How I treat myelodysplastic syndromes of childhood

[Pathogenesis and treatment progression of myelodysplastic syndrome combined with Behçets syndrome]

Myelodysplastic syndromes (MDS) are clonal hematopoietic neoplasms characterized by chronic cytopenias and abnormal cell morphology, with a propensity of progressing to bone marrow failure or acute myeloid leukemia. Behçet's syndrome is a systemic vasculitis characterized by recurrent oral ulcers, skin lesions, and ocular inflammation. In recent years, an increasing number of clinical cases with coexistence of MDS and Behçet's syndrome have been reported, suggesting a potential pathological relationship between these conditions. Abnormal immune cell activation, dysregulated cytokine secretion, and cytogenetic alterations are thought to play critical roles in the pathogenesis of MDS combined with Behçet's syndrome. Currently, treatment strategies for MDS combined with Behçet's syndrome are primarily individualized and include immunosuppressive therapy, cytotoxic drug therapy, targeted therapy, and hematopoietic stem cell transplantation. However, due to the limited number of case reports and insufficient research on the underlying mechanisms, selecting appropriate treatment options remains challenging. This article reviews the pathogenesis and interrelationships of MDS combined with Behçet's syndrome and summarizes recent advancements in treatment strategies, providing a reference for clinical management and further researches on related mechanisms.

Effectiveness of isavuconazole in invasive cerebral aspergillosis during hematopoietic stem cell transplantation in a pediatric patient with myelodysplastic syndrome: A case report

Pediatric myelodysplasia syndrome is often characterized by hypoplastic bone marrow morphology and predisposition to infection. Invasive aspergillosis during hematopoietic stem cell transplantation poses a significant threat and often requires voriconazole (VRCZ) therapy. However, difficulties in achieving appropriate VRCZ blood levels due to drug interactions have prompted the exploration of alternative treatments, such as isavuconazole (ISCZ). We present the case of a 4-year-old boy with myelodysplasia syndrome who developed multiple abscesses, including a brain abscess caused by Aspergillus fumigatus, and was successfully treated with ISCZ. Despite initial treatment with liposomal amphotericin B and VRCZ, the patient's condition deteriorated. Transitioning to ISCZ treatment resulted in significant clinical improvement, resolution of the abscesses, and reduced antigen levels. Although ISCZ induced hepatic enzyme elevation, supportive care improved without discontinuation of treatment. This case highlights the potential of ISCZ in cases of pediatric invasive aspergillosis where traditional therapies fail, underscoring the need for further research and formulation development to optimize its use in this population. As more cases accumulate, ISCZ may become a promising option for treating severe invasive aspergillosis in pediatric patients undergoing hematopoietic stem cell transplantation.

How we diagnose Myelodysplastic syndromes

The Myelodysplastic syndromes (MDS) are a heterogenous group of clonal bone marrow (BM) stem cell myeloid neoplasms, characterized by ineffective hematopoiesis that results in dysplasia in hematopoietic cells and peripheral cytopenias, especially anemia, and a propensity to leukemic transformation. The suspicion of MDS is raised by a typical but not specific clinical picture and routine laboratory findings, but the gold standard for MDS diagnosis is still BM examination with the presence of uni-or multi-lineage dysplasia and increased blast percentage, together with exclusion of other reasons. Cytogenetics is also an essential part of the diagnostic and prognostic processes. Flow cytometry and full genetic characterization are helpful but not mandatory for MDS diagnosis. This review summarizes the current steps of diagnostic approach for a patient suspected of having MDS. We also express our hopes that within the near future, non-invasive technologies, especially digital and peripheral blood genetics, will mature and be introduced into practice.

Characteristics and outcomes of children, adolescent, and young adult patients with myelodysplastic neoplasms: A single-center retrospective analysis

Myelodysplastic syndrome, or myelodysplastic neoplasms, are a rare finding in pediatric, adolescent, and young adult (AYA) patients. More literature is needed to highlight trends of survival or treatment resistance in subpopulations to improve treatment. Here we report a single center retrospective analysis of pediatric and AYA patients from 2000 to 2022 including molecular and cytogenetic data. Using the IPSS-R and IPSS-M, which have been reported exclusively in adults, and excluding patients with bone marrow failure syndromes, we analyzed 119 pediatric and AYA patients with myelodysplastic neoplasms. Therapy-related myelodysplastic neoplasms were present in 36 % of patients, and 31 % of patients developed acute myeloid leukemia. The 5-year overall survival (OS) rate for the entire cohort was 45 %. Contrary to young adults and older adults, mutations were not common in pediatrics. Those who underwent stem cell transplant (SCT)(at any time) had significantly longer median OS. Although SCT at any time improved OS in the de novo myelodysplastic neoplasm group, the choice of the initial treatment with intensive chemotherapy, hypomethylating agents, or SCT did not significantly alter OS. Median OS was shorter in the pediatric group (<18 years old) and longer for those with isolated deletion of 5q or TET2 mutation, but these were not significant findings. Median OS was significantly shorter in those with monosomy 7 or 7q deletion and those with therapy-related myelodysplastic neoplasms. These findings build on previously reported findings and encourage the use of SCT along with molecular and cytogenetic analysis.

Venetoclax: a new player in the treatment of children with high-risk myeloid malignancies?

ABSTRACT

Venetoclax selectively inhibits B-cell lymphoma 2 (BCL-2) and restores apoptotic signaling of hematologic malignant cells. Venetoclax, in combination with hypomethylating and low-dose cytotoxic agents, has revolutionized the management of older patients affected by acute myeloid leukemia (AML) and that of patients unfit to receive intensive chemotherapy. In a single phase 1 pediatric trial conducted on relapsed or refractory AML, the combination of venetoclax and intensive chemotherapy was shown to be safe and yielded promising response rates. In addition, several retrospective studies in children with AML reported that venetoclax, when combined with hypomethylating agents and cytotoxic drugs, seems to be a safe and efficacious bridge to transplant. The promising results on the use of venetoclax combinations in advanced myelodysplastic syndromes (MDS) and therapy-related MDS/AML have also been reported in small case series. This review summarizes the available current knowledge about venetoclax use in childhood high-risk myeloid neoplasms and discusses the possible integration of BCL-2 inhibition in the current treatment algorithm of these children. It also focuses on specific genetic subgroups potentially associated with response in preclinical and clinical studies.

