HTLV-1 Tax 11-19–specific T-cell frequency is higher in patients with HAM/TSP than in asymptomatic HTLV-1 carriers.

Frequency of HTLV-1 Tax 11-19–specific CD8⁺ T cells in CD8⁺ cell population was measured both in 47 patients with HAM/TSP and 32 asymptomatic HTLV-1 carriers (AC). The mean ± SD was 1.90% ± 2.68% and 0.25% ± 0.21%, respectively. The HAM/TSP patients had significantly higher frequency of HTLV-1 Tax 11-19–specific T cells than the carriers (P < .0001, Mann-Whitney U test).