IFNG and tropical spastic paraparesis: Patients with HAM/TSP showed a higher production of IFN-γ by PBMCs than HC (1,979 pg/mL, ranging 38–3,661 pg/mL vs 863 pg/mL, ranging 0–3,666 pg/mL, respectively), P = 0.03, and also a greater proviral load (231,016 copies/106cells, ranging 932–1.186,254 copies/106cells, vs 22,665 copies/106cells, ranging 81–255,319 copies/106cells, respectively), P = 0,0004.