Different mechanisms causing loss of mismatched human leukocyte antigens in relapsing t(6;11)(q27;q23) acute myeloid leukemia after haploidentical transplantation

作者：Tamaki Hiroya^*; Fujioka Tatsuya; Ikegame Kazuhiro; Yoshihara Satoshi; Kaida Katsuji; Taniguchi Kyoko; Kato Ruri; Tokugawa Taduko; Nakata Jun; Inoue Takayuki; Yano Aya; Eguchi Ryoji; Okada Masaya; Maruya Etsuko; Saji Hiroh; Ogawa Hiroyasu

来源：European Journal of Haematology, 2012, 89(6): 497-500.

DOI：10.1111/ejh.12017

• Copy number neutral-loss of heterozygosity
• Uniparental disomy
• Haploidentical transplantation
• 11q23 translocations
• MLL-AF6

Mismatched human leukocyte antigens (HLAs) on leukemic cells can be targeted by donor T cells in HLA-mismatched/haploidentical stem cell transplantation. In two cases of acute myeloid leukemia with t(6;11)(q27;q23) abnormality presented here, flow cytometry analysis showed a lack of HLA-A unshared between recipients and donors in relapsing leukemic cells after HLA-haploidentical transplantation. However, high-resolution HLA genotyping showed that one case lacked a corresponding HLA haplotype, whereas the other preserved it. These cases suggest that leukemic cells, which lacked mismatched HLA expression, might have an advantage in selective expansion under donor T-cell immune surveillance after HLA-haploidentical transplantation. Most importantly, down-regulation of unshared HLA expression potentially occurs by genetic alterations other than loss of HLA alleles.

• 出版日期2012-12