Significant correlation between the degree of WT1 expression and the International Prognostic Scoring System Score in patients with myelodysplastic syndromes

Monitoring molecular changes in the management of myelodysplastic syndromes

The ongoing or anticipated therapeutic advances as well as previous experience in other malignancies, including acute myeloid leukaemia, have made molecular monitoring a potential interesting tool for predicting outcomes and demonstrating treatment efficacy in patients with myelodysplastic syndromes (MDS). The important genetic heterogeneity in MDS has made challenging the establishment of recommendations. In this context, high-throughput/next-generation sequencing (NGS) has emerged as an attractive tool, especially in patients with high-risk diseases. However, its implementation in clinical practice still suffers from a lack of standardization in terms of sensitivity, bioinformatics and result interpretation. Data from literature, mostly gleaned from retrospective cohorts, show NGS monitoring when used appropriately could help clinicians to guide therapy, detect early relapse and predict disease evolution. Translating these observations into personalized patient management requires a prospective evaluation in clinical research and remains a major challenge for the next years.

Vaccines: a promising therapy for myelodysplastic syndrome

Myelodysplastic neoplasms (MDS) define clonal hematopoietic malignancies characterized by heterogeneous mutational and clinical spectra typically seen in the elderly. Curative treatment entails allogeneic hematopoietic stem cell transplant, which is often not a feasible option due to older age and significant comorbidities. Immunotherapy has the cytotoxic capacity to elicit tumor-specific killing with long-term immunological memory. While a number of platforms have emerged, therapeutic vaccination presents as an appealing strategy for MDS given its promising safety profile and amenability for commercialization. Several preclinical and clinical trials have investigated the efficacy of vaccines in MDS; these include peptide vaccines targeting tumor antigens, whole cell-based vaccines and dendritic cell-based vaccines. These therapeutic vaccines have shown acceptable safety profiles, but consistent clinical responses remain elusive despite robust immunological reactions. Combining vaccines with immunotherapeutic agents holds promise and requires further investigation. Herein, we highlight therapeutic vaccine trials while reviewing challenges and future directions of successful vaccination strategies in MDS.

Performance evaluation and clinical impact of the Oncomine Myeloid Research Assay for gene expression analysis in myeloid haematologic malignancies

AIM

Gene expression analysis facilitates the detection of diagnostic and prognostic biomarkers for myeloid haematological malignancies. The Oncomine Myeloid Research Assay (OMA; Thermo Fisher Scientific, Massachusetts, USA) provides a comprehensive analysis of gene expression of five target genes, along with gene alteration and fusion. Here, we present the performance of the OMA for gene expression analysis.

METHODS

In total, 53 RNA samples from patients diagnosed with acute myeloid leukaemia (AML) or myelodysplastic syndrome were included. Of these 53 samples, 3 were evaluated for reproducibility and 50 were evaluated for comparison with RNA-sequencing (RNA-seq). The prognostic impact of the gene expression profile produced by both OMA and RNA-seq in AML was investigated using follow-up data from 33 patients with AML.

RESULTS

The OMA showed good intrarun and interrun reproducibility. Compared with the RNA-seq results, high correlations were found in BAALC, MECOM and WT1 (all r>0.9), with moderate correlations in MYC (r=0.75, p<0.001) and SMC1A (r=0.42, p=0.002). The agreement between OMA and RNA-seq in classifying the dysregulated expression group was almost perfect, except for SMC1A (κ=0.175). Among these five genes, only BAALC showed a significant clinical impact in patients with AML. Patients with high BAALC expression showed significantly shorter overall survival based on both OMA (p=0.037) and RNA-seq (p=0.003).

CONCLUSIONS

OMA gene expression analysis offers reproducible and accurate gene expression data for most targeted genes and demonstrates the utility of BAALC expression as a prognostic marker in AML.

Clinical significance of the increased expression of the WT1 gene in peripheral blood of patients with acquired aplastic anemia

To determine the significance of increased Wilms tumor 1 (WT1) gene expression in the peripheral blood of patients with acquired aplastic anemia (AA), we analyzed serial changes in WT1 mRNA copy number (WT1cn) in 63 patients with AA as well as in five patients with myelodysplastic syndromes (MDS) and seven patients with paroxysmal nocturnal hemoglobinuria (PNH). WT1cn was higher than the cut-off (≥50 copies/μg RNA) at the time of the first measurement in 41% of untreated (60-190 copies/μg RNA [median 130]) and 59% of treated (59-520 copies/μg RNA [median 150]) AA patients. Although WT1cns gradually increased in most AA patients during the 2-105 months follow-up period, they did not lead to clonal evolution except in three patients in whom the maximum change ratio of WT1cn (WT1cn-change max), defined as the ratio of WT1cn at the first examination to that of the maximum value, exceeded 20.0 and who developed MDS at 2, 46, and 105 months. Increased WT1 gene expression was enriched in granulocytes rather than in mononuclear cells in most WT1-positive AA patients and did not correlate with mutations of genes associated with myeloid malignancy. WT1cns were high at 690-5700 (median 2000) in MDS patients and remained high thereafter, while WT1cns in PNH patients (77-200; median 96) were similar to those in AA. Thus, moderate increases in WT1cns up to 600 are common in AA patients in stable remission. An increase in the WT1cn-change max over 20.0 may portend transformation from AA to MDS.

Dynamic change in peripheral blood WT1 mRNA levels within three cycles of azacitidine predict treatment response in patients with high-risk myelodysplastic syndromes

Azacitidine (AZA) improves overall survival (OS) in patients with high-risk myelodysplastic syndromes (MDS). However, predictive factors for response to AZA remain largely unknown. To elucidate whether dynamic change in peripheral blood (PB) Wilms' Tumor 1 (WT1) mRNA levels could predict response to AZA, we retrospectively identified 75 treatment-naïve patients with high-risk MDS who received at least 3 cycles of AZA. We classified patients into 4 groups, low-increase (LI), low-stable (LS), high-decrease (HD), and high-stable (HS) based on the dynamic change in PB WT1 mRNA levels within 3 cycles of AZA. Cumulative incidence of overall response after 10 cycles of AZA was significantly higher in LS/HD than in HS/LI (75.5% vs 4.5%, P < 0.001). The median OS for LS/HD was 18.2 months (95% CI, 12.8-28.1 months), whereas it was 11.6 months for HS/LI (95% CI, 6.6-14.1 months; P < 0.001). Multivariate analysis demonstrated that poor-/very poor-IPSS-R cytogenetic risk and HS/LI were independently associated with poor OS (poor-/very poor-IPSS-R cytogenetic risk: HR, 2.26; 95% CI, 1.10-4.68, P = 0.03, HS/LI: HR, 2.32; 95% CI, 1.21-4.46, P = 0.01). Patients with HS/LI did not show any further response to continuous AZA, and they should be considered for alternative therapy from earlier cycles.

