Abstract Details

Title Longitudinal Stability of Anti-JC Virus Antibody Status in Multiple Sclerosis Patients: Results of STRATIFY-1

Topic MS and Related Diseases

Presentation(s) S30 - (-)

Poster/Presentation
Number 001

Objective

Background Baseline STRATIFY-1 results demonstrated 56% anti-JCV seroprevalence with an assay false-negative rate of 2.7% when using the original 2-step assay. Recently, an enhanced second-generation anti-JCV antibody assay was developed to improve consistency of detection of low antibody responses and assay ease of use.

Design/Methods Serum and plasma samples from STRATIFY-1collected at 6-month intervals over 24 months were tested for anti-JCV antibodies. Urine collected at the same time points was tested for JCV DNA. Longitudinal stability of anti-JCV serostatus and a false-negative rate were assessed using both original and second-generation assays. Because of higher dropout of anti-JCV antibody positive than negative patients at month 24, analyses were performed on data through 18 months.

Results At baseline (n=1096), anti-JCV antibody prevalence employing the second-generation assay was 55%, similar to that of the original assay. Repeated tests with the original and the second-generation assays demonstrated that 39% and 38% of patients, respectively, tested consistently antibody negative; 47% and 52%, respectively, tested consistently positive; 14% of patients changed anti-JCV serostatus using the original assay (5.4% intermittent-positive, 4.0% converters, and 4.4% reverters), and 10% changed serostatus employing the second-generation assay (4.0% intermittent-positives, 5.1% converters and 1.0% reverters). Anti-JCV serostatus change (negative to positive status) between the 2 tests was 3.8%-5.9% and 3.9%-7.4% when original and second-generation assays were used, respectively. Based on all time points, the false-negative rate was 3.4% and 2.4% with the original and second-generation assays, respectively.

Conclusions Anti-JCV antibody status is consistent over time, with 38%-39% of patients being consistently negative over 18 months of 6-month testing. The second-generation anti-JCV antibody assay demonstrated similar performance to the original assay, but resulted in a lower false-negative rate and lower proportion of patients changing antibody status.

Authors/Disclosures
Tatiana Plavina, PhD PRESENTER	No disclosure on file
Sophia S. Lee, PhD	No disclosure on file
	No disclosure on file
	No disclosure on file
Sandra R. Richman, MD	No disclosure on file
Gary Bloomgren, MD, MBA (Biogen Idec)	No disclosure on file
Barry S. Ticho, MD, PhD (Biogen Idec)	No disclosure on file
Meena Subramanyam, PhD	No disclosure on file
Dawn W. Langdon, PhD (Royal Holloway)	Prof. Langdon has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for Merck. Prof. Langdon has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for Novartis. The institution of Prof. Langdon has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Celgene. Prof. Langdon has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Celgene. Prof. Langdon has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Merck. Prof. Langdon has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Bayer. The institution of Prof. Langdon has received research support from Merck. The institution of Prof. Langdon has received research support from Novartis. The institution of Prof. Langdon has received research support from MS Society (UK). The institution of Prof. Langdon has received research support from Multiple Sclerosis Trust (UK).

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