Validation and comparison of 5th edition World Health Organization classification (WHO 2022) and International Consensus Classification proposals for MDS-SFB31.

The criteria of myelodysplastic syndromes (MDS) with mutated SFB31 (MDS-SFB31) proposed by the 5th edition of the WHO classification (WHO 2022) and the International Consensus Classification (ICC) need validation. We analysed 125 consecutive MDS cases with SFB31 mutation or ring sideroblasts (RS) ≥15% without excess blasts. We found that SFB31-negative MDS with RS had significantly different clinical features and worse prognosis. According to WHO 2022, the detection of ≥15% RS may substitute for SF3B1 mutation and our analyses support this proposal for similar prognosis of two groups after excluding high-risk genetic features referred by WHO 2022. Patients with variant allele frequency (VAF) <10% SFB31 tend to have briefer survival, supporting the VAF 10% threshold of ICC. Patients with multilineage dysplasia (MLD) had significantly shorter OS than those with single lineage dysplasia. MLD is still a powerful morphological marker of worse outcome in WHO 2022 and ICC-defined MDS-SF3B1.

Impact of the International Consensus Classification of myelodysplastic syndromes.

The impact of the 2022 International Consensus Classification (ICC) of myelodysplastic syndromes (MDS) needs study. We analysed data from 989 MDS subjects classified using the 2016 World Health Organization (WHO) criteria to determine the impact of the new proposal. Our analyses suggested the ICC criteria of MDS-SF3B1 identifies a more homogenous disease entity than the WHO 2016 criteria of myelodysplastic syndromes with ring sideroblasts (MDS-RS). MDS, not otherwise specified with single lineage dysplasia (MDS, NOS-SLD) patients had a better prognosis than MDS, NOS with multilineage dysplasia (MDS, NOS-MLD) patients. MDS with mutated TP53 and MDS/acute myeloid leukaemia with mutated TP53 patients had the briefest survivals. These data support the ICC of MDS, which allows more accurate diagnoses and risk stratification.

ASXL1 mutations accelerate bone marrow fibrosis via EGR1-TNFA axis-mediated neoplastic fibrocyte generation in myeloproliferative neoplasms.

Apart from the central role of the activated JAK/STAT signaling pathway, ASXL1 mutations are the most recurrent additional mutations in myeloproliferative neoplasms and occur much more commonly in myelofibrosis than in essential thrombocythemia and polycythemia vera. However, the mechanism of the association with ASXL1 mutations and bone marrow fibrosis remains unknown. Here, integrating our own data from patients with myeloproliferative neoplasms and a hematopoietic-specific Asxl1 deletion/Jak2V617F mouse model, we show that ASXL1 mutations are associated with advanced myeloproliferative neoplasm phenotypes and onset of myelofibrosis. ASXL1 mutations induce skewed monocyte/macrophage and neoplastic monocyte-derived fibrocyte differentiation, consequently they enhance inflammation and bone marrow fibrosis. Consistently, the loss of ASXL1 and JAK2V617F mutations in hematopoietic stem and progenitor cells leads to enhanced activation of polycomb group target genes, such as EGR1. The upregulation of EGR1, in turn, accounts for increased hematopoietic stem and progenitor cell commitment to the monocyte/macrophage lineage. Moreover, EGR1 induces the activation of TNFA and thereby further drives the differentiation of monocytes to fibrocytes. Accordingly, combined treatment with a TNFR antagonist and ruxolitinib significantly reduces fibrocyte production in vitro. Altogether, these findings demonstrate that ASXL1 mutations accelerate fibrocyte production and inflammation in myeloproliferative neoplasms via the EGR1-TNFA axis, explaining the cellular and molecular basis for bone marrow fibrosis and the proof-ofconcept for anti-fibrosis treatment.

Ruxolitinib combined with prednisone, thalidomide and danazol in patients with myelofibrosis: Results of a pilot study.

