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Tracking of the Somatic Mutations in MDS Patients During Disease Restaging Improves Prediction of Oncoming Relapse or Disease Progression
Poster Presentations – 14th International Symposium on Myelodysplastic Syndromes / Leukemia Research 55 S1 (2017) S45–S167
the MDS cell cycle. Moreover, the expression of PI-PLCs and Beta-Globin could be associated with a favourable clinical response to the combination therapy, hinting at a specific contribution of lenalidomide on erythroid activation, whilst the frequent demethylation of PI-PLCbeta1 promoter could be specifically linked to azacitidine. At baseline, the most frequent gene mutations were ASXL1 (59%), TET2 (41%), RUNX1 (35%) and SRSF2 (29%). Interestingly, all patients showing SRSF2 mutations evolved into AML. Moreover, all patients maintaining a stable disease during the therapy had increasing variant allele frequencies, showing a genetic instability. Finally, microRNA analysis revealed specific clusters associated with the treatment: 14 microRNAs were overexpressed and 28 were under-expressed as compared to baseline levels. Interestingly, down-regulation of 5 microRNAs was significantly associated with the lack of response. Conclusions: Our results show that the combination of azacitidine and lenalidomide can affect PI-PLC signalling, possibly regulating MDS cell cycle, myeloid and erythroid differentiation. Moreover, the therapy can induce a change in the specific gene mutation and microRNA profile that, if confirmed by larger studies, could be important to better evaluate the response to this therapy.
87 MUTATIONAL AND CLONAL DYNAMICS DURING PROGRESSION FROM MDS TO SAML BY WHOLE-EXOME AND TARGETED-DEEP SEQUENCING M. Martín Izquierdo1, M. Abáigar1, J.M. Hernández-Sánchez1, D. Tamborero2, M. Díez-Campelo3, M. Hernández-Sánchez1, F. Ramos4, M. Megido5, C. Aguilar6, E. Lumbreras1, A. Redondo-Guijo3, I. Recio7, C. Olivier8, R. Benito1, N. López-Bigas2, M.C. del Cañizo3, J.M. Hernández-Rivas3 1 Centro de Investigación del Cáncer, Unidad de Diagnóstico Molecular y Celular del Cáncer, Salamanca, Spain; 2IMIM Hospital del Mar Medical Research Institute and Universitat Pompeu Fabra, Research Program on Biomedical Informatics, Barcelona, Spain; 3IBSALHematology Department, Hospital Universitario de Salamanca, Salamanca, Spain; 4Hospital de León, IBIOMED- University of LeónHematology Department, León, Spain; 5Hematology Department, Hospital del Bierzo, Ponferrada, Spain; 6Hematology Department, Hospital Santa Bárbara, Soria, Spain; 7Hematology Department, Hospital Nuestra Señora de Sónsoles, Ávila, Spain; 8Hematology Department, Hospital General de Segovia, Segovia, Spain Introduction: Myelodysplastic syndromes (MDS) are hematological disorders at high risk of progression to acute myeloid leukemia (sAML). Due to recent high-throughput sequencing studies, the mutational dynamics and clonal evolution underlying disease progression have just begun to be understood. However, large longitudinal sequencing genomic studies are still required. Methods: Sixty-eight serially collected samples (34MDS/CMML patients evolving to sAML) were studied at two time-points: at diagnosis and at progression to a sAML. At diagnosis, patients were classified into: 18 RAEB-1/2, 9 RCMD and 7 CMML. Whole-exome sequencing (WES) was carried out on 40 diagnosis/ progression-matched samples. To validate mutations and precise variant allele frequencies (VAFs) estimation, targeteddeep sequencing (TDS) using a custom MDS/AML-related capture enrichment panel (Illumina®) of 117 genes was performed in 30 out of 40 of the initial cohort. Moreover, a total of 28 paired-samples from a cohort of 14 patients were analyzed by TDS. Results: Combining both WES and TDS approaches, a total of 143 mutations in 50 different genes were identified at the sAML stage. The most recurrently mutated genes were SRSF2 (41%), TET2 (41%), STAG2 (28%), SF3B1 (21%), ASXL1 (21%), TP53 (21%) and NRAS (21%). However, it should be noted that 68% genes were mutated only in
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less than 10% of the patients, highlighting the great heterogeneity that exists in mechanisms of transformation. To study the mutational dynamics during disease progression we compared VAFs of mutations detected at both time-points (sAML to MDS/CMML stage) in each patient. We identified 4 different clonal dynamics: mutations that were initially present but increased VAF (type-1), decreased (type-2), were newly acquired (type-3) or persisted with similar allelic burden (type-4) at sAML stage. Interestingly, most of type-1 mutations were detected in STAG2 gene. Thus, mutational burden of STAG2 were markedly increased (6/8 patients) at sAML progression. Moreover, type-3 mutations, only detected at the sAML-stage, were predominantly identified in FLT3 (3/4) and NRAS (5/6). Conversely, type-4 mutations were present in MDS-related genes such as SRSF2 (9/12), SF3B1 (3/6) and TET2 (8/12). Most of mutations in these genes showed no changes during progression to sAML. Conclusions: Progression from MDS to sAML could be explained by different mutational processes, as well as by the occurrence of unique and complex changes in the clonal architecture of the disease during the evolution. Mutations in genes such as STAG2, FLT3 or NRAS could play an important role during disease progression. [FP7/2007-2013] n°306242-NGS-PTL; BIO/SA52/14;FEHH 2015-16 (MA).
