Acute megakaryoblastic leukemia, unlike acute erythroid leukemia, predicts an unfavorable outcome after allogeneic HSCT

Unmanipulated haploidentical hematopoietic stem cell transplantation for pediatric de novo acute megakaryoblastic leukemia without Down syndrome in China: A single-center study

Background

AMKL without DS is a rare but aggressive hematological malignant disease in children, and it is associated with inferior outcomes. Several researchers have regarded pediatric AMKL without DS as high-risk or at least intermediate-risk AML and proposed that upfront allogenic hematopoietic stem cell transplantation (HSCT) in first complete remission might improve long-term survival.

Patients and method

We conducted a retrospective study with twenty-five pediatric (< 14 years old) AMKL patients without DS who underwent haploidentical HSCT in the Peking University Institute of Hematology, Peking University People's Hospital from July 2016 to July 2021. The diagnostic criteria of AMKL without DS were adapted from the FAB and WHO: ≥ 20% blasts in the bone marrow, and those blasts expressed at least one or more of the platelet glycoproteins: CD41, CD61, or CD42. AMKL with DS and therapy related AML was excluded. Children without a suitable closely HLA-matched related or unrelated donor (donors with more than nine out of 10 matching HLA-A, HLA-B, HLA-C, HLA-DR, and HLA-DQ loci), were eligible to receive haploidentical HSCT. Definition was adapted from international cooperation group. All statistical tests were conducted with SPSS v.24 and R v.3.6.3.

Results

The 2-year OS was 54.5 ± 10.3%, and the EFS was 50.9 ± 10.2% in pediatric AMKL without DS undergoing haplo-HSCT. Statistically significantly better EFS was observed in patients with trisomy 19 than in patients without trisomy 19 (80 ± 12.6% and 33.3 ± 12.2%, respectively, P = 0.045), and OS was better in patients with trisomy 19 but with no statistical significance (P = 0.114). MRD negative pre-HSCT patients showed a better OS and EFS than those who were positive (P < 0.001 and P = 0.003, respectively). Eleven patients relapsed post HSCT. The median time to relapse post HSCT was 2.1 months (range: 1.0-14.4 months). The 2-year cumulative incidence of relapse (CIR) was 46.1 ± 11.6%. One patient developed bronchiolitis obliterans and respiratory failure and died at d + 98 post HSCT.

Conclusion

AMKL without DS is a rare but aggressive hematological malignant disease in children, and it is associated with inferior outcomes. Trisomy 19 and MRD negative pre-HSCT might contribute to a better EFS and OS. Our TRM was low, haplo-HSCT might be an option for high-risk AMKL without DS.

Erythroblast predominance without CD41/cyCD41-positive blasts predicts favorable prognosis in patients with myelodysplastic syndromes and acute myeloid leukemias treated with azacitidine

This study examined the prognostic impact of erythroblast predominance (EP) in 61 patients with myelodysplastic syndromes (MDS) (n = 51) or acute myeloid leukemia (n = 10) treated with azacitidine. Median age was 78 years. EP, defined as > 40% erythroblasts and M/E < 1.0, was found in 21 patients, including 9 complex karyotypes (CK). In the 24 CK of the entire cohort, 5 were hyperdiploid and 15 were monosomal karyotype with -5/5q-, and 10 had immunophenotypically CD41/cyCD41 positive blasts (cyCD41+). The complete response (CR) rate was 32.8%. Median follow-up was 14 months, and median overall survival (OS) was 17 months. Although all patients with EP achieved high CR rates (61.9%) and extended OS (28 M, P = 0.056), patients with EP and cyCD41+ blasts had shorter OS (8 M, P = 0.002). EP (HR 0.39, P = 0.009) and cyCD41+ (HR 3.49, P = 0.018) were identified as prognostic factors in multivariate analysis. All patients with cyCD41+ had hyperdiploid or CK with -5/5q-. In conclusion, we divided patients into three risk categories: high (cyCD41+), low (EP without cyCD41+), and intermediate (non-CD41+ and non-EP), and median OS in these categories was 34, 17 and 8 months, respectively (P < 0.001).

Salvage Cord Blood Transplantation for Sustained Remission of Acute Megakaryoblastic Leukemia That Relapsed Early after Myeloablative Transplantation

Acute megakaryoblastic leukemia (AMKL) is a rare subtype of acute myeloid leukemia accompanied by an aggressive clinical course and dismal prognosis. We herein report a case of AMKL preceded by mediastinal germ cell tumor that relapsed early after allogeneic hematopoietic stem cell transplantation with myeloablative conditioning but was successfully treated using salvage cord blood transplantation (CBT) with reduced-intensity conditioning. Although several serious complications developed, sustained remission with a favorable general condition was ultimately achieved. Although an optimal therapeutic strategy remains to be established, the graft-versus-leukemia effect of CBT may be promising, even for the treatment of refractory AMKL.

[Clinical features and prognosis of pediatric acute megakaryocytic leukemia]

OBJECTIVE

To study the clinical features and prognosis of children with acute megakaryocytic leukemia (AMKL) and the clinical effect of acute myeloid leukemia 03 (AML03) regimen for the treatment of pediatric AMKL.

METHODS

The clinical data were collected from 47 children with AMKL who were diagnosed from May 2011 to December 2019. The treatment outcomes and prognostic factors were analyzed. The Kaplan-Meier method and the log-rank test were used for survival analysis.

