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Case Reports
. 2024 Nov;205(5):1995-1999.
doi: 10.1111/bjh.19712. Epub 2024 Aug 18.

Haematopoietic regeneration by HLA-A*0206-deficient clones in severe aplastic anaemia without definitive immunosuppressive treatment

Yoshitaka Zaimoku  1   2 , Kazuya Sakai  3   4 , Noriaki Tsuji  1 , Kazuyoshi Hosomichi  5 , Shinya Yamada  1   2   3 , Dung Cao Tran  1 , Miku Kobayashi  6 , Ayana Sugiyama  6 , Kouyuki Hirayasu  7 , Hiroki Mizumaki  1 , Ken Ishiyama  1 , Rikinari Hanayama  8 , Yoshiaki Tomiyama  9 , Shinji Nakao  1
Affiliations
Case Reports

Haematopoietic regeneration by HLA-A*0206-deficient clones in severe aplastic anaemia without definitive immunosuppressive treatment

Yoshitaka Zaimoku et al. Br J Haematol. 2024 Nov.

Abstract

We describe the case of a 74-year-old man with severe aplastic anaemia who experienced persistent remission attributed to proliferation of HLA allele-deficient clones. Despite an initial worsening of pancytopenia with eltrombopag and ciclosporin treatment, gradual trilineage haematopoietic recovery occurred, with blood counts normalizing over 3 years. Flow cytometry and deep nucleotide sequencing revealed that haematopoiesis was primarily supported by several clones with somatic mutations that inactivated antigen presentation via HLA-A*0206. This suggests that monitoring haematopoietic regeneration by immune escape clones could be an alternative approach for immune aplastic anaemia patients who possess HLA allele-deficient clones and cannot tolerate standard therapy.

Keywords: HLA loss; aplastic anaemia; immune escape; spontaneous remission.

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References

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