No evidence of JC-virus reactivation in natalizumab-treated Multiple Sclerosis patients: a 18-month follow-up

• Published in: Journal of neurology, neurosurgery and psychiatry Vol. 81; no. 12
• Main Authors: Rinaldi, Luciano, Rinaldi, Francesca, Perini, Paola, Calabrese, Massimiliano, Seppi, Dario, Grossi, Paola, Mattisi, Irene, Barzon, Luisa, Mengoli, Carlo, Sanzari, Mariacolomba, Palu', Giorgio, Gallo, Paolo
• Format: Journal Article
• Language: English
• Published: BMJ Publishing Group 14-06-2010
• Subjects: VIROLOGY; MULTIPLE SCLEROSIS
• ISSN: 0022-3050; 1468-330X
• DOI: 10.1136/jnnp.2009.201079

Background and aim: Natalizumab in multiple sclerosis (MS), has been associated to progressive multifocal leukoencephalopathy (PML), a fatal disease caused by JC virus (JCV), not predictable by specific markers. We evaluated JCV reactivation in the urine and plasma in 42 MS patients, treated with natalizumab over 18-months. Methods: Fourty-two patients have been followed-up by: urine and plasma JCV-DNA PCR assay, immune cell subsets analysis, clinical and MRI evaluation, quality of life, fatigue and mood assessment. Results: JCV data. At baseline 11/42 (26%) patients had JCV viruria, persistent at serial controls. One patient got viruric at month 1, one at month 12. No patient had JCV viraemia at baseline; 3 patients got viraemic: one at month 6, the others at month 12 and 13. The prevalence of JCV both in urine and plasma did not change significantly from baseline to month 12 and 18. No patient had clinical and MRI evidence of PML. Immunological data. Circulating B cells showed the greater expansion since the first dosage. NK cell count doubled with no change in percentage, while T cell count increased with a reduced percentage. CD4+ and CD8+ T cells increased proportionally, with no change in their percentage. Clinical data. Twenty-seven patients (64%) were disease free after 1 year. A marked improvement in the quality of life was reported by 72 % of patients. Conclusions: we found no evidence of subclinical JCV reactivation in our natalizumab treated MS patients up to the 18th month of therapy, notwithstanding the marked increase in circulating B cells observed. Moreover, we confirmed natalizumab efficacy, its tolerability, and the positive impact on quality of life.