Leukemia Research 35 (2011) 1276–1278 Contents lists available at ScienceDirect Leukemia Research jou rnal h omepa g e: www.elsevier.com/locate/leukres Case of the Month Efficacy of lenalidomide in a patient with myelodysplastic syndrome with isolated del(5q) and JAK2 V617F mutation Meritxell Nomdedeu ∗ , Margherita Maffioli, Xavier Calvo, Alejandra Martínez-Trillos, Tycho Baumann, Marina Díaz-Beyá, Josep-Lluís Aguilar, María Rozman, Dolors Costa, Jordi Esteve, Francisco Cervantes, Dolors Colomer, Benet Nomdedeu Department of Hematology, Hospital Clínic de Barcelona, Villarroel 170, 08036 Barcelona, SpainHematopathology Unit, Pathology Department, Hospital Clínic de Barcelona, Villarroel 170, 08036 Barcelona, SpainDepartment of Hematology, Hospital Clínic de Barcelona, Villarroel 170, 08036 Barcelona, SpainHematopathology Unit, Pathology Department, Hospital Clínic de Barcelona, Villarroel 170, 08036 Barcelona, SpainDepartment of Hematology, Hospital Clínic de Barcelona, Villarroel 170, 08036 Barcelona, Spain a r t i c l e i n f o Article history: Received 31 May 2011 Available online 20 July 2011 1. Introduction The efficacy of lenalidomide in the acquisition of transfusion independence and even cytogenetic remission in a high propor- tion of transfusion-dependent lower-risk patients with MDS and del(5q) has been demonstrated [1,2]. However, it is not known whether the presence of a concomitant JAK2 V617F mutation might influence such favorable results. We herein report a patient with 5q-syndrome and coexis- tent JAK2 V617F mutation who, following lenalidomide treatment, achieved a marked reduction of the JAK2 V617F clone in addition to complete hematologic and cytogenetic MDS response. 2. Case report A 54-year-old woman was admitted to the outpatient clinic in June 2009 following a five-year history of macrocytic anemia and progressive thrombocytosis. In 2006, after she had a transi- tory ischemic accident, essential thrombocythemia was suspected and cytoreductive therapy with hydroxyurea and low-dose aspirin were started. In spite of the cytoreductive treatment, the platelet counts progressively increased and the anemia worsened prompt- ing the patient to seek further medical advice. On physical examination, the patient was pale, with no other relevant findings. Laboratory analyses showed macrocytic anemia (hemoglobin 88 g/L, MCV 117.5 fL, MCH 36.3 pg), with a normal reticulocyte count (53 × 10 9 /L), and thrombocytosis (1482 × 10 9 /L). The white blood cell count was normal. A peripheral blood smear ∗ Corresponding author. Tel.: +34 932 275511; fax: +34 932 275484. E-mail address: mnomde@clinic.ub.es (M. Nomdedeu). showed degranulated dysplastic platelets with pseudo nuclei, hypogranularity of the neutrophils, and macrocytosis. The bone marrow aspirate was rich with more than 10% of the elements of the three hematopoietic lineages showing dysplastic features, pres- ence of erythroid hypoplasia and outstanding large mononuclear megakaryocytic hyperplasia. No ring sideroblasts were observed. Bone marrow cytogenetic analysis showed del(5q)(q13q33) as the sole abnormality in 12 out of the 16 analyzed metaphases. On molecular study, the BCR/ABL rearrangement was negative and the JAK2 V617F mutation was identified by quantitative PCR (JAK2 MutaQuant kit ® , Ipsogen). The mutant allele burden in periph- eral blood granulocytes and bone marrow mononuclear cells were 18.74% and 54.69%, respectively. A diagnosis of MDS with isolated del(5q) and JAK2 V617F mutation was established, corresponding to the IPSS low risk group [3]. As the hemoglobin values decreased below 90 g/L, hydroxyurea was with- drawn and lenalidomide was started on a compassionate-use basis, after approval by a Scientific Review Committee and the local Insti- tutional Review Board. Informed consent was obtained from the patient in accordance with the Declaration of Helsinki. Lenalido- mide was given at 10 mg daily for 21 days every 28 days. During lenalidomide treatment, G-CSF was administered to maintain the neutrophil counts above 0.5 × 10 9 /L. A rapid decrease in the platelet count was noted reaching normal values in 2 weeks, as well as a progressive increase in the hemoglobin which was normal at 38 days of treatment (Fig. 1). A complete reevaluation was performed after completing 6 lenalidomide cycles. Peripheral blood cell count was strictly normal and the bone marrow aspirate showed normal cellularity, with the three hematopoietic cell lineages being normal in both proportion and appearance. Del(5q) was not found neither by conventional cytogenetic analysis (20 metaphases) nor by fluo- rescence in situ hybridization. In turn, quantitative analysis of the 0145-2126/$ – see front matter © 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.leukres.2011.06.008