Detection of SF3B1 p.Lys700Glu Mutation by PNA-PCR Clamping in Myelodysplastic Syndromes and Myeloproliferative Neoplasms

Mutations in SF3B1 are found in 20% of myelodysplastic syndromes and 5–10% of myeloproliferative neoplasms, where they are considered important for diagnosis and therapy decisions. Sanger sequencing and NGS are the currently available methods to identify SF3B1 mutations, but both are time-consuming and expensive techniques that are not practicable in most small-/medium-sized laboratories. To identify the most frequent SF3B1 mutation, p.Lys700Glu, we developed a novel fast and cheap assay based on PNA-PCR clamping. After setting the optimal PCR conditions, the limit of detection of PNA-PCR clamping was evaluated, and the method allowed up to 0.1% of mutated SF3B1 to be identified. Successively, PNA-PCR clamping and Sanger sequencing were used to blind test 90 DNA from patients affected by myelodysplastic syndromes and myeloproliferative neoplasms for the SF3B1 p.Lys700Glu mutation. PNA-PCR clamping and Sanger sequencing congruently identified 75 negative and 13 positive patients. Two patients identified as positive by PNA-PCR clamping were missed by Sanger analysis. The discordant samples were analyzed by NGS, which confirmed the PNA-PCR clamping result, indicating that these samples contained the SF3B1 p.Lys700Glu mutation. This approach could easily increase the characterization of myelodysplastic syndromes and myeloproliferative neoplasms in small-/medium-sized laboratories, and guide patients towards more appropriate therapy.

Diagnostic Workup of Acute Myeloid Leukemia: What Is Really Necessary? An Italian Survey

Acute myeloid leukemia (AML) is a heterogeneous disease with a wide variety of clinical presentations, morphological features, and immunophenotypes. The diagnostic approaches to AML that are adopted in Italy have been explored using an online Delphi-based process to expand the global discussion on mandatory tests for the correct diagnosis and, consequently, for optimal management of AML in clinical practice. The final results of the panel of Italian hematologists involved in this work highlight the importance of genetic evaluation for classification and risk stratification and firmly establish that karyotyping, fluorescence in situ hybridization in cases with non-evaluable karyotype, and molecular tests must be performed in every case of AML, regardless of age. Obtaining clinically relevant genetic data at diagnosis is the basis for the success of patient-tailored therapy. The Italian specialists also confirm the role of multidisciplinary diagnostics for AML, now mandatory and expected to become more important in the future context of “precision” medicine.

Possible prognostic impact of WT1 mRNA expression at day + 30 after haploidentical peripheral blood stem cell transplantation with posttransplant cyclophosphamide for patients with myeloid neoplasm: a multicenter study from the Okayama Hematological Study Group

BACKGROUND

Previous studies have revealed that relapse of myeloid neoplasms after allogeneic hematopoietic stem cell transplantation (allo-HSCT) could be predicted by monitoring Wilms' tumor 1 (WT1) mRNA expression. However, only a few studies have investigated patients who received human leukocyte antigen-haploidentical stem cell transplantation with posttransplant cyclophosphamide (PTCY-haplo). In this study, we investigated the relationship between WT1 mRNA levels and clinical outcomes in the PTCY-haplo group, and compared them with those in the conventional graft-versus-host disease prophylaxis group (conventional group).

METHODS

We retrospectively analyzed 130 patients who received their first allo-HSCT between April 2017 and December 2020, including 26 who received PTCY-haplo.

RESULTS

The WT1 mRNA expression level at day + 30 after allo-HSCT associated with increased risk of 1-year cumulative incidence of relapse (CIR) was ≥ 78 copies/μg RNA in the conventional group (p < 0.01) and ≥ 50 copies/μg RNA in the PTCY-haplo group (p = 0.03).

CONCLUSIONS

The appropriate cutoff level of WT1 mRNA at day + 30 after allo-HSCT for predicting prognosis in patients treated with PTCY-haplo may be < 50 copies/μg RNA.

Successful allogeneic bone marrow transplantation after massive gastrointestinal bleeding in a patient with myelodysplastic syndrome associated with intestinal Behçet-like disease

A 45-year-old woman was diagnosed with myelodysplastic syndrome (MDS) with trisomy 8 and Behçet-like disease (BLD) with multiple colorectal ulcers. Nonspecific inflammatory cells were infiltrated in the intestinal mucosa, whereas fluorescence in situ hybridization (FISH) analysis revealed only sporadic trisomy 8-positive cells. She presented massive lower gastrointestinal bleeding early after bone marrow transplantation but achieved long-term remission of both MDS and BLD. This is the first report of massive gastrointestinal bleeding after transplantation for MDS with BLD. Based on FISH analysis, dysregulation of systemic inflammation may be involved in BLD rather than direct invasion by trisomy 8-positive MDS clones.

From Immune Dysregulations to Therapeutic Perspectives in Myelodysplastic Syndromes: A Review

The pathophysiology of myelodysplastic syndromes (MDSs) is complex and often includes immune dysregulation of both the innate and adaptive immune systems. Whereas clonal selection mainly involves smoldering inflammation, a cellular immunity dysfunction leads to increased apoptosis and blast proliferation. Addressing immune dysregulations in MDS is a recent concept that has allowed the identification of new therapeutic targets. Several approaches targeting the different actors of the immune system have therefore been developed. However, the results are very heterogeneous, indicating the need to improve our understanding of the disease and interactions between chronic inflammation, adaptive dysfunction, and somatic mutations. This review highlights current knowledge of the role of immune dysregulation in MDS pathophysiology and the field of new drugs.

Phase I dose escalation safety and feasibility study of autologous WT1-sensitized T cells for the treatment of patients with recurrent ovarian cancer

Background

This phase I dose escalation trial evaluated the feasibility of production, safety, maximum tolerated dose, and preliminary efficacy of autologous T cells sensitized with peptides encoding Wilms’ tumor protein 1 (WT1) administered alone or following lymphodepleting chemotherapy, in the treatment of patients with recurrent WT1⁺ ovarian, primary peritoneal, or fallopian tube carcinomas.

Methods

A 3+3 dose escalation design was used to determine dose-limiting toxicity (DLT). In cohort I, patients received WT1-sensitized T cells dosed at 5×10⁶/m² (level I) without cyclophosphamide lymphodepletion. In cohorts II–IV, patients received lymphodepleting chemotherapy (a single intravenous dose of cyclophosphamide 750 mg/m²), 2 days prior to the first intravenous infusion of WT1-sensitized T cells administered at escalating doses (2×10⁷/m² (level II), 5×10⁷/m² (level III), and 1×10⁸/m² (level IV)).

Results

Twelve patients aged 23–72 years, with a median of 7 prior therapies (range 4–14), were treated on the study. No DLT was observed, even at the highest dose level of 1×10⁸/m² WT1-sensitized T cells tested. Common adverse events reported were grade 1–2 fatigue, fever, nausea, and headache. Median progression-free survival (PFS) was 1.8 months (95% CI, 0.8 to 2.6); 1 year PFS rate 8.3% (95% CI, 0.5 to 31.1). Median overall survival (OS) was 11.0 months (95% CI, 1.1 to 22.6); OS at 1 year was 41.7% (95% CI, 15.2% to 66.5%). Best response was stable disease in one patient (n=1) and progressive disease in the others (n=11). We observed a transient increase in the frequencies of WT1-specific cytotoxic T lymphocyte precursors (CTLp) in the peripheral blood of 9 of the 12 patients following WT1-sensitized T-cell infusion.

