Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Comparative Study
. 2025 Jun;206(6):1689-1698.
doi: 10.1111/bjh.20097. Epub 2025 Apr 22.

Comparison of severe aplastic anaemia and lower risk hypoplastic myelodysplastic neoplasms: Critical role of megakaryocyte count in distinguishing aplastic anaemia from myelodysplastic neoplasms

Tomoya Maeda  1 , Akira Matsuda  1 , Junya Kanda  2 , Hiroshi Kawabata  3 , Takayuki Ishikawa  4 , Kaoru Tohyama  5 , Akira Kitanaka  6 , Kayano Araseki  7 , Kei Shimbo  8 , Tomoko Hata  9 , Takahiro Suzuki  10 , Hidekazu Kayano  11 , Kensuke Usuki  12 , Maki Shindo-Ueda  13 , Nobuyoshi Arima  14 , Masaharu Nohgawa  15 , Akiko Ohta  16 , Shigeru Chiba  17   18 , Yasushi Miyazaki  19 , Shinji Nakao  20   21 , Keiya Ozawa  22 , Shunya Arai  23 , Mineo Kurokawa  24 , Akifumi Takaori-Kondo  2 , Kinuko Mitani  25 ; Japanese National Research Group on Idiopathic Bone Marrow Failure Syndromes
Affiliations
Comparative Study

Comparison of severe aplastic anaemia and lower risk hypoplastic myelodysplastic neoplasms: Critical role of megakaryocyte count in distinguishing aplastic anaemia from myelodysplastic neoplasms

Tomoya Maeda et al. Br J Haematol. 2025 Jun.

Abstract

Although genetic abnormalities are increasingly crucial for diagnosing and classifying haematopoietic diseases, dysplasia remains crucial for distinguishing myelodysplastic neoplasms (MDS) from aplastic anaemia (AA). Erythroid dysplasia may be observed in AA, complicating the differentiation between these conditions. In a previous study using the data from the Japan Idiopathic Myelodysplastic Syndrome Study Group's registry, we found that erythroid dysplasia does not affect the prognosis of AA. This current study was designed to compare the prognosis of patients with lower risk hypoplastic MDS (LR-hMDS), as determined by our review, and patients with severe AA (SAA), all enrolled concurrently, to validate our diagnostic approach. Stringent criteria were used to rule out MDS, considering bone marrow cellularity and megakaryocyte counts, with a confirmed AA diagnosis only following a reduced megakaryocyte count. The study comprised 39 severe cases extracted from a cohort of 100 AA patients previously reported and 41 patients with LR-hMDS. Significant differences in overall and leukaemia-free survival were observed between the two groups (p < 0.0001). Even among patients undergoing immunosuppressive therapy, a marked prognostic distinction became evident after 5 years, although their response to the therapy did not differ significantly. Therefore, the megakaryocyte count is pivotal in differentiating MDS from AA.

Keywords: aplastic anaemia; hypoplastic MDS; megakaryocyte count; myelodysplastic neoplasms; survival.

PubMed Disclaimer

Conflict of interest statement

TM received research funding from Chugai and Sumitomo and honoraria from Novartis, Nippon Shinyaku, Nippon Becton Dickinson, Pfizer, Otsuka, AbbVie, Amgen, Bristol‐Myers Squibb, Janssen, Astellas, CSL Behring, Asahi Kasei and Daiichi Sankyo. AM received consulting fees from Kyowa Kirin, honoraria from Alexion, Nippon Shinyaku, Sumitomo, Novartis and Chugai, and serves on an advisory board for Kyowa Kirin. HKawa received honoraria from Nippon Shinyaku and Bristol‐Myers Squibb. KS received honoraria from Astellas, Sysmex, Kyowa Kirin, Ishiyaku Publishers, Maruzen Publishing and Igaku Shoin and held leadership roles in several boards, including chairman of the Committee on Hematological Technology (JCLS), and Hematology subcommittees on Standardization of Blood Cell Morphology (JSLH). TH received grants or contracts from Sysmex. TS received honoraria from Novartis, Kyowa Kirin, Chugai, Nippon Shinyaku, Bristol‐Myers Squibb and Sanofi, and is a member of advisory boards for Bristol‐Myers Squibb. KU received grants or contracts from Astellas, AbbVie, Bristol‐Myers Squibb, Janssen, Ono, Otsuka, Chugai, Aperis, Yakult, MSD, Amgen, Alxion, Incyte, Eisai, Kyowa Kirin, Sanofi, SymBio, Celgene, Daichi Sankyo, Sumitomo, Nippon Shinyaku, Novartis, Mundian and Takeda; consulting fees from Astellas, Amgen, Alnylam Japan, Alexion, Eisai, Otsuka, Kyowa Kirin, Sanofi, Sando, SymBio, Takeda, Chugai and Nippon Shinyaku; and honoraria from Novartis, AbbVie, Alexion, Incyte, Ono, Kyowa Kirin, Sanofi, Takeda, Nippon Shinyaku, Pfizer and Bristol‐Myers Squibb. SC received grants or contracts from Eisai, Chugai, Astellas, Thyas, Kyowa Kirin and Bayer. SN received honoraria from Kyowa Kirin. MK received grants or contracts from AbbVie, Kyowa Kirin, Otsuka, Chugai, Nippon Shinyaku, Takeda, Sumitomo Dainippon Pharma, Asahi Kasei, Teijin, Shionogi and Daiichi Sankyo; consulting fees from Mochida, Nippon Shinyaku and Nippon Kayaku; and honoraria from BeiGene, MSD, Sebia Japan, AstraZeneca, AbbVie, Amgen, Alexion, Eisai, Gilead Sciences, Genmab, Novartis, Pharma Essentia, Pfizer, Bristol‐Myers Squibb, Janssen, Kyowa Kirin, Sumitomo, Ono, Otsuka, Daiichi Sankyo, Chugai, Nippon Kayaku, Takeda, Asahi Kasei, Astellas, Sanofi and Mochida; and participated on advisory boards for AstraZeneca, Incyte and Daiichi Sankyo. AT‐K received grants or contracts from AbbVie, Asahi Kasei, Chugai, DKS Co. Ltd., Eisai, Kyowa Kirin, Nippon Shinyaku, Ono, Otsuka, Pharma Essentia and Shionogi; consulting fees from Megakaryon Co.; and honoraria from AbbVie, AstraZeneca, Bristol‐Myers Squibb, Chugai, Gilead Sciences Inc., Janssen, Novartis and Otsuka. KM received grants or contracts from Kyowa Kirin and Chugai; consulting fees from Kyowa Kirin and Bristol‐Myers Squibb; honoraria from Kyowa Kirin, Chugai, Novartis, Bristol‐Myers Squibb and Sanofi; support for attending meetings and/or travel from Kyowa Kirin; and served on advisory boards for Novartis and Bristol‐Myers Squibb. All other authors declare no competing financial interests.