88 TRACKING OF THE SOMATIC MUTATIONS IN MDS PATIENTS DURING DISEASE RESTAGING IMPROVES PREDICTION OF ONCOMING RELAPSE OR DISEASE PROGRESSION K. Polgarova1,2, V. Kulvait2, K. Vargova3, L. Minarik1,2, N. Dusilkova2,3, Z. Zemanova4, A. Jonasova1, T. Stopka1,2,3 1 First Internal Clinic – Clinic of Haematology, 1st Faculty of Medicine & General University Hospital- Charles University Prague, Prague, Czech Republic; 21st Faculty of Medicine & General University HospitalCharles University Prague, Biocev, Prague, Czech Republic; 31st Faculty of Medicine & General University Hospital- Charles University Prague, Institute of Pathological Physiology, Prague, Czech Republic; 41st Faculty of Medicine & General University Hospital- Charles University Prague, Center of Oncocytogenetics, Prague, Czech Republic Myelodysplastic syndromes (MDS) are clonal stem cell disorders with dysplasia, ineffective hematopoiesis and acute myeloid leukemia (AML) development. 90% of patients with MDS carry somatic mutations in bone marrow (BM). We herein asked whether the treatment with azacitidine (AZA) selects some of the somatic mutations and whether some mutation-bearing clones are sensitive to AZA, and finally how AZA influence the clonal architecture and how these changes reflect the clinical course. We analyzed in duplicates the 98 BM samples of 39 high-risk AZAtreated patients before treatment and in different restaging points using Illumina Myeloid TruSight panel. To ensure reliable data, samples were sequenced twice and germinal variants were filtered using data from in parallel-sequenced CD3+ non-malignant cell fraction. MDS subtypes were as follows: RAEB2 (n = 18, 46%), RAEB1 (n = 13, 33%), AML/MDS (n = 5, 13%), CMML (n = 2, 4%), and RCMD (n = 1, 2%). 18% of patients had complex karyotypes, 46% were progressions of 5q-. MedianOS was 24 months, medianPFS was 16 months; CR/mCR was reached in 41% (n = 16); 64% patients (n = 25) progressed to AML. 92% of patients bear somatic mutation in at least one out of 54 analyzed genes with median 3 mutations (range 1–9) per patient. The most frequently mutated genes at diagnosis were: TP53 (n = 11), TET2 (n = 10), CUX1 (n = 9), BCORL1 (n = 8) and ASXL1 (n = 7). Out of the mutations observed before AZA therapy, 40% remained stable during the disease course including TET2 (80%),
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Poster Presentations – 14th International Symposium on Myelodysplastic Syndromes / Leukemia Research 55 S1 (2017) S45–S167
BCORL1 (66%), CDKN2A (80%, n = 5), and EZH2 (75%, n = 4). On the contrary, mutations with increasing abundance on AZA were observed in genes encoding IDH2 (75%, n = 4) and RUNX1 (62%, n = 8), the latter often related to the progression. There were also de novo mutations that developed on AZA involving seven genes: TP53, BCORL1, STAG2, DNMT3A, ASXL1, SMC3, PTPN11; again, last three related to progression. We conclude that dynamic changes observed in the mutational pattern often reflect the disease course with a decrease/elimination of allelic burden during remission. Mutation reappearance was observable upon progression or relapse while stable pattern was seen in cases of stable disease. Furthermore, in 5 patients (13%) we noted the progression-preceding mutations in ASXL1, RUNX1, SRSF2, STAG2, SF3B1 with markedly increasing allele frequency at morphological remission which was within 2–6 months exchanged into progression. We conclude that tracking of somatic mutations helps to monitor the genetic development of the mutant clone/s and to predict forthcoming disease progression. Acknowledgement: Grant support: AZV16-27790A, GAČ R1605649S, UNCE204021, LH15170, Progres Q26/Q28, NPU2 LQ1604 & RVO-VFN64165.