Conclusion

We demonstrated the safety of administration of WT1-sensitized T cells and the short-term increase in the WT1 CTLp. However, at the low doses evaluated we did not observe therapeutic activity in recurrent ovarian cancer. In this heavily pretreated population, we encountered challenges in generating sufficient numbers of WT1-reactive cytotoxic T cells. Future studies employing WT1-specific T cells generated from lymphocytes are warranted but should be done earlier in the disease course and prior to intensive myelosuppressive therapy.

Trial registration number

NCT00562640.

One-sentence summary

The authors describe the first human application of autologous WT1-sensitized T cells in the treatment of patients with recurrent ovarian, primary peritoneal, and fallopian tube carcinomas.

Myelodysplastic syndrome and immunotherapy novel to next in-line treatments

Patients with Myelodysplastic syndromes (MDS) have few therapy options for sustainable responses in the frontline setting, and even less after hypomethylating agent (HMA) failure in relapsed and refractory setting. The only potential cure is an allogeneic hematopoietic stem cell transplant which is an unrealistic option for the majority of MDS patients. Immunotherapy with checkpoint inhibition, CAR-T cells, and vaccine therapy few have shown promise in a variety cancer and have now been tested in patients with MDS. Most trials have focused on AML patients and included small numbers of MDS patients. Until now, a dedicated review of immunotherapy outcomes in MDS patients has been lacking. Thus, herein we review outcomes of MDS patients after immunotherapies on a variety of clinical trials reported to date.

DNA methylation identifies genetically and prognostically distinct subtypes of myelodysplastic syndromes

Recurrent mutations implicate several epigenetic regulators in the early molecular pathobiology of myelodysplastic syndromes (MDS). We hypothesized that MDS subtypes defined by DNA methylation (DNAm) patterns could enhance our understanding of MDS disease biology and identify patients with convergent epigenetic profiles. Bisulfite padlock probe sequencing was used to measure DNAm of ∼500 000 unique cytosine guanine dinucleotides covering 140 749 nonoverlapping regulatory regions across the genome in bone marrow DNA samples from 141 patients with MDS. Application of a nonnegative matrix factorization (NMF)-based decomposition of DNAm profiles identified 5 consensus clusters described by 5 NMF components as the most stable grouping solution. Each of the 5 NMF components identified by this approach correlated with specific genetic abnormalities and categorized patients into 5 distinct methylation clusters, each largely defined by a single NMF component. Methylation clusters displayed unique differentially methylated regulatory loci enriched for active and bivalent promoters and enhancers. Two clusters were enriched for samples with complex karyotypes, although only one had an increased number of TP53 mutations. Each of the 3 most frequently mutated splicing factors, SF3B1, U2AF1, and SRSF2, was enriched in different clusters. Mutations of ASXL1, EZH2, and RUNX1 were coenriched in the SRSF2-containing cluster. In multivariate analysis, methylation cluster membership remained independently associated with overall survival. Targeted DNAm profiles identify clinically relevant subtypes of MDS not otherwise distinguished by mutations or clinical features. Patients with diverse genetic lesions can converge on common DNAm states with shared pathogenic mechanisms and clinical outcomes.

Overexpression of WT1 and PRAME predicts poor outcomes of patients with myelodysplastic syndromes with thrombocytopenia

Thrombocytopenia is associated with life-threatening bleeding and is common in myelodysplastic syndromes (MDS). Robust molecular prognostic biomarkers need to be developed to improve clinical decision making for patients with MDS with thrombocytopenia. Wilms tumor 1 (WT1) and preferentially expressed antigen in melanoma (PRAME) are promising immunogenic antigen candidates for immunotherapy, and their clinical effects on patients with MDS with thrombocytopenia are still not well understood. We performed a multicenter observational study of adult patients with MDS with thrombocytopenia from 7 different tertiary medical centers in China. We examined bone marrow samples collected at diagnosis for WT1 and PRAME transcript levels and then analyzed their prognostic effect for patients with MDS with thrombocytopenia. In total, we enrolled 1110 patients diagnosed with MDS with thrombocytopenia. Overexpression of WT1 and PRAME was associated with elevated blast percentage, worse cytogenetics, and higher Revised International Prognostic Scoring System (IPSS-R) risk. Further, both WT1 and PRAME overexpression were independent poor prognostic factors for acute myeloid leukemia evolution, overall survival, and progression-free survival. Together, the 2 genes overexpression identified a population of patients with MDS with substantially worse survival. On the basis of WT1 and PRAME transcript levels, patients with MDS with IPSS-R low risk were classified into 2 significantly divergent prognostic risk groups: a low-favorable group and a low-adverse group. The low-adverse group had survival similar to that of patients in the intermediate-risk group. Our study demonstrates that the evaluation of WT1/PRAME transcript analysis may improve the prognostication precision and better risk-stratify the patients.

Prognostic impact of peripheral blood WT1-mRNA expression in patients with MDS

Few reports suggested a prognostic impact of Wilms'Tumor-1 (WT1)-mRNA overexpression in MDS, but translation into clinical routine was hampered by limited patients numbers, differing sample sources, non-standardized methods/cut-offs. To evaluate whether WT1-mRNA expression yields additional prognostic information, we measured peripheral blood (PB) WT1-mRNA expression in 94 MDS using a standardized assay offering a validated cut-off to discriminate between normal and WT1-mRNA overexpression. Overall, 54 patients (57%) showed WT1-mRNA overexpression, while 40 patients (43%) had normal WT1-mRNA expression. This enabled discrimination between MDS and both healthy controls and non-MDS cytopenias. Furthermore, WT1-mRNA expression correlated with WHO 2016 subcategories and IPSS-R as indicated by mean WT1-mRNA expression and frequency of WT1-mRNA overexpressing patients within respective subgroups. Regarding the entire group, PB WT1-mRNA expression was associated with prognosis, as those patients showing WT1-mRNA overexpression had higher risk for disease progression and AML transformation and accordingly shorter progression-free, leukemia-free and overall survival in univariate analysis. In multivariate analysis, prognostic impact of PB WT1-mRNA expression status was independent of IPSS-R and enabled more precise prediction of PFS, but not OS, within IPSS-R very low/low and intermediate risk groups. Overall, measuring PB WT1-mRNA appears valuable to support diagnostics and refine prognostication provided by the IPSS-R.

Enhanced polo-like kinase 1 expression in myelodysplastic syndromes

Background

Cancer is characterized by uncontrolled cellular proliferation, and Polo-like kinase 1 (PLK1), a key regulator of the cell cycle, is overexpressed in many cancers, including acute leukemia and lymphoma. However, the dynamics of PLK1 transcription in myelodysplastic syndromes (MDS) are unknown. This study aimed to investigate the transcript dynamics of PLK1 and determine its role in the pathophysiology of MDS.

