Human leukocyte antigen-DP in leukemia

Abstract
Human leukocyte antigen-DP (HLA-DP) typing was performed on patients with chronic myelogenous leukemia (CML, n = 44), acute nonlymphoblastic leukemia (ANLL, n = 34), or acute lymphoblastic leukemia (ALL, n = 41). Frequencies of DPw alleles in CML and ANLL patients were not significantly different from 254 controls, except that in ANLL DPw1 was absent. This was most likely due to the concurrent absence of DR3 with which DPw1 is in linkage. In contrast, in ALL, frequencies of DPw2 and DPw5 were significantly increased (corrected P < 0.05, relative risk (RR) = 2.19 and corrected P < 0.01, RR = 6.92, respectively). This was not due to linkage with DR. The frequency of DPw1 also tended to be reduced, but this was not caused by a similar decrease of DR3 in ALL. These results, therefore, demonstrate both positive and negative associations between major histocompatibility complex (MHC) gene products which are in only very weak linkage with the rest of HLA, and acute lymphocytic, but neither acute nor chronic myelogenous, leukemias. The HLA-DP region could thus contain long sought-after genes influencing susceptibility and resistance to leukemogenesis.