Gerevini S, Capra R, Bertoli D, Sottini A, Imberti L.
Mult Scler. 2019 Apr 9:1352458519832259.
A 31-year-old woman affected by multiple sclerosis (MS) experienced generalized tonic-clonic seizures 2 months after the second alemtuzumab cycle. Positive JC virus (JCV)-DNA in cerebrospinal fluid (CSF) and lesion iconography at magnetic resonance imaging (MRI) were suggestive of progressive multifocal leukoencephalopathy (PML). After 1 month, during full-blown immune reconstitution inflammatory syndrome, JCV-DNA became negative and symptoms gradually improved. New T- and B-cell output and T- and B-cell diversity were low and lymphocytes poorly responded to stimulation. This is the first case of an alemtuzumab-treated patient with clinical symptoms and radiological features compatible with PML. The lack of large T- and B-cell diversity, necessary for JCV recognition, is likely to have concurred to PML insurgence.
This person had been treated with alemtuzumab and developed PML 14 months after the intial course so hard to suggest this is carry over PML course. Now this is not good news but it does suggest something, because this person did not die of PML as occurred in a previous case of carry-over PML, meaning that they had enough immune cells to deal with the virus, if fact they got attack of the virus by the immune system, indicating that once the drug is gone, which lasts about 2 weeks, immune responses can be generated. This supports the idea that there is not a large window of immunosuppression with alemtuzumab.
Maybe ProfG will come out of retirement to tell us about this case as I am sure Genzyme have been briefing about this