Methods

PLK1 mRNA obtained from the bone marrow samples of 67 patients with MDS, 16 patients with secondary acute myeloid leukemia (sAML), and 10 healthy controls were analyzed using quantitative real-time PCR and compared according to various clinical parameters.

Results

The median PLK1 expression levels differed slightly, but not significantly, between MDS and sAML patients [661.21 (range, 29.38-8,987.31) vs. 1,462.05 (32.22-5,734.09), respectively], but were significantly higher (P<0.001) than the levels in the healthy controls [19.0 (1.60-49.90)]. Further analyses of PLK1 levels according to the WHO classification of MDS, prognostic risk groups, karyotype risk groups, marrow blast percentage, and depth of cytopenia did not reveal any significant associations. In patients progressing to sAML, PLK1 expression levels differed significantly according to the presence or absence of resistance to hypomethylation treatment (2,470.58 vs. 415.98, P=0.03).

Conclusion

PLK1 is upregulated in MDS patients; however, its role in the pathophysiology of MDS is unclear. Gene upregulation in cases with pharmacotherapeutic resistance warrants further investigation.

Generation of donor-derived Wilms tumor antigen 1-specific cytotoxic T lymphocytes with potent anti-leukemia activity for somatic cell therapy in children given haploidentical stem cell transplantation: a feasibility pre-clinical study

BACKGROUND

The Wilms tumor antigen 1 (WT1) is over-expressed in a vast majority of adult and childhood acute leukemia and myelodysplastic syndromes, being lowly or transiently expressed in normal tissues and hematopoietic stem cells (HSCs). A number of HLA-restricted WT1 epitopes are immunogenic, allowing the in vitro induction of WT1-specific cytotoxic T lymphocytes (CTLs) from patients and healthy donors.

AIM

The aim of the study was to investigate the feasibility of producing WT1-specific CTLs suitable for somatic cell therapy to prevent or treat relapse in children with acute myeloid or lymphoblastic leukemia given haploidentical HSC transplantation (haplo-HSCT).

METHODS

For WT1-specific CTL production, donor-derived either peripheral blood mononuclear cells (PBMCs) or CD8+ lymphocytes were stimulated with WT1 peptide-loaded donor dendritic cells in the presence of interleukin (IL)-7 and IL-12. Effector cells were re-stimulated once with irradiated donor PBMCs pulsed with WT1-peptides, and then expanded in an antigen-independent way.

RESULTS

WT1-specific CTLs, displaying high-level cytotoxicity against patients' leukemia blasts and negligible activity against patients' non-malignant cells, were obtained from both PBMCs and CD8+ lymphocytes. WT1-specific CTLs obtained from PBMCs showed a better expansion capacity and better anti-leukemia activity than those obtained from CD8+ lymphocytes, even though the difference was not statistically significant. In CTLs derived from PBMCs, both CD8+ and CD4+ subpopulations displayed strong anti-leukemia cytotoxic activity.

DISCUSSION

Results of this pre-clinical study pave the way to a somatic cell therapy approach aimed at preventing or treating relapse in children given haplo-HSCT for WT1-positive leukemia.

Wilms' tumor 1 mRNA expression: a good tool for differentiating between myelodysplastic syndrome and aplastic anemia in children?

Objectives: To evaluate the value of Wilms' tumor 1 mRNA (WT1) expression in the differential diagnosis of childhood myelodysplastic syndrome (MDS) and aplastic anemia (AA). Methods: This study compared WT1 expression levels in children of MDS and AA to evaluate its value in differential diagnosis. Results: WT1 overexpression rate and mean WT1 expression level were significantly higher in MDS compared to AA (P = 0.000 and P = 0.013, respectively). Patients with RCC and normal cytogenetics exhibited significantly greater portion of patients exposing WT1 overexpression, compared to all AA subtypes (P = 0.001, P = 0.000 and P = 0.001, respectively). ROC curve analysis revealed that WT1 expression could differentiate between RCC with normal cytogenetics and non-severe AA. Based on a cut-off value of 1.45%, WT1 expression provided a sensitivity of 23.2% and a specificity of 100%. Discussion: In the present study, WT1 overexpression rate was gradually decreased in RAEB group, RCC group and AA subtypes, and the mean WT1 expression level of the MDS patients was significantly higher than that of the AA group. It is very difficult to differentiate between RCC with normal cytogenetics and NSAA in children. Our results showed significant differences in WT1 overexpression rate between these two groups. When we set the cut-off value as 1.45%, WT1 expression levels could be used to differentiate between cases of RCC with normal cytogenetics and NSAA in children. Conclusion: WT1 expression might be useful for distinguishing between myelodysplastic syndrome and aplastic anemia in children.

[Changes of WT1 mRNA expression level in patients with myelodysplastic syndromes after hypomethylating agents and its prognostic significance]

Objective: To monitor the WT1 mRNA level and its dynamic changes in patients with myelodysplastic syndromes (MDS) after hypomethylating agents (HMA) , as well as to assess the significance of WT1 mRNA levels and its dynamic changes in evaluating the efficacy of HMA and distinguishing the disease status of heterogeneous patients with stable disease (SD) . Methods: Bone marrow or peripheral blood samples of 56 patients with MDS who underwent hypomethylating agents (≥4 cycles) from November 2009 to March 2018 were tested by real-time quantitative polymerase chain reaction (PCR) to detect the expression of WT1 mRNA, and to observe the correlation between the dynamic changes of WT1 mRNA expression and clinical efficacy and prognosis of patients. Results: WT1 mRNA expression levels of MDS patients decreased significantly after 3 cycles of hypomethylating agent treatment. Besides, the WT1 mRNA expression levels of patients increased significantly after diseases progression. According to the dynamic changes of WT1 mRNA expression levels during SD, 45 cases could be further divided into increased group and non-increased group. In those SD patients with increased WT1 mRNA expression level, the ratio of suffering disease progression or transformation to AML was 95.65% (22/23) , whereas the ratio turned to be 9.09% (2/22) for the non-increased group (χ(2)=33.852, P<0.001) . Compared with those SD patients reporting no increase in WT1 mRNA expression level, the overall survival[17 (95%CI 11-23) months vs not reached, P<0.001] and progression-free survival [13 (95%CI 8-18) months vs not reached, P<0.001] of those SD patients reporting increase in WT1 mRNA expression level were significantly shorter. Conclusion: WT1 mRNA expression level is a useful indicator to assess the efficacy of hypomethylating agents in MDS patients. Especially in patients with SD, detection of the changes in WT1 mRNA expression level is able to predict disease progression and help to make clinical decision.

