IDH1 and IDH2 mutations confer an adverse effect in patients with acute myeloid leukemia lacking the NPM1 mutation

We examined the incidence and prognostic effect of IDH1 and IDH2 mutations in 233 Japanese adults with acute myeloid leukemia (AML). IDH1 R132 mutations were detected in 20 (8.6%) patients with AML. IDH2 mutations were found in 19 (8.2%, 17 R140 and two R172) patients. IDH1 and IDH2 mutations were mutually exclusive and were associated with normal karyotype AML, cytogenetic intermediate‐risk group, and NPM1 mutations. Five‐year overall survival (OS) rates were significantly lower (15.6%) in patients harboring the IDH mutations than in patients lacking the IDH mutation (32.0%) in the entire cohort of AML (P = 0.005). Among patients aged 59 yr or younger with IDH mutations, 5‐yr OS in patients who underwent allogeneic stem cell transplantation (SCT) was significantly higher than that in those not receiving allogeneic SCT (50% vs. 10.6%, P = 0.020). Of 51 patients with NPM1 mutations, there was no significant difference in 5‐yr OS rates between patients with and those without the IDH mutations. In contrast, among 175 patients lacking the NPM1 mutations, 5‐yr OS rate in patients with IDH mutations was significantly lower than that in those without IDH mutations (0% vs. 34.7%, P = <0.001). These data suggest that IDH mutations have an unfavorable effect in AML, especially AML with the NPM1 wild type and younger AML patients with IDH mutations may benefit from allogeneic SCT.     

Presence of isocitrate dehydrogenase mutations may predict clinical response to hypomethylating agents in patients with acute myeloid leukemia

Mutations in IDH1 and IDH2 occur in 15–20% of AML cases, resulting in the production of 2‐hydroxyglutarate, which promotes aberrant hypermethylation of DNA in leukemic cells. Although these mutations have been shown to have prognostic implications for patients with AML, optimal treatment strategies have yet to be defined. We retrospectively identified forty‐two patients with AML treated with DNA methyltransferase inhibitors (DNMTIs) decitabine (n = 36) or azacitidine (n = 6) and performed analysis of stored samples for the presence of IDH1 and IDH2 mutations. Of the forty‐two samples analyzed, seven (16.7%) had IDH mutations. Thirteen patients (31%) achieved remission [(complete remission (CR)/complete remission with incomplete count recovery (CRi)/partial response (PR)] after treatment with a DNMTI, five of seven (71.4%) with IDH mutations and eight of thirty‐five (22.9%) without IDH mutations (P = 0.01). When adjusted for age at diagnosis, sex, bone marrow blast percentage and cytogenetic, the odds of achieving response after administration of a DNMTI among patients with an IDH mutation was 14.2 when compared to patients without an IDH mutation (95%CI: 1.3–150.4). IDH1 and IDH2 mutations may predict a favorable response to DNMTI in patients with AML. Am. J. Hematol. 90:E77–E79, 2015. © 2015 Wiley Periodicals, Inc.     

The Synonymous Isocitrate Dehydrogenase 1 315C&gt;T SNP Confers an Adverse Prognosis in Egyptian Adult Patients with NPM1-/CEBPA-Negative Acute Myeloid Leukemia

Although the clinical features of isocitrate dehydrogenase (IDH) genetic aberrations have been well-characterized in acute myeloid leukemia (AML), definitive information on their prognostic significance is lacking. We aimed to explore the prognostic significance of IDH gene alterations in an Egyptian cohort of adult patients with de novo AML. Diagnostic peripheral blood samples from 51 AML patients were analyzed for the presence of mutations/SNPs in exon 4 of IDH1 and IDH2 genes using polymerase chain reaction amplification followed by direct sequencing. IDH mutational status had no impact on event-free survival (EFS) and overall survival (OS), whereas the presence of IDH1 315C>T SNP was significantly associated with inferior EFS (P = 0.037) and OS (P = 0.034) as compared with wild-type IDH1. IDH1 315C>T SNP but not IDH mutations is associated with unfavorable outcomes, suggesting that AML patients with IDH1 315C>T SNP can represent a new subgroup of patients which allows refined risk stratification.     