Figures

FIGURE 1
FIGURE 1
Kaplan–Meier survival analysis of OS and LFS: A comparison between SAA and LR‐hMDS. (A) OS and (B) LFS in patients with SAA and those with LR‐hMDS. A significant difference in OS and LFS was observed between SAA and LR‐hMDS (both, p < 0.0001). LFS, leukaemia‐free survival; LR‐hMDS, lower risk hypoplastic myelodysplastic neoplasms; OS, overall survival; SAA, severe aplastic anaemia.
FIGURE 2
FIGURE 2
Kaplan–Meier survival analysis of OS and LFS in patients treated with IST: A comparison between SAA and LR‐hMDS. (A) OS and (B) LFS in patients with SAA and LR‐hMDS who received IST. IST included anti‐thymocyte globulin combined with CsA and CsA alone, with 28 patients in the SAA group and 6 in the LR‐hMDS group. A significant difference in OS and LFS was noted between SAA and LR‐hMDS (p = 0.002). CsA, ciclosporin A; IST, immunosuppressive therapy; LFS, leukaemia‐free survival; LR‐hMDS, lower risk hypoplastic myelodysplastic neoplasms; OS, overall survival; SAA, severe aplastic anaemia.
FIGURE 3
FIGURE 3
Kaplan–Meier survival analysis of OS and LFS in patients responding to IST: A comparison between SAA and LR‐hMDS. (A) OS and (B) LFS in patients with SAA and LR‐hMDS who responded to IST. IST treatment responses observed up to 12 months were used. The treatment responses include complete responses and partial responses, with details provided in Table 2. A significant difference in OS and LFS was observed between SAA and LR‐hMDS (p = 0.001). IST, immunosuppressive therapy; LFS, leukaemia‐free survival; LR‐hMDS, lower risk hypoplastic myelodysplastic neoplasms; OS, overall survival; SAA, severe aplastic anaemia.
See this image and copyright information in PMC

References

    1. Hasserjian RP, Germing U, Malcovati L. Diagnosis and classification of myelodysplastic syndromes. Blood. 2023;142(26):2247–2257. - PubMed
    1. Khoury JD, Solary E, Abla O, Akkari Y, Alaggio R, Apperley JF, et al. The 5th edition of the World Health Organization classification of haematolymphoid tumours: myeloid and histiocytic/dendritic neoplasms. Leukemia. 2022;36(7):1703–1719. - PMC - PubMed
    1. Makishima H, Yoshizato T, Yoshida K, Sekeres MA, Radivoyevitch T, Suzuki H, et al. Dynamics of clonal evolution in myelodysplastic syndromes. Nat Genet. 2017;49(2):204–212. - PMC - PubMed
    1. Bernard E, Tuechler H, Greenberg PL, Hasserjian RP, Arango Ossa JE, Nannya Y, et al. Molecular international prognostic scoring system for myelodysplastic syndromes. NEJM Evid. 2022;1(7):EVIDoa2200008. 10.1056/EVIDoa2200008 - DOI - PubMed
    1. Zeidan AM, Bewersdorf JP, Buckstein R, Sekeres MA, Steensma DP, Platzbecker U, et al. Finding consistency in classifications of myeloid neoplasms: a perspective on behalf of the International Workshop for Myelodysplastic Syndromes. Leukemia. 2022;36(12):2939–2946. - PubMed

Publication types

MeSH terms