WT1 gene is overexpressed in myeloproliferative neoplasms, especially in myelofibrosis

Classical Philadelphia-negative myeloproliferative neoplasms include Polycythemia Vera (PV), Essential Thrombocythemia (ET) and Primary Myelofibrosis (PMF). They are characterized by the presence of driver mutations of JAK2, CALR or MPL genes. Overexpression of WT1 is used as a marker of minimal residual disease in acute myeloid leukemia, especially after allogeneic stem cell transplantation (SCT). We investigated WT1 expression at diagnosis in 152 MPN patients and showed that the WT1 transcript was overexpressed in PMFs and PVs compared to controls. In particular, WT1 transcript levels were higher in PMF than in ET and PV. WT1 transcript levels were significantly increased during myelofibrotic transformation of ET or PV. Using multivariate linear regression, high WT1 transcript levels in PMF were associated with age over 65, splenomegaly and thrombocytopenia. The ROC curve analysis showed that a level of WT1 transcript >10 WT1 copies/10⁴ABL1 enabled the diagnosis of PMF with a specificity of 95.8% (PMF vs ET; ROC AUC = 0.91). In myelofibrosis, studying follow-ups of WT1 transcript showed that this marker is of interest after allogeneic SCT. These results demonstrate that WT1 overexpression is a simple marker of myelofibrosis in MPN and could be used during patient follow-up.

The genetic and molecular pathogenesis of myelodysplastic syndromes

Myelodysplastic syndromes (MDS) comprise a diverse group of clonal and malignant myeloid disorders characterized by ineffective hematopoiesis, resultant peripheral cytopenias, and a meaningful increased risk of progression to acute myeloid leukemia. A wide array of recurring genetic mutations involved in RNA splicing, histone manipulation, DNA methylation, transcription factors, kinase signaling, DNA repair, cohesin proteins, and other signal transduction elements has been identified as important substrates for the development of MDS. Cytogenetic abnormalities, namely those characterized by loss of genetic material (including 5q- and 7q-), have also been strongly implicated and may influence the clonal architecture which predicts such mutations and may provoke an inflammatory bone marrow microenvironment as the substrate for clonal expansion. Other aspects of the molecular pathogenesis of MDS continue to be further elucidated, predicated upon advances in gene expression profiling and the development of new, and improved high-throughput techniques. More accurate understanding of the genetic and molecular basis for the development of MDS directly provides additional opportunity for treatment, which to date remains limited. In this comprehensive review, we examine the current understanding of the molecular pathogenesis and pathophysiology of MDS, as well as review future prospects which may enhance this understanding, treatment strategies, and hopefully outcomes.

Variable but consistent pattern of Meningioma 1 gene (MN1) expression in different genetic subsets of acute myelogenous leukaemia and its potential use as a marker for minimal residual disease detection

Meningioma 1 (MN1) gene overexpression has been reported in acute myeloid leukaemia (AML) patients and identified as a negative prognostic factor. In order to characterize patients presenting gene overexpression and to verify if MN1 transcript could be a useful marker for minimal residual disease detection, MN1 was quantified in 136 AML patients with different cytogenetic risk and in 50 normal controls. In 20 patients bearing a fusion gene transcript suitable for minimal residual disease quantitative assessment and in 8 patients with NPM1 mutation, we performed a simultaneous analysis of MN1 and the fusion-gene transcript or NPM1 mutation during follow-up. Sequential MN1 and WT1 analysis was also performed in 13 AML patients lacking other molecular markers. The data obtained show that normal cells consistently express low levels of MN1 transcript. In contrast, high levels of MN1 expression are present in 47% of patients with normal karyotype and in all cases with inv(16). MN1 levels during follow-up were found to follow the pattern of other molecular markers (fusion gene transcripts, NPM1 and WT1). Increased MN1 expression in the BM during follow up was always found to be predictive of an impending hematological relapse.

WT1 peptide vaccine in Montanide in contrast to poly ICLC, is able to induce WT1-specific immune response with TCR clonal enrichment in myeloid leukemia

Background

The optimal strategy for vaccination to induce CD8⁺ T cell responses against WT1 is not known.

Methods

A pilot randomized study in HLA-A02⁺ patients to receive vaccination with WT1 in Montanide or in poly ICLC, a TLR3 agonist, to explore the novel immune adjuvant was conducted. Seven patients were randomized. Four patients received WT1 in Montanide, and three with WT1 in poly ICLC. Five patients were in morphologic remission and two had residual morphologic disease at the study entry.

Results

All patients finished the induction phase without any major toxicity except mild transient local injection reaction. One patient on the Montanide arm developed aseptic ulceration at two vaccine sites which healed without antibiotics. Three of 4 patients on the Montanide arm had a decreased expression of WT1 after WT1 vaccination, and two of them demonstrated generation of WT1-specific cytotoxic CD8⁺ T cell responses with biased TCR beta chain enrichment. In contrast, no obvious WT1-specific immune responses were detected in two patients on the poly ICLC arm, nor was there clonal enrichment by TCR alpha/beta sequencing; however, these patients did also have decreased WT1 expression and remained in remission several years after the initiation of treatment.

Conclusions

WT1 peptide vaccine with Montanide as an adjuvant induces detectable WT1-specific CD8⁺ T cell responses with clonal TCR enrichment, which may be capable of controlling leukemia recurrence in the setting of minimal residual disease. Poly ICLC may induce anti-leukemic activity in the absence of detectable WT1 specific CD8⁺ T cell responses.

Trial registration NCT01842139, 7/3/2012 retrospectively registered; https://clinicaltrials.gov/ct2/show/NCT01842139.

Bone marrow fibrosis in myelodysplastic syndromes: a prospective evaluation including mutational analysis

The biological and molecular events that underlie bone marrow fibrosis in patients with myelodysplastic syndromes are poorly understood, and its prognostic role in the era of the Revised International Prognostic Scoring System (IPSS-R) is not yet fully determined. We have evaluated the clinical and biological events that underlie bone marrow fibrotic changes, as well as its prognostic role, in a well-characterized prospective patient cohort (n=77) of primary MDS patients. The degree of marrow fibrosis was linked to parameters of erythropoietic failure, marrow cellularity, p53 protein accumulation, WT1 gene expression, and serum levels of CXCL9 and CXCL10, but not to other covariates including the IPSS-R score. The presence of bone marrow fibrosis grade 2 or higher was associated with the presence of mutations in cohesin complex genes (31.5% vs. 5.4%, p=0.006). By contrast, mutations in CALR, JAK2, PDGFRA, PDGFRB,and TP53 were very rare. Survival analysis showed that marrow fibrosis grade 2 or higher was a relevant significant predictor for of overall survival, and independent of age, performance status, and IPSS-R score in multivariate analysis.

The diverse expression of the WT1 gene in patients with acquired bone marrow failure syndromes

Acquired bone marrow failure syndromes (aBMFS) encompass a wide range of diseases. A study to investigate WT1 expression in BM was conducted in 387 patients with aBMFS in China. The WT1 level in patients with aplastic anemia (AA) was significantly lower than that in patients with paroxysmal nocturnal hemoglobinuria (PNH, p = .023) and myelodysplastic syndrome (MDS, p < .001). In addition, the WT1 level in patients with MDS significantly increased as the disease progressed to an advanced stage. Patients with hypoplastic MDS had a differentiated expression level of WT1 compared with that of NSAA (p < .001). Furthermore, post-treatment patients of AA with partial response (PR) or complete response (CR) status had relatively higher WT1 levels than those with naive AA (p = .017, p = .003, respectively). Thus, the WT1 expression level could be a useful genetic marker for routine clinical work in aBMFS.