Results: 152 MDS pts were diagnosed in 2009 or later. Lactate dehydrogenase (LDH), bilirubin (BILI) and reticulocyte count (RETICS) were measured (elevated) in 96 (23), 109 (10) and 142 (14) pts, respectively, and haptoglobin (HAPTO) decreased in 2 of 7 measured. The direct antiglobulin test (DAT) was negative in 9 of 13 pts and serum ferritin level <100 ng/mL in 14 of 116. No pts had hemoglobinuria. 79 (52%) pts were RBC TD, with a median TR of 4 (1–8) units/8 weeks. PNH testing was positive in 1 of 11 pts tested. Reasons for PNH testing were: anemia, n = 3 (with abdominal symptoms in 1); new MDS dx, n = 2; hypoplastic MDS, n = 2; decreased HAPTO; increased TR; and iron deficiency, n = 1 each; see Figure. At a median follow up of 21.1 (0.7–69.9) months for all patients, 113 were alive and the median OS was not reached. Conclusions: PNH was tested for infrequently in MDS patients in clinical practice. Only 11 (7%) of MDS pts since 2009 had PNH testing done despite potential indicators of hemolysis in 27%. Clinical rather than laboratory indicators prompted PNH testing in 6 of 11 pts. Complement mediated hemolysis could exacerbate anemia in MDS. As there is now an effective treatment available, screening for PNH in MDS should be considered.
89 PAROXYSMAL NOCTURNAL HEMOGLOBINURIA (PNH) SCREENING IN PATIENTS WITH MYELODYSPLASTIC SYNDROME (MDS) IN CLINICAL PRACTICE: FREQUENCY AND INDICATIONS S. Wong1, B. Dalal2, H.A. Leitch3 1 Medicine, The Royal College of Surgeons in Ireland, Dublin, Ireland; 2 Division of Laboratory Hematology, Vancouver General Hospital, Vancouver- British Columbia, Canada; 3Hematology, St. Paul’s Hospital and the University of British Columbia, Vancouver, Canada
90 CYTOGENETIC CLONAL EVOLUTION IN MYELODYSPLASTIC SYNDROMES (MDS) WITH ISOLATED DEL(5Q) Z. Zemanova1, K. Michalova1, J. Brezinova2, K. Svobodova1, H. Lhotska1, I. Sarova2, L. Lizcova1, S. Izakova1, S. Ransdorfova2, L. Pavlistova1, A. Berkova1, K. Skipalova1, M. Belickova3, M. Siskova4, R. Neuwirtova4, J. Cermak5, T. Stopka4, A. Jonasova4 1 General University Hospital and First Faculty of Medicine- Charles University in Prague, Center of Oncocytogenetics- Institute of Medical Biochemistry and Laboratory Diagnostics, Prague 2, Czech Republic; 2 Cytogenetic Department, Institute of Hematology and Blood Transfusion, Prague 2, Czech Republic; 3Department of Genomics, Institute of Hematology and Blood Transfusion, Prague 2, Czech Republic; 4General University Hospital and First Faculty of MedicineCharles University in Prague, 1st Medical Department, Prague 2, Czech Republic; 5Clinical Department, Institute of Hematology and Blood Transfusion, Prague 2, Czech Republic
Background: MDS is characterized by ineffective hematopoiesis and peripheral blood cytopenias including anemia which may lead to red blood cell (RBC) transfusion dependence (TD). In paroxysmal nocturnal hemoglobinuria (PNH), complement-mediated lysis occurs. PNH clones are detected in up to 50% of MDS pts might confound the reason for RBC TD. The first specific treatment for PNH was approved in Canada in 2009. Eculizumab reduces hemolysis and RBC transfusion requirements (TR) and has other benefits. We wanted to determine whether PNH as a contributor to anemia is considered in MDS pts in the Eculizumab era. Methods: Pts with a bone marrow biopsy confirmed MDS diagnosis (dx) since 2009 were reviewed. Data extracted included baseline clinical and laboratory features, clinical course, treatment, outcome and indicators of hemolysis. High resolution PNH testing was done by flow cytometry for expression of FLAER, CD24, CD14, and CD59 on neutrophils, monocytes and RBC.
