Neutralizing Antibodies to Interferon-Beta

Laboratory Requisition

*Download the requisition onto a computer and open with Adobe Acrobat/Reader for a writeable PDF

Neutralizing Antibodies to Interferon-Beta in Multiple Sclerosis

Interferon-beta is the first immunomodulatory drug shown to change the natural history of multiple sclerosis. Several recombinant preparations are currently available.

A proportion of patients receiving interferon-beta develop drug-induced antibodies. Binding antibodies are measured by binding assays. Such antibodies bind to the drug but may not block the biological activity of the drug. Neutralizing antibodies (NAbs), on the other hand, bind to the drug and block the biological activity of the drug and high levels of antibodies reduce drug efficiency. Several methods have been used to measure NAbs to IFN-beta.

The price of Neutralizing Antibody test – MSP#91858, $205.52 CAD*
* Please note: Prices are set by the British Columbia Ministry of Health and may be subject to change.

Anti-IFN-beta NAb Testing at the Neuro-Immunology Laboratory

We have been routinely measuring NAbs since July 2007. From July 2007 to February 2011, 1409 samples from 1053 patients have been received from Canada and assayed at the UBC Neuro-Immunology Labs.

NAbs Results by province

We use a Reporter Gene Assay which was developed and validated in 2007 (Lam et al. 2008). The method uses a cell line which has been transfected with the IFI-161 promoter linked to a luciferase reporter (See image below). Patient sera are initially screened for NAb positivity using IFNb-1a, and positive samples are further tested to determine NAb Titre using homologous antigen (interferon which the patient has received).

NAbs to IFN Luciferase Reporter Gene Assay

Antibody results are reported in Tenfold Reduction Units (TRU)/ml as recommended by the World Health Organization. Antibody titres below 20TRU/ml are considered negative and antibody levels above 20TRU/ml are categorized into 3 tiers: low, medium or high titres depending on their rank amongst other samples from patients receiving the same interferon (i.e. a group injected and assayed on beta-1a and a group injected and assayed on beta-1b.)

Positive NAb titres (reported in TRU/ml) from all samples received from July 2007 to February 2011 were ranked by order of increasing titers and stratified into three equal tiers independently for each IFN to construct a NAb reporting reference range.

NAb Titers

Technical Information

Serum samples should be collected in SST tubes, clotted, centrifuged and transferred to cryovials.

Two (2) to five (5) ml of serum should be shipped according to IATA, ICAO and Canadian transportation goods regulation. Samples do not need to be frozen. Please courier your samples together with a completely filled out requisition (see below).

The patient’s current interferon-beta treatment is required to be filled out by the referring physician (whom we will call or write in case of discrepant results) for the test to be done.

The test is run monthly or more frequently, if the number of samples we receive warrants it.

Ship samples to:
Neuro-Immunology Laboratory
University of British Columbia Hospital
Room S-157, 2211 Wesbrook Mall
Vancouver, B.C, Canada
V6T 2B5

Results will be faxed if requested (please include a fax number on the requisition).