Prospective genetic germline evaluation in a consecutive group of adult patients aged <60 years with myelodysplastic syndromes

Relevance of germline (GL) predisposition in myelodysplastic syndromes (MDSs) was stressed in both 2022 WHO and International Consensus classifications, but its incidence is probably underestimated, especially in young adult patients. We selected a cohort of 31 consecutive de novo MDS patients with unusual young age (<60 years). We performed exome sequencing (ES) on DNA extracted from noninvasive sources (peripheral blood and saliva), filtering for a panel of 344 genes specifically tailored for detecting GL variants related to clonal and nonclonal cytopenia. We observed at least one high- or low-confidence GL MDS variant in 7/31 (22.6%) and 9/31 (29.0%) of cases, respectively. Four of 31 patients (12.9%) confirmed having established MDS/AML predisposing disorders. We found heterozygous variants in genes involved in DNA repair/cancer predisposition (ATM, ATR, FANCM, PARN, BRCA1, BRCA2, CHEK2, MSH2) in 9/31 (29.0%) cases and variants affecting ribosome biogenesis (SBDS), hematopoietic stem cell (GATA2), and megakaryocyte (ANKRD26) differentiation in single cases. Two cases had variants in RBBP6, a gene previously described exclusively in familial myeloproliferative neoplasms. Lastly, four cases had variants in genes related to inherited anemias (CUBN and PIEZO1 genes). Our results showed that "young" MDS patients aged 40-60 years carried reported and unreported GL variants with an unexpectedly high proportion, and these events co-occurred with somatic mutations recurrent in myeloid neoplasms. We explored the "no man's land" of the young adult MDS cases adopting a practical and scalable diagnostic tool, capable to detect GL variants avoiding invasive methods.

Childhood myelodysplastic syndromes: Is cytoreductive therapy useful before allogeneic hematopoietic stem cell transplantation?

For most patients with childhood myelodysplastic syndrome (cMDS), allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains the only curative option. In the case of increased blasts (cMDS-IB), the benefit of pretransplant cytoreductive therapy remains controversial. In this multicenter retrospective study, the outcomes of all French children who underwent allo-HSCT for cMDS reported in the SFGM-TC registry between 2000 and 2020 were analyzed (n = 84). The median age at transplantation was 10.2 years. HSCT was performed from matched sibling donors (MSD) in 29% of the cases, matched unrelated donors (MUD) in 44%, haploidentical in 6%, and cord blood in 21%. Myeloablative conditioning was used in 91% of cases. Forty-eight percent of patients presented with cMDS-IB at diagnosis (median BM blasts: 8%). Among them, 50% received pretransplant cytoreductive therapy. Five-year overall survival (OS), cumulative incidence of nonrelapse mortality (NRM), and relapse were 67%, 26%, and 12%, respectively. Six-month cumulative incidence of grade II-IV acute graft-versus-host disease was 46%. Considering the whole cohort, age under 12, busulfan/cyclophosphamide/melphalan conditioning or MUD were associated with poorer 5-year OS. In the cMDS-IB subgroup, pretransplant cytoreductive therapy was associated with a better OS in univariate analysis. This seems to be mainly due to a decreased NRM since no impact on the incidence of relapse was observed. Overall, those data may argue in favor of cytoreduction for cMDS-IB. They need to be confirmed on a larger scale and prospectively.

Romiplostim for Treatment of Children and Young Adults With Severe Aplastic Anemia and Myelodysplastic Syndrome

Thrombopoietin receptor agonists (TPO-RAs) induce trilineage hematopoiesis under conditions with acquired hematopoietic failure. We evaluated safety, tolerability, and preliminary efficacy of a TPO-RA, romiplostim (Nplate), with or without standard-of-care immunosuppressive therapy (±IST) for children (ages < 21 y) with newly diagnosed and relapsed/refractory severe aplastic anemia (SAA) and myelodysplastic syndrome (MDS). Data were collected from an observational study and a single arm interventional pilot study. The safety outcome was treatment-related adverse events (AEs). Efficacy was evaluated by complete hematopoietic response (CHR) at week 24. Romiplostim was commenced at 5 µg/kg/week, with dose escalation of 2.5 µg/kg/week (maximum, 20 µg/kg/dose) based on platelet response. Romiplostim was continued until CHR was observed. Ten subjects (SAA, 9 [IST, 4; without IST, 5]; MDS, 1) completed the study (median age: 9.2 y). Median romiplostim dose was 10 µg/kg/week (range: 5 to 17.5 µg/kg/week). The cumulative incidence of CHR was 70.4% (95% CI, 20.2%-92.6%). Among 21 AEs (Grade 1 to 3), 3 were attributed to romiplostim. At a median posttherapy follow-up of 10.9 months (range: 0.7 to 77.5), no clonal evolution, bone marrow fibrosis or mortality was reported. This proof-of-concept study provides data about short-term safety, tolerability, and preliminary efficacy of romiplostim (±IST) for treatment of pediatric SAA/MDS.

The different faces of GATA2 deficiency: implications for therapy and surveillance

GATA2 deficiency is one of the most common genetic predispositions to pediatric myelodysplastic syndrome (MDS) in children and adolescents. The wide spectrum of disease comprises, among others, hematological, immunological and pulmonary manifestations, as well as occasionally distinct organ anomalies. Due to the elevated risk of progression, nearly all individuals with GATA2-related MDS eventually undergo a hematopoietic stem cell transplantation (HSCT) at some point in their lives. Nevertheless, the optimal timing, method, and even the indication for HSCT in certain cases are still matter of debate and warrant further research. In this article, we report five patients with different hematological and immunological manifestations of GATA2 deficiency ranging from immunodeficiency and refractory cytopenia of childhood without chromosomal aberrations to relapsed MDS-related acute myeloid leukemia. We discuss the adopted strategies, including intensity of surveillance, indication and timing of HSCT, based on morphological, clinical and molecular markers, as well as individual patient needs. We conclude that a better characterization of the natural disease course, a better understanding of the prognostic significance of somatic aberrations and a thorough evaluation of patients´ perspectives and preferences are required to achieve a personalized approach aimed at improving the care of these patients.