Ruxolitinib is a safe and effective therapy of myeloproliferative neoplasm-associated (MPN) myelofibrosis. However, often there are dose reductions and/or therapy interruptions because of therapy-related adverse events (AEs), especially anemia and thrombocytopenia. We previously reported combined therapy with prednisone, thalidomide and danazol (PTD) reversed anemia and thrombocytopenia in people with MPN-associated myelofibrosis. We wondered whether adding PTD to ruxolitinib might mitigate the hematologic AEs and thereby avoid the dose reduction of ruxolitinib and improve the efficacy. To test this hypothesis, we conducted a baseline hemoglobin and platelet concentration assignment prospective observational study in 72 patients comparing 3-month dose adjustment and efficacy of ruxolitinib with (N = 53, the study group) or without (N = 19, the control group) PTD. According to the platelet counts, the median daily ruxolitinib doses in the study group increased from 30 to 40 mg by week 12, whereas in the control group it remained at 30 mg (p = 0.019). In the study group 35 patients had a hemoglobin increase ≥10 g/L compared with no patient receiving ruxolitinib only (p < 0.001). Platelet increases >100 × 10E+9/L were seen in 56.6% and 5.3% of patients in the two groups, respectively (p < 0.001). In patients with anemia and thrombocytopenia, 18 patients in the study group had an anemia response at week 12 and 12 had a platelet increase of ≥50 × 10E+9/L. No patient in the control group achieved either response (p < 0.001 and p = 0.078). The study group had a more spleen response than the control group (p = 0.046). Peripheral edema and transaminase elevation were the main nonhematologic AEs of PTD. These AEs can be alleviated by adjusting the danazol dose. In conclusion, adding PTD to ruxolitinib improved ruxolitinib-associated anemia and thrombocytopenia, and resulted in a higher ruxolitinib dose.

Molecular and clinical features of myeloid neoplasms with somatic DDX41 mutations.

We screened 47 subjects with DDX41 variants among 1529 subjects with myeloid neoplasms. The most common germline variants included Splice c.935 + 4A>T, p.T360Ifs*33, p.V152G, p.S217Ifs*4, p.R311* and p.R369*. Except for the p.R369*, no other variants have been previously reported. Clinical covariates of subjects with simple DDX41 somatic variants and germline/somatic biallelic variants are similar. The two-year overall survival (OS) of subjects with DDX41 variants was 85%. Overall response rate to demethylation therapy in subjects with DDX41 variants was 69%. The response did not correlate with the presence of a germline variant.

Is race important in genomic classification of hematological neoplasms?

In recent years, genome-based classifications for hematological neoplasms have been proposed successively and proved to be more accurate than histologic classifications. However, some previous studies have reported the racial differences of genetic landscape in persons with hematological neoplasms including myelodysplastic syndromes (MDS), which may cause a genomic classification based on a particular ethnic group does not operate in other races. To determine whether race plays an important role in the genomic-based classification, we validated a newly proposed genomic classification of MDS (J Clin Oncol.2021; JCO2001659), which was based on a large European database, in Chinese patients from our center. Our results showed significant differences between Chinese and European patients including proportion of each group to overall cohort when applying this novel genomic classification. Our data indicate that a genomic classification of hematological neoplasms probably should be revised according to specific genetic features in different races.

Evaluation of Reduced-Dose Decitabine and Azacitidine for Treating Myelodysplastic Syndromes: A Retrospective Study.

