| 1. |
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| 2. |
- Arthur, Cecilia, et al.
(författare)
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Patient-Specific Assays Based on Whole-Genome Sequencing Data to Measure Residual Disease in Children With Acute Lymphoblastic Leukemia : A Proof of Concept Study
- 2022
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Ingår i: Frontiers in Oncology. - : Frontiers Media S.A.. - 2234-943X. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Risk-adapted treatment in acute lymphoblastic leukemia (ALL) relies on genetic information and measurable residual disease (MRD) monitoring. In this proof of concept study, DNA from diagnostic bone marrow (BM) of six children with ALL, without stratifying genetics or central nervous system (CNS) involvement, underwent whole-genome sequencing (WGS) to identify structural variants (SVs) in the leukemic blasts. Unique sequences generated by SVs were targeted with patient-specific droplet digital PCR (ddPCR) assays. Genomic DNA (gDNA) from BM and cell-free DNA (cfDNA) from plasma and cerebrospinal fluid (CSF) were analyzed longitudinally. WGS with 30x coverage enabled target identification in all cases. Limit of quantifiability (LoQ) and limit of detection (LoD) for the ddPCR assays (n = 15) were up to 10(-5) and 10(-6), respectively. All targets were readily detectable in a multiplexed ddPCR with minimal DNA input (1 ng of gDNA) at a 10(-1) dilution, and targets for half of the patients were also detectable at a 10(-2) dilution. The level of MRD in BM at end of induction and end of consolidation block 1 was in a comparable range between ddPCR and clinical routine methods for samples with detectable residual disease, although our approach consistently detected higher MRD values for patients with B-cell precursor ALL. Additionally, several samples with undetectable MRD by flow cytometry were MRD-positive by ddPCR. In plasma, the level of leukemic targets decreased in cfDNA over time following the MRD level detected in BM. cfDNA was successfully extracted from all diagnostic CSF samples (n = 6), and leukemic targets were detected in half of these. The results suggest that our approach to design molecular assays, together with ddPCR quantification, is a technically feasible option for accurate MRD quantification and that cfDNA may contribute valuable information regarding MRD and low-grade CNS involvement.
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| 3. |
- Kern, Wolfgang, et al.
(författare)
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Multicenter prospective evaluation of diagnostic potential of flow cytometric aberrancies in myelodysplastic syndromes by the ELN iMDS flow working group
- 2023
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Ingår i: Cytometry Part B - Clinical Cytometry. - : Wiley. - 1552-4949 .- 1552-4957. ; 104:1, s. 51-65
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Tidskriftsartikel (refereegranskat)abstract
- Background: Myelodysplastic syndromes (MDS) represent a diagnostic challenge. This prospective multicenter study was conducted to evaluate pre-defined flow cytometric markers in the diagnostic work-up of MDS and chronic myelomonocytic leukemia (CMML). Methods: Thousand six hundred and eighty-two patients with suspected MDS/CMML were analyzed by both cytomorphology according to WHO 2016 criteria and flow cytometry according to ELN recommendations. Flow cytometric readout was categorized ‘non-MDS’ (i.e. no signs of MDS/CMML and limited signs of MDS/CMML) and ‘in agreement with MDS’ (i.e., in agreement with MDS/CMML). Results: Flow cytometric readout categorized 60% of patients in agreement with MDS, 28% showed limited signs of MDS and 12% had no signs of MDS. In 81% of cases flow cytometric readouts and cytomorphologic diagnosis correlated. For high-risk MDS, the level of concordance was 92%. A total of 17 immunophenotypic aberrancies were found independently related to MDS/CMML in ≥1 of the subgroups of low-risk MDS, high-risk MDS, CMML. A cut-off of ≥3 of these aberrancies resulted in 80% agreement with cytomorphology (20% cases concordantly negative, 60% positive). Moreover, >3% myeloid progenitor cells were significantly associated with MDS (286/293 such cases, 98%). Conclusion: Data from this prospective multicenter study led to recognition of 17 immunophenotypic markers allowing to identify cases ‘in agreement with MDS’. Moreover, data emphasizes the clinical utility of immunophenotyping in MDS diagnostics, given the high concordance between cytomorphology and the flow cytometric readout. Results from the current study challenge the application of the cytomorphologically defined cut-off of 5% blasts for flow cytometry and rather suggest a 3% cut-off for the latter.
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| 4. |
- Mollgard, Lars, et al.