Assessment of a novel NRAS in-frame tandem duplication causing a myelodysplastic/myeloproliferative neoplasm

Myelodysplastic/myeloproliferative diseases of childhood cause a relevant disease burden, and many of these diseases may have a fatal course. The use of next-generation sequencing (NGS) has led to the identification of novel genetic variants in patients with these diseases, advancing our understanding of the underlying pathophysiology. However, novel mutations can often only be interpreted as variants of unknown significance (VUS), hindering adequate diagnosis and the use of a targeted therapy. To improve variant interpretation and test targeted therapies in a preclinical setting, we are using a rapid zebrafish embryo model that allows functional evaluation of the novel variant and possible therapeutic approaches within days. Thereby, we accelerate the translation from genetic findings to treatment options. Here, we establish this workflow on a novel in-frame tandem duplication in NRAS (c.192_227dup; p.G75_E76insDS65_G75) identified by Sanger sequencing in a 2.5-year-old patient with an unclassifiable myelodysplastic/myeloproliferative neoplasm (MDS/MPN-U). We show that this variant results in a myeloproliferative phenotype in zebrafish embryos with expansion of immature myeloid cells in the caudal hematopoietic tissue, which can be reversed by MEK inhibition. Thus, we could reclassify the variant from likely pathogenic to pathogenic using the American College of Medical Genetics (ACMG) criteria.

Efficacy and safety of azacitidine in pediatric patients with newly diagnosed advanced myelodysplastic syndromes before hematopoietic stem cell transplantation in the AZA-JMML-001 trial

Here we report efficacy, pharmacokinetics, and safety data obtained in treatment-naive, pediatric patients with newly diagnosed advanced MDS receiving azacitidine in the AZA-JMML-001 study. The primary endpoint was response rate (proportion of patients with complete response [CR], partial response [PR], or marrow CR, sustained for ≥4 weeks). Of the 10 patients enrolled, one had an unconfirmed marrow CR and none had confirmed responses after three cycles; the study was therefore closed after stage 1. Azacitidine was well tolerated. The lack of efficacy of azacitidine in pediatric patients with newly diagnosed advanced MDS highlights the need for effective new treatments in these patients.

Outcome of Allogeneic Hematopoietic Stem Cell Transplantation in a Child with Myelodysplastic Neoplasm with Complex Karyotype and ETV6 Variant

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the only treatment with the potential for cure in patients with myelodysplastic neoplasm (MDS). Nevertheless, disease relapse is the main cause of treatment failure. Due to the rarity of childhood MDS (cMDS), there are few studies showing the impact of cytogenetic alterations and genetic variants on outcomes of allo-HSCT, mainly focusing on clonal chromosomal evolution (CCE) during relapse post-transplant. Here, we describe a 3-year-old boy with cMDS-IB, who evolved to MDS/AML. At diagnosis, the patient showed a complex karyotype with chromosomal abnormalities not yet reported together in the same clone, and likely a pathogenic variant in the ETV6 gene. The patient was treated with HLA-matched sibling HSCT, but unfortunately relapsed after HSCT with clonal cytogenetic evolution. This unfavorable outcome suggests that the treatment of pediatric MDS associated with predictive factors of poor prognosis, such as complex karyotype and ETV6 variant remains a challenge.

Decitabine-containing conditioning improved outcomes for children with higher-risk myelodysplastic syndrome undergoing allogeneic hematopoietic stem cell transplantation

Myelodysplastic syndrome (MDS) is a rare clonal hematopoietic disorder in children. The risk stratification system and treatment strategy for adults are unfit for children. The role of hypomethylating agents (HMAs) in higher-risk childhood MDS has not been identified. This study aimed to investigate the outcomes of hematopoietic stem cell transplantation (HSCT) in children with higher-risk MDS at one single center. A retrospective study was conducted in children with higher-risk MDS undergoing HSCT between September 2019 and March 2023 at Blood Diseases Hospital CAMS. The clinical characteristics and transplantation information were reviewed and analyzed. A total of 27 patients were analyzed, including 11 with MDS with excess blasts (MDS-EB), 14 with MDS-EB in transformation (MDS-EBt) or acute myeloid leukemia with myelodysplasia-related changes (AML-MRC), and 2 with therapy-related MDS/AML (t-MDS/AML). Eight patients harbored monosomy 7. Before transplantation, induction therapy was administered to 25 patients, and 19 of them achieved bone marrow blasts <5% before HSCT. The stem cell source was unmanipulated-related bone marrow or peripheral blood stem cells for nineteen patients and unrelated cord blood for eight. All patients received decitabine-containing and Bu/Cy-based myeloablative conditioning; 26 patients achieved initial engraftment. The cumulative incidences of grade II-IV and grade III-IV acute graft-versus-host disease (GvHD) at 100 days were 65.4% and 42.3%, respectively. The incidence of cGvHD was 38.5%. The median follow-up was 26 (range 4-49) months after transplantation. By the end of follow-up, two patients died of complications and two died of disease progression. The probability of 3-year overall survival (OS) was 84.8% (95%CI, 71.1 to 98.5%). In summary, decitabine-containing myeloablative conditioning resulted in excellent outcomes for children with higher-risk MDS undergoing allogeneic HSCT.

Rare Hematologic Malignancies and Pre-Leukemic Entities in Children and Adolescents Young Adults

There are a variety of rare hematologic malignancies and germline predispositions syndromes that occur in children and adolescent young adults (AYAs). These entities are important to recognize, as an accurate diagnosis is essential for risk assessment, prognostication, and treatment. This descriptive review summarizes rare hematologic malignancies, myelodysplastic neoplasms, and germline predispositions syndromes that occur in children and AYAs. We discuss the unique biology, characteristic genomic aberrations, rare presentations, diagnostic challenges, novel treatments, and outcomes associated with these rare entities.

The role of genetic factors in pediatric myelodysplastic syndromes with different outcomes

BACKGROUND

Pediatric myelodysplastic syndromes (MDS) are rare disorders with an unrevealed pathogenesis. Our aim is to explore the role of genetic factors in the pathogenesis of MDS in children with different outcomes and to discover the correlation between genetic features and clinical outcomes as well as disease characteristics.

METHODS

We conducted an analysis of archived genetic data from 26 patients diagnosed with pediatric MDS at our institution between 2015 and 2021, examining the association between different genetic characteristics and clinical manifestations as well as prognosis. Additionally, We presented three cases with distinct genetic background and outcomes as examples to elaborate the role of genetic factors in pediatric MDS with different prognoses.

RESULTS

Genetic variations were detected in 13 out of the 26 patients, including 8 patients with co-occurrence of somatic and germline mutations (CSGMs) and 5 patients with somatic mutations alone. Our analysis revealed that advanced MDS (4/8, 50% vs. 1/5, 20% and 4/11, 36.4%), PD (3/8, 37.5% vs. 1/5, 20% and 1/11 9.1%), and TD (6/8, 75% vs. 2/5, 40% and 2/11, 18.2%) were more common in patients with CSGMs than those with somatic mutations alone or without any mutations. We also found out in our study that 8 patients with CSGMs had evidently different clinical outcomes, and we presented 3 of them as examples for elaboration. Case 1 with germline and somatic mutations of unknown significance had a relatively slow disease course and a good prognosis. Case 2 with compound heterozygous germline SBDS variants and somatic mutations like del20q had a stable disease course and a reversed outcome. Case 3 with a germline GATA2 variant and somatic mutations including - 7 had a rapidly progressive disease course and a worst prognosis.

