HighlightsActivation of NF-κB signaling in mesenchymal cells is common in LR-MDS.Activation of NF-κB in mesenchymal cells leads to transcriptional overexpression of inflammatory factors including ...negative regulators of hematopoiesis.Activation of NF-κB attenuates HSPC numbers and function ex vivo.
Red blood cell transfusions remain one of the cornerstones in supportive care of lower-risk patients with myelodysplastic syndromes. We hypothesized that patients develop oxidant-mediated tissue ...injury through the formation of toxic iron species, caused either by red blood cell transfusions or by ineffective erythropoiesis. We analyzed serum samples from 100 lower-risk patients with myelodysplastic syndromes at six-month intervals for transferrin saturation, hepcidin-25, growth differentiation factor 15, soluble transferrin receptor, non-transferrin bound iron and labile plasma iron in order to evaluate temporal changes in iron metabolism and the presence of potentially toxic iron species and their impact on survival. Hepcidin levels were low in 34 patients with ringed sideroblasts compared to 66 patients without. Increases of hepcidin and non-transferrin bound iron levels were visible early in follow-up of all transfusion-dependent patient groups. Hepcidin levels significantly decreased over time in transfusion-independent patients with ringed sideroblasts. Increased soluble transferrin receptor levels in transfusion-independent patients with ringed sideroblasts confirmed the presence of ineffective erythropoiesis and suppression of hepcidin production in these patients. Detectable labile plasma iron levels in combination with high transferrin saturation levels occurred almost exclusively in patients with ringed sideroblasts and all transfusion-dependent patient groups. Detectable labile plasma iron levels in transfusion-dependent patients without ringed sideroblasts were associated with decreased survival. In conclusion, toxic iron species occurred in all transfusion-dependent patients and in transfusion-independent patients with ringed sideroblasts. Labile plasma iron appeared to be a clinically relevant measure for potential iron toxicity and a prognostic factor for survival in transfusion-dependent patients.
In myelodysplastic syndromes (MDSs), the evolution of risk for disease progression or death has not been systematically investigated despite being crucial for correct interpretation of prognostic ...risk scores. In a multicenter retrospective study, we described changes in risk over time, the consequences for basal prognostic scores, and their potential clinical implications. Major MDS prognostic risk scoring systems and their constituent individual predictors were analyzed in 7212 primary untreated MDS patients from the International Working Group for Prognosis in MDS database. Changes in risk of mortality and of leukemic transformation over time from diagnosis were described. Hazards regarding mortality and acute myeloid leukemia transformation diminished over time from diagnosis in higher-risk MDS patients, whereas they remained stable in lower-risk patients. After approximately 3.5 years, hazards in the separate risk groups became similar and were essentially equivalent after 5 years. This fact led to loss of prognostic power of different scoring systems considered, which was more pronounced for survival. Inclusion of age resulted in increased initial prognostic power for survival and less attenuation in hazards. If needed for practicability in clinical management, the differing development of risks suggested a reasonable division into lower- and higher-risk MDS based on the IPSS-R at a cutoff of 3.5 points. Our data regarding time-dependent performance of prognostic scores reflect the disparate change of risks in MDS subpopulations. Lower-risk patients at diagnosis remain lower risk whereas initially high-risk patients demonstrate decreasing risk over time. This change of risk should be considered in clinical decision making.
•Hazards regarding mortality and leukemic transformation in MDS diminish over time in higher-risk but remain stable in lower-risk patients.•This change of hazard indicates time-dependent attenuation of power of basal risk scores, which is relevant for clinical decision making.