BACKGROUND Hypomethylating agents (HMA) are considered the first-line therapy for high-risk myelodysplastic syndromes (MDS). However, as the efficacy and safety of rational dosing regimens are lacking, we evaluated the effectiveness and safety of reduced-dose azacitidine (AZA) vs. decitabine (DAC) in adult MDS patients. MATERIAL AND METHODS This retrospective study was conducted at the Institute of Hematology & Blood Diseases Hospital, for hospitalized MDS patients diagnosed (WHO 2008 classification criteria) from May 2006 to February 2020. These AZA- and DCA-naive patients treated with AZA 100 mg/(m²·day) for 5 days to 7 days or DAC 20 mg/(m²·day) for 3 days to 4 days, or 20 mg/(m²·day) 1 day/week for 3 weeks/month were assessed for treatment responses and adverse events. RESULTS Of the 158 enrolled MDS patients, 120 and 38 patients were administered reduced-dose DAC and AZA, respectively. All the patients received a median of 2 treatment cycles. The overall response rates (ORR) were 50.0% and 73.3% in the AZA and DAC groups, respectively (P=0.007). The percentage of platelet transfusion dependence in the AZA group was lower than the DAC group (P=0.026). The multivariate analysis demonstrated that the DAC treatment was a significant factor for improved responses (OR 2.928; 95% CI 1.267-6.896; P=0.012), and the absolute neutrophil count (ANC) was a predictor of the ORR (OR 0.725; 95% CI 0.558-0.898; P=0.008). Neutropenia (P=0.016) and infection (P=0.032) incidences were higher in the DAC group. CONCLUSIONS The reduced-dose DAC group demonstrated a better response than the AZA group in MDS patients with different prognostic risks. The patients' pre-treatment ANC was a significant factor associated with the ORR.

Clinical features and biological implications of different U2AF1 mutation types in myelodysplastic syndromes.

U2AF1 mutations (U2AF1MT) occur commonly in myelodysplastic syndromes (MDS) without ring sideroblasts. The aim of this study was to investigate the clinical and biological implications of different U2AF1 mutation types in MDS. We performed targeted gene sequencing in a cohort of 511 MDS patients. Eighty-six patients (17%) were found to have U2AF1MT, which occurred more common in younger patients (P = .001) and represented ancestral lesions in a substantial proportion (71%) of cases. ASXL1MT and isolated +8 were significantly enriched in U2AF1MT-positive cases, whereas TP53MT, SF3B1MT, and complex karyotypes were inversely associated with U2AF1MT. U2AFS34 subjects were enriched for isolated +8 and were inversely associated with complex karyotypes. U2AF1MT was significantly associated with anemia, thrombocytopenia, and poor survival in both lower-risk and higher-risk MDS. U2AF1S34 subjects had more frequently platelet levels of <50 × 109 /L (P = .043) and U2AF1Q157 /U2AF1R156 subjects had more frequently hemoglobin concentrations at <80 g/L (P = .008) and more often overt fibrosis (P = .049). In conclusion, our study indicates that U2AF1MT is one of the earliest genetic events in MDS patients and that different types of U2AF1MT have distinct clinical and biological characteristics.

Unique features of primary myelofibrosis in Chinese.

Clinical and laboratory features of 642 consecutive Chinese subjects with primary myelofibrosis (PMF) were analyzed and compared with those of 1054 predominately white subjects with PMF. Chinese subjects were significantly younger, fewer had constitutional symptoms, and fewer had a palpable spleen or liver. Anemia, in contrast, was significantly more common in Chinese as was an increased white blood cell count and low platelet count. The reason for these differences is unclear, but it does not seem to be correlated with delayed diagnosis. A small but significantly increased proportion of Chinese had the JAK2(V617F) mutation but no difference in the frequency of haplotypes associated with PMF in whites. Survival of Chinese with PMF was also significantly longer than that of whites with PMF. We found commonly used staging systems for PMF such as the International Prognostic Scoring System and the Dynamic International Prognostic Scoring System were suboptimal predictors of survival in Chinese with PMF, and we developed a revised prognostic score that should help in comparison of data between studies of PMF in different populations and planning of clinical trials.

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.

Cytogenetic studies and their prognostic contribution in 565 Chinese patients with primary myelofibrosis.