CONCLUSION

Our findings indicate that genetic background of pediatric MDS is closely linked with disease characteristics as well as outcomes and that CSGMs may lead to disease progression. It should be emphasized that the interaction between certain germline variants and somatic mutations, such as SBDS and del20q, may result in hematopoietic stem cell adaptation (improved hematopoiesis) and reversed clinical outcomes, which can facilitate the development of targeted therapy.

New-Onset Monosomy 7-Induced Pancytopenia in a 66-Year-Old Woman

Myelodysplastic syndrome (MDS) is characterized by failure to initiate hematopoiesis or impaired maturation of cells, often presenting with pancytopenias with or without associated fatigue, infections, or inappropriate bleeding and bruising. Karyotype analyses of MDS patients commonly show deletion of the q arm of chromosome 7, suggesting loss of this region is likely implicated in the insufficient hematopoiesis seen in MDS. The predisposition to deletion of 7q is commonly inherited, with clinical presentation in early childhood associated with pancytopenia or hematological malignancy. In this case, we present a 66-year-old female who was incidentally found to be pancytopenic in the emergency department while being evaluated for dyspnea, with a bone marrow biopsy later confirming a diagnosis of MDS with monosomy 7. Sporadic loss of 7q can occur at any stage in life without any family history of hematological disease. Our patient has no known personal or family history of MDS, with normal blood counts during hospitalization three years prior, suggesting de novo loss of 7q occurring at greater than 60 years of age.

Application of serum Raman spectroscopy in rapid and early discrimination of aplastic anemia and myelodysplastic syndrome

BACKGROUND

Raman spectroscopy of hematological diseases has gained attention from various researchers. However, serum analysis of bone marrow failure (BMF), represented by aplastic anemia (AA) and myelodysplastic syndromes (MDS) has not been fully investigated. In this study, we aimed at establishing a simple, non-invasive serum detection method for AA and MDS.

METHOD

Serum samples from 35 AA patients (N = 35), MDS patients (N = 25), and control volunteers (N = 23) were systematically analyzed via laser Raman spectroscopy, and orthogonal partial least squares discrimination analysis (OPLS-DA). Then, discrimination models between the BMFs and control were constructed and evaluated using the prediction set.

RESULTS

Compared to control volunteers, serum spectral data for BMF patients were specific. The intensities of Raman peaks representing nucleic acids (726, 781, 786, 1078, 1190, 1415 cm-1), proteins (1221 cm-1), phospholipid/cholesterol (1285 cm-1), and β-carotene (1162 cm-1) significantly decreased, while the intensity of lipids (1437 and 1446 cm-1) significantly increased. Intensities of Raman peaks representing nucleic acids (726 cm-1) and collagen (1344 cm-1) in the AA group were significantly lower than in the control group. Intensities of Raman peaks representing nucleic acids (726 and 786 cm-1), proteins (1003 cm-1), and collagen (1344 cm-1) in the MDS group were significantly lower than those of the control group. The intensity of Raman peaks representing lipids (1437 and 1443 cm-1) in the MDS group was significantly higher than in the control group. Patients with AA and MDS exhibited increased serum triglyceride levels and decreased high-density lipoprotein levels.

CONCLUSIONS

The relationship between serological test data for patients and typing of AA and MDS provides essential information for rapid and early identification of BMF. This study shows the potential of Raman spectroscopy for non-invasive detection of different BMF types.

Treatment Considerations of Myelodysplastic Syndromes/Neoplasms for Pathologists

The diagnosis of myelodysplastic syndromes/neoplasms (MDS) has evolved over the years with the incorporation of genetic abnormalities to establish a diagnosis, their impact on risk stratification, prognostication, and therapeutic options. Hematopathologists are the cornerstone to establish an accurate diagnosis and ensure patients receive the best available treatment option. Hematopathologists and clinicians must work closely together to establish the best disease subclassification, by combining pathologic findings with the clinical presentation. This will ensure patients receive the best therapeutic approach by better understanding the disease entity. In this review, we discuss how we approach a bone marrow biopsy report in the management of MDS.

Childhood Myelodysplastic Syndrome

Myelodysplastic syndrome (MDS) in children is rare, accounting for < 5% of all childhood hematologic malignancies. With the advent of next-generation sequencing, the etiology of many childhood MDS (cMDS) cases has been elucidated with the finding of predisposing germline mutations in one-quarter to one-third of cases; somatic mutations have also been identified, indicating that cMDS is different than adult MDS. Herein, cMDS classification schema, clinical presentation, laboratory values, bone marrow histology, differential diagnostic considerations, and the recent molecular findings of cMDS are described.

Pediatric Bone Marrow Failure: A Broad Landscape in Need of Personalized Management

Irreversible severe bone marrow failure (BMF) is a life-threatening condition in pediatric patients. Most important causes are inherited bone marrow failure syndromes (IBMFSs) and (pre)malignant diseases, such as myelodysplastic syndrome (MDS) and (idiopathic) aplastic anemia (AA). Timely treatment is essential to prevent infections and bleeding complications and increase overall survival (OS). Allogeneic hematopoietic stem cell transplantation (HSCT) provides a cure for most types of BMF but cannot restore non-hematological defects. When using a matched sibling donor (MSD) or a matched unrelated donor (MUD), the OS after HSCT ranges between 60 and 90%. Due to the introduction of post-transplantation cyclophosphamide (PT-Cy) to prevent graft versus host disease (GVHD), alternative donor HSCT can reach similar survival rates. Although HSCT can restore ineffective hematopoiesis, it is not always used as a first-line therapy due to the severe risks associated with HSCT. Therefore, depending on the underlying cause, other treatment options might be preferred. Finally, for IBMFSs with an identified genetic etiology, gene therapy might provide a novel treatment strategy as it could bypass certain limitations of HSCT. However, gene therapy for most IBMFSs is still in its infancy. This review summarizes current clinical practices for pediatric BMF, including HSCT as well as other disease-specific treatment options.

