infliximab: drug levels and...
TRANSCRIPT
Why measure infliximab (IFX) drug levels and
antibodies to infliximab (ATI)? Evidence from the Inflammatory Bowel Disease literature
1. To examine the reason for loss/lack of response to treatment and determine
subsequent management.
2. To optimize dose to give the best chance of remission whilst reducing the risk
of adverse effects.
Testing algorithm and suggested interpretation for the
scenario of loss/lack of response to treatment
ATI will only be performed if IFX is <2 mg/L
The presence of IFX in concentrations >2 mg/L interferes with the detection of ATI
therefore ATI will not be performed if the drug level is higher than this. The ATI will be
automatically performed if the IFX level is <2 mg/L.
Infliximab: drug levels and antibodies
April 2016
Department of Immunology
SSWPS Liverpool
Ordering the
tests
Paperwork Fill in the
preprinted request form. Testing
will proceed according to the algorithm shown at left.
Consent form –
required for any drug level or antibody testing to proceed (EXCEPT if on Inflectra. See explanation on following page)
Instructions to
patient Blood should
be collected as a trough level, just prior to the next dose of infliximab
The patient should have their blood collected at a public pathology collection centre or a centre that is happy to forward the sample to SSWPS Liverpool
>3 mg/L <2 mg/L 2 - 3 mg/L
Confirm symptoms are due to
active disease
ATI automatically performed
by the laboratory
Consider increasing IFX therapy
by increasing dose or decreasing
interval between infusions
Consider changing to
non-TNF based therapy
ATI not detected
or between
10-200 ng/mL
ATI >200 ng/mL
Recommend switching
to an alternative
Anti-TNF agent
Trough level IFX
(steady state)
Consent to charges for testing
Infliximab (IFX) level
If this is the only test which is performed, there
will be no charge over Medicare (no gap). This
test is performed at a loss to the laboratory.
However, testing will not begin without consent
in advance to the charge for ATI testing, if
required (see below).
Antibodies to infliximab (ATI)
ATI are NOT covered by the Medicare benefits
schedule (MBS).
There will be a charge (currently $140) for ATI if
this test is deemed to be required according to the
algorithm above.
… Except Inflectra
However, if the brand of infliximab called
Inflectra has been prescribed, no payment is
required. Testing is provided (IFX level and ATI if
required) as part of the distributor’s care program
for patients receiving Inflectra.
No consent form is required in this case.
Department of Immunology, Sydney South West Pathology Service (Liverpool Hospital)
Supervising Immunologist: Dr Catherine Toong
Phone: (02) 8738 5068 (laboratory)
Specimen reception: Cnr Campbell & Forbes St, Liverpool, NSW 2170. Ph: (02) 8738 5045. Fax: (02) 8738 9465
References and further reading
Baert, F. et al. Influence of immunogenicity on the long-term efficacy of infliximab in Crohn’s disease. New England Journal
of Medicine 2003; 348: 601-608.
Bortlik, M. et al. Infliximab trough levels may predict sustained response to infliximab in patients with Crohn’s disease.
Journal of Crohn’s and Colitis 2013; 7: 736-743.
Paul, S. et al. Therapeutic drug monitoring of infliximab and mucosal healing in inflammatory bowel disease: a prospective
study. Inflammatory Bowel Diseases 2013; 19: 2568-76
Steenholdt, C. et al. Use of infliximab and anti-infliximab antibody measurements to evaluate and optimize efficacy and
safety of infliximab maintenance therapy in Crohn’s disease. Danish Medical Journal 2013; 60: B4616.
Ternant, D. et al. Infliximab pharmacokinetics in inflammatory bowel disease patients. Therapeutic Drug Monitoring 2008;
30: 523-529.
Vande Casteele, N. et al. Antibody response to infliximab and its impact on pharmacokinetics can be transient. American
Journal of Gastroenterology 2013; 108: 962-971.
Vande Casteele, N. et al. Trough concentrations of infliximab guide dosing for patients with inflammatory bowel disease.
Gastroenterology 2015; 148: 1320-1329.
Specimen requirement
5 ml blood in a serum tube will be sufficient
for both tests. The serum sample should be
kept refrigerated.
Central Specimen Reception: RPAH Level 5 Building 77, RPAH Missenden Rd Camperdown NSW 2050 ph: 61 2 9515 8279 fax: 61 2 9515 7931 Liverpool – Cnr Campbell & Forbes St, Liverpool, NSW 2170
Ph: 61 2 8378 5045 Fax: 61 2 8738 9465 V3
Patient Consent for Non Rebateable (nonmbs) Test/s Please print all details clearly
I _______________________ (Patient name) understand that my medical practitioner has
requested a pathology test(s) that are not covered by Medicare Australia, Department of
Veteran Affairs or a private health fund.
I understand that I will receive an invoice from Sydney South West Pathology Service or
another pathology service depending on the test performed.
I agree to accept all responsibility for any out of pocket expenses for the test(s) as
requested.
Signature: _________________________ Date: ____________ Amount: $_____.___
Test Description Cost Required
N02085 ADH (Vasopressin) – MBS Unlisted Hormone Test $30.70
N02085 Adiponectin – MBS Unlisted Hormone Test $30.70
N05235 Allergy Array – Allergen Component Microarray $340.00
N05305 Antibodies to infliximab (Remicade) $140.00
N02051 Apolipoprotein A1 $19.90
N02050 Apolipoprotein E Genotype $40.00
N02010 Bile Acids – Miscellaneous Fluid $20.00
N02010 Bile Acids (If not pregnant or limit 3 reached) $20.00
N09012 Carbohydrate Deficient Transferrin $120.00
N02150 Cholinesterase Genotyping Screen – BCHE Butyrylcholinesterase $100.00
N02160 Cholinesterase Genotyping Sequence $100.00
N02085 Chromogranin A – MBS Unlisted Hormone Test $30.70
N05220 Eosinophilic Cationic Protein (>12 years old) $75.00
N05230 Interleukin 6 (IL6) $40.00
N02085 Leptin – MBS Unlisted Hormone Test $30.70
N02040 Lipoprotein (a) $30.20
N01330 Liquid Based Cytology – CYThinPrep Pap $35.00
N02170 Retinol Binding Protein $20.00
N96398 S/A Inhibin B level $80.00
N02096 Seminal Plasma Fructose $30.00
N06050 TB Interferon Gamma Release Assay $66.00
N02111 Transferrin Receptor (Soluble) $25.00
N02085 Vasopressin (ADH) - MBS Unlisted Hormone Test $30.70
N02060 VLDL Cholesterol (Ultracentrifuged) $30.20
N02060 VLDL Triglycerides (Ultracentrifuged) $30.20
Patient First Name Patient Surname Contact number
_____________________ ________________________ __________________
Affix addressograph or
lab sticker here.
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