The interstitial deletion of the long arm of chromosome 5 – del (5q) – is the most common cytogenetic finding in patients with MDS (∼30% of abnormal karyotypes). According to IPSS-R, MDS with isolated del(5q) are associated with a favorable clinical course. However in some cases, acquisition of additional genetic aberrations may occur during the course of the disease. The aim of the study was: to evaluate the frequency of cytogenetic clonal evolution (CCE) in MDS patients with isolated del(5q); to analyze the pattern of acquired cytogenetic abnormalities; and to assess the impact of CCE on transformation to AML and/or overall survival. A detailed genome-wide analysis of fixed bone-marrow cells of 184 adults with del(5q), identified with G-banding at the diagnosis of MDS, was performed during the follow-up using FISH (Vysis DNA probes, Abbott), mFISH/mBAND (MetaSystems) and array CGH/SNP (CytoChip Cancer SNP 180K, BlueGnome or SurePrint G3 Cancer CGH+SNP 4 × 180K, Agilent). Amplicon deep sequencing of TP53 mutations (exons 4–11) was performed on a 454 GS Junior system (Roche). CCE was observed in 25/184 patients with isolated del(5q). The clinical progression occurred in 24 of them. One woman lives 56 months after CCE with no signs of disease progression. CCE was detected between 2 and 145 months after first cytogenetic evaluation (median 26 months). Median survival from the first emergence of CCE was 11 months (range 1–56 months; 22 patients died, 3 patients live). In 20/25 cases (80%), clones with del(5q)
the MDS cell cycle. Moreover, the expression of PI-PLCs and Beta-Globin could be associated with a favourable clinical response to the combination therapy, hinting at a specific contribution of lenalidomide on erythroid activation, whilst the frequent demethylation of PI-PLCbeta1 promoter could be specifically linked to azacitidine. At baseline, the most frequent gene mutations were ASXL1 (59%), TET2 (41%), RUNX1 (35%) and SRSF2 (29%). Interestingly, all patients showing SRSF2 mutations evolved into AML. Moreover, all patients maintaining a stable disease during the therapy had increasing variant allele frequencies, showing a genetic instability. Finally, microRNA analysis revealed specific clusters associated with the treatment: 14 microRNAs were overexpressed and 28 were under-expressed as compared to baseline levels. Interestingly, down-regulation of 5 microRNAs was significantly associated with the lack of response. Conclusions: Our results show that the combination of azacitidine and lenalidomide can affect PI-PLC signalling, possibly regulating MDS cell cycle, myeloid and erythroid differentiation. Moreover, the therapy can induce a change in the specific gene mutation and microRNA profile that, if confirmed by larger studies, could be important to better evaluate the response to this therapy.
