Abstract

The Class II human leukocyte antigen (HLA) DRB1 antigen DR4 is associated with autoimmune disorders and response to cyclosporine immunosuppression in T-lymphoproliferative disorders. We retrospectively reviewed the role of HLA DR4 on outcomes in 77 related and 22 unrelated consecutive first HLA-matched alloHSCT patients with lymphoid malignancies treated between 1992 and 2003. HLA DRB1 typing was determined by molecular (n = 69) or serologic (n = 30) methods. The proportion of patients with one HLA DR4 antigen was 18% (18/99). At a median follow-up of 5.6 years, there were no significant differences in aGvHD, cGvHD and OS between the HLA DR4 positive versus negative patients in any disease or donor subgroups. Nine of 18 (50%) DR4 positive patients and 20 of 81 (25%) DR4 negative patients had disease progression post HSCT (p = 0.033). Progression-free survival (PFS) at 3 years was 29% in the DR4 positive group and 70% in the DR4 negative group (p = 0.004). In univariate and multivariate analyses, DR4 positivity was the only significant factor associated with PFS (RR = 3.2, p = 0.007). Our results suggest that in addition to the known role of HLA DRB1 disparity in mediating histocompatibility, HLA DR4 is associated with inferior PFS in patients with lymphoid malignancy undergoing alloHSCT.