Bone Marrow Transplantation (2006) 38, 319–320 & 2006 Nature Publishing Group All rights reserved 0268-3369/06 $30.00
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LETTER TO THE EDITOR
Allogeneic bone marrow transplantation for hypereosinophilic syndrome: long-term follow-up with eradication of FIP1L1-PDGFRA fusion transcript
Bone Marrow Transplantation (2006) 38, 319–320. doi:10.1038/sj.bmt.1705437; published online 3 July 2006
As the fusion gene FIP1L1-PDGFRA was identified as being responsible for clonal evolution in some patients clinically diagnosed with hypereosinophilic syndrome (HES), effective treatment with imatinib became available.1 The inhibitory effect of imatinib on the fusion tyrosine kinase leads to molecular remission in a subset of patients after several months of therapy.2 The first report of effective imatinib treatment in HES was published in 2001, but the mechanism of action was not known at that time.3 Here, we describe a patient transplanted for HES in 2001 in whom the FIP1L1-PDGFRA transcript was retrospectively shown to be eradicated after transplantation. A 29-year-old male patient was diagnosed with HES in October 1998. At presentation, the patient had bronchospasm, liver and spleen enlargement as well as enlargement of axillary lymph nodes. WBC count was 21.2 with 15.3 G/l eosinophils. A bone marrow aspirate revealed 21.5% eosinophils with no left-shift. Cytogenetic analysis showed a normal male karyotype. RNA was isolated to subsequently test for the presence of BCR/ABL transcript. The result of the examination was negative by nested PCR and the remaining RNA was stored in liquid nitrogen. Extensive examination for secondary eosinophilia proved negative and the patient was finally diagnosed with HES. Initial treatment with steroids was considered unsatisfactory, and in December 1998, hydroxyurea was added and continued until June 2001. During that time, the eosinophil count in the peripheral blood ranged from 3 to 6 G/l. Echocardiography carried out in February 2001 showed valvular abnormalities and bicuspid reverse flow, which were not present at diagnosis. In May 2001, the patient was admitted for spastic paresis of the lower extremities and cerebellar disturbances. Computed tomography scan was normal and all symptoms resolved on high-dose pulsed methylprednisolone. In June 2001, further progression of the disease was noted with the WBC count exceeding 30 G/l and eosinophils 18 G/l, despite continued hydroxyurea/ prednisone. The patient’s condition deteriorated. He reported fatigue, fever above 381C, loss of appetite, weight loss, sweating and abdominal discomfort. Physical examination and abdominal ultrasonography showed general enlargement of lymph nodes and liver and spleen enlargement (8 and 4 cm below costal margin, respectively). The patient was given cytosine b-D-arabinofuranoside hydro-
chloride and mitoxantrone, which led to prompt resolution of symptoms and a reduction in the eosinophil count to 0.3 G/l. The patient was found to have an HLA-compatible sister. Allogeneic transplantation was performed in July 2001. Conditioning consisted of Bu/Cy120 with standard cyclosporine/methotrexate GvHD prophylaxis. Engraftment was achieved on day þ 21 post transplant, and on day þ 39, a rising eosinophil count was noted. On day þ 46, it reached 3.0 G/l and relapse of the disease was suspected. However, short tandem repeat (STR) analysis showed only traces of recipient DNA (less than 1%) both in the bone marrow and peripheral blood. On day þ 70, the patient developed grade III aGvHD (skin rash 450% surface and bilirubin concentration of 6.3 mg/dl). Eosinophil count was 3.8 G/l at that time. Steroid treatment was complicated 10 days later by haemorrhagic cystitis owing to adenovirus infection, confirmed by direct immunofluorescence. Treatment with gancyclovir and ribavirine was instituted, and all the symptoms were resolved within 4 weeks. The patient developed mild chronic GvHD with mucosal and hepatic involvement, which required steroid and cyclosporine treatment for 18 months after transplantation. During that time, repeated blood and marrow examinations revealed 8–15% eosinophils with otherwise normal peripheral blood and bone marrow. STR analyses performed every 3 months uniformly showed 100% donor chimerism and cardiac involvement resolved. In July 2004, when the method became routinely available, the patient was tested for the presence of FIP1L1-PDGFRA transcript along with other HES patients. His RNA sample from October 1998 was analysed together with the current one. The first-strand complementary DNA was synthesized from total RNA using Moloney murine leukaemia virus reverse transcriptase with random primers (Invitrogen, Frederic, Maryland, USA). Fusion FIP1L1 to PDGFRA gene was analysed by nested PCR using primers FIP1L1 F1 (50 -ACCTGGTGCTGATCTTTCTGAT-30 ) and PDFRA R1 (50 -TGAGAGCTTGTTTTTCACTGGA-30 ) for the first reaction and FIP1L1 F2 (50 -AAAGAGGATACGAA TGGGACTTG-30 ) and PDGFRA R2 (50 -GGGACCGG CTTAATCCATAG-30 ) for the second reaction (the reagents from Fermentas, Vilnius, Lithuania). The nested PCR product was direct sequenced using ABI PRISM 310 Genetic Analyzer (Applied Biosystems, Foster City, California, USA). The presence of FIP1L1-PDGFRA transcript was confirmed in the sample stored at diagnosis (Figure 1), whereas the current one was negative by nested PCR, which showed eradication of the fusion gene by allogeneic bone marrow transplantation. At present, the patient is in excellent clinical condition, with no signs of
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Figure 1 Sequencing reaction for FIP1L1/PDGFRA gene. The arrow shows site of the fusion. Upper part belongs to FIP1L1 gene and lower part belongs to PDGFRA.
