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Haematological and molecular responses in refractory anaemia with ring sideroblasts and thrombocytosis treated with lenalidomide
Author(s) -
Caers Jo,
Hafraoui Kaoutar,
Keutgens Aurore,
Caberg JeanHubert,
Lambert Frederic,
Tassin Francoise,
Beguin Yves
Publication year - 2014
Publication title -
european journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.904
H-Index - 84
eISSN - 1600-0609
pISSN - 0902-4441
DOI - 10.1111/ejh.12233
Subject(s) - hematology , thrombocytosis , medicine , lenalidomide , platelet , multiple myeloma
To the Editor: Refractory anaemia with ring sideroblasts and thrombocytosis (RARS-T) is a rare entity and is defined as an overlap syndrome with clinical and morphologic features of both myelodysplastic syndrome (MDS) and BCR-ABL-negative myeloproliferative neoplasm, including marked thrombocytosis associated with abnormal megakaryocytes (1). Mutations in the Janus Kinase 2 gene (JAK2) and/or Splicing Factor 3B subunit 1 (SF3B1) gene have been detected in 50–70% of patients with RARS-T (2–4). The presence of such a mutation in either JAK2 or SF3B1 was associated with a better overall survival in a recent European study (5). Because of its activity in lower-risk MDS with or without the 5qcytogenetic abnormality (6) and in myelofibrosis (7), lenalidomide treatment has been given with success in two patients with RARS-T. In this letter, we would like to report a case of RARS-T that was successfully treated by lenalidomide. An 84-years-old woman was referred for unexplained normocytic anaemia (Hb 7.7 g/dL) with marked thrombocytosis (1515 9 10/L). Peripheral blood smear showed a left shift in neutrophils. Bone marrow cytology disclosed hypercellularity (illustrated in Fig. 1A) with 15.6% erythroid cells, 77.6% granulopoietic cells, 3.2% monocytes, 4.0% lymphocytes, 1% blasts and numerous megakaryocytes. Ring sideroblasts constituted 90% of erythroid precursors (Fig. 1B). Erythropoiesis and granulopoiesis were both hyperplasic with evidence of dysplasia. The most prominent feature was the presence of numerous atypical megakaryocytes of different sizes and shapes, many with hypolobated nuclei (Fig. 1C). Metaphase cytogenetics revealed the presence of 5qin one mitosis, which could not be confirmed by FISH using a specific EGR1(5q31) probe, or Array-CGH analysis (SurePrint G3 Human CGH Microarray). We could not detect any mutation in the SF3B1 gene, but the JAK2V617F mutation was retrieved and estimated at 12.5–31% of JAK2 alleles. Based on these findings, RARS-T with a JAK2-V617F mutation was diagnosed. Because of her anaemia, cytoreductive treatment was not an attractive option. After transfusion of 4 units of red blood