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Adalimumab Level and Anti-drug Antibody for Rheumatic Diseases
Test Code36297
CPT Codes
83520, 80145<br /> **This test is not available for New York patient testing**
Preferred Specimen
2 mL serum collected in a red-top tube (no gel)
Patient Preparation
No biotin supplements 48 hours prior to blood draw
Minimum Volume
1 mL
Instructions
The blood should be drawn just before the next infusion of adalimumab to measure the trough drug level.
Transport Temperature
Refrigerated (cold packs)
Specimen Stability
Room temperature: 48 hours
Refrigerated: 7 days
Frozen -20° C: 14 days
Frozen -70° C: 42 days
Refrigerated: 7 days
Frozen -20° C: 14 days
Frozen -70° C: 42 days
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Gross hemolysis • Serum Separator Tube (SST®)
Methodology
Enzyme Linked Immunosorbent Assay (ELISA)
Setup Schedule
Set up: Mon, Tues, Thurs-Sat; Report available: 1-2 days
Clinical Significance
Several studies suggest a target adalimumab trough concentration of 5-12 mcg/mL. Sub-therapeutic adalimumab levels may be due to a patient not yet achieving a steady state trough level early in therapy, inadequate dosing, a dosing interval that is too long, or accelerated adalimumab clearance. Accelerated adalimumab clearance may be explained by the presence of adalimumab anti-drug antibody or rheumatoid factor in the patient's serum, or may be caused by other diseases that indirectly lead to immunoglobulin loss (i.e. kidney disease, protein-losing gastroenteropathy).
If adalimumab level is sub-therapeutic but total adalimumab anti-drug antibody is not detected: Patients with a sub-therapeutic adalimumab trough level, but no anti-drug antibody, may benefit from an increased adalimumab dose.
If adalimumab level is sub-therapeutic and total adalimumab anti-drug antibody is detected: Detectable serum adalimumab anti-drug antibody may cause accelerated adalimumab clearance leading to reduced trough levels and a compromised clinical response. Such patients are more likely to benefit from a switch in biologic therapy than from an increase in adalimumab dose.
If adalimumab level is therapeutic and total adalimumab anti-drug antibody is not detected: Patients who do not respond or who lose their clinical response, inflammation is likely to be driven by a process that is not TNF alpha dependent. A switch to a different class of therapy should be considered.
If adalimumab level is therapeutic and total adalimumab anti-drug antibody is detected: If the patient is responding clinically, the detected anti-drug antibody may not be clinically significant because the detected anti-drug antibody may not be functional or the level is inadequate to accelerate adalimumab clearance. Anti-drug antibody may disappear over time or increase, and, if increased, may cause sub-therapeutic adalimumab levels and a loss of response in the future. Patients with a loss of adalimumab response despite therapeutic trough levels may benefit from a switch to a different class of therapy. Addition of methotrexate to the treatment regimen may suppress development of ADA.
If adalimumab level is sub-therapeutic but total adalimumab anti-drug antibody is not detected: Patients with a sub-therapeutic adalimumab trough level, but no anti-drug antibody, may benefit from an increased adalimumab dose.
If adalimumab level is sub-therapeutic and total adalimumab anti-drug antibody is detected: Detectable serum adalimumab anti-drug antibody may cause accelerated adalimumab clearance leading to reduced trough levels and a compromised clinical response. Such patients are more likely to benefit from a switch in biologic therapy than from an increase in adalimumab dose.
If adalimumab level is therapeutic and total adalimumab anti-drug antibody is not detected: Patients who do not respond or who lose their clinical response, inflammation is likely to be driven by a process that is not TNF alpha dependent. A switch to a different class of therapy should be considered.
If adalimumab level is therapeutic and total adalimumab anti-drug antibody is detected: If the patient is responding clinically, the detected anti-drug antibody may not be clinically significant because the detected anti-drug antibody may not be functional or the level is inadequate to accelerate adalimumab clearance. Anti-drug antibody may disappear over time or increase, and, if increased, may cause sub-therapeutic adalimumab levels and a loss of response in the future. Patients with a loss of adalimumab response despite therapeutic trough levels may benefit from a switch to a different class of therapy. Addition of methotrexate to the treatment regimen may suppress development of ADA.