HLA-DRB1*1501 and response to copolymer-1 therapy in relapsing-remitting multiple sclerosis

Background: Copolymer 1 (Cop-1) is a random synthetic amino acid copolymer, effective in the treatment of the relapsing-remitting form of MS (RRMS). In vitro and in vivo studies suggest that the mechanism of Cop-1 involves its binding to major histocompatibility complex class II molecules as an initial step. Objective: To assess a possible relationship between human leukocyte antigen (HLA) alleles and response to Cop-1 therapy. Methods: Eighty-three patients with RRMS, 44 treated with Cop-1 and 39 with interferon β-1a (IFNβ-1a) for 2 years, were typed by molecular methods for HLA class II genes and subgrouped according to clinical outcome. Results: Data have shown a possible positive correlation between presence of DRB1*1501 and response to Cop-1 therapy ( p = 0.008). No relationship between HLA alleles and therapy has been found in IFNβ-1a treated patients. Conclusions: Results suggest that DRB1*1501 might be relevant for the clinical outcome in Cop-1 treated patients and, if confirmed in larger studies, it could be helpful in the selection of RRMS patients for different therapeutic options.