cGvHD or recurrent disease as documented by repeated chimerism and FIP1L1-PDGFRA assessments. Attempts of allogeneic stem cell transplantation in HES have been published as far back as 1988.4 However, owing to relatively high treatment-related mortality, allogeneic transplantation is reserved only for patients with aggressive disease failing frontline treatment. Introduction of nonmyeloablative conditioning has made transplantation available even for patients, with severe organ dysfunction during the course of the disease.5 Papers describing allogeneic transplantation in HES published are mostly case reports or deal with small series of patients. It is therefore difficult to establish a transplantation standard for HES patients, particularly given the heterogeneity of the syndrome.6,7 Recently, FIP1L1-PDGFRA fusion gene was identified as a detrimental factor causing disease evolution in a subset of patients. Accumulating data confirm imatinib efficacy in those patients. Unfortunately, less than 20% of HES patients carry the mutation.6,8 Only those patients have a sustained response to imatinib, whereas others mostly show a transient improvement. It is not known whether molecular remissions will be sustained if therapy is interrupted, how long the treatment should be continued or if resistance to imatinib will emerge at some point of treatment. Also, it is not well established whether or not prolonged imatinib administration will result in resolution of organ involvement.2 As in many myeloproliferative disorders, allogeneic stem cell transplantation is the only confirmed curative option in HES. In case of imatinib failure in FIP1L1-PDGFRA-positive patients undergoing transplantation, the fusion transcript may serve as a highly sensitive tool for the evaluation of molecular remission after grafting. K Halaburda1, W Prejzner1, D Szatkowski1, J Limon2 and A Hellmann1 1 Department of Haematology, Medical University of Gdan´sk, Gdan´sk, Poland and Bone Marrow Transplantation
2
Department of Biology and Genetics, Medical University of Gdan´sk, Gdan´sk, Poland E-mail:
[email protected]
References 1 Gotlib J, Cools J, Malone III JM, Schrier SL, Gilliland DG, Coutre SE. The FIP1L1-PDGFRa´ fusion tyrosine kinase in hypereosinophilic syndrome and chronic eosinophilic leukemia: implications for diagnosis, classification and management. Blood 2004; 103: 2879–2891. 2 Klion AD, Robyn J, Akin C, Noel P, Brown M, Law M et al. Molecular remission and reversal of myelofibrosis in response to imatinib mesylate treatment in patients with the myeloproliferative variant of hypereosinophilic syndrome. Blood 2004; 103: 473–478. 3 Schaller JL, Burkland GA. Case report: rapid and complete control of idiopathic hypereosinophilia with imatinib mesylate. Med Gen Med 2001; 3: 9. 4 Archimbaud E, Guyotat D, Guillame C, Godard J, Fiere D. Hypereosinophilic syndrome with multiple organ dysfunction treated by allogeneic bone marrow transplantation. Am J Hematol 1988; 27: 302–303. 5 Juvonen E, Volin L, Koponen A, Ruutu T. Allogeneic blood stem cell transplantation following non-myeloablative conditioning for hypereosinophilic syndrome. Bone Marrow Transplant 2002; 29: 457–458. 6 Roche-Lestienne C, Lepers S, Soenen-Cornu V, Kahn JE, Lai JL, Hachulla E et al. Molecular characterization of the idiopathic hypereosinophilic syndrome (HES) in 35 French patients with normal conventional cytogenetics. Leukemia 2005; 19: 792–798. 7 Tefferi A. Modern diagnosis and treatment of primary eosinophilia. Acta Haematol 2005; 114: 52–60. 8 Pardanani A, Brockman SR, Paternoster SF, Flynn HC, Ketterling RP, Lasho TL et al. FIP1L1-PDGFRA fusion: prevalence and clinicopathologic correlates in 89 consecutive patients with moderate to severe eosinophilia. Blood 2004; 104: 3038–3045.
