A novel and rapid assay for the detection of neutralizing antibodies against interferon-beta

Abstract

There is evidence that neutralizing antibodies (NA B) have a negative influence on the clinical and magnetic resonance imaging effects of interferon-beta (IFNb) in multiple sclerosis (MS) patients. The current methods for NA B detectio n are restricted to specialized laboratories because they require a cell culture and sometimes a viral culture. Results are typically obtained after several weeks. Therefore, the development of a simple and rapid assay for the detectio n of NA B was sought. Whole blood samples from 28 NAB-positive patients and 110 NAB-negative patients (52 with IFNb and 58 without IFNb therapy) were incubated with IFNb 976 IU/mL for 24 hours. MxA protein levels-a specific marker of class 1 IFN bioactivity-were measured in paired samples with and without IFNb incubatio n and the difference in MxA levels was calculated. The mean increase of MxA levels after stimulation with IFNb in the NAB-positive group was 8 ng/mL (range 0-44 ng/mL) and in the NA B-negative group was 84 ng/mL (range 0-302 ng/mL). Using an increase of 22.5 ng/mL as cut-off, the specificity of the MxA stimulation assay was 81.2% and the sensitivity was 96.4%. The whole blood MxA stimulation assay is virtually as sensitive as the conventional NA B assay but somewhat less specific. However, this is outweighed by the procedural advantage of the assay, which is simpler, quicker and much less expensive.

Keywords

antibodies biological availability blood interferon-beta multiple sclerosis neutralization test

Get full access to this article

View all access options for this article.

References

IFNB Multiple Sclerosis Study Group . Interferon beta-1b is effective in relapsing-remitting multiple sclerosis. I. Clinical results of a multicenter, randomized, double-blind, placebo-controlled trial . Neurology 1993; 43: 655-661 .

Paty DW , Li DK , UBC MS/MRI Study Group , IFNB Multiple Sclerosis Study Group . Interferon beta-1b is effective in relapsing-remitting multiple sclerosis. II. MRI analysis results of a multicenter, randomized, double-blind, placebo-controlled trial . Neurology 1993; 43: 662-667 .

[published erratum appears in Ann Neurol 1996; 40: 480-480 ].

The PRISMS Study Group , The University of British Columbia MS/MRI Analysis Group . PRISMS-4: long-term efficacy of interferon-beta-1a in relapsing MS . Neurology 2001; 56: 1628-1636 .

European Study Group on Interferon . Placebo-controlled multicentre randomised trial of interferon b-1b in treatment of secondary progressive multiple sclerosis . Lancet 1998; 352: 1491-1497 .

The IFNB Multiple Sclerosis Study Group , The University of British Columbia MS/MRI Analysis Group . Neutralizing antibodies during treatment of multiple sclerosis with interferon beta-1b: experience during the first three years . Neurology 1996; 47: 889-894 .

Antonelli G , Dianzani F. Development of antibodies to inter-feron beta in patients: technical and biological aspects . Eur Cytokine Netw 1999; 10: 413-422 .

Rudick RA , Simonian NA , Alam JA , Campion M , Scaramucci JO , Jones W et al. Incidence and significance of neutralizing antibodies to interferon beta-1a in multiple sclerosis. Multiple Sclerosis Collaborative Research Group (MSCRG) [see comments] . Neurology 1998; 50: 1266-1272 .

Bertolotto A , Malucchi S , Milano E , Castello A , Capobianco M , Mutani R. Interferon beta neutralizing antibodies in multiple sclerosis: neutralizing activity and cross-reactivity with three different preparations . Immunopharmacology 2000; 48: 95-100 .

10.

Pungor E , Files JG , Gabe JD , Do LT , Foley WP , Gray JL et al. A novel bioassay for the determination of neutralizing antibodies to IFN-b1b . J Interferon Cytokine Res 1998; 18: 1025-1030 .

11.

Deisenhammer F , Mayringer I , Harvey J , Dilitz E , Gasse T , Stadlbauer D et al. A comparative study of the relative bioavailability of different interferon beta preparations . Neurology 2000; 54: 2055-2060 .

12.

Towbin H , Schmitz A , Jakschies D , Von Wussow P , Horisberger MA. A whole blood immunoassay for the interferon-inducible human Mx protein . J Interferon Res 1992; 12: 67-74 .

13.

Khan OA , Dhib-Jalbut SS. Neutralizing antibodies to inter-feron beta-1a and interferon beta-1b in MS patients are cross-reactive . Neurology 1998; 51: 1698-1702 .

14.

Kracke A , Von Wussow P , Al-Masari AN , Dalley G , Windhagen A , Heidenreich F. Mx proteins in blood leukocytes for monitoring interferon beta-1b therapy in patients with MS . Neurology 2000; 54: 193-199 .

15.

Deisenhammer F , Reindl M , Berger T. Immunoglobulin subclasses in patients with serum-binding and neutralizing antibodies against interferon- 1b . J Interferon Cytokine Res 2001; 21: 167-171 .

16.

Ross C , Clemmesen KM , Svenson M , Sorensen PS , Koch-Henriksen N , Skovgaard GL et al. Immunogenicity of inter-feron-beta in multiple sclerosis patients: influence of preparation, dosage, dose frequency, and route of administration. Danish Multiple Sclerosis Study Group . Ann Neurol 2000; 48: 706-712 .

17.

Deisenhammer F , Reindl M , Harvey J , Gasse T , Dilitz E , Berger T. Bioavailability of interferon beta 1b in MS patients with and without neutralizing antibodies . Neurology 1999; 52: 1239-1243 .

18.

Perini P , Wadhwa M , Buttarello M , Meager A , Facchinetti A , Thorpe R et al. Effect of IFNbeta and anti-IFNbeta antibodies on NK cells in multiple sclerosis patients . J Neuroimmunol 2000; 105: 91-95 .

19.

Rice GPA , Paszner B , Oger J , Lesaux J , Paty D , Ebers G. The evolution of neutralizing antibodies in multiple sclerosis patients treated with interferon b-1b . Neurology 1999; 52: 1277-1279 .

20.

Pozzilli C , Antonini G , Bagnato F , Mainero C , Tomassini V , Onesti E et al. Monthly corticosteroids decrease neutralizing antibodies to IFNbeta1 b: a randomized trial in multiple sclerosis . J Neurol 2002; 249: 50-56 .