DETECTION OF CSF-SPECIFIC OLIGOCLONAL ANTIBODIES TO RECOMBINANT JC VIRUS VP1 IN PATIENTS WITH PROGRESSIVE MULTIFOCAL LEUKOENCEPHALOPATHY

The intrathecal synthesis of antibodies against recombinant VP1, the m ajor structural protein of JC virus (JCV), was studied in 18 patients with progressive multifocal leukoencephalopathy (PML) and in 31 patien ts with various neurological disorders. Two methods were used, the cal culation of an antibody specific index (ASI) on one hand and an antige n-driven immunoblotting for the detection of oligoclonal antibodies on the other. Most PML patients displayed an elevated (> 1.5) ASI (78%) and anti-VP1 oligoclonal antibodies restricted to the cerebrospinal fl uid (55%). Only two other patients (one case each of multiple sclerosi s and of neuroborreliosis) also showed an intrathecal synthesis of ant i-VP1 oligoclonal antibodies, likely as a result of a 'polyspecific' r eaction within the central nervous system.