RESULTS

Among the 47 children with AMKL, 22 with non-Down syndrome-AMKL were treated by the AML03 regimen, with a median follow-up time of 11.4 months. For the 22 non-Down syndrome-AMKL patients, the remission rate of bone marrow cytology was 85% and the negative rate of minimal residual disease (MRD) was 79% after induction Ⅱ, with a 2-year overall survival (OS) rate of (50±13)% and a 2-year event-free survival (EFS) rate of (40±12)%. The group with positive immunophenotypic marker CD56 had significantly lower 2-year EFS and OS rates than the group with negative CD56 (P < 0.05). The group without remission of bone marrow cytology after induction Ⅱ had significantly lower 2-year EFS and OS rates than the group with remission (P < 0.05). The group with positive MRD after induction Ⅱ had a significantly lower 2-year EFS rate than the group with negative MRD (P < 0.05). There was no significant difference in 2-year OS and EFS rates between the patients with transplantation and those without transplantation (P > 0.05).

CONCLUSIONS

Children with AMKL tend to have a low remission rate and a poor prognosis. Positive immunophenotypic marker CD56, bone marrow cytology during early treatment response, and MRD results are important factors influencing the prognosis. Allogeneic hematopoietic stem cell transplantation has no significant effect on the prognosis of AMKL.

Clinical diagnosis of adult patients with acute megakaryocytic leukemia

Acute megakaryocytic leukemia (AMKL) is a rare subtype of acute myeloid leukemia (AML), which is challenging to diagnose due to frequent myelofibrosis (MF) and a low percentage of blast cells. In the present study, clinical characteristics and experimental observations in 9 adult patients diagnosed with AMKL, who were recruited by the Sino-U.S. Shanghai Leukemia Co-operative Group, were analyzed in order to summarize the diagnostic experience and provide recommendations on diagnosing AMKL. All the patients were diagnosed according to the 2008 World Health Organization diagnostic criteria. The mean age of the patients with AMKL was 59 years (range, 53–68 years). A total of 8 patients had different degrees of anemia, and 2 patients had <5% marrow blasts present in the bone marrow; however, the percentage of positive cells with cluster of differentiation (CD)41 and CD61 expression was >20%, as demonstrated by flow cytometry. A total of 6 patients were positive for platelet-specific antigens, as indicated by immunocytochemistry. Furthermore, 7 patients presented with moderate or marked MF, as demonstrated by a bone marrow biopsy. Karyotypic analysis indicated that 6 patients had abnormal karyotypes. Only 1 patient exhibited the Janus kinase 2V617F mutation. Treatment efficiency was notably poor, with a median survival time of 6.0 months (range, 1.1–24.0 months). In conclusion, the diagnosis of AMKL requires a combination of the results of bone marrow smears and bone marrow biopsy, immunophenotype or immunohistochemistry. We recommend that routine immunophenotypic analysis should include the CD41 and CD61 markers for diagnosing acute leukemia when bone marrow morphology does not indicate the diagnosis.

Normal and pathological erythropoiesis in adults: from gene regulation to targeted treatment concepts

Pathological erythropoiesis with consequent anemia is a leading cause of symptomatic morbidity in internal medicine. The etiologies of anemia are complex and include reactive as well as neoplastic conditions. Clonal expansion of erythroid cells in the bone marrow may result in peripheral erythrocytosis and polycythemia but can also result in anemia when clonal cells are dysplastic and have a maturation arrest that leads to apoptosis and hinders migration, a constellation typically seen in the myelodysplastic syndromes. Rarely, clonal expansion of immature erythroid blasts results in a clinical picture resembling erythroid leukemia. Although several mechanisms underlying normal and abnormal erythropoiesis and the pathogenesis of related disorders have been deciphered in recent years, little is known about specific markers and targets through which prognosis and therapy could be improved in anemic or polycythemic patients. In order to discuss new markers, targets and novel therapeutic approaches in erythroid disorders and the related pathologies, a workshop was organized in Vienna in April 2017. The outcomes of this workshop are summarized in this review, which includes a discussion of new diagnostic and prognostic markers, the updated WHO classification, and an overview of new drugs used to stimulate or to interfere with erythropoiesis in various neoplastic and reactive conditions. The use and usefulness of established and novel erythropoiesis-stimulating agents for various indications, including myelodysplastic syndromes and other neoplasms, are also discussed.

Hematopoietic stem cell transplantation for acute myeloid leukemia

Although allogeneic hematopoietic stem cell transplantation (allo-HSCT) yields a high rate of curability for acute myeloid leukemia (AML), it is also associated with transplant-related morbidity and mortality (TRM). The risk and severity of TRM increase with the use of an alternative donor graft in the absence of an HLA-matched sibling donor (MSD). With the declining birthrate and aging of the population, the numbers of patients with an MSD are decreasing, and alternative donor transplants, including the post-transplant cyclophosphamide method using haplo-identical donors, are increasing. Autologous (auto)-HSCT, which enables the intensification of chemotherapy, has the advantage of high availability of a transplant graft, and is associated with a lower TRM, but these benefits may be offset by a higher rate of relapse due to the lack of a graft-versus-leukemia (GVL) effect. Although allo-HSCT remains the first-line treatment for poor and very-poor-risk patients, auto-HSCT is again gaining increased attention. It has also recently been suggested that cord blood grafts may induce a stronger GVL effect than other grafts; as such, the positioning of cord blood transplantation should also be reconsidered for AML patients.

Adult acute megakaryoblastic leukemia: rare association with cytopenias of undetermined significance and p210 and p190 BCR-ABL transcripts

Acute megakaryocytic leukemia (M7-AML) is a rare form of acute myeloid leukemia (AML), which is associated with poor prognosis. The case presented in the current report is a statement for the difficult diagnosis and clinical management of M7-AML in the context of a previous hematologic disorder of undetermined significance and associated genetic abnormalities. Probably, following the complete hematologic remission and further with induction chemotherapy plus tyrosine kinase inhibitor therapy, the clinical management of this case will be followed by a allogeneic bone marrow transplantation, the only proven therapy to improve overall survival.