Test Details
Methodology
Electrochemiluminescence immunoassays (ECLIA)
Result Turnaround Time
14 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Use
This test provides abatacept drug (µg/mL) and anti-abatacept antibody (ng/mL) concentrations. These measurements may be used to monitor abatacept therapy in individuals with rheumatoid arthritis, juvenile idiopathic arthritis, psoriatic arthritis or other autoimmune conditions.
Serum concentrations of abatacept drug and anti-abatacept antibodies may be used to optimize dosing and form and to facilitate clinical decision-making.
Drug assay: In the absence of anti-abatacept antibodies, the abatacept drug level reflects the total abatacept concentration. In the presence of anti-abatacept antibodies, the abatacept concentration reflects the antibody-unbound fraction of abatacept.
Anti-drug antibody assay: This anti-abatacept antibody assay is drug tolerant, i.e., the presence of abatacept drug in patient serum, even at concentrations well above target treatment levels (up to 100 micrograms/mL), does not impede the detection and quantitation of anti-abatacept antibodies. All positive anti-abatacept antibody results are verified by a confirmatory step that confirms abatacept drug specificity of antibodies.
Limitations
Correct interpretation of results depends upon the timing of specimen collection. Trough timing should be just before the next injection or infusion.
This test may exhibit interference when sample is collected from a person who is consuming a supplement with a high dose of biotin (also termed as vitamin B7 or B8, vitamin H, or coenzyme R). It is recommended to ask all patients who may be indicated for this test about biotin supplementation. Patients should be cautioned to stop biotin consumption at least 72 hours prior to the collection of a sample.
Specimen Requirements
Specimen
Serum (preferred); sodium heparin plasma is acceptable
Volume
2.0 mL
Minimum Volume
1.0 mL
Container
Red-top tube, gel-barrier tube, transfer tube or green-top (heparin) tube
Collection Instructions
Allow a minimum clotting time of 30 to 60 minutes with serum separation within two hours of collection. Send serum in a plastic transport tube. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested.
Stability Requirements
- Room temperature: 14 days
- Refrigerated: 14 days
- Frozen: 14 days
- Freeze/thaw cycle: Stable x6
Storage Instructions
Refrigerated or frozen
Causes for Rejection
EDTA plasma is not acceptable.
References
Genovese MC, Covarrubias A, Leon G, et al. Subcutaneous abatacept versus intravenous abatacept: a phase IIIb noninferiority study in patients with an inadequate response to methotrexate. Arthritis Rheum. 2011 Oct;63(10):2854-2864. PubMed 21618201
Genovese MC, Pacheco-Tena C, et al. Longterm Safety and Efficacy of Subcutaneous Abatacept in Patients with Rheumatoid Arthritis: 5-year Results from a Phase IIIb Trial. J Rheumatol. 2018 Aug;45(8):1085-1092. PubMed 29657147
Li, X, Roy, A, Murthy B. Population Pharmacokinetics and Exposure-Response Relationship of Intravenous and Subcutaneous Abatacept in Patients with Rheumatoid Arthritis. J Clin Pharmacol. 2019 Feb;59(2):245-257. PubMed 30229926
Mora JR, Wong R, Shaikh M, Askelson M. Analysis of the Immunogenicity from Abatacept-Treated Pediatric Patients with Polyarticular-Course Juvenile Idiopathic Arthritis: Findings from Two Phase III Clinical Trials. ACR Open Rheumatol. 2022 Feb;4(2):177-186. PubMed 34792858
Nash P, Nayiager S, Genovese MC, et al. Immunogenicity, safety, and efficacy of abatacept administered subcutaneously with or without background methotrexate in patients with rheumatoid arthritis: results from a phase III, international, multicenter, parallel-arm, open-label study. Arthritis Care Res (Hoboken). 2013 May;65(5):718-728. PubMed 23097311
Orencia [package insert]. Princeton, NJ: Bristol-Myers Squibb; October 2023.
Schaeverbeke T, Truchetet ME, Kostine M, Barnetche T, Bannwarth B, Richez C. Immunogenicity of biologic agents in rheumatoid arthritis patients: lessons for clinical practice. Rheumatology (Oxford). 2016 Feb;55(2):210-220. PubMed 26268816
Weisman MH, Durez P, Hallegua D, et al. Reduction of inflammatory biomarker response by abataceptin treatment of rheumatoid arthritis. J Rheumatol. 2006 Nov;33(11):2162-2166. PubMed 17014006