Comparison of high‐resolution melting analysis with direct sequencing for the detection of recurrent mutations in DNA methyltransferase 3A and isocitrate dehydrogenase 1 and 2 genes in acute myeloid leukemia patients

Acute myeloid leukemia (AML) cells harbor frequent mutations in genes responsible for epigenetic modifications. Increasing evidence of clinical role of DNMT3A and IDH1/2 mutations highlights the need for a robust and inexpensive test to identify these mutations in routine diagnostic work‐up. Herein, we compared routinely used direct sequencing method with high‐resolution melting (HRM) assay for screening DNMT3A and IDH1/2 mutations in patients with AML. We show very high concordance between HRM and Sanger sequencing (100% samples for IDH2‐R140 and DNMT3‐R882 mutations, 99% samples for IDH1‐R132 and IDH2‐R172 mutations). HRM method reported no false‐negative results, suggesting that it can be used for mutations screening. Moreover, HRM displayed much higher sensitivity in comparison with DNA sequencing in all assessed loci. With Sanger sequencing, robust calls were observed when the sample contained 50% of mutant DNA in the background of wild‐type DNA. In marked contrast, the detection limit of HRM improved down to 10% of mutated DNA. Given the ubiquitous presence of wild‐type DNA background in bone marrow aspirates and clonal variations regarding mutant allele burden, these results favor HRM as a sensitive, specific, labor‐, and cost‐effective tool for screening and detection of mutations in IDH1/2 and DNMT3A genes in patients with AML.     

Rapid detection of IDH2 (R140Q and R172K) mutations in acute myeloid leukemia

NADP-dependent enzyme isocitrate dehydrogenase (IDH) mutations, IDH1 and IDH2, have been described in acute myeloid leukemia (AML) using next generation sequencing approaches. IDH2 mutations are heterozygous; they alter a single arginine residue at position 140 or 172 and have distinct prognostic significance. The current detection methods of IDH2 mutations are laborious and time consuming as they require DNA sequencing. Herein, we report a new allele-specific oligonucleotide–polymerase chain reaction (ASO-PCR) method to detect the IDH2 mutations. Analysis of leukemic DNA samples from 120 AML patients enabled to identify IDH2 mutations in 22 cases which were confirmed by direct DNA sequencing. Of these, 17 harbored IDH2 (R140Q) and 5 IDH2 (R172K) mutations. Serial dilution experiments showed that the assay enable to detect mutations in 10^?3 dilutions. Our ASO-PCR method appears useful for routine diagnostic screening of these prognostically relevant alterations in AML and may be conveniently included in the diagnostic workup.     

Isocitrate Dehydrogenase (IDH)1/2 Mutations as Prognostic Markers in Patients With Glioblastomas

The purpose of this study was to perform a meta-analysis examining the association of isocitrate dehydrogenase (IDH)1/2 mutations with overall survival (OS) and progression-free survival (PFS) in patients with glioblastomas.Medline, Cochrane, EMBASE, and Google Scholar were searched from inception to January 28, 2015, using combinations of the following keywords: IDH mutation, brain tumor, glioma, glioblastoma, oligodendroglioma, prognosis. Randomized controlled trials, and prospective and retrospective studies of patients with glioblastomas that provided IDH mutation and survival data were included. OS and PFS were used to evaluate the association of IDH1 and IDH1/2 mutations and prognosis. Hazard ratios (HRs) with corresponding 95% confidence intervals (CIs) for OS and PFS were calculated and compared between patients with and without mutations.Of 165 studies that were identified, 136 nonrelevant studies were excluded. Twenty-nine full-text articles were assessed, and of these, 5 were excluded as they did not provide a quantitative outcome. Therefore, 24 studies were included in the qualitative synthesis. The pooled HR of 0.358 (95% CI 0.264–0.487, P < 0.001) indicated that IDH mutations were associated with better OS. Similarly, the pooled HR of 0.322 (95% CI 0.24200.455, P < 0.001) indicated that IDH mutations were associated with better PFS. When patients were stratified by surgery versus no surgery or IDH1 versus IDH1/2 mutations, the results also indicated that the presence of IDH mutations was associated with better OS and PFS.The IDH mutations are associated with improved survival in patients with glioblastomas.     

IDH mutations are closely associated with mutations of DNMT3A,ASXL1 and SRSF2 in patients with myelodysplastic syndromes and are stable during disease evolution

Current information about clinical significance of IDH mutations in myelodysplastic syndromes (MDS), their association with other genetic alterations and the stability during disease progression is limited. In this study, IDH mutations were identified in 4.6% of 477 patients with MDS based on the FAB classification and in 2.2 % of 368 patients based on the 2008 WHO classification. IDH mutations were closely associated with older age, higher platelet counts, and mutations of DNMT3A (36.4% vs. 8.7%, P < 0.001), ASXL1 (47.6% vs. 22.0%, P = 0.007), and SRSF2 (45.5% vs. 11.8%, P < 0.001). IDH2 mutation was a poor prognostic factor for overall survival in patients with lower‐risk MDS, based on international prognosis scoring system (IPSS), FAB classification, WHO classification, or revised IPSS (all P ≦ 0.001), but not in higher‐risk groups. Sequential studies in 151 patients demonstrated that all IDH‐mutated patients retained the same mutation during disease evolution while none of the IDH‐wild patients acquired a novel mutation during follow‐ups. In conclusion, IDH mutation is a useful biomarker for risk stratification of patients with lower‐risk MDS. IDH mutations are stable during the clinical course. The mutation, in association with other genetic alterations, may play a role in the development, but not progression of MDS.Am. J. Hematol. 89:137–144, 2014. © 2013 Wiley Periodicals, Inc.     

Allogeneic hematopoietic stem cell transplantation could improve survival of cytogenetically normal adult acute myeloid leukemia patients with DNMT3A mutations

DNMT3A mutations are frequent in cytogenetically normal acute myeloid leukemia (cn‐AML) patients and associated with poor survival. The role of allogeneic hematopoietic stem cell transplantation (allo‐HSCT) in DNMT3A^mut cn‐AML patients remains unclear. In this study, we retrospectively analyzed the prognostic impact of DNMT3A mutations and explored the role of allo‐HSCT in 308 cn‐AML patients who received consolidation of intensive chemotherapy or allo‐HSCT in our center from March 2005 to May 2014. In the whole cohort, 63 patients (20.5%) were identified with DNMT3A exon 23 mutations and R882H was the most frequent variant. DNMT3A^mut patients had shorter overall survival (3‐year OS: 31.9% vs. 52.0%, P = 0.009) and disease‐free survival (3‐year DFS: 21.8% vs. 40.1%, P = 0.004) compared with DNMT3A^wt patients. Based on FLT3/NPM1/CEBPA mutations, 308 cn‐AML patients were divided into favorable/intermediate group (n = 262) and unfavorable group (n = 46). There were no significant differences in 3‐year OS and 3‐year DFS between DNMT3A^mut and DNMT3A^wt patients in both favorable/intermediate and unfavorable groups. Additionally, in multivariate analysis, DNMT3A mutation remained an independent adverse prognostic factor for the survival. In the DNMT3A^mut cohort, 23 complete remission (CR) patients received allo‐HSCT consolidation and 32 CR patients received chemotherapy consolidation, dramatic differences were observed in 3‐year OS (51.7% vs. 28.9%, P = 0.048) and 3‐year DFS (41.6% vs. 14.9%, P = 0.024) between allo‐HSCT group and chemotherapy group. Collectively, DNMT3A mutation is a poor prognostic factor for cn‐AML patients and allo‐HSCT could improve survival of cn‐AML patients with DNMT3A mutations. Am. J. Hematol. 90:992–997, 2015. © 2015 Wiley Periodicals, Inc.     

A distinct immunophenotype identifies a subset of NPM1‐mutated AML with TET2 or IDH1/2 mutations and improved outcome

Recent work has identified distinct molecular subgroups of acute myeloid leukemia (AML) with implications for disease classification and prognosis. NPM1 is one of the most common recurrently mutated genes in AML. NPM1 mutations often co‐occur with FLT3‐ITDs and mutations in genes regulating DNA methylation, such as DNMT3A, TET2, and IDH1/2. It remains unclear whether these genetic alterations are associated with distinct immunophenotypic findings or affect prognosis. We identified 133 cases of NPM1‐mutated AML and correlated sequencing data with immunophenotypic and clinical findings. Of 84 cases (63%) that lacked monocytic differentiation (“myeloid AML”), 40 (48%) demonstrated an acute promyelocytic leukemia‐like (APL‐like) immunophenotype by flow cytometry, with absence of CD34 and HLA‐DR and strong myeloperoxidase expression, in the absence of a PML‐RARA translocation. Pathologic variants in TET2, IDH1, or IDH2 were identified in 39/40 APL‐like cases. This subset of NPM1‐mutated AML was associated with longer relapse‐free and overall survival, when compared with cases that were positive for CD34 and/or HLA‐DR. The combination of NPM1 and TET2 or IDH1/2 mutations along with an APL‐like immunophenotype identifies a distinct subtype of AML. Further studies addressing its biology and clinical significance may be especially relevant in the era of IDH inhibitors and recent work showing efficacy of ATRA therapy in NPM1 and IDH1‐mutated AML.     

Fludarabine and cytarabine versus high‐dose cytarabine in consolidation treatment of t(8; 21) acute myeloid leukemia: A prospective,randomized study

Acute myeloid leukemia (AML) patients with t(8;21) aberration often have favorable outcomes, however, relapse still occurs in 30–40% patients, with only 50–60% of patients with t(8;21) AML cured with regimens containing high‐dose cytarabine (HD‐Ara‐C). To evaluate the effects of fludarabine and cytarabine (FA) consolidation therapy for t(8;21) AML patients, a prospective randomized study was performed. A total of 45 patients with t(8;21) AML after achieving complete remission (CR) were randomly assigned to receive four course consolidation with FA (n = 23) or HD‐Ara‐C (n = 22). Our study showed that at 36‐months, relapse‐free survival (RFS) was 81.73% in the FA arm and 50.73% in the HD‐Ara‐C arm (P = 0.04), overall survival (OS) was 91.1% and 48.4% (P = 0.01) in the FA arm and in the HD‐Ara‐C arm respectively; whereas cumulative incidence of relapse (CIR) was 18.27% and 47.39%, in the FA arm and in the HD‐Ara‐C arm respectively (P = 0.05). In our study, treatment with FA, MRD2 status (reduction ≥ 3‐log) and absence of c‐kit mutations were identified as independent prognostic factors for lower risk of relapse, improved RFS and OS. We also found RFS for patients without c‐kit mutations was 100% in FA arm, and 57.8% in HD‐Ara‐C arm at 36 months (P = 0.005); OS of both groups at 36 months was 100% and 51.4%, respectively (P = 0.004), suggesting a benefit of consolidation therapy with FA for t(8;21) AML patients, especially, those without c‐kit mutations (Clinicaltrials.org ID NCT# 02024308). Am. J. Hematol. 92:12–17, 2017. © 2016 Wiley Periodicals, Inc.     

Gene mutation patterns and their prognostic impact in a cohort of 1185 patients with acute myeloid leukemia

To evaluate the prognostic value of genetic mutations for acute myeloid leukemia (AML) patients, we examined the gene status for both fusion products such as AML1 (CBFα)-ETO, CBFβ-MYH11, PML-RARα, and MLL rearrangement as a result of chromosomal translocations and mutations in genes including FLT3, C-KIT, N-RAS, NPM1, CEBPA, WT1, ASXL1, DNMT3A, MLL, IDH1, IDH2, and TET2 in 1185 AML patients. Clinical analysis was mainly carried out among 605 cases without recognizable karyotype abnormalities except for 11q23. Of these 605 patients, 452 (74.7%) were found to have at least 1 mutation, and the relationship of gene mutations with clinical outcome was investigated. We revealed a correlation pattern among NPM1, DNMT3A, FLT3, IDH1, IDH2, CEBPA, and TET2 mutations. Multivariate analysis identified DNMT3A and MLL mutations as independent factors predicting inferior overall survival (OS) and event-free survival (EFS), whereas biallelic CEBPA mutations or NPM1 mutations without DNMT3A mutations conferred a better OS and EFS in both the whole group and among younger patients < 60 years of age. The use of molecular markers allowed us to subdivide the series of 605 patients into distinct prognostic groups with potential clinical relevance.     

Prognostic Impact of NPM1 Mutations in Serbian Adult Patients with Acute Myeloid Leukemia

Based on current findings, the presence of NPM1 mutations in acute myeloid leukemia (AML) patients is associated with an increased probability of complete remission (CR) and better overall survival (OS). We determined the incidence and prognostic relevance of NPM1 mutations, their association with FLT3 and IDH mutations, and other clinical characteristics in Serbian adult AML patients. Samples from 111 adult de novo AML patients, including 73 AML cases with a normal karyotype (NK-AML), were studied. NPM1, FLT3, and IDH mutations were detected by PCR and direct sequencing. NPM1 mutations were detected in 22.5% of patients. The presence of NPM1 mutations predicted a low CR rate and shorter OS. NPM1 mutations showed an association with both FLT3 and IDH mutations. Survival analysis based on NPM1/FLT3 mutational status revealed a lower OS for NPM1(+)/FLT3(-) compared to the NPM1(-)/FLT3(-) group in NK-AML patients. The lack of impact or unfavorable prognostic effect of NPM1 mutations found in this study can be assigned to a small cohort of analyzed AML patients, as can the presence of FLT3 and IDH mutations or other genetic lesions that cooperate with NPM1 mutations influencing prognosis.     

Clonal leukemic evolution in myelodysplastic syndromes with TET2 and IDH1/2 mutations

Somatic mutations of TET2, IDH1, and IDH2 have been described in myelodysplastic syndrome. The impact of these mutations on outcome of myelodysplastic syndrome and their progression to secondary acute myeloid leukemia remains unclear. Mutation status of TET2, IDH1 and IDH2 was investigated in a cohort of 46 paired myelodysplastic syndrome/acute myeloid leukemia samples and 122 non-paired cases with de novo myelodysplastic syndrome, to clarify their roles in the evolution of myelodysplastic syndrome to acute myeloid leukemia. Among the 168 de novo myelodysplastic syndrome patients, the frequency of TET2, IDH1, and IDH2 mutations was 18.5%, 4.2% and 6.0%, respectively. TET2/IDH mutations had no impact on survivals, while TET2 mutations were significantly associated with rapid progression to acute myeloid leukemia. Seventeen of the 46 paired myelodysplastic syndrome/secondary acute myeloid leukemia samples harbored TET2/IDH mutations; none acquired these mutations in acute myeloid leukemia phase. Progression to acute myeloid leukemia was accompanied by evolution of a novel clone or expansion of a minor pre-existing subclone of one or more distinct mutations in 12 of the 17 cases with TET2/IDH mutations. A minor subclone in 3 cases with biallelic TET2 inactivation subsequently expanded, indicating biallelic TET2 mutations play a role in acute myeloid leukemia progression. Twelve patients acquired other genetic lesions, and/or showed increased relative mutant allelic burden of FLT3-ITD, N/K-RAS, CEBPA or RUNX1 during acute myeloid leukemia progression. Our findings provide a novel insight into the role of TET2/IDH mutation in the pathogenesis of myelodysplastic syndrome and subsequent progression to acute myeloid leukemia.     

TET2, ASXL1, IDH1, IDH2, and c-CBL genes in JAK2- and MPL-negative myeloproliferative neoplasms

Mutations in the TET2 and ASXL1 genes have been described in approximately 14% and 8% of patients, respectively, with classic myeloproliferative neoplasms (MPN), but their role as possible new diagnostic molecular markers is still inconclusive. In addition, other genes such as IDH1, IDH2, and c-CBL have also been reported in several myeloid neoplasms. We have studied the mutational status of TET2 (complete coding region), ASXL1 (exon12), IDH1 (R132), IDH2 (R140 and R172), and c-CBL (exons 8 and 9) in 62 MPN patients (52 essential thrombocythemia (ET), five polycythemia vera (PV), and five primary myelofibrosis (PMF)) negative for both JAK2 (V617F and exon 12) and MPL (exon 10) mutations. Pathogenic alterations in the TET2 gene were detected in three out 52 ET cases (4.8%). ASXL1 gene pathogenic mutations were also detected in three cases (two ET and one PMF). One ET patient harbored, simultaneously, one TET2 and one ASXL1 mutations. Mutations in the TET2 and ASXL1 genes showed no association with the JAK2 46/1 haplotype. Analysis of a JAK2V617F-positive cohort of 50 ET patients showed no mutations in either the TET2 or ASXL1 genes. Regarding IDH1, IDH2, and c-CBL genes, no mutations were found in any patient. In conclusion, TET2 and ASXL1 pathogenic mutations are found in 8% of MPN lacking JAK2 and MPL mutations, whereas IDH1, IDH2, and c-CBL mutations are not detected in this subset of patients.     