We report on a series of sequential events leading to long-term survival and cure of pediatric X-linked chronic granulomatous disease (X-CGD) patients after gamma-retroviral gene therapy (GT) and ...rescue HSCT. Due to therapyrefractory life-threatening infections requiring hematopoietic stem cell transplantation (HSCT) but absence of HLAidentical donors, we treated 2 boys with X-CGD by GT. Following GT both children completely resolved invasive Aspergillus nidulans infections. However, one child developed dual insertional activation of ecotropic viral integration site 1 (EVI1) and signal transducer and activator of transcription 3 (STAT3) genes, leading to myelodysplastic syndrome (MDS) with monosomy 7. Despite resistance to mismatched allo-HSCT with standard myeloablative conditioning, secondary intensified rescue allo-HSCT resulted in 100 % donor chimerism and disappearance of MDS. The other child did not develop MDS despite expansion of a clone with a single insertion in the myelodysplasia syndrome 1 (MDS1) gene and was cured by early standard allo-HSCT. The slowly developing dominance of clones harboring integrations in MDS1-EVI1 may guide clinical intervention strategies, i.e. early rescue allo-HSCT, prior to malignant transformation. GT was essential for both children to survive and to clear therapy-refractory infections, and future GT with safer lentiviral self-inactivated (SIN) vectors may offer a therapeutic alternative for X-CGD patients suffering from life-threatening infections and lacking HLA-identical HSC donors.
The World Health Organization (WHO) classification contributes to refined classification and prognostication of myelodysplastic syndromes (MDSs). Flow cytometry might add significantly to diagnostic ...and prognostic criteria. Our analysis of bone marrow samples from 50 patients with MDS showed aberrant expression of differentiation antigens in the myelomonocytic lineage. This also accounted for refractory anemia (RA) with or without ringed sideroblasts (RS), indicating multilineage dysplasia. In 38% of patients, CD34+ myeloid blasts expressed CD5, CD7, or CD56. Flow cytometry data were translated into a numerical MDS flow-score. Flow-scores increased significantly from RA with or without RS, refractory cytopenia with multilineage dysplasia (RCMD) with or without RS up to refractory anemia with excess of blasts-1 (RAEB-1) and RAEB-2. No significant differences were observed between WHO cytogenetic subgroups. Flow-scores were highly heterogeneous within International Prognostic Scoring System (IPSS) subgroups. Patients in progression to advanced MDS or acute myeloid leukemia had a significantly higher flow-score compared with non–transfusion-dependent patients. In 60% of patients with transfusion dependency or progressive disease, myeloid blasts expressed CD7 or CD56, in contrast to only 9% of non–transfusion-dependent patients. Moreover, all patients with pure RA with or without RS with aberrant myeloid blasts showed an adverse clinical course. In conclusion, flow cytometry in MDS identified aberrancies in the myelomonocytic lineage not otherwise determined by cytomorphology. In addition, flow cytometry identified patients at risk for transfusion dependency and/or progressive disease independent of known risk groups, which might have impact on treatment decisions and the prognostic scoring system in the near future.
Flow cytometric analysis is a recommended tool in the diagnosis of myelodysplastic syndromes. Current flow cytometric approaches evaluate the (im)mature myelo-/monocytic lineage with a median ...sensitivity and specificity of ~71% and ~93%, respectively. We hypothesized that the addition of erythroid lineage analysis could increase the sensitivity of flow cytometry. Hereto, we validated the analysis of erythroid lineage parameters recommended by the International/European LeukemiaNet Working Group for Flow Cytometry in Myelodysplastic Syndromes, and incorporated this evaluation in currently applied flow cytometric models. One hundred and sixty-seven bone marrow aspirates were analyzed; 106 patients with myelodysplastic syndromes, and 61 cytopenic controls. There was a strong correlation between presence of erythroid aberrancies assessed by flow cytometry and the diagnosis of myelodysplastic syndromes when validating the previously described erythroid evaluation. Furthermore, addition of erythroid aberrancies to two different flow cytometric models led to an increased sensitivity in detecting myelodysplastic syndromes: from 74% to 86% for the addition to the diagnostic score designed by Ogata and colleagues, and from 69% to 80% for the addition to the integrated flow cytometric score for myelodysplastic syndromes, designed by our group. In both models the specificity was unaffected. The high sensitivity and specificity of flow cytometry in the detection of myelodysplastic syndromes illustrates the important value of flow cytometry in a standardized diagnostic approach. The trial is registered at www.trialregister.nl as NTR1825; EudraCT n.: 2008-002195-10.