(författare)
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Clinical effect of increasing doses of lenalidomide in high-risk myelodysplastic syndrome and acute myeloid leukemia with chromosome 5 abnormalities
- 2011
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Ingår i: Haematologica. - : Ferrata Storti Foundation (Haematologica). - 0390-6078 .- 1592-8721. ; 96:7, s. 963-971
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Tidskriftsartikel (refereegranskat)abstract
- Background Patients with chromosome 5 abnormalities and high-risk myelodysplastic syndromes or acute myeloid leukemia have a poor outcome. We hypothesized that increasing doses of lenalidomide may benefit this group of patients by inhibiting the tumor clone, as assessed by fluorescence in situ hybridization for del(5q31). Design and Methods Twenty-eight patients at diagnosis or with relapsed disease and not eligible for standard therapy (16 with acute myeloid leukemia, 12 with intermediate-risk 2 or high-risk myelodysplastic syndrome) were enrolled in this prospective phase II multicenter trial and treated with lenalidomide up to 30 mg daily for 16 weeks. Three patients had isolated del(5q), six had del(5q) plus one additional aberration, 14 had del(5q) and a complex karyotype, four had monosomy 5, and one had del(5q) identified by fluorescence in situ hybridization only. Results Major and minor cytogenetic responses, assessed by fluorescence in situ hybridization, were achieved in 5/26 (19%) and 2/26 (8%) patients, respectively, who received one or more dose of lenalidomide, while two patients achieved only a bone marrow response. Nine of all 26 patients (35%) and nine of the ten who completed the 16 weeks of trial responded to treatment. Using the International Working Group criteria for acute myeloid leukemia and myelodysplastic syndrome the overall response rate in treated patients with acute myeloid leukemia was 20% (3/15), while that for patients with myelodysplastic syndrome was 36% (4/11). Seven patients stopped therapy due to progressive disease and nine because of complications, most of which were disease-related. Response rates were similar in patients with isolated del(5q) and in those with additional aberrations. Interestingly, patients with TP53 mutations responded less well than those without mutations (2/13 versus 5/9, respectively; P = 0.047). No responses were observed among 11 cases with deleterious TP53 mutations. Conclusions Our data support a role for higher doses of lenalidomide in poor prognosis patients with myelodysplastic syndrome and acute myeloid leukemia with deletion 5q. (Clinicaltrials.gov identifier NCT00761449).
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| 5. |
- Porwit, Anna, et al.
(författare)
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Multiparameter flow cytometry in the evaluation of myelodysplasia : Analytical issues: Recommendations from the European LeukemiaNet/International Myelodysplastic Syndrome Flow Cytometry Working Group
- 2023
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Ingår i: Cytometry Part B - Clinical Cytometry. - : Wiley. - 1552-4949 .- 1552-4957. ; 104:1, s. 27-50
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Forskningsöversikt (refereegranskat)abstract
- Multiparameter flow cytometry (MFC) is one of the essential ancillary methods in bone marrow (BM) investigation of patients with cytopenia and suspected myelodysplastic syndrome (MDS). MFC can also be applied in the follow-up of MDS patients undergoing treatment. This document summarizes recommendations from the International/European Leukemia Net Working Group for Flow Cytometry in Myelodysplastic Syndromes (ELN iMDS Flow) on the analytical issues in MFC for the diagnostic work-up of MDS. Recommendations for the analysis of several BM cell subsets such as myeloid precursors, maturing granulocytic and monocytic components and erythropoiesis are given. A core set of 17 markers identified as independently related to a cytomorphologic diagnosis of myelodysplasia is suggested as mandatory for MFC evaluation of BM in a patient with cytopenia. A myeloid precursor cell (CD34+CD19−) count >3% should be considered immunophenotypically indicative of myelodysplasia. However, MFC results should always be evaluated as part of an integrated hematopathology work-up. Looking forward, several machine-learning-based analytical tools of interest should be applied in parallel to conventional analytical methods to investigate their usefulness in integrated diagnostics, risk stratification, and potentially even in the evaluation of response to therapy, based on MFC data. In addition, compiling large uniform datasets is desirable, as most of the machine-learning-based methods tend to perform better with larger numbers of investigated samples, especially in such a heterogeneous disease as MDS.
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| 6. |
- Ranta, Susanna, et al.
(författare)
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Detection of Central Nervous System Involvement in Childhood Acute Lymphoblastic Leukemia by Cytomorphology and Flow Cytometry of the Cerebrospinal Fluid
- 2015
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Ingår i: Pediatric Blood & Cancer. - : Wiley. - 1545-5009 .- 1545-5017. ; 62:6, s. 951-956
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Tidskriftsartikel (refereegranskat)abstract
- Background: Therapy directed at the central nervous system (CNS) is an essential part of the treatment for childhood acute lymphoblastic leukemia (ALL). The current evaluation of CNS involvement based on cytomorphological examination of the cerebrospinal fluid (CSF) alone is not as sensitive with low cell counts as flow cytometric immunophenotyping (FCI) of the CSF. However, the importance of low CSF blasts counts at diagnosis is uncertain. We sought to determine the significance of FCI in relation to conventional morphological examination.Procedure: We retrospectively compared FCI of the CSF with cytomorphology at diagnosis or relapse of childhood ALL. All patients were diagnosed 2000–2012 in Stockholm or Umeå, Sweden. Clinical data were collected from medical records and the Nordic leukemia registry. Treatment assignment was based on morphological examination only.Results: The cohort was comprised of 214 patients with ALL. CSF involvement was detected by both methods in 20 patients, in 17 by FCI alone, and in one patient by cytomorphology alone. The relapse rate was higher for patients with negative cytology but positive FCI compared to those without CNS involvement using both methods. The difference was especially marked in the current protocol. However, none of the patients with negative CSF cytology but positive FCI had a CNS relapse.Conclusions: FCI of the CSF increased the detection rate of CNS involvement of ALL approximately two times compared to cytomorphology. Patients with low-level CNS involvement may benefit from additional intensified systemic or CNS-directed therapy, but larger studies are needed.
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| 7. |
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| 8. |
- Rubio, Carlos A., et al.
(författare)
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Reliability of the reported size of removed colorectal polyps
- 2006
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Ingår i: Anticancer Research. - 0250-7005 .- 1791-7530. ; 26:6C, s. 4895-4899
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Tidskriftsartikel (refereegranskat)abstract
- Background: The size of colorectal polyps is important in the clinical management of these lesions. Aim: To audