Predicting survival in patients with myelodysplastic/myeloproliferative neoplasms with SF3B1 mutation and thrombocytosis.

We investigated data from 180 consecutive patients with myelodysplastic/myeloproliferative neoplasms with SF3B1 mutation and thrombocytosis (MDS/MPN-SF3B1-T) who were diagnosed according to the 2022 World Health Organization (WHO) classification of myeloid neoplasms to identify covariates associated with survival. At a median follow-up of 48 months (95% confidence interval [CI] 35-61 months), the median survival was 69 months (95% CI 59-79 months). Patients with bone marrow ring sideroblasts (RS) < 15% had shorter median overall survival (OS) than did those with bone marrow RS ≥ 15% (41 months [95% CI 32-50 months] versus 76 months [95% CI 59-93 months]; P < 0.001). According to the univariable analyses of OS, age ≥ 65 years (P < 0.001), hemoglobin concentration (Hb) < 80 g/L (P = 0.090), platelet count (PLT) ≥ 800 × 10E + 9/L (P = 0.087), bone marrow RS < 15% (P < 0.001), the Revised International Prognostic Scoring System (IPSS-R) cytogenetic category intermediate/poor/very poor (P = 0.005), SETBP1 mutation (P = 0.061) and SRSF2 mutation (P < 0.001) were associated with poor survival. Based on variables selected from univariable analyses, two separate survival prediction models, a clinical survival model, and a clinical-molecular survival model, were developed using multivariable analyses with the minimum value of the Akaike information criterion (AIC) to specifically predict outcomes in patients with MDS/MPN-SF3B1-T according to the 2022 WHO classification.

Multiplex ligation-dependent probe amplification and fluorescence in situ hybridization for detecting chromosome abnormalities in myelodysplastic syndromes: A retrospective study.

ABSTRACT: This study aimed to compare interphase fluorescence in situ hybridization (iFISH) and multiplex ligation dependent probe amplification (MLPA) for identifying genetic changes in myelodysplastic syndromes (MDS).The frequencies of cytogenetic changes in MDS patients treated at the Institute of Hematology and Blood Disease Hospital (China) in 2009 to 2018 were assessed by iFISH based on bone marrow samples. Then, the effectiveness of MLPA in detecting these anomalies was evaluated.Specimens from 287 MDS patients were assessed. A total of 36.9% (103/279) of MDS cases had chromosomal abnormalities detected by iFISH; meanwhile, 44.1% (123/279) harbored ≥1 copy-number variation (CNV) based on MLPA: +8 (n=46), -5 (n = 39), -7 (n = 27), del 20 (n = 32) and del 17 (n = 17). Overall, 0 to 4 aberrations/case were detected by MLPA, suggesting the heterogeneous and complex nature of MDS cytogenetics. There were 29 cases detected by MLPA, which were undetected by FISH or showed low signals. Sixteen of these cases had their risk classification changed due to MLPA detection, including 9 reassigned to the high-risk IPSS-R group. These findings demonstrated that MLPA is highly efficient in assessing cytogenetic anomalies, with data remarkably corroborating FISH findings (overall consistency of 97.1%). The sensitivities of MLPA in detecting +8, -5, -7, del 20 and del 17 were 92.3%, 97.1%, 100%, 100%, and 90%, respectively, with specificities of 95.8%, 97.6%, 97.7%, 97.6%, and 97%, respectively.MLPA represents a reliable approach, with greater efficiency, accuracy, and speed than iFISH in identifying cytogenetic aberrations in MDS.

Multiplex ligation-dependent probe amplification identifies copy number changes in normal and undetectable karyotype MDS patients.

Chromosomal abnormalities play an important role in classification and prognostication of myelodysplastic syndrome (MDS) patients. However, more than 50% of low-risk MDS patients harbor a normal karyotype. Recently, multiplex ligation-dependent probe amplification (MLPA) has emerged as an effective and robust method for the detection of cytogenetic aberrations in MDS patients. To characterize the subset of MDS with normal karyotype or failed chromosome banding analysis, we analyzed 144 patient samples with normal karyotype or undetectable through regular chromosome banding analysis, which were subjected to parallel comparison via fluorescence in situ hybridization (FISH) and MLPA. MLPA identifies copy number changes in 16.7% of 144 MDS patients, and we observed a significant difference in overall survival (OS) (median OS: undefined vs 27 months, p=0.0071) in patients with normal karyotype proved by MLPA versus aberrant karyotype cohort as determined by MLPA. Interestingly, patients with undetectable karyotype via regular chromosome banding indicated inferior outcome. Collectively, MDS patients with normal or undetectable karyotype via chromosome banding analysis can be further clarified by MLPA, providing more prognostic information that benefit for individualized therapy.

A new HLA-DQB1 allele, HLA-DQB1*04:62, identified in a Chinese family.

HLA-DQB1*04:62 differs from HLA-DQB1*04:01:01:01 by a single nucleotide in exon 3 (433A->G, N113D).

[The Correlation of Minimal Residual Disease with Prognosis in TCF3-PBX1+ Acute Lymphoblastic Leukemia in Children].

OBJECTIVE: To investigate the consistency between FCM and PCR on the detecting of MRD in TCF3-PBX1+ ALL, and to investigate the prognosis value of these 2 methods. METHODS: 55 cases of paediatric TCF3-PBX1+ ALL patients from April 2008 to April 2015 were enrolled and analyzed. The FCM and PCR was used to detect the MRD in 239 bone marrow samples of 55 patients. All statistical analyses were carried out by using SPSS software version 16. RESULTS: Among the 55 children with TCF3-PBX1+ ALL, there were 30 male and 25 female. The median age was 5 (1-14) years. 20 patients relapsed during follow-up. The MRD results from PCR and FCM showed a strong correlation between both methods (K=0.774, P<0.001). There was no significant difference in 5-years DFS and OS between the patients in PCR+ and PCR- groups on day 15 or day 33. The 5 year DFS rate between the patients in FCM- and FCM+ was 63.9%±7.0% and 0; the 5 year OS rate was 66.5%±7.9% and 0. Combined with the result of FCM and PCR, at the d 33 of treatment, the 5-year DFS rate in FCM-/PCR- and single positive group was 65.4%±7.2% and 25.0%±15.3% (P<0.01). CONCLUSION: The detection result of MRD in TCF3-PBX1 detect by FCM and PCR shows better consistency. MRD positivity detected by FCM at the end of induction therapy (day 33) predicts a high risk of relapse in TCF3-PBX1 ALL patients.

A new HLA-C allele, HLA-C*15:144, identified in a Chinese family.

HLA-C*15:144 differs from HLA-C*15:07 (343G->A, G91R).

[Diagnostic Significance of BIOMED-2 Standardized Gene Rearran-gement System in Patients with Non-Hodgkin's Lymphoma].

OBJECTIVE: To detect the immunoglobulin(Ig) and T cell receptor(TCR) gene rearrangement in bone marrow of non-Hodgkin's lymphoma(NHL) patients by using BIOMED-2 standardized system, and to explore the potential clinical significance of Ig/TCR gene rearrangement. METHODS: DNA was extracted in bone marrow and Formalin-fixed and Paraffin-embedded(FFPE) samples of NHL patients, the Ig/TCR gene rearrangements were analyzed by using BIOMED-2 multiple primers system and multiplex PCR assay. RESULTS: Among 235 T-NHL cases, 71.9% showed TCR gene rearrangement. The positive rate of TCRγ and the TCRß were 57.9% and 50.2%. Out of 583 B-NHL cases, 81.6% showed Ig gene rearrangement. The positive rate of IgH and the IgK were 70.7% and 69.3%. MCL patients showed 84.8% IgH rearrangement and 75.8% IgK rearrangement, as compared with FL(34.0%, 50.9%) and DLBCL(9.2%, 16.1%) patients, the difference was statistically significant (P<0.05). Out of Ig rearrangement positive B-NHL cases, 65 showed TCR gene rearrangement. None TCR rearrangement positive T-NHL cases showed Ig gene rearrangement, 25 cases(83.3%) showed Ig gene rearrangement in FFPE samples of 30 DLBCL patients, as compared to Ig rearrangement positive rate of bone marrow, the difference was statistically significant (P<0.001). CONCLUSION: BIOMED-2 standardized Ig/TCR gene rearrangement system shows assistance for lymphoma diagnosis. The PCR sequencing analysis is much more sensitive and specific and has significance for clinical diagnosis.

Multiplex ligation-dependent probe amplification assay identifies additional copy number changes compared with R-band karyotype and provide more accuracy prognostic information in myelodysplastic syndromes.

Cytogenetic analysis provides important diagnostic and prognostic information for patients with Myelodysplastic syndromes (MDS) and plays an essential role in the International Prognostic Scoring System (IPSS) and the revised International Prognostic Scoring System (IPSS-R). Multiplex ligation-dependent probe amplification (MLPA) assay is a recently developed technique to identify targeted cytogenetic aberrations in MDS patients. In the present study, we evaluated the results obtained using an MLPA assay in 437 patients with MDS to determine the efficacy of MLPA analysis. Using R-banding karyotyping, 45% (197/437) of MDS patients had chromosomal abnormalities, whereas MLPA analysis detected that 35% (153/437) of MDS cases contained at least one copy-number variations (CNVs) .2/5 individuals (40%) with R-band karyotype failures had trisomy 8 detected using only MLPA. Clonal cytogenetic abnormalities were detected in 20/235 (8.5%) MDS patients with a normal R-band karyotype, and 12/20 (60%) of those patients were reclassified into a higher-risk IPSS-R prognostic category. When sequencing and cytogenetics were combined, the fraction of patients with MDS-related oncogenic lesions increased to 87.3% (233/267 cases). MLPA analysis determined that the median OS of patients with a normal karyotype (n=218) was 65 months compared with 27 months in cases with an aberrant karyotype (P=0.002) in 240 patients with normal or failed karyotypes by R-banding karyotyping. The high-resolution MPLA assay is an efficient and reliable method that can be used in conjunction with R-band karyotyping to detect chromosomal abnormalities in patients with suspected MDS. MLPA may also provide more accurate prognostic information.

[Application of Combined Detection of Fusion Gene and BIOMED-2 Standardized Ig Gene Rearrangement System in Childhood B-cell Acute Lymphoblastic Leukemia].

OBJECTIVE: To explore the application of combined detection of fusion gene and BIOMED-2 standardized immunoglobulin (Ig) gene rearrangement system in diagnosis and treatment of children with acute lymphoblastic leukemia (ALL). METHODS: Multiplex-PCR amplifications and RQ-PCR of RNA/DNA were performed using ALL fusion gene detection kit and BIOMED-2 primer. The Ig gene rearrangements were analyzed by using PCR fragment analysis system. RESULTS: Out of 251 children with B-ALL, 77 cases were TEL-AML1(+) , 28 cases were E2A-PBX1(+) , 10 cases were MLL-AF4(+) , 11 cases were BCR-ABL(+) , the total positive rate was 50.2%, 82.5% showed IgH VH-JH rearrangement, 53.4% showed IgK rearrangement. The positive rate of combined detection of fusion gene and gene rearrangement was 99%. E2A-PBX1(+) and MLL-AF4(+) with IgK(+) gene rearrangement group was compared with negative control group, the difference was statistically significant (P < 0.001 or P = 0.005); 105 ALL fusion gene positive cases had been detected by fluorescence in situ hybridization (FISH) simultaneously, the accordance rate of fusion gene and FISH was more than 94%. CONCLUSION: The combined detection of ALL fusion gene and BIOMED-2 standardized clonality analysis system can improve the positive detected rate of B-ALL dramatically, and make the grouping of disease prognosis more accurately; this combined detection is a more faster and sensitive method than FISH.

Long-term outcomes of imatinib in patients with FIP1L1/ PDGFRA associated chronic eosinophilic leukemia: experience of a single center in China.

BACKGROUND: The FIP1L1/PDGFRA (F/P) fusion gene is the most common clonal genetic abnormality of chronic eosinophilic leukemia (CEL). Tyrosine kinase inhibitors (TKI), such as imatinib, have been demonstrated to be effective therapies for F/P mutated disease. The aim of this study was to analyze the treatment response and long term prognosis in patients with F/P mutated CEL. METHODS: The clinical features and treatment responses of 33 consecutive patients with F/P mutated CEL between August 2006 and October 2014 were analyzed. The 33 cases received imatinib therapy at an initial dose of 100 mg/day (30 patients) or 200 mg/day (3 patients); the maintenance dose depended on the response condition and patient willingness. Through the follow up, the molecular responses were regularly monitored. RESULTS: With a median follow up of 64 months, 94% of the 33 patients with F/P mutated CEL achieved a complete hematologic remission (CHR), and 97% achieved a complete molecular remission (CMR) after a median of 3 (1.5-12) months. Twenty-four cases received maintenance therapy, with a median CMR duration of 43 (5-88) months. Imatinib therapy was discontinued in 8 cases, including 4 cases who experienced relapse, and 4 patients who maintained CHR or CMR after discontinuing therapy with a median time of 47 (2-74) months. One case exhibited primary resistance with a PDGFRA T674I mutation. CONCLUSIONS: F/P mutated CEL has an excellent long-term prognosis following imatinib therapy. A 100 mg daily dose of imatinib is sufficient to induce remission, and a single 100 mg weekly dose maintains a durable remission. A subgroup of patients may maintain a durable remission after discontinuing therapy with a CMR.

[Application of BIOMED- 2 standardized Ig gene rearrangement system in multiple myeloma].

OBJECTIVE: To explore the application of BIOMED- 2 standardized immunoglobulin (Ig) gene rearrangement system in the diagnosis of multiple myeloma (MM), and the significance of clonality analysis by multiplex-PCR amplifications. METHODS: A total of 167 cases of MM bone marrow samples from 2009 to 2013, and 20 cases of reactive plasmacytosis used as the controls were included in this study. Multiplex-PCR amplifications were performed and the Ig gene rearrangements were analyzed using BIOMED-2 standardized clonality analysis system. RESULTS: ① Of 167 MM cases, 107 showed IgH VH-JH rearrangement, 33 showed IgH DH-JH rearrangement, and 30% showed IgH DH-JH rearrangement in 60 IgH VH-JH rearrangement negative MM cases. The difference was statistically significant between IgH VH-JH rearrangement positive and negative cases (14.0% vs 30.0%, P=0.032). The total positive rate of IgH VH-JH, IgH DH-JH and IgK was 94.6%. The 20 reactive plasmacytosis (RP) cases showed negative Ig gene rearrangement. 2 of 167 MM cases, 9 (5.4%) showed clonal IgH rearrangement by agarose electrophoresis were confirmed as polyclonality by capillary electrophoresis. ③ Of 53 MM cases who have been detected by Ig gene rearrangement system and fluorescence in situ hybridization (FISH) for IgH simultaneously, 36 showed IgH rearrangement, 26 showed FISH IgH positive, and the difference was statistically significant (67.9% vs 49.1%, P=0.049). CONCLUSION: Combined detection of IgH VH- JH, IgH DH- JH and IgK could improve the positive rate of MM clonality dramatically, and measurement of IgH DH-JH rearrangement was more important in the IgH VH- JH negative cases. Ig gene rearrangement system was a faster and more sensitive method than FISH IgH. Application of BIOMED- 2 standardized immunoglobulin (Ig) gene rearrangement system is of significance for MM diagnosis.

Detection of recurrent cytogenetic aberrations in multiple myeloma: a comparison between MLPA and iFISH.

Multiple myeloma (MM) is a genetically heterogeneous disease with diverse clinical characteristics and outcomes. Recently, multiplex ligation-dependent probe amplification (MLPA) has emerged as an effective and robust method for the detection of cytogenetic aberrations in MM patients. In the present study, MLPA analysis was applied to analyze cytogenetics of CD138 tumor cells of 59 MM samples, and its result was compared, retrospectively, with the interphase fluorescence in situ hybridization (iFISH) data. We firstly established the normal range of each of the 42 diagnostic probes using healthy donor samples. A total of 151 aberrations were detected in 59 patient samples, and 49/59 cases (83.1%) harbored at least one copy number variation. Overall, 0-7 aberrations were detected per case using MLPA, indicating the heterogeneity and complexity of MM cytogenetics. We showed the high efficiency of MLPA and the high congruency of the two methods to assess cytogenetic aberrations. Considering that MLPA analysis is not reliable when the aberration only exits in a small population of tumor cells, it is essential to use both MLPA and iFISH as complementary techniques for the diagnosis of MM.

The Prevalence of JAK2, MPL, and CALR Mutations in Chinese Patients With BCR-ABL1-Negative Myeloproliferative Neoplasms.

OBJECTIVES: To evaluate the mutation frequency of JAK2 V617F, JAK2 exon 12, MPL exon 10, and CALR exon 9 and the value of the combined tests in the diagnosis of BCR-ABL1-negative myeloproliferative neoplasms (MPNs). METHODS: In the current study, mutations of JAK2 V617F, JAK2 exon 12, MPL exon 10, and CALR exon 9 were analyzed in 929 Chinese patients with BCR-ABL1-negative MPN, including 234 cases of polycythemia vera (PV), 428 ETs, 187 PMFs, and 80 unclassifiable MPNs (MPN-Us). RESULTS: Our result showed that the positive rate of any of four mutations in patients with PV, ET, PMF, and MPN-U was 89.3%, 83.4%, 87.2%, and 77.5%, respectively, which significantly improved the diagnostic rate, especially in ET and PMF. Meanwhile, we also found that the patients without any of four mutations were younger than those with one or more mutations. Unexpectedly, the coexistence of JAK2 V617F and CALR exon 9 was identified in six (0.6%) patients, and JAK2 V617F and MPL exon 10 were present simultaneously in two (0.2%) patients. In addition, we also identified several novel mutation types in CALR exon 9. CONCLUSIONS: The combined genetic tests of JAK2 V617F, JAK2 exon 12, MPL exon 10, and CALR exon 9 help improve the diagnostic rate for BCR-ABL1-negative MPN.

[Significance of BIOMED-2 standardized IG/TCR gene rearrangement detection in paraffin-embedded section in lymphoma diagnosis].

OBJECTIVE: To explore the feasibility of detecting lymphoma with the application of BIOMED-2 standardized immunoglobulin/T cell receptor (IG/TCR) gene rearrangement system in formalin fixed paraffin-embedded (FFPE) tissue samples, and to discuss the relationship between the longest amplification fragment of extracted DNA and positive detection rate of different IGH V-J primers. METHODS: DNA was extracted from 50 cases of FFPE tissue samples. Multiplex-PCR amplifications were performed and then the IG/TCR gene rearrangements were analyzed using BIOMED-2 standardized clonality analysis system. RESULTS: (1)When the DNA concentration was diluted to 50-100 ng/µl from 100-500 ng/µl, the proportion of the longest amplification fragment (300-400 bp) of DNA was improved from 10.0% to 90.0% in 30 cases of diffuse large B cell lymphoma (DLBCL) wax roll samples (P<0.01). The positive rate of IGH+IGK was increased from 46.7% to 83.3%, the difference was statistically significant (P=0.006). The lengths of the longest amplification fragments of DNA were all longer than 300 bp in the paraffin section samples of DLBCL. The positive rate of IGH+IGK of these samples was 96.7%. The difference of the positive rate of IGH+IGK between the wax roll samples and the paraffin section samples had no statistical significance (P=0.195). (2)When the concentration of DNA was high, most of the longest amplification fragments of extracted DNA were 100 bp or 200 bp, and the detection rate of short fragment IGH FR3 was more stable than that of long fragment IGH FR1. (3)The clonality analysis of TCRG+TCRB in all 13 cases of peripheral T cell lymphoma samples showed positive results, while no positive IG/TCR clones were found in 7 cases of reactive lymphoid tissue hyperplasia in control group. CONCLUSION: Dilution of DNA is the only method to improve not only the proportion of longest fragment amplification but also the detection rate of clonality. The detection rate of IGH FR3 would not be affected by the concentration of DNA. The application of BIOMED-2 standardized IG/TCR gene rearrangement system in FFPE tissue samples plays an important role in the lymphoma diagnosis.

Calreticulin mutations in Chinese with primary myelofibrosis.

We tested 357 Chinese with primary myelofibrosis for mutations in CALR, JAK2 and MPL. CALR mutations were detected in 76 subjects (21%). There were 24 (32%) type-1 (L367fs*46) and 49 (64%) type-2 (K385fs*47) mutations. Seventy-two of 168 subjects (43%) without a JAK2 or MPL mutation had a CALR mutation. Subjects with a type-2 CALR mutation had lower hemoglobin concentrations (P=0.001), lower WBC counts (P<0.001), a higher percentage of blood blasts (P=0.009), and higher conventional (P<0.001) and Chinese-adjusted Dynamic International Prognostic Scoring System (P<0.001) scores compared with subjects with JAK2 mutations. Subjects with a type-2 CALR mutation were also likely to have abnormal platelet levels (<100 × 10(9)/L, P=0.01 or >450 × 10(9)/L, P=0.042) and no splenomegaly (P=0.004). Type-2 CALR mutation or no detectable mutation was an independent high-risk factor for survival in multivariate analyses. These data suggest the ratio between type-1 and type-2 mutations is reversed in Chinese with primary myelofibrosis compared with populations of subjects with primary myelofibrosis of predominately European descent. The unfavorable prognostic impact of CALR mutations in Chinese with primary myelofibrosis is only seen in those with type-2 mutations. These data underscore the need to evaluate the prognostic impact of genetic mutations in different populations.

