Postpolio syndrome: poliovirus persistence is involved in the pathogenesis

The pathogenesis of the postpolio syndrome (PPS) remains unclear. In this s tudy we looked for poliovirus (PV) persistence in the CSF of 20 patients wi th PPS, in a control group including 20 patients with unrelated neurologica l diseases, and in 7 patients with stable poliomyelitis sequelae. CSF sampl es and sera were examined using reverse transcriptase-polymerase chain reac tion (RT-PCR) for the detection of PV or other enterovirus genomes; this as say allows the detection from as little as I fg viral RNA. Sequencing of am plified products from 5 patients was performed, PV genomic sequences were d etected in the CSF of II of 20 patients with PPS and in none of the control group. Sequencing in the 5' untranslated region confirmed the presence of mutated PV sequences. These findings suggest that PFS is related to the per sistence of PV in the central nervous system.