[Juvenile myelomonocytic leukemia and pediatric myelodysplastic syndromes]

Juvenile myelomonocytic leukemia (JMML) and myelodysplastic syndromes (MDS) of children are rare and aggressive diseases. They both have the particularity of being very frequently associated with an underlying predisposition syndrome, which must be systematically investigated by meticulous clinical exam completed by molecular analysis on fibroblasts, in order to guarantee the best therapeutic management. New generation sequencing techniques have made it possible to better define the landscape of constitutional predisposing pathologies, to understand the clonal evolution that leads to the development of hematological malignancies and to identify new prognostic markers. In these two diseases, the only curative treatment is allogeneic hematopoietic stem cell transplantation, for which the appropriate timeframe, the type of donor and the conditioning must be decided in consultation with the expert teams in each entity.

Treatment of recurrent pediatric myelodysplastic syndrome post hematopoietic stem cell transplantation

Treatment of recurrent myelodysplastic syndrome (MDS) after hematopoietic cell transplantation (HCT) remains challenging. We present a 4-year-old girl experiencing early MDS relapse post-HCT treated with a multimodal strategy encompassing a second HCT and innovative targeted therapies. We underscore the potential of a comprehensive treatment approach in managing recurrent pediatric MDS.

Azacitidine (Vidaza®) in Pediatric Patients with Relapsed Advanced MDS and JMML: Results of a Phase I/II Study by the ITCC Consortium and the EWOG-MDS Group (Study ITCC-015)

BACKGROUND

Advanced myelodysplastic syndrome (MDS) and juvenile myelomonocytic leukemia (JMML) are rare hematological malignancies in children. A second allograft is recommended if a relapse occurs after hematopoietic stem cell transplantation, but the outcome is poor.

OBJECTIVE

We conducted a phase I/II multicenter study to evaluate the safety, pharmacokinetics, and activity of azacitidine in children with relapsed MDS/JMML prior to the second hematopoietic stem cell transplantation.

METHODS

Patients enrolled from June 2013 to March 2019 received azacitidine intravenously/subcutaneously once daily on days 1-7 of a 28-day cycle. The MDS and JMML cohorts followed a two-stage design separately, with a safety run-in for JMML. Response and safety data were used to evaluate efficacy and establish the recommended dose. Pharmacokinetics was also analyzed. The study closed prematurely because of low recruitment.

RESULTS

Six patients with MDS and four patients with JMML received a median of three and five cycles, respectively. Azacitidine 75 mg/m2 was well tolerated and plasma concentration-time profiles were similar to observed in adults. The most prevalent grade 3-4 adverse event was myelotoxicity. No responses were seen in patients with MDS, but 83% achieved stable disease; four patients underwent an allotransplant. Overall response rate in the JMML cohort was 75% (two complete responses; one partial response) and all responders underwent hematopoietic stem cell transplantation. One-year overall survival was 67% (95% confidence interval 38-100) in MDS and 50% (95% confidence interval 19-100) in JMML.

CONCLUSIONS

Azacitidine 75 mg/m2 prior to a second hematopoietic stem cell transplantation is safe in children with relapsed MDS/JMML. Although the long-term advantage remains to be assessed, this study suggests that azacitidine is an efficacious option for relapsed JMML.

CLINICAL TRIAL REGISTRATION

EudraCT 2010-022235-10.

Haploidentical Hematopoietic Stem Cell Transplantation in Pediatric Patients with Acquired Hypocellular Bone Marrow Failure

Children with acquired hypocellular bone marrow failure of unknown cause (AHBMF) are usually diagnosed either with severe aplastic anemia (SAA) or refractory cytopenia of childhood (RCC). Patients with AHBMF who lack a matched donor and who failed or relapsed after immunosuppressive therapy (IST) need alternative therapies. Haploidentical hematopoietic stem cell transplantation (haplo-HSCT) offers a curative treatment for these patients. We report a multicenter Spanish experience with haplo-HSCT in pediatric patients with AHBMF. Eleven pediatric patients (SAA, n = 9; RCC, n = 2) underwent haplo-HSCT with different lymphodepletion strategies. Most patients (10 of 11) had previously failed to respond or relapsed after IST. The conditioning regimen was reduced intensity in SAA and myeloablative in RCC. Patients with SAA received low-dose radiotherapy as part of their conditioning regimen. All patients engrafted. Viral reactivation was common (8 of 11). Acute GVHD grade ≥II was seen in 5 patients. Chronic GVHD was diagnosed in 4 of the long-term survivors. Transplantation-associated microangiopathy was a frequent complication in SAA patients and was related to worse outcome. Two patients died of transplantation-related complications. Overall survival was 81%, with a median follow-up of 36 months. Haplo-HSCT can be a successful salvage curative treatment for pediatric patients with AHBMF, but with significant toxicities that must be addressed. Transplantation-associated microangiopathy was the most critical complication.

Optimizing diagnostic methods and stem cell transplantation outcomes in pediatric bone marrow failure: a 50-year single center experience

Peripheral blood cytopenia, a frequent presenting symptom in pediatric patients, can be caused by bone marrow failure (BMF). Timely identification of patients with non-reversible BMF is of crucial importance to reduce the risks of invasive infections and bleeding complications. Most pediatric patients with severe persistent cytopenia, independent of the underlying cause, are offered allogeneic hematopoietic stem cell transplantation (HSCT) as curative therapy. Here we report on our management guidelines and HSCT outcomes of pediatric BMF patients to pinpoint improvements and future challenges. We formulated recommendations based on this 50 years' experience, which were implemented at our center in 2017. By analysis of the HSCT cohort of 2017-2023, the 5-year outcome data is presented and compared to historical outcome data. In addition, outcomes of patients transplanted for identified inherited bone marrow failure syndromes (IBMFS) are compared to severe aplastic anemia (SAA) outcomes to underline the often multiorgan disease in IBMFS with implications for long-term survival. Survival of pediatric patients with irreversible BMF has improved tremendously. SAA patients transplanted after 2017 had a superior 5-year overall (OS) and event-free survival (EFS) of 97% and 85% compared to 68% and 59% in the cohort transplanted before 2017 (p = 0.0011 and p = 0.017). A similar trend was seen for BMF, with an OS and EFS of 89% for those transplanted after 2017 compared to 62% and 59% (p > 0.05). This improvement is mainly related to better survival in the first months after HSCT. The long-term survival after HSCT is lower in IBMFS patients as compared to SAA patients due to secondary malignancies and multiorgan toxicity.   Conclusion: Unbiased protocolized in-depth diagnostic strategies are crucial to increase the frequency of identifiable causes within the heterogeneous group of pediatric BMF. A comprehensive approach to identify the cause of BMF can prevent treatment delay and be useful to tailor treatment and follow-up protocols. What is Known: • Irreversible BMF in pediatric patients can be caused by a wide spectrum of underlying diseases including (pre)malignant disease, IBMFS and AA. Identifying the exact underlying cause of BMF is crucial for tailored therapy, however often challenging and time-consuming. • Frontline allogeneic HSCT is offered to most pediatric patients with severe BMF as curative treatment. What is New: • Protocolized unbiased diagnostics, short time to treatment (< 3 months) and maximal supportive care until curative treatment can prevent complications with a negative effect on survival such as infection and bleeding. • Personalized follow-up protocols for IBMFS patients are essential to prevent a second decline in survival due to long-term treatment toxicity and extra-hematological disease complications.

