We identified new alleles that were associated with increased PVL in the AC group, carriers of the alleles -C*06, and -DRB1*15, and in the HAM/TSP group, carriers of the alleles -A*30, -A*34, -C*06, -C*17 and -DRB1*09. This evidence concerns the gene HLA-DRB1 and tropical spastic paraparesis.