Research: JC virus antibodies

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Epub: Warnke et al.  to anti-JCV antibody levels in a Swedish national MS cohort. J Neurol Neurosurg Psychiatry. 2013 Mar 5. 


BACKGROUND: The anti-JC virus (JCV) antibody status has been introduced to stratify MSers for higher or lower risk of progressive multifocal leukoencephalopathy (PML).


OBJECTIVE: To assess the potential utility of anti-JCV antibody levels for earlier diagnosis or prediction of PML.

METHODS: An analytically validated antibody assay was used to determine serological status, normalised optical density values, and dilution titres for anti-JCV antibodies. The method was applied to stored sera of 1157 MSers including five cases of PML, all enrolled in the Swedish pharmacovigilance study for natalizumab (NAT). Anti-cytomegalovirus (CMV) and anti-varicella-zoster (VZV) antibody levels served as controls.


RESULTS: Prior to treatment with NAT, anti-JCV antibody levels were stable in the anti-JCV positive MSers. During therapy, a slight decrease in anti-JCV and anti-VZV antibody levels, but not anti-CMV antibody levels, was observed. All five MSers who developed PML showed a mild to moderate increase in anti-JCV antibody levels at time of PML diagnosis; pre-PML samples suggested that this increase might start already prior to diagnosis of PML.


CONCLUSIONS: Treatment initiation with NAT may lead to a slight decrease in anti-JCV and anti-VZV antibody levels, suggestive of a mild suppressive effect of NAT on antibody levels. Our findings in five cases of PML demonstrate that the onset of PML can be accompanied by increasing anti-JCV antibodies in serum. Monitoring of anti-JCV antibody levels could potentially be used as a tool for prediction or earlier diagnosis of PML during NAT treatment for MS.


JCV particles


This will need replication and you would need serial JCV tests for this to be of use. News on the block is that Biogen have data to confirm this observation; watch this space.

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