Test Id : ECULI
Eculizumab, Serum
Useful For
Suggests clinical disorders or settings where the test may be helpful
Assessing the response to eculizumab therapy
Assessing the need for dose escalation
Evaluating the potential for dose de-escalation or discontinuation of therapy in remission states
Monitoring patients who need to be above a certain eculizumab concentration in order to improve the odds of a clinical response for therapy optimization
Method Name
A short description of the method used to perform the test
Liquid Chromatography Tandem Mass Spectrometry, High-Resolution Accurate Mass (LC-MS/MS HRAM)
NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.
Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test
Aliases
Lists additional common names for a test, as an aid in searching
ECULI
ECUMP
Soliris
Eculizumab
Specimen Type
Describes the specimen type validated for testing
Serum
Ordering Guidance
Therapeutic drug monitoring of eculizumab may be useful when providers are considering personalized treatment decisions, such as therapy discontinuation of extended dose intervals when patients are in remission states.
For a panel that includes both eculizumab concentration and eculizumab complement blockage testing; order ECMP / Eculizumab Monitoring Panel, Serum.
Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing
Patient Preparation: Suggest discontinuing natalizumab at least 4 weeks prior to testing for eculizumab quantitation in serum. Patient should consult the healthcare provider who prescribed this drug to determine if discontinuation is an option. If not, ok to proceed with testing while taking natalizumab.
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions:
1. Draw blood immediately before next scheduled dose.
2. Immediately after specimen collection, place the tube on wet ice.
3. After specimen has clotted on wet ice, centrifuge at 4 degrees C and aliquot serum into plastic vial.
4. Freeze specimen within 30 minutes of centrifugation. Specimen must be placed on dry ice if not frozen immediately.
Forms
If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:
-Renal Diagnostics Test Request (T830)
-Coagulation Test Request (T753)
-Therapeutics Test Request (T831)
Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. The minimum volume is sufficient for one attempt at testing.
0.5 mL
Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected
| Gross hemolysis | Reject |
| Gross lipemia | Reject |
| Gross icterus | OK |
Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Frozen (preferred) | 28 days | |
| Ambient | 28 days | ||
| Refrigerated | 28 days |
Useful For
Suggests clinical disorders or settings where the test may be helpful
Assessing the response to eculizumab therapy
Assessing the need for dose escalation
Evaluating the potential for dose de-escalation or discontinuation of therapy in remission states
Monitoring patients who need to be above a certain eculizumab concentration in order to improve the odds of a clinical response for therapy optimization
Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Eculizumab (Soliris, Alexion Pharmaceuticals) is a humanized monoclonal IgG2/4 kappa antibody therapeutic directed against complement component 5 (C5). By association with C5, eculizumab inhibits the terminal complement pathway through simultaneous blockade of the generation of the potent prothrombotic and proinflammatory molecule, C5a, and the formation of membrane attack complex initiator, C5b.
Eculizumab is administered as an IV infusion. The dosing regimen prescribed for an average adult diagnosed with paroxysmal nocturnal hemoglobinuria (PNH) is 600 mg weekly for the first 4 weeks, followed by 900 mg for the fifth dose 1 week later, and 900 mg every 2 weeks thereafter. Eculizumab has been evaluated in patients with atypical hemolytic uremic syndrome (aHUS) through 2 prospective, open-label, single-arm studies (C08-002 and C08-003) as well as a single-arm retrospective study. In aHUS, it is prescribed for an average adult at 900 mg weekly for the first 4 weeks, followed by 1200 mg for the fifth dose 1 week later, then 1200 mg every 2 weeks thereafter. Eculizumab was generally well tolerated, and no significant adverse effects were attributed to drug treatment; some adverse reactions included upper respiratory tract infections and diarrhea in prospective and retrospective studies, hypertension, headache, and leucopenia (C08-002/C08-003), and fever (C09-001R). Additional case reports suggest that eculizumab may prevent post transplantation recurrence of aHUS, even in those patients harboring CFH/CFHR1 hybrid gene variants, who are at very high risk of recurrence. Further research is needed to determine the duration of eculizumab therapy in the context of the genetic background of aHUS cases and risk of disease relapse.
Therapeutic drug monitoring of eculizumab is helpful when providers are considering personalized treatment decisions, such as therapy discontinuation or extending dose intervals when patients are in remission states. In PNH, a minimum therapeutic concentration is expected to be above 35 mcg/mL. In aHUS, the therapeutic concentrations are expected to be above 50 to 100 mcg/mL of eculizumab. Complement blockage studies can aid in determining if a therapeutic concentration of the drug has blocked the complement function and subsequent production of sC5b-9. A panel that includes both eculizumab concentration and eculizumab complement blockage testing is available; see ECMP / Eculizumab Monitoring Panel, Serum.
Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
Lower limit of quantitation =5.0 mcg/mL
>35 mcg/mL: Therapeutic concentration for paroxysmal nocturnal hemoglobinuria (PNH)
>50 mcg/mL: Therapeutic concentration for atypical hemolytic uremic syndrome (aHUS)
Interpretation
Provides information to assist in interpretation of the test results
Minimum trough therapeutic concentrations (immediately before next infusion) of eculizumab are expected to be above 35 mcg/mL for paroxysmal nocturnal hemoglobinuria and above 50 mcg/mL for atypical hemolytic uremic syndrome.
Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Patients in transition between eculizumab (ECULI / Eculizumab, Serum) and ravulizumab administration may have a skewed therapeutic level of the respective analytes reported under the relative orderable. Test results cannot be interpreted as absolute evidence for the presence or absence of malignant disease. This test should not form the sole basis for a diagnosis or treatment decisions.
Patients actively undergoing therapy with both natalizumab and eculizumab (extremely rare scenario) could present as assay interference. It is suggested patients discuss with their doctors the possibility of discontinuing natalizumab 4 weeks prior to testing. If discontinuation is not possible, ok to proceed with testing.
Clinical Reference
Recommendations for in-depth reading of a clinical nature
1. Ladwig PM, Barnidge DR, Willrich MA. Quantification of the IgG2/4 kappa monoclonal therapeutic eculizumab from serum using isotype specific affinity purification and microflow LC-ESI-Q-TOF mass spectrometry. J Am Soc Mass Spectrom. 2017;28(5):811-817
2. Willrich MA, Murray DL, Barnidge DR, et al. Quantitation of infliximab using clonotypic peptides and selective reaction monitoring by LC-MS/MS. Int Immunopharmacol. 2015;28(1):513-520
3. Ladwig PM, Barnidge DR, Willrich MA. Mass spectrometry approaches for identification and quantitation of therapeutic monoclonal antibodies in the clinical laboratory. Clin Vaccine Immunol. 2017;24(5):e00545-16
Method Description
Describes how the test is performed and provides a method-specific reference
Eculizumab is extracted from serum and measured by liquid chromatography high-resolution accurate-mass mass spectrometry.(Unpublished Mayo method)
PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information
Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.
Wednesday
Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.
Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location
Indicates the location of the laboratory that performs the test
Fees :
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.
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- Prospective clients should contact their account representative. For assistance, contact Customer Service.
Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.
CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
CPT codes are provided by the performing laboratory.
CPT codes are provided by the performing laboratory.
80299
LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.
| Test Id | Test Order Name | Order LOINC Value |
|---|---|---|
| ECULI | Eculizumab, S | 90240-3 |
| Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
|---|---|---|
| 65676 | Eculizumab, S | 90240-3 |