Myelodysplastic syndromes: advantages of a combined cytogenetic and molecular diagnostic workup

In this study we present a new diagnostic workup for the myelodysplastic syndromes (MDS) including FISH, aCGH, and somatic mutation assays in addition to the conventional cytogenetics (CC). We analyzed 61 patients by CC, FISH for chromosome 5, 7, 8 and PDGFR rearrangements, aCGH, and PCR for ASXL1, EZH2, TP53, TET2, RUNX1, DNMT3A, SF3B1 somatic mutations. Moreover, we quantified WT1 and RPS14 gene expression levels, in order to find their possible adjunctive value and their possible clinical impact. CC analysis showed 32% of patients with at least one aberration. FISH analysis detected chromosomal aberrations in 24% of patients and recovered 5 cases (13.5%) at normal karyotype (two 5q- syndromes, one del(7) case, two cases with PDGFR rearrangement). The aGCH detected 10 "new" unbalanced cases in respect of the CC, including one with alteration of the ETV6 gene. After mutational analysis, 33 patients (54%) presented at least one mutation and represented the only marker of clonality in 36% of all patients. The statistical analysis confirmed the prognostic role of CC either on overall or on progression-free-survival. In addition, deletions detected by aCGH and WT1 over-expression negatively conditioned survival. In conclusion, our work showed that 1) the addition of FISH (at least for chr. 5 and 7) can improve the definition of the risk score; 2) mutational analysis, especially for the TP53 and SF3B1, could better define the type of MDS and represent a "clinical warning"; 3) the aCGH use could be probably applied to selected cases (with suboptimal response or failure).

Prognostic significance of Wilms tumor 1 mRNA expression levels in peripheral blood and bone marrow in patients with myelodysplastic syndromes

BACKGROUND

This present study was designed to follow up 82 patients among 115 MDS patients registered in study ODK-0801 for 5 years, to analyze the relationship between the WT1 mRNA expression level and prognosis.

OBJECTIVE

This study aimed to investigate the clinical utility of WT1 mRNA expression levels.

METHODS

After study ODK-0801, we investigated the conditions of the same patients once a year, including any clinical and laboratory findings supporting the diagnosis, and treatment among the living patients.

RESULTS

When we assessed the survival time of 82 MDS patients by WT1 mRNA expression level, there were significant differences between the < 500 and ≥ 104 copies/μ g RNA groups and between the 500-104 and ≥ 104 copies/μ g RNA groups for BM levels (p < 0.01). Examination of the time of freedom from acute myeloid eukemia (AML) transformation indicated that a high WT1 mRNA expression level (> 104 copies/μ g RNA) was a strong prognostic factor for a short time to AML transformation.

CONCLUSION

The results indicate that the tumorigenesis of MDS is likely to originate at the stem cell level, suggesting that the WT1 mRNA level measurement in the BM is an effective prognostic marker in patients with MDS.

Use of Wilms Tumor 1 Gene Expression as a Reliable Marker for Prognosis and Minimal Residual Disease Monitoring in Acute Myeloid Leukemia With Normal Karyotype Patients

BACKGROUND

Acute myeloid leukemia with normal karyotype (AML-NK) represents the largest group of AML patients classified with an intermediate prognosis. A constant need exists to introduce new molecular markers for more precise risk stratification and for minimal residual disease (MRD) monitoring.

PATIENTS AND METHODS

Quantitative assessment of Wilms tumor 1 (WT1) gene transcripts was performed using real-time polymerase chain reaction. The bone marrow samples were collected at the diagnosis from 104 AML-NK patients and from 34 of these patients during follow-up or disease relapse.

RESULTS

We found that overexpression of the WT1 gene (WT1^high status), present in 25.5% of patients, was an independent unfavorable factor for achieving complete remission. WT1^high status was also associated with resistance to therapy and shorter disease-free survival and overall survival. Assessment of the log reduction value of WT1 expression, measured in paired diagnosis/complete remission samples, revealed that patients with a log reduction of < 2 had a tendency toward shorter disease-free survival and overall survival and a greater incidence of disease relapse. Combining WT1 gene expression status with NPM1 and FLT3-ITD mutational status, we found that the tumor behavior of intermediate patients (FLT3-ITD^-/NPM1^- double negative) with WT1^high status is almost the same as the tumor behavior of the adverse risk group.

CONCLUSION

WT1 expression status represents a good molecular marker of prognosis, response to treatment, and MRD monitoring. Above all, the usage of the WT1 expression level as an additional marker for more precise risk stratification of AML-NK patients could lead to more adapted, personalized treatment protocols.

Wilms Tumor 1 (WT1) mRNA Expression Level at Diagnosis Is a Significant Prognostic Marker in Elderly Patients with Myelodysplastic Syndrome

BACKGROUND/AIMS

A high expression of Wilms tumor 1 (WT1) mRNA occurs in most cases of acute leukemia and myelodysplastic syndrome (MDS). Although there are many reports suggesting that acute myeloid leukemia patients with high expression levels of WT1 mRNA have a relatively poor long-term survival, there are few reports addressing the relationship between WT1 levels and prognosis in MDS.

METHODS

We retrospectively analyzed 42 elderly patients with MDS whose WT1 levels at diagnosis were available, and we assessed the relationships between WT1 levels in peripheral blood and preexisting prognostic factors such as World Health Organization prognostic scores and Revised International Prognostic Scoring System risk categories, bone marrow blast percentages, and chromosomal abnormalities linked to a poor prognosis. We also evaluated the relationship between WT1 levels and prognosis.

RESULTS

WT1 levels were significantly different between high- and low-risk MDS patients (p < 0.05). There was a trend towards a significant difference between those with and those without poor prognostic chromosomal rearrangements (p = 0.051). Moreover, the overall survival and progression-free survival were significantly worse in elderly patients with higher levels of WT1 (p = 0.00039 and p = 0.00077, respectively).

CONCLUSIONS

The WT1 mRNA expression level at diagnosis may be a significant independent prognostic marker for elderly patients with MDS.

How I diagnose and manage individuals at risk for inherited myeloid malignancies

Although inherited hematopoietic malignancies have been reported clinically since the early twentieth century, the molecular basis for these diseases has only recently begun to be elucidated. Growing utilization of next-generation sequencing technologies has facilitated the rapid discovery of an increasing number of recognizable heritable hematopoietic malignancy syndromes while also deepening the field's understanding of the molecular mechanisms that underlie these syndromes. Because individuals with inherited hematopoietic malignancies continue to be underdiagnosed and are increasingly likely to be encountered in clinical practice, clinicians need to have a high index of suspicion and be aware of the described syndromes. Here, we present the methods we use to identify, test, and manage individuals and families suspected of having a hereditary myeloid malignancy syndrome. Finally, we address the areas of ongoing research in the field and encourage clinicians and researchers to contribute and collaborate.

