HLA-DRB1 and myeloid sarcoma: However, the data are inconsistent: some researchers demonstrated that HLA DRB1*15 was related to a better course and prognosis of MS [9], while others reported that HLA DRB1 alleles had no impact on the severity of the disease, except for a possible relation between HLA DRB1*15 and younger age at the onset of MS [11].