CD8A and tropical spastic paraparesis: In addition, previous reports on the TCR repertoire analysis using PCR-based techniques showed higher clonal expansions, especially in CD8+ T cell subsets of HAM/TSP patients by complementarity determining region 3 (CDR3) spectratyping (20, 21) and some conserved motifs in the CDR3 region of Tax-specific CTL clones generated from HAM/TSP patients with HLA-A*0201 by cloning and sequencing (22, 23).