Glycine‐Valine Dimorphism at the 86th Amino Acid ofHLA‐DRB1Influenced the Prognosis of Postschistosomal Hepatic Fibrosis

Chinese patients (n = 113) with schistosomal hepatic fibrosis diagnosed by ultrasonography (grade I, II, or III) and 184 age- and sex-matched persons with no clinical information of schistosomal infection were typed for their HLA-DRB1 alleles by DNA typing. There was no single allele that conferred susceptibility or resistance to fibrosis. However, there were three groups of alleles that showed decreased (resistant), increased (susceptible), or neutral frequency in the patients with fibrosis. The susceptible alleles, DRBI *1202, DRB1 *1404, and DRBI *1405, shared a valine at amino acid residue 86, whereas the resistant alleles, DRB1*11011, DRB1*0409, and DRB1*0701, all had glycine at position 86. Therefore, this study focused on the glycine-valine dimorphism at aa 86, which influences the depth of the P1 pocket in the antigen binding groove, and found that the 86th valine allele was significantly increased in the patients with fibrosis (odds ratio = 2.2; 95% CI = 1.34-3.61, corrected P < .05).