A Rare Concurrence of Myelodysplastic Neoplasia and Tetrasomy 8 in a 3-Year-Old Bahraini Male

Myelodysplastic neoplasia (MDS) is a group of stem cell disorders involving ineffective hematopoiesis. It can be associated with an increased risk of progression toward acute myeloid leukemia (AML). In Bahrain, MDS is the fifth most common primary hematologic malignancy. MDS has an annual incidence of up to 4 million cases. Some of the presenting signs and symptoms of MDS are often nonspecific, such as fatigue, pallor, malaise, fevers, bleeding, bruising, weight loss, and anorexia. Approximately 40% of patients with MDS progress to AML. This paper outlines a case of a 3-year-old Bahraini male (known to have sickle cell trait) who presented to the emergency department of Salmaniya Medical Complex with a five-day history of fever, congested throat, left ear pain, and abdominal pain. He had one episode of vomiting gastric content the previous day. He had previously gone to a private clinic with similar symptoms. Physical examination revealed a short neck and short stature, which was found to be below the 5th percentile. He had generalized pallor and hepatosplenomegaly. A blood smear showed leukopenia and normochromic normocytic anemia. There were excessive blasts found which consisted of 17% of nucleated cells and few granulopoietic cells. Erythropoiesis was active with a few showing mild megaloblastic changes. There were rare megakaryocytes noted. Moreover, the bone marrow aspirate showed two populations on dim CD45. The first population consisted of 3.15% on dim CD45 comprising of hematogones which brightly expressed CD19, HLA-DR, CD79a, and dim CD10. The second population consisted of 14.85% on dim CD45 which expressed CD34, CD13, CD117, HLA-DR, and dim CD7. Based on the peripheral blood smear and bone marrow immunophenotyping findings, a diagnosis of myelodysplastic syndrome with excessive blasts was made, which soon transformed into a diagnosis of AML. Furthermore, increased levels of dysplastic changes and percentage of blasts in the peripheral blood smear and bone marrow lead to a higher possibility of transformation into AML. As per the WHO classification, a diagnosis of MDS needs evaluation of the morphology of blood and bone marrow.

Pediatric Hematopathology in the Era of Advanced Molecular Diagnostics: What We Know and How We Can Apply the Updated Classifications

Pediatric hematologic malignancies often show genetic features distinct from their adult counterparts, which reflect the differences in their pathogenesis. Advances in the molecular diagnostics including the widespread use of next-generation sequencing technology have revolutionized the diagnostic workup for hematologic disorders and led to the identification of new disease subgroups as well as prognostic information that impacts the clinical treatment. The increasing recognition of the importance of germline predisposition in various hematologic malignancies also shapes the disease models and management. Although germline predisposition variants can occur in patients with myelodysplastic syndrome/neoplasm (MDS) of all ages, the frequency is highest in the pediatric patient population. Therefore, evaluation for germline predisposition in the pediatric group can have significant clinical impact. This review discusses the recent advances in juvenile myelomonocytic leukemia, pediatric acute myeloid leukemia, B-lymphoblastic leukemia/lymphoma, and pediatric MDS. This review also includes a brief discussion of the updated classifications from the International Consensus Classification (ICC) and the 5th edition World Health Organization (WHO) classification regarding these disease entities.

Telomere biology: from disorders to hematological diseases

Variations in the length of telomeres and pathogenic variants involved in telomere length maintenance have been correlated with several human diseases. Recent breakthroughs in telomere biology knowledge have contributed to the identification of illnesses named "telomeropathies" and revealed an association between telomere length and disease outcome. This review emphasizes the biology and physiology aspects of telomeres and describes prototype diseases in which telomeres are implicated in their pathophysiology. We also provide information on the role of telomeres in hematological diseases ranging from bone marrow failure syndromes to acute and chronic leukemias.

Multiple synchronous malignancies in an infant with concomitant homozygous BRCA2 and PMS2 mutations with Fanconi anemia phenotype

Hereditary cancer predisposition accounts for more than 10% of all cancers in pediatric age group and this is increasingly recognized as an important entity because of modern sequencing techniques. We report a rare association of two concurrent cancer predisposition syndromes, BRCA2 and PMS2, in a young child who presented with concurrent malignancies including Wilms tumor, myelodysplastic syndrome and an indeterminate brain lesion who succumbed to his disease. Multiple synchronous malignancies present difficult clinical and psycho-social challenges which need to be carefully addressed in the setting of a multi-disciplinary team approach.

Inherited bone marrow failure syndromes: a review of current practices and potential future research directions

PURPOSE OF REVIEW

Recent advances in diagnosis and treatment of inherited bone marrow failure syndromes (IBMFS) have significantly improved disease understanding and patient outcomes. Still, IBMFS present clinical challenges that require further progress. This review aims to provide an overview of the current state of diagnosis and treatment modalities of the major IBMFS seen in paediatrics and present areas of prioritization for future research.

RECENT FINDINGS

Haematopoietic cell transplantation (HCT) for IBMFS has greatly improved in recent years, shifting the research and clinical focus towards cancer predispositions and adverse effects of treatment. Each year, additional novel genes and pathogenic variants are described, and genotype-phenotype mapping becomes more sophisticated. Moreover, novel therapeutics exploring disease-specific mechanisms show promise to complement HCT and treat patients who cannot undergo current treatment options.

SUMMARY

Research on IBMFS should have short-term and long-term goals. Immediate challenges include solidifying diagnostic and treatment guidelines, cancer detection and treatment, and continued optimization of HCT. Long-term goals should emphasize genotype-phenotype mapping, genetic screening tools and gene-targeted therapy.

