HBZ and tropical spastic paraparesis: Using our HBZ-specific ELISA, we screened 210 plasma samples, including 48 from ACs, 120 from HAM/TSP patients, and 42 from ATL patients, for immunoreactivity against HBZ, and the results were compared to both the HBZ mRNA levels and the PVL in PBMCs of these HTLV-1-infected individuals.