87 MUTATIONAL AND CLONAL DYNAMICS DURING PROGRESSION FROM MDS TO SAML BY WHOLE-EXOME AND TARGETED-DEEP SEQUENCING M. Martín Izquierdo1, M. Abáigar1, J.M. Hernández-Sánchez1, D. Tamborero2, M. Díez-Campelo3, M. Hernández-Sánchez1, F. Ramos4, M. Megido5, C. Aguilar6, E. Lumbreras1, A. Redondo-Guijo3, I. Recio7, C. Olivier8, R. Benito1, N. López-Bigas2, M.C. del Cañizo3, J.M. Hernández-Rivas3 1 Centro de Investigación del Cáncer, Unidad de Diagnóstico Molecular y Celular del Cáncer, Salamanca, Spain; 2IMIM Hospital del Mar Medical Research Institute and Universitat Pompeu Fabra, Research Program on Biomedical Informatics, Barcelona, Spain; 3IBSALHematology Department, Hospital Universitario de Salamanca, Salamanca, Spain; 4Hospital de León, IBIOMED- University of LeónHematology Department, León, Spain; 5Hematology Department, Hospital del Bierzo, Ponferrada, Spain; 6Hematology Department, Hospital Santa Bárbara, Soria, Spain; 7Hematology Department, Hospital Nuestra Señora de Sónsoles, Ávila, Spain; 8Hematology Department, Hospital General de Segovia, Segovia, Spain Introduction: Myelodysplastic syndromes (MDS) are hematological disorders at high risk of progression to acute myeloid leukemia (sAML). Due to recent high-throughput sequencing studies, the mutational dynamics and clonal evolution underlying disease progression have just begun to be understood. However, large longitudinal sequencing genomic studies are still required. Methods: Sixty-eight serially collected samples (34MDS/CMML patients evolving to sAML) were studied at two time-points: at diagnosis and at progression to a sAML. At diagnosis, patients were classified into: 18 RAEB-1/2, 9 RCMD and 7 CMML. Whole-exome sequencing (WES) was carried out on 40 diagnosis/ progression-matched samples. To validate mutations and precise variant allele frequencies (VAFs) estimation, targeteddeep sequencing (TDS) using a custom MDS/AML-related capture enrichment panel (Illumina®) of 117 genes was performed in 30 out of 40 of the initial cohort. Moreover, a total of 28 paired-samples from a cohort of 14 patients were analyzed by TDS. Results: Combining both WES and TDS approaches, a total of 143 mutations in 50 different genes were identified at the sAML stage. The most recurrently mutated genes were SRSF2 (41%), TET2 (41%), STAG2 (28%), SF3B1 (21%), ASXL1 (21%), TP53 (21%) and NRAS (21%). However, it should be noted that 68% genes were mutated only in
S55
less than 10% of the patients, highlighting the great heterogeneity that exists in mechanisms of transformation. To study the mutational dynamics during disease progression we compared VAFs of mutations detected at both time-points (sAML to MDS/CMML stage) in each patient. We identified 4 different clonal dynamics: mutations that were initially present but increased VAF (type-1), decreased (type-2), were newly acquired (type-3) or persisted with similar allelic burden (type-4) at sAML stage. Interestingly, most of type-1 mutations were detected in STAG2 gene. Thus, mutational burden of STAG2 were markedly increased (6/8 patients) at sAML progression. Moreover, type-3 mutations, only detected at the sAML-stage, were predominantly identified in FLT3 (3/4) and NRAS (5/6). Conversely, type-4 mutations were present in MDS-related genes such as SRSF2 (9/12), SF3B1 (3/6) and TET2 (8/12). Most of mutations in these genes showed no changes during progression to sAML. Conclusions: Progression from MDS to sAML could be explained by different mutational processes, as well as by the occurrence of unique and complex changes in the clonal architecture of the disease during the evolution. Mutations in genes such as STAG2, FLT3 or NRAS could play an important role during disease progression. [FP7/2007-2013] n°306242-NGS-PTL; BIO/SA52/14;FEHH 2015-16 (MA).