Monosomal karyotype improves IPSS‐R stratification in MDS and AML patients treated with Azacitidine

IPSS‐R classifies cytogenetic abnormalities into five prognostic groups for survival. Monosomal karyotype (MK) is not a subgroup of IPSS‐R. Additional prognostic information from MK in poor and very poor karyotype has been recently shown. The aim of our study was to determine the prognostic value of IPSS‐R and MK for response and survival in AZA‐treated high‐risk MDS and AML with 20–30% of blasts patients. The study population included 154 patients who were classified according to IPSS‐R. IPSS‐R was not predictive of response (intermediate, 64%; poor, 44%; very poor, 56%; P = 0.28) or survival (intermediate, 25 months; poor, 12 months; very poor, 11 months; P = 0.14). Twenty‐one patients (15%) presented with MK and had a median OS of 9 months. Patients with a very high IPSS‐R score without MK had a median OS of 15 months, while patients with a high IPSS‐R score without MK had a median OS of 13 months (P = 0.18). We reclassified patients into the following three groups to include MK status: very high (MK only; OS median: 9 months), high (very high IPSS‐R without MK and high IPSS‐R without MK; OS median: 14 months) and intermediate (OS median: 25 months). As in recent publication including MK prognostic, we confirmed that this classification was predictive for survival in AZA treated patients (P = 0.008). IPSS‐R failed to discriminate between the prognostic subgroups. Stratification with MK has value in the prognosis of our cohort of AZA‐treated patients. Am. J. Hematol. 88:780–783, 2013. © 2013 Wiley Periodicals, Inc.     

IDH1 and IDH2 mutation analysis in Chinese patients with acute myeloid leukemia and myelodysplastic syndrome

The somatic mutations of isocitrate dehydrogenase genes (IDH1 and IDH2) have been identified in a proportion of hematologic malignancies. We examined IDH1 R132 and IDH2 R140/R172 mutations by high resolution melting analysis and direct sequencing in Chinese patients with different myeloid malignancies including 198 acute myeloid leukemia (AML), 82 myelodysplastic syndrome (MDS), 85 chronic myeloid leukemia, and 57 myeloproliferative neoplasms. IDH1 and IDH2 mutations were found in four (2.0%) and ten (5.0%) AML and in two (2.4%) and three (3.6%) MDS cases, but not in other patients. IDH1 and IDH2 mutations were heterozygous and mutually exclusive. IDH1/2 mutations were significantly more frequently observed in cytogenetically normal AML or MDS compared to those without mutations. There was no difference in overall survival of both AML and MDS patients with or without IDH1/2 mutations (P = 0.177 and 0.407, respectively). In conclusion, IDH1/2 mutations are recurrent but rare molecular aberrations in Chinese AML and MDS.     

IDH2 mutations are frequent in Chinese patients with acute myeloid leukemia and associated with NPM1 mutations and FAB-M2 subtype

Introduction: Gene mutations play an important role in acute myeloid leukemia (AML) pathogenesis. Several genes have been identified in AML, such as FLT3, KIT, NPM1, and JAK2. This study investigated the frequency of novel mutations in IDH1 (amino acid R132) and IDH2 (R140 and R172) and analyzed their impact on disease biology and interaction with other mutations in Chinese patients with de novo AML. Methods: A total of 195 patients were screened for mutations in the IDH1, IDH2, JAK2 V617F, NPM1, FLT3, and KIT genes, using polymerase chain reaction (PCR)-based and direct sequencing assays. Results: IDH mutations occurred at a considerable frequency of 15.89% in Chinese AML cases; IDH2 R140Q was the most frequent genetic alteration and was associated with older age, normal karyotype, and French-American-British classification M2 at diagnosis. There was a strong association of IDH2 mutation with NPM1 mutations and a trend with FLT3-internal-tandem duplication. Conclusion: IDH mutations may be a novel genetic marker in cytogenetically normal AML and may cooperate in leukemogenesis.