A Pediatric Case of Treatment-related Myelodysplastic Syndrome While on Therapy for Pre-B Acute Lymphoblastic Leukemia

BACKGROUND

Treatment-related myelodysplastic syndrome (t-MDS) is a rare late effect of cancer therapy. After alkylating agents, this typically occurs years after completion of therapy. Treatment of t-MDS in pediatrics is an allogeneic stem cell transplant, however, the prognosis remains poor.

OBSERVATIONS

This case demonstrates t-MDS developing in a patient receiving treatment for pre-B acute lymphoblastic leukemia. This patient was treated with a combination of hematopoietic stem cell transplant and hypomethylating agents.

CONCLUSIONS

These agents should be considered for use in patients with t-MDS, before transplant to limit additional chemotherapy and as maintenance therapy post-transplant to reduce the risk of relapse.

The International Consensus Classification (ICC) of hematologic neoplasms with germline predisposition, pediatric myelodysplastic syndrome, and juvenile myelomonocytic leukemia

Updating the classification of hematologic neoplasia with germline predisposition, pediatric myelodysplastic syndrome (MDS), and juvenile myelomonocytic leukemia (JMML) is critical for diagnosis, therapy, research, and clinical trials. Advances in next-generation sequencing technology have led to the identification of an expanding group of genes that predispose to the development of hematolymphoid neoplasia when mutated in germline configuration and inherited. This review encompasses recent advances in the classification of myeloid and lymphoblastic neoplasia with germline predisposition summarizing important genetic and phenotypic information, relevant laboratory testing, and pathologic bone marrow features. Genes are organized into three major categories including (1) those that are not associated with constitutional disorder and include CEBPA, DDX41, and TP53; (2) those associated with thrombocytopenia or platelet dysfunction including RUNX1, ANKRD26, and ETV6; and (3) those associated with constitutional disorders affecting multiple organ systems including GATA2, SAMD9, and SAMD9L, inherited genetic mutations associated with classic bone marrow failure syndromes and JMML, and Down syndrome. A provisional category of germline predisposition genes is created to recognize genes with growing evidence that may be formally included in future revised classifications as substantial supporting data emerges. We also detail advances in the classification of pediatric myelodysplastic syndrome (MDS), expanding the definition of refractory cytopenia of childhood (RCC) to include early manifestation of MDS in patients with germline predisposition. Finally, updates in the classification of juvenile myelomonocytic leukemia are presented which genetically define JMML as a myeloproliferative/myelodysplastic disease harboring canonical RAS pathway mutations. Diseases with features overlapping with JMML that do not carry RAS pathway mutations are classified as JMML-like. The review is based on the International Consensus Classification (ICC) of Myeloid and Lymphoid Neoplasms as reported by Arber et al. (Blood 140(11):1200-1228, 2022).

The International Consensus Classification of myelodysplastic syndromes and related entities

The International Consensus Classification (ICC) of myeloid neoplasms and acute leukemia has updated the classification of myelodysplastic syndromes (MDSs) and placed MDS in a broader group of clonal cytopenias that includes clonal cytopenia of undetermined significance (CCUS) and related entities. Although subject to some interobserver variability and lack of specificity, morphologic dysplasia remains the main feature that distinguishes MDS from other clonal cytopenias and defines MDS as a hematologic malignancy. The ICC has introduced some changes in the definition of MDS whereby some cases categorized as MDS based on cytogenetic abnormalities are now classified as CCUS, while SF3B1 and multi-hit TP53 mutations are now considered to be MDS-defining in a cytopenic patient. The ICC has also recognized several cytogenetic and molecular abnormalities that reclassify some cases of MDS with excess blasts as acute myeloid leukemia (AML) and has introduced a new MDS/AML entity that encompasses cases with 10-19% blasts that lie on the continuum between MDS and AML. Two new genetically defined categories of MDS have been introduced: MDS with mutated SF3B1 and MDS with mutated TP53, the latter requiring bi-allelic aberrations in the TP53 gene. The entity MDS, unclassifiable has been eliminated. These changes have resulted in an overall simplification of the MDS classification scheme from 8 separate entities (including 1 that was genetically defined) in the revised 4th edition WHO classification to 7 separate entities (including 3 that are genetically defined) in the ICC.

Anemia in the pediatric patient

The World Health Organization estimates that approximately a quarter of the world's population suffers from anemia, including almost half of preschool-age children. Globally, iron deficiency anemia is the most common cause of anemia. Other important causes of anemia in children are hemoglobinopathies, infection, and other chronic diseases. Anemia is associated with increased morbidity, including neurologic complications, increased risk of low birth weight, infection, and heart failure, as well as increased mortality. When approaching a child with anemia, detailed historical information, particularly diet, environmental exposures, and family history, often yield important clues to the diagnosis. Dysmorphic features on physical examination may indicate syndromic causes of anemia. Diagnostic testing involves a stepwise approach utilizing various laboratory techniques. The increasing availability of genetic testing is providing new mechanistic insights into inherited anemias and allowing diagnosis in many previously undiagnosed cases. Population-based approaches are being taken to address nutritional anemias. Novel pharmacologic agents and advances in gene therapy-based therapeutics have the potential to ameliorate anemia-associated disease and provide treatment strategies even in the most difficult and complex cases.

High-grade myelodysplastic syndrome in a pediatric multi-organ transplant recipient: A case report and literature review

BACKGROUND

Pediatric myelodysplastic syndrome is a rare but life-threatening condition requiring prompt recognition and management.

METHODS

We herein present the only reported case of a pediatric multi-organ transplant recipient developing myelodysplastic syndrome.

RESULTS

The patient was a 14-year-old girl on chronic calcineurin inhibitor therapy who presented with peri-rectal pain approximately 13 years after liver, small bowel, and pancreas transplant. The initial workup revealed pancytopenia and parvovirus B19 viremia. Her definitive diagnosis was complicated by a lack of adequate bone marrow biopsy specimens and expert consultation that resulted in treatment for hemophagocytic lymphohistiocytosis. She was later diagnosed with high-grade myelodysplastic syndrome. Although curative treatment with chemotherapy and hematopoietic stem cell transplantation was strongly considered, it was not performed due to the child's rapid clinical progression, ventilator status, and active infections. The patient died approximately 6 months following symptom onset.

CONCLUSIONS

This case emphasizes the importance of early recognition of myelodysplastic syndrome in multi-organ transplant recipients on chronic immunosuppression. Pancytopenia is a common presentation in the post-transplant period that requires thorough investigation. Multiple confounding considerations such as infection, immunosuppression, and systemic inflammation can delay the diagnosis of underlying hematological malignancies. Transplant care providers should be aware of myelodysplastic syndrome and advocate for a comprehensive evaluation, given early recognition and intervention can significantly improve outcomes.