Immune responses to WT1 in patients with AML or MDS after chemotherapy and allogeneic stem cell transplantation

Wilms' tumor gene 1 (WT1) is overexpressed in leukemia and WT1-derived CD8(+) T-cell epitopes for immunotherapies targeting WT1 have been defined. Here, we analyzed expression of WT1 in 226 peripheral blood and bone marrow samples from patients with acute myeloid leukemia or myelodysplastic syndrome (AML/MDS) before and after allogeneic stem cell transplantation (SCT). Transcripts were assessed by quantitative polymerase chain reaction, and WT1-specific CD8+ cytotoxic T cells (CTL) were monitored by tetramer staining and enzyme-linked immunospot (ELISPOT) assays. Reduction of WT1 levels correlated with a longer survival (p < 0.01). Increment of WT1 transcripts eventually resulted in relapse and subsequent death of the patients. In patients with longer survival and continuous complete remission (cCR) after SCT, higher and enduring frequencies of WT1-specific CTL than in patients developing a relapse were detected. These cells were effector T cells secreting interferon gamma and granzyme B. In summary, WT1 is a suitable marker for the detection of minimal residual disease after SCT or chemotherapy. A rising WT1 signal correlated with a dismal prognosis of the patients. WT1-specific CD8(+) T cells might contribute to the maintenance of a cCR. Targeting WT-1 by peptide/protein vaccination as well as adoptive transfer of genetically modified T cells are future options in the individualized therapy for AML/MDS patients.

T-cell depleted allogeneic hematopoietic cell transplants as a platform for adoptive therapy with leukemia selective or virus-specific T-cells

Allogeneic hematopoietic cell transplants adequately depleted of T-cells can reduce or prevent acute and chronic GVHD in both HLA-matched and haplotype-disparate hosts, without post-transplant prophylaxis with immunosuppressive drugs. Recent trials indicate that high doses of CD34+ progenitors from G-CSF mobilized peripheral blood leukocytes isolated and T-cell depleted by immunoadsorption to paramagnetic beads, when administered after myeloablative conditioning with TBI and chemotherapy or chemotherapy alone can secure consistent engraftment and abrogate GVHD in patients with acute leukemia without incurring an increased risk of a recurrent leukemia. Early clinical trials also indicate that high doses of in vitro generated leukemia-reactive donor T-cells can be adoptively transferred and can induce remissions of leukemia relapse without GVHD. Similarly, virus-specific T-cells generated from the transplant donor or an HLA partially matched third party, have induced remissions of Rituxan-refractory EBV lymphomas and can clear CMV disease or viremia persisting despite antiviral therapy in a high proportion of cases. Analyses of treatment responses and failures illustrate both the advantages and limitations of donor or banked, third party-derived T-cells, but underscore the potential of adoptive T-cell therapy in the absence of ongoing immunosuppression.

Increased expression of interferon signaling genes in the bone marrow microenvironment of myelodysplastic syndromes

Introduction

The bone marrow (BM) microenvironment plays an important role in the pathogenesis of myelodysplastic syndromes (MDS) through a reciprocal interaction with resident BM hematopoietic cells. We investigated the differences between BM mesenchymal stromal cells (MSCs) in MDS and normal individuals and identified genes involved in such differences.

Materials and Methods

BM-derived MSCs from 7 MDS patients (3 RCMD, 3 RAEB-1, and 1 RAEB-2) and 7 controls were cultured. Global gene expression was analyzed using a microarray.

Result

We found 314 differentially expressed genes (DEGs) in RCMD vs. control, 68 in RAEB vs. control, and 51 in RAEB vs. RCMD. All comparisons were clearly separated from one another by hierarchical clustering. The overall similarity between differential expression signatures from the RCMD vs. control comparison and the RAEB vs. control comparison was highly significant (p = 0), which indicates a common transcriptomic response in these two MDS subtypes. RCMD and RAEB simultaneously showed an up-regulation of interferon alpha/beta signaling and the ISG15 antiviral mechanism, and a significant fraction of the RAEB vs. control DEGs were also putative targets of transcription factors IRF and ICSBP. Pathways that involved RNA polymerases I and III and mitochondrial transcription were down-regulated in RAEB compared to RCMD.

Conclusion

Gene expression in the MDS BM microenvironment was different from that in normal BM and exhibited altered expression according to disease progression. The present study provides genetic evidence that inflammation and immune dysregulation responses that involve the interferon signaling pathway in the BM microenvironment are associated with MDS pathogenesis, which suggests BM MSCs as a possible therapeutic target in MDS.

Preferentially Expressed Antigen of Melanoma (PRAME) and Wilms' Tumor 1 (WT 1) Genes Expression in Childhood Acute Lymphoblastic Leukemia, Prognostic Role and Correlation with Survival

BACKGROUND:

Acute lymphocytic leukemia (ALL) is the most common hematologic malignancy in children. In young children it is also largely curable, with more than 90% of afflicted children achieving long-term remission. PRAME (Preferentially expressed antigen of melanoma) gene belongs to Group 3 class I HLA-restricted widely expressed antigens in which genes encoding widely expressed tumor antigens have been detected in many normal tissues as well as in histologically different types of tumors with no preferential expression on a certain type of cancer. It has been found to be expressed in a variety of cancer cells as leukemia & lymphoma. PRAME monitoring can be useful for detection of minimal residual disease and subsequent relapses particularly those leukemias in which specific tumor markers are unavailable. Wilms’ tumor1 (WT1) gene was identified as a gene that plays an important role in normal kidney development and inactivation of its function was shown to result in the development of Wilms’ tumors in paediatric patients. Disruption of WT1 function has been implicated in the formation of many different tumor types.

AIM:

to study how PRAME & WT 1 genes expression patterns influence cancer susceptibility & prognosis.

PATIENTS & METHODS:

50 patients with denovo childhood acute lymphoblastic leukemia, as well as 50 age and sex matched apparently healthy volunteers were genotyped for PRAME and WT1 genes expression by reverse transcription polymerase chain reaction (RT-PCR).

RESULTS:

PRAME gene was expressed in 34 of the patients (68%) and WT1 gene was expressed in 26 of the patients (52%). Expression of both genes was significantly higher compared to controls (P < 0.0001). Analysis of relapse free survival among our patients revealed that patients expressing PRAME gene or WT1 gene had better relapse free survival (p value=0.02 and 0.01 respectively). Relapse free survival increased significantly among patients coexpressing PRAME and WT 1(p value =0.001).

CONCLUSION:

It is concluded that the expression of PRAME and WT1 genes are indicators of favorable prognosis and can be useful tools for monitoring minimal residual disease (MRD) in acute leukemia especially in patients without known genetic markers. Differential expression between acute leukemia patients and healthy volunteers suggests that the immunogenic antigens (PRAME and WT1) are potential candidates for immunotherapy in childhood acute leukemia.

Does the level of WT1 expression predict the outcome in Philadelphia-negative myeloproliferative neoplasms?