[NPM1 and CEBPA mutations in pediatric cytogenetically normal acute myeloid leukemia].

OBJECTIVE: To evaluate the frequency of the nucleophosmin (NPM1) gene and the CCAAT/enhancer binding protein α gene (CEBPA) through polymerase chain reaction (PCR) array in pediatric patients with cytogenetically normal acute myeloid leukemia (CN-AML) and explore the clinical significances of these mutations. METHOD: Between August 2009 and December 2012, 30 children (<16 years old) with newly diagnosed CN-AML were included. The clinical characteristics were analyzed in these patients. PCR combined with direct sequencing was used to detect NPM1, CEBPA gene mutations. All the data were statistically analyzed using SPSS17.0 software. RESULT: The gene mutations were detected in each of the 30 patients. NPM1 mutation was positive in three patients (10%) with type A mutation, while CEBPA mutation was positive in two patients (6.7%) with double mutations (TAD, bZIP) . Besides, FLT3/ITD mutation was positive in three patients. Patients with NPM1 or FLT3/ITD had a significantly elevated diagnostic WBC count with a median diagnostic WBC count of 102.80×10(9)/L compared with 18.56×10(9)/L for the patients without mutations(t = 2.353, P = 0.043), as well as the marrow blast percentage (94.0% vs. 80.0%, t = 3.804, P = 0.002). The complete remission was achieved in all the 3 patients with NPM1 mutations and 2 patients with CEBPA mutations. All the patients with these mutations also achieved 2-year event-free survival (EFS) and 2-year overall survival (OS), while 2-year EFS and 2-year OS of the other patients were (40.1 ± 11.2)% and (51.8 ± 10.9)% (P = 0.044, 0.091, respectively). CONCLUSION: NPM1 and CEBPA mutations may indicate a favorable prognosis in pediatric CN-AML.

[CEBPA gene mutation analysis in acute myeloid leukemia].

OBJECTIVE: To investigate the incidence, molecular features and clinical significance of CCAAT/enhancer binding protein alpha (CEBPA) gene mutation in patients with acute myeloid leukemia (AML). METHODS: Mutation analysis of the entire coding region of CEBPA gene in 206 de novo AML patients was performed by using polymerase chain reaction (PCR) followed by sequence analysis and fragment length analysis. RESULTS: Of 206 AML patients, 31 (15%) had CEBPA gene mutations, including 23 with double mutations (duCEBPA) and 8 with single mutation (siCEBPA). CEBPA gene mutations presented mainly in M2 subtype or intermediate risk patients. As compared with those with wild type CEBPA gene, patients with mutated CEBPA gene were of higher white blood cell counts [20.92(0.86-351.43)× 10(9)//L vs 8.17(0.47-295.2) × 10(9)/L, P=0.003], higher hemoglobin levels [97.5(51-128) g/L vs 80.5(13-153) g/L, P=0.015] and lower platelet counts [27.5(5-81)× 10(9)//L vs 44(3-548)× 10(9)/L, P=0.004]. Patients with CEBPA gene mutation had higher complete remission (CR) rate than those with wild type (P=0.009). While co-existing of NPM1 and siCEBPA mutations was observed in M5 subtype (2/8, 25%), NPM1 gene mutation was not present in any patients with duCEBPA mutation (0/23, 0%). Dynamic tracking analysis showed that CEBPA mutations disappeared at CR, and the same mutations re-appeared at relapse. When compared to sequence analysis, the coincidence rate of CEBPA mutations detected by fragment length analysis was 100% (54/54). CONCLUSION: CEBPA gene mutation is a recurring genetic change in AML patients and has a certain correlation with clinical and laboratory features. It could be reliably used as a potential marker for minimal residual disease follow up. The prognostic significance of co-existing of siCEBPA with NPM1 mutations in patients with AML-M5 subtype needs further investigation.