88 TRACKING OF THE SOMATIC MUTATIONS IN MDS PATIENTS DURING DISEASE RESTAGING IMPROVES PREDICTION OF ONCOMING RELAPSE OR DISEASE PROGRESSION K. Polgarova1,2, V. Kulvait2, K. Vargova3, L. Minarik1,2, N. Dusilkova2,3, Z. Zemanova4, A. Jonasova1, T. Stopka1,2,3 1 First Internal Clinic – Clinic of Haematology, 1st Faculty of Medicine & General University Hospital- Charles University Prague, Prague, Czech Republic; 21st Faculty of Medicine & General University HospitalCharles University Prague, Biocev, Prague, Czech Republic; 31st Faculty of Medicine & General University Hospital- Charles University Prague, Institute of Pathological Physiology, Prague, Czech Republic; 41st Faculty of Medicine & General University Hospital- Charles University Prague, Center of Oncocytogenetics, Prague, Czech Republic Myelodysplastic syndromes (MDS) are clonal stem cell disorders with dysplasia, ineffective hematopoiesis and acute myeloid leukemia (AML) development. 90% of patients with MDS carry somatic mutations in bone marrow (BM). We herein asked whether the treatment with azacitidine (AZA) selects some of the somatic mutations and whether some mutation-bearing clones are sensitive to AZA, and finally how AZA influence the clonal architecture and how these changes reflect the clinical course. We analyzed in duplicates the 98 BM samples of 39 high-risk AZAtreated patients before treatment and in different restaging points using Illumina Myeloid TruSight panel. To ensure reliable data, samples were sequenced twice and germinal variants were filtered using data from in parallel-sequenced CD3+ non-malignant cell fraction. MDS subtypes were as follows: RAEB2 (n = 18, 46%), RAEB1 (n = 13, 33%), AML/MDS (n = 5, 13%), CMML (n = 2, 4%), and RCMD (n = 1, 2%). 18% of patients had complex karyotypes, 46% were progressions of 5q-. MedianOS was 24 months, medianPFS was 16 months; CR/mCR was reached in 41% (n = 16); 64% patients (n = 25) progressed to AML. 92% of patients bear somatic mutation in at least one out of 54 analyzed genes with median 3 mutations (range 1–9) per patient. The most frequently mutated genes at diagnosis were: TP53 (n = 11), TET2 (n = 10), CUX1 (n = 9), BCORL1 (n = 8) and ASXL1 (n = 7). Out of the mutations observed before AZA therapy, 40% remained stable during the disease course including TET2 (80%),
S56
Poster Presentations – 14th International Symposium on Myelodysplastic Syndromes / Leukemia Research 55 S1 (2017) S45–S167
BCORL1 (66%), CDKN2A (80%, n = 5), and EZH2 (75%, n = 4). On the contrary, mutations with increasing abundance on AZA were observed in genes encoding IDH2 (75%, n = 4) and RUNX1 (62%, n = 8), the latter often related to the progression. There were also de novo mutations that developed on AZA involving seven genes: TP53, BCORL1, STAG2, DNMT3A, ASXL1, SMC3, PTPN11; again, last three related to progression. We conclude that dynamic changes observed in the mutational pattern often reflect the disease course with a decrease/elimination of allelic burden during remission. Mutation reappearance was observable upon progression or relapse while stable pattern was seen in cases of stable disease. Furthermore, in 5 patients (13%) we noted the progression-preceding mutations in ASXL1, RUNX1, SRSF2, STAG2, SF3B1 with markedly increasing allele frequency at morphological remission which was within 2–6 months exchanged into progression. We conclude that tracking of somatic mutations helps to monitor the genetic development of the mutant clone/s and to predict forthcoming disease progression. Acknowledgement: Grant support: AZV16-27790A, GAČ R1605649S, UNCE204021, LH15170, Progres Q26/Q28, NPU2 LQ1604 & RVO-VFN64165.
Results: 152 MDS pts were diagnosed in 2009 or later. Lactate dehydrogenase (LDH), bilirubin (BILI) and reticulocyte count (RETICS) were measured (elevated) in 96 (23), 109 (10) and 142 (14) pts, respectively, and haptoglobin (HAPTO) decreased in 2 of 7 measured. The direct antiglobulin test (DAT) was negative in 9 of 13 pts and serum ferritin level <100 ng/mL in 14 of 116. No pts had hemoglobinuria. 79 (52%) pts were RBC TD, with a median TR of 4 (1–8) units/8 weeks. PNH testing was positive in 1 of 11 pts tested. Reasons for PNH testing were: anemia, n = 3 (with abdominal symptoms in 1); new MDS dx, n = 2; hypoplastic MDS, n = 2; decreased HAPTO; increased TR; and iron deficiency, n = 1 each; see Figure. At a median follow up of 21.1 (0.7–69.9) months for all patients, 113 were alive and the median OS was not reached. Conclusions: PNH was tested for infrequently in MDS patients in clinical practice. Only 11 (7%) of MDS pts since 2009 had PNH testing done despite potential indicators of hemolysis in 27%. Clinical rather than laboratory indicators prompted PNH testing in 6 of 11 pts. Complement mediated hemolysis could exacerbate anemia in MDS. As there is now an effective treatment available, screening for PNH in MDS should be considered.