Case Report: Refractory Cytopenia With a Switch From a Transient Monosomy 7 to a Disease-Ameliorating del(20q) in a NHEJ1-Deficient Long-term Survivor

We report the case of a male Pakistani patient with a pathogenic homozygous loss of function variant in the non-homologous end-joining factor 1 (NHEJ1) gene. The growth retarded and microcephalic boy with clinodactyly of both hands and hyperpigmentation of the skin suffered from recurrent respiratory infections. He was five and a half years old when he came to our attention with refractory cytopenia and monosomy 7. Hematopoietic stem cell transplantation was considered but not feasible because there was no suitable donor available. Monosomy 7 was not detected anymore in subsequent bone marrow biopsies that were repeated in yearly intervals. Instead, seven and a half years later, a novel clone with a del(20q) appeared and steadily increased thereafter. In parallel, the patient’s blood count, which had remained stable for over 20 years without necessitating any specific therapeutic interventions, improved gradually and the erythropoiesis-associated dysplasia resolved.

The effect of decitabine-combined minimally myelosuppressive regimen bridged allo-HSCT on the outcomes of pediatric MDS from 10 years' experience of a single center

Background

Myelodysplastic syndrome (MDS) is a rare disease in children and the treatment option before the allogeneic hematopoietic stem cell transplantation (allo-HSCT) is rarely reported. Our main objective was to report our single-center experience with the DNA-hypomethylating agent, decitabine-combined minimally myelosuppressive regimen (DAC + MMR) bridged allo-HSCT in children with MDS.

Methods

Twenty-eight children with de novo MDS who underwent allo-HSCT between 2011 and 2020 were enrolled. Patients were divided into subgroups (refractory cytopenia of childhood [RCC] and advanced MDS [aMDS]) and treated by HSCT alone or pre-transplant combination treatment based on risk stratification. The patients’ clinical characteristics, treatment strategies and outcomes were retrospectively evaluated.

Results

Twenty patients with aMDS had received pre-transplant treatment (three were treated with decitabine alone, thirteen with DAC + MMR, and four with acute myeloid leukemia type [AML-type] induction therapy). DAC + MMR was well tolerated and the most common adverse events were myelosuppression and gastrointestinal reaction. DAC + MMR had shown an improved marrow complete remission (mCR) compared with AML-type chemotherapy (13/13, 100% versus 2/4, 50%, P = 0.044). The median follow-up for total cohort was 53.0 months (range, 2.3-127.0 months) and the 4-year overall survival (OS) was 71.4 ± 8.5%. In the subgroup of aMDS, pretreatment of DAC + MMR resulted in a much better survival rate than AML-type chemotherapy (84.6 ± 10.0% versus 0.0 ± 0.0%, P < 0.001).

Conclusions

The DAC + MMR bridged allo-HSCT may be recommended as a novel and effective approach.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03376-1.

Diagnostic work-up for severe aplastic anemia in children: Consensus of the North American Pediatric Aplastic Anemia Consortium

The North American Pediatric Aplastic Anemia Consortium (NAPAAC) is a group of pediatric hematologist-oncologists, hematopathologists, and bone marrow transplant physicians from 46 institutions in North America with interest and expertise in aplastic anemia, inherited bone marrow failure syndromes, and myelodysplastic syndromes. The NAPAAC Bone Marrow Failure Diagnosis and Care Guidelines Working Group was established with the charge of harmonizing the approach to the diagnostic workup of aplastic anemia in an effort to standardize best practices in the field. This document outlines the rationale for initial evaluations in pediatric patients presenting with signs and symptoms concerning for severe aplastic anemia.

Divergent leukaemia subclones as cellular models for testing vulnerabilities associated with gains in chromosomes 7, 8 or 18

Haematopoietic malignancies are frequently characterized by karyotypic abnormalities. The development of targeted drugs has been pioneered with compounds against gene products of fusion genes caused by chromosomal translocations. While polysomies are equally frequent as translocations, for many of them we are lacking therapeutic approaches aimed at synthetic lethality. Here, we report two new cell lines, named MBU-7 and MBU-8, that differ in complete trisomy of chromosome18, a partial trisomy of chromosome 7 and a tetrasomy of the p-arm of chromosome 8, but otherwise share the same mutational pattern and complex karyotype. Both cell lines are divergent clones of U-937 cells and have the morphology and immunoprofile of monocytic cells. The distinct karyotypic differences between MBU-7 and MBU-8 are associated with a difference in the specific response to nucleoside analogues. Taken together, we propose the MBU-7 and MBU-8 cell lines described here as suitable in vitro models for screening and testing vulnerabilities that are associated with the disease-relevant polysomies of chromosome 7, 8 and 18.

Pediatric myelodysplastic syndrome with inflammatory manifestations: Diagnosis, genetics, treatment, and outcome

BACKGROUND

Inflammatory manifestations (IM) are well described in adult patients with myelodysplastic syndrome (MDS), but the presentation is highly variable and no standardized treatment exists. This phenomenon is rarely reported in children. As more pediatric patients are hematopoietic stem cell transplantation (HSCT) candidates, the role of anti-inflammatory treatment in relation to HSCT should be defined.

PROCEDURE

Here, we report a series of five children from a tertiary center. We describe the clinical presentation, molecular findings, and treatment options.

RESULTS

All patients presented with advanced MDS with blast percentages ranging 10-30%, all had severe IM. One patient had MDS secondary to severe congenital neutropenia, the other four patients had presumably primary MDS. All four were found to harbor a PTPN11 gene driver mutation, which is found in 35% of cases of juvenile myelomonocytic leukemia (JMML). The mutation was present in the myeloid lineage but not in T lymphocytes. Three had symptoms of Behcet's-like disease with trisomy 8 in their bone marrow. All patients were treated with anti-inflammatory medications (mainly systemic steroids) in an attempt to bring them to allogeneic HSCT in a better clinical condition. All demonstrated clinical improvement as well as regression in their MDS status post anti-inflammatory treatment. All have recovered from both MDS and their inflammatory symptoms post HSCT.

CONCLUSION

Primary pediatric MDS with IM is driven in some cases by PTPN11 mutations, and might be on the clinical spectrum of JMML. Anti-inflammatory treatment may reverse MDS progression and improve the outcome of subsequent HSCT.