To study the feature and prognostic contribution of cytogenetic information in Chinese patients with primary myelofibrosis (PMF), we analyzed cytogenetic data from 565 patients with PMF. One hundred and sixty-two subjects (29%) had abnormal karyotypes, including trisomy 8 (45; 28%), deletion of 20q (25; 15%), deletion of 13q (13; 8%), deletion of 11q (12; 7%), and abnormal chromosome 1 (21; 13%); balanced translocations (14; 9%); a complex karyotype (CK; 30; 19%), and a monosomal karyotype (MK; 19; 12%). Using these data, we showed that the Dynamic International Prognostic Scoring System (DIPSS)-plus, which includes cytogenetic information, is a better survival predictor than the DIPSS. We next used our data to construct the following two cytogenetic-based cohorts: (1) favorable karyotype-subjects with a normal karyotype, a CK that is not a MK, +8 only or a balanced translocation only and (2) unfavorable karyotype-all others. The median survival times were not reached and were 52 month (95% CI, 32-72 months; P = 0.01) in patients with favorable and unfavorable karyotypes, respectively. These data provided the detailed cytogenetic information in Chinese patients with PMF and confirmed the impact of cytogenetic abnormalities on survival in Chinese patients.

Monosomal karyotype is an independent predictor of survival in patients with higher-risk myelodysplastic syndrome.

A monosomal karyotype (MK) correlates with poor survival in patients with acute myeloid leukemia, although whether this is also the case in patients with myelodysplastic syndrome (MDS) remains controversial. Some studies report a correlation between a MK and a worse survival, whereas others claim that this correlation arises because of a confounding effect between a MK and a complex karyotype (CK). To address this question, we analyzed the clinical data and karyotypes of 610 adults with MDS. A MK was identified in 60 patients, of whom 55 (92%) also fulfilled the criteria for a CK. Conversely, a CK was found in 85 patients, of whom 55 (65%) also had a MK. To determine the impact of a MK on survival, 464 patients who received nonintensive therapies for MDS were analyzed separately. Patients with a MK demonstrated worse survival than those without a MK in univariate analyses (median, 8 months [95% CI, 3-12 months] versus 83 months [63-103 months]; P < 0.001). This effect was observed predominately in the cohorts of higher-risk patients according to the Revised International Prognostic Scoring System and the World Health Organization Prognostic Scoring System (HR [hazard ratio] 3.94 [1.97-7.89]; P < 0.001 and 4.937 [2.45-9.94]; P < 0.001, respectively) and surpassed the impact of a CK in the final survival models. Our data suggest that the addition of MK as a binary variable could improve the predictive accuracy of current models to estimate the survival of patients with MDS.

Combination therapy with venetoclax and azacitidine for the treatment of myelodysplastic syndromes with DDX41 mutations.

Myelodysplastic syndromes (MDS) patients with DEAD-box helicase 41 (DDX41) mutations have been reported to be treated effectively with lenalidomide; however, there are no randomized studies to prove it. Venetoclax and azacitidine are safe and effective in high-risk MDS/AML. In this study, we evaluated the efficacy of venetoclax and azacitidine combination therapy in eight consecutive MDS patients with DDX41 mutations at our centre from March 2021 to November 2023. We retrospectively analyzed the genetic features and clinical characteristics of these patients. Our findings suggest that MDS patients with DDX41 mutation may benefit from the therapy, for six subjects received this regimen as initial therapy and five of the six subjects achieved complete remission.

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.

Gadd45g insufficiency drives the pathogenesis of myeloproliferative neoplasms.

Despite the identification of driver mutations leading to the initiation of myeloproliferative neoplasms (MPNs), the molecular pathogenesis of MPNs remains incompletely understood. Here, we demonstrate that growth arrest and DNA damage inducible gamma (GADD45g) is expressed at significantly lower levels in patients with MPNs, and JAK2V617F mutation and histone deacetylation contribute to its reduced expression. Downregulation of GADD45g plays a tumor-promoting role in human MPN cells. Gadd45g insufficiency in the murine hematopoietic system alone leads to significantly enhanced growth and self-renewal capacity of myeloid-biased hematopoietic stem cells, and the development of phenotypes resembling MPNs. Mechanistically, the pathogenic role of GADD45g insufficiency is mediated through a cascade of activations of RAC2, PAK1 and PI3K-AKT signaling pathways. These data characterize GADD45g deficiency as a novel pathogenic factor in MPNs.