89 PAROXYSMAL NOCTURNAL HEMOGLOBINURIA (PNH) SCREENING IN PATIENTS WITH MYELODYSPLASTIC SYNDROME (MDS) IN CLINICAL PRACTICE: FREQUENCY AND INDICATIONS S. Wong1, B. Dalal2, H.A. Leitch3 1 Medicine, The Royal College of Surgeons in Ireland, Dublin, Ireland; 2 Division of Laboratory Hematology, Vancouver General Hospital, Vancouver- British Columbia, Canada; 3Hematology, St. Paul’s Hospital and the University of British Columbia, Vancouver, Canada
90 CYTOGENETIC CLONAL EVOLUTION IN MYELODYSPLASTIC SYNDROMES (MDS) WITH ISOLATED DEL(5Q) Z. Zemanova1, K. Michalova1, J. Brezinova2, K. Svobodova1, H. Lhotska1, I. Sarova2, L. Lizcova1, S. Izakova1, S. Ransdorfova2, L. Pavlistova1, A. Berkova1, K. Skipalova1, M. Belickova3, M. Siskova4, R. Neuwirtova4, J. Cermak5, T. Stopka4, A. Jonasova4 1 General University Hospital and First Faculty of Medicine- Charles University in Prague, Center of Oncocytogenetics- Institute of Medical Biochemistry and Laboratory Diagnostics, Prague 2, Czech Republic; 2 Cytogenetic Department, Institute of Hematology and Blood Transfusion, Prague 2, Czech Republic; 3Department of Genomics, Institute of Hematology and Blood Transfusion, Prague 2, Czech Republic; 4General University Hospital and First Faculty of MedicineCharles University in Prague, 1st Medical Department, Prague 2, Czech Republic; 5Clinical Department, Institute of Hematology and Blood Transfusion, Prague 2, Czech Republic
Background: MDS is characterized by ineffective hematopoiesis and peripheral blood cytopenias including anemia which may lead to red blood cell (RBC) transfusion dependence (TD). In paroxysmal nocturnal hemoglobinuria (PNH), complement-mediated lysis occurs. PNH clones are detected in up to 50% of MDS pts might confound the reason for RBC TD. The first specific treatment for PNH was approved in Canada in 2009. Eculizumab reduces hemolysis and RBC transfusion requirements (TR) and has other benefits. We wanted to determine whether PNH as a contributor to anemia is considered in MDS pts in the Eculizumab era. Methods: Pts with a bone marrow biopsy confirmed MDS diagnosis (dx) since 2009 were reviewed. Data extracted included baseline clinical and laboratory features, clinical course, treatment, outcome and indicators of hemolysis. High resolution PNH testing was done by flow cytometry for expression of FLAER, CD24, CD14, and CD59 on neutrophils, monocytes and RBC.
The interstitial deletion of the long arm of chromosome 5 – del (5q) – is the most common cytogenetic finding in patients with MDS (∼30% of abnormal karyotypes). According to IPSS-R, MDS with isolated del(5q) are associated with a favorable clinical course. However in some cases, acquisition of additional genetic aberrations may occur during the course of the disease. The aim of the study was: to evaluate the frequency of cytogenetic clonal evolution (CCE) in MDS patients with isolated del(5q); to analyze the pattern of acquired cytogenetic abnormalities; and to assess the impact of CCE on transformation to AML and/or overall survival. A detailed genome-wide analysis of fixed bone-marrow cells of 184 adults with del(5q), identified with G-banding at the diagnosis of MDS, was performed during the follow-up using FISH (Vysis DNA probes, Abbott), mFISH/mBAND (MetaSystems) and array CGH/SNP (CytoChip Cancer SNP 180K, BlueGnome or SurePrint G3 Cancer CGH+SNP 4 × 180K, Agilent). Amplicon deep sequencing of TP53 mutations (exons 4–11) was performed on a 454 GS Junior system (Roche). CCE was observed in 25/184 patients with isolated del(5q). The clinical progression occurred in 24 of them. One woman lives 56 months after CCE with no signs of disease progression. CCE was detected between 2 and 145 months after first cytogenetic evaluation (median 26 months). Median survival from the first emergence of CCE was 11 months (range 1–56 months; 22 patients died, 3 patients live). In 20/25 cases (80%), clones with del(5q)