP
356-8593
Specimen(s):
Serum
Specimen
Instructions:
Collect specimens before infliximab or biosimilar treatment.
Collection Medium:
 |
| Red top tube 5 mL (Clot Activator) |
Minimum:
Preferred Minimum: 1 mL serum
Absolute Minimum: 0.5 mL serum
Absolute Minimum: 0.5 mL serum
Rejection Criteria:
Contaminated, hemolyzed, icteric, or lipemic specimens.
Turn Around
Time:
2-3 days upon receipt at reference laboratory
Reference Range:
Infliximab Activity - Not Detected
Infliximab Neutralizing Antibody Titer - Not Detected
Infliximab Neutralizing Antibody Titer - Not Detected
Interpretive Data:
This test measures the capacity of infliximab to neutralize TNF activity. Additionally, infliximab neutralizing antibodies (NAb) are titered, reporting the minimal serum dilution at which blocking of infliximab activity is no longer observed.
This test is used to evaluate secondary response failures to infliximab therapy. Secondary response failure is defined as loss of clinical response after initial improvement of clinical signs and symptoms. Therapeutic decision should rest on both the clinical response and the knowledge of the fate of the drug including the emergence of immunogenicity in individual patients.
Circulating infliximab levels have been shown to vary considerably between patients. These differences relate to route and frequency of administration and patient-related features such as age, gender, weight, drug metabolism, and concomitant medications such as methotrexate and other immunosuppressants.
Clinical Interpretation of Infliximab and Antibody Testing Results in the Context of Treatment Failure
This test is used to evaluate secondary response failures to infliximab therapy. Secondary response failure is defined as loss of clinical response after initial improvement of clinical signs and symptoms. Therapeutic decision should rest on both the clinical response and the knowledge of the fate of the drug including the emergence of immunogenicity in individual patients.
Circulating infliximab levels have been shown to vary considerably between patients. These differences relate to route and frequency of administration and patient-related features such as age, gender, weight, drug metabolism, and concomitant medications such as methotrexate and other immunosuppressants.
Clinical Interpretation of Infliximab and Antibody Testing Results in the Context of Treatment Failure
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Infliximab Infliximab Interpretation
Activity Neutralizing
Ab. Titer
Not Detected Not Detected Sub-therapeutic dose. A higher
dosage of infliximab or shortening
the dosing interval may be
appropriate.
Not Detected Detected Likely immune-mediated treatment
failure. A change to another anti-
TNF drug may be appropriate.
Detected-Below N/A Sub-therapeutic dose. A higher
Target dosage of infliximab or shortening
the dosing interval may be
appropriate.
Detected-Above N/A A change to another type of therapy
Target (not targeting TNF) may be
appropriate if patient is not
responding.Methodology:
Cell Culture/Quantitative Chemiluminescent Immunoassay/Semi-Quantitative Chemiluminescent Immunoassay
CPT Code:
80230; 82397