Summary
The myelodysplastic syndromes (MDS) constitute a group of heterogeneous clonal haemopoietic stem cell disorders, characterized by ineffective and dysplastic haematopoiesis with varying ...degrees of peripheral cytopenia. Low‐risk MDS is characterized by increased apoptosis in the bone marrow (BM) with autoimmune characteristics whereas the advanced or high‐risk stages involve immune evasion and secondary DNA damage, giving cells growth potential to progress into acute myeloid leukaemia (AML). Nevertheless, the causes of MDS remain poorly defined and it is not clear how the disease progresses from an early stage to advanced MDS and AML. Although there are clear indications for a role of the immune system, the exact mechanism by which the immune response contributes to the progression is not yet clear. New insights into the pathophysiology of MDS with regard to the immune system will be instrumental for the development of novel patient‐oriented therapies. This review is focused on the role of immune responses in MDS and the implications for the development of novel immune therapies.
5-Azacitidine (AZA) therapy is used in high-risk myelodysplastic syndrome (MDS) patients who often show abnormalities in their immunophenotype. We explored the potential impact of AZA on these ...immunophenotypic abnormalities in serial bone marrow studies performed in 81 patients from five centers. We compared the immunophenotypic features before and after therapy with AZA, established definitions consistent with flow cytometry immunophenotyping (FCI) improvement, and explored its clinical significance. After a median of 6 cycles of AZA, 41% of patients showed a FCI improvement and this finding associated with best possible clinical response (
P
< 0.001). FCI improvement also correlated with hematological improvement (HI) (53/78 patients; 68%), independently of their eligibility for stem cell transplantation. Among patients who achieved a HI after 6 cycles of AZA, the probability of maintaining this response at 12 cycles of AZA was twice as large (67%) for those patients who also achieved a FCI improvement after 6 cycles of AZA as compared to patients who did not (33%,
P
< 0.01). These findings support that monitoring of the immunophenotypic abnormalities during therapy with AZA may assist in redefining the quality of response in patients with MDS.
Myelodysplastic syndromes (MDS) comprise hematological disorders that originate from the neoplastic transformation of hematopoietic stem cells (HSCs). However, discrimination between HSCs and their ...neoplastic counterparts in MDS-derived bone marrows (MDS-BMs) remains challenging. We hypothesized that in MDS patients immature CD34
CD38
cells with aberrant expression of immunophenotypic markers reflect neoplastic stem cells and that their frequency predicts leukemic progression. We analyzed samples from 68 MDS patients and 53 controls and discriminated HSCs from immunophenotypic aberrant HSCs (IA-HSCs) expressing membrane aberrancies (CD7, CD11b, CD22, CD33, CD44, CD45RA, CD56, CD123, CD366 or CD371). One-third of the MDS-BMs (23/68) contained IA-HSCs. The presence of IA-HSCs correlated with perturbed hematopoiesis (disproportionally expanded CD34
subsets beside cytopenias) and an increased hazard of leukemic progression (HR = 25, 95% CI: 2.9-218) that was independent of conventional risk factors. At 2 years follow-up, the sensitivity and specificity of presence of IA-HSCs for predicting leukemic progression was 83% (95% CI: 36-99%) and 71% (95% CI: 58-81%), respectively. In a selected cohort (n = 10), most MDS-BMs with IA-HSCs showed genomic complexity and high human blast counts following xenotransplantation into immunodeficient mice, contrasting MDS-BMs without IA-HSCs. This study demonstrates that the presence of IA-HSCs within MDS-BMs predicts leukemic progression, indicating the clinical potential of IA-HSCs as a prognostic biomarker.
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