AIMS

Despite the clinical importance of the leukemic transformation of chronic myeloproliferative neoplasms (MPNs), very little is known about markers that predict leukemic transformation. We studied WT1 expression in 37 MPN patients diagnosed as bcr-abl negative and JAK2 (V617F) positive with a molecular genetic test, and 23 healthy controls.

RESULTS

WT1 expression is higher in MPN patients compared with normal controls (p=0.002). According to the WT1 expression levels, patients were divided into two groups: high (≥0.205) and low (0-0.205) WT1 expression. Two out of six patients with a high WT1 expression level transformed to myelodysplastic syndrome at a 42- and 46-month follow-up, respectively.

CONCLUSIONS

Our results suggest that the overexpression of WT1 may play an important role in the leukemic transformation of MPNs.

MDS prognostic scoring systems – past, present, and future

The myelodysplastic syndromes (MDS) are a heterogeneous group of clonal myeloid haemopathies characterized by defective differentiation of haematopoietic cells and expansion of the abnormal clone. This leads to bone marrow failure with the resulting peripheral blood cytopenias and evolution to or toward acute myeloid leukaemia that characterize MDS clinically. The clinical heterogeneity of MDS has led several groups to analyze patient and clinical characteristics to develop prognostic scoring systems yielding estimates of overall and leukaemia-free survival to guide clinical decision-making. These models have evolved over time as our understanding of the pathogenesis, natural history, and treatment of MDS has improved. Rapid advances in flow cytometric analysis, adjuncts to standard metaphase cytogenetics, and gene mutation analysis are revolutionizing our understanding of MDS pathogenesis and prognosis. Despite the existence of multiple well-validated prognostic scoring systems, further refinements of current models with these new sources of prognostic data are needed and are described herein.

Real-time assessment of relapse risk based on the WT1 marker in acute leukemia and myelodysplastic syndrome patients after hematopoietic cell transplantation

Relapse is the major cause of treatment failure after allogeneic hematopoietic cell transplantation (alloHCT) for acute leukemia and myelodysplastic syndrome (MDS). Wilms' tumor Ag (WT1) is overexpressed in the majority of acute leukemia and MDS patients and has been proposed as a universal diagnostic marker for detection of impending relapse. Comprehensive studies have shown that WT1 transcript levels have predictive value in acute leukemia patients in CR after chemotherapy. However, the focus of this study is the period after alloHCT for predicting relapse onset. We analyzed the accumulation of WT1 mRNA transcripts in PB of 82 leukemia and MDS patients and defined specific molecular ratios for relapse prediction. The extensively validated WT1/c-ABL ratio was used to normalize increases in WT1 transcript levels. The observed lead time of crossing or exceeding set WT1 levels is presented along with linear interpolation to estimate the calculated day the WT1 thresholds were crossed. The WT1/c-ABL transcript ratio of 50 or above yielded 100% specificity and 75% sensitivity reliably predicting future relapse with an observed average of 29.4 days (s.d.=19.8) and a calculated average of 63 days (s.d.=29.3) lead time before morphologic confirmation. A lower ratio of 20 or above gave lower specificity, but higher sensitivity (84.8% and 87.5%, respectively) identified more patients who relapsed, at earlier times, providing an earlier warning with actual average lead time of 49.1 days (s.d.=30.8) and calculated average of 78 days (s.d.=28.8). WT1 transcript levels serve as a diagnostic relapse test with greater sensitivity than the morphologic approach used in the clinic as a readout.

Prognostic impact of WT1 expression prior to hematopoietic stem cell transplantation in children with malignant hematological diseases

PURPOSE

Malignant hematological diseases represent the most common pediatric cancer. As they cannot always be cured by chemotherapy alone, leukemia and myelodysplastic syndrome (MDS) are frequent medical indications for hematopoietic stem cell transplantation, yet even this treatment is not capable of preventing relapse for certain. Therefore, molecular markers are used to monitor minimal residual disease (MRD) to be enabled to react early to an impeding relapse. As specific markers are not always available, Wilms' tumor gene 1 (WT1) has been suggested as a universal marker, but has not yet been established clinically.

METHODS

We determined the level of WT1 gene expression in 130 children, adolescents and young adults with malignant hematological diseases prior to transplantation and evaluated its impact on patients' outcome. A real-time quantitative RT-PCR was used for this purpose.

RESULTS

The relationship between a high level of WT1 and the cumulative incidence of relapse, event-free survival and overall survival proved to be highly significant in univariate and multivariate analyses. Forty-eight percent of all patients with high WT1 levels suffered from a relapse, whereas only eight percent showing normal WT1 levels before transplantation relapsed. The most convincing result was found for acute myeloid leukemia (AML) and MDS.

CONCLUSION

We conclude that WT1 expression prior to transplantation qualifies as an independent prognostic factor and should be further evaluated for MRD monitoring. It might especially be useful for patients with AML or MDS missing specific markers.

Role of genotype-based approach in the clinical management of adult acute myeloid leukemia with normal cytogenetics

Acute myeloid leukemia (AML) is the most common form of acute leukemia affecting adults. Although it is a complex disease driven by numerous genetic and epigenetic abnormalities, nearly 50% of patients exhibit a normal karyotype (CN-AML) with an intermediate cytogenetic risk. However, a widespread genomic analysis has recently shown the recurrence of genomic aberrations in this category (mutations of FLT3, CEBPA, NPM1, RUNX1, TET2, IDH1/2, DNMT3A, ASXL1, MLL and WT1) thus revealing its marked genomic heterogeneity. In this perspective, a global gene expression analysis of AML patients provides an independent prognostic marker to categorize each patient into clinic-pathologic subgroups based on its molecular genetic defects. Consistently such classification, taking into account the uniqueness of each AML patient, furnishes an individualized treatment approach leading a step closer to personalized medicine. Overall the genome-wide analysis of AML patients, by providing novel insights into biology of this tumor, furnishes accurate prognostic markers as well as useful tools for selecting the most appropriate treatment option. Moreover it provides novel therapeutic targets useful to enhance efficacy of the current anti-AML therapeutics. Here we describe the prognostic relevance of such new genetic data and discuss how this approach can be used to improve survival and treatment of AML patients.

Risk stratification in myelodysplastic syndromes: is there a role for gene expression profiling?

Evaluation of: Pellagatti A, Benner A, Mills KI et al. Identification of gene expression-based prognostic markers in the hematopoietic stem cells of patients with myelodysplastic syndromes. J. Clin. Oncol. 31(28), 3557-3564 (2013). Patients with myelodysplastic syndromes (MDS) exhibit wide heterogeneity in clinical outcomes making accurate risk-stratification an integral part of the risk-adaptive management paradigm. Current prognostic schemes for MDS rely on clinicopathological parameters. Despite the increasing knowledge of the genetic landscape of MDS and the prognostic impact of many newly discovered molecular aberrations, none to date has been incorporated formally into the major risk models. Efforts are ongoing to use data generated from genome-wide high-throughput techniques to improve the 'individualized' outcome prediction for patients. We here discuss an important paper in which gene expression profiling (GEP) technology was applied to marrow CD34(+) cells from 125 MDS patients to generate and validate a standardized GEP-based prognostic signature.