Abstract Details

Title Flow-Cytometry and the Detection of Anti-Natalizumab NAB in Multiple Sclerosis

Topic MS and Related Diseases

Presentation(s) P05 - (-)

Poster/Presentation
Number 193

Objective

Background BACKGROUND: NAB occur in approximately 5-15% of natalizumab-treated multiple sclerosis (MS) patients. In patients with persisting NAB natalizumab treatment has to be terminated.

Design/Methods DESIGN/METHODS: Cell bound natalizumab and the natalizumab saturation of alpha-4 integrins on T cells from 11 MS patients were detected using a monoclonal anti-human IgG4 antibody by flow cytometry before start and after 4, 8, and 12 weeks of natalizumab therapy. Natalizumab saturation (in %) of T cells was determined by relating median fluorescence intensities (MFI) of in vivo bound natalizumab to the MFI after in vitro incubation with saturating amounts of natalizumab (10 [micro]g/ml, 100% natalizumab saturation). Determination of serum NAB was performed by ELISA.

Results RESULTS: In 8 patients the median natalizumab saturation of T cells over 4, 8, and 12 weeks of natalizumab treatment reached 75% (range 65-86%; SD 6%) and was associated with no NABs. Three patients showed differences in the natalizumab saturation of T cells with a clear reduction in 2 patients after 8 weeks and a pronounced decline approximating baseline levels in all three patients after 12 weeks . High- and low-titre NAB were equally effective in reducing the cellular natalizumab saturation.

Conclusions CONCLUSIONS: Monitoring the natalizumab saturation on T cells might serve as an early and sensitive method to identify patients with a reduced treatment effect due to NAB. Interestingly, both high- and low-titer NAB equally effectively reduced the cellular natalizumab saturation.

Authors/Disclosures
Joerg R. Kraus, MD (Ordination Dr. Kraus) PRESENTER	No disclosure on file
	No disclosure on file
	No disclosure on file
Peter Wipfler	Peter Wipfler has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Novartis. Peter Wipfler has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Biogen. Peter Wipfler has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Roche. Peter Wipfler has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Sanofi. Peter Wipfler has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Merck. Peter Wipfler has received personal compensation in the range of $500-$4,999 for serving as a Consultant for BMS/Celgene. Peter Wipfler has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Janssen. Peter Wipfler has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Merck. Peter Wipfler has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Novartis. Peter Wipfler has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for BMS. Peter Wipfler has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Merck.
Barbara J. Holl, MD	No disclosure on file
Florian Deisenhammer, MD	Dr. Deisenhammer has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Alexion. Dr. Deisenhammer has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Almirall. Dr. Deisenhammer has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Biogen. Dr. Deisenhammer has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for BMS/Celgene. Dr. Deisenhammer has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Sanofi/Genzyme. Dr. Deisenhammer has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Merck. Dr. Deisenhammer has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Novartis. Dr. Deisenhammer has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Roche. Dr. Deisenhammer has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Almirall. Dr. Deisenhammer has received personal compensation in the range of $10,000-$49,999 for serving on a Speakers Bureau for Biogen. Dr. Deisenhammer has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Celgene. Dr. Deisenhammer has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Genzyme. Dr. Deisenhammer has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Merck. Dr. Deisenhammer has received personal compensation in the range of $5,000-$9,999 for serving on a Speakers Bureau for Novartis. Dr. Deisenhammer has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Roche. Dr. Deisenhammer has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for SOBI.
	No disclosure on file
	No disclosure on file
Janet Benesh, BSMT (Abbott Laboratories)	No disclosure on file
Eugen Trinka	Eugen Trinka has received personal compensation in the range of $500-$4,999 for serving as a Consultant for UCB. Eugen Trinka has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Eisai. Eugen Trinka has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Bial. Eugen Trinka has received personal compensation in the range of $500-$4,999 for serving as a Consultant for GW Pharmaceuticals. The institution of Eugen Trinka has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Rapport. The institution of Eugen Trinka has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Abbott. The institution of Eugen Trinka has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for UCB. Eugen Trinka has received research support from European Union. Eugen Trinka has received publishing royalties from a publication relating to health care.
	No disclosure on file

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