HLA-DRB1 and tropical spastic paraparesis: On the other hand, HLA-B*40:06 (P = 3.03 × 10−5), HLA-DRB1*15:01 (P = 1.06 × 10−5), and HLA-DQB1*06:02 (P = 1.78 × 10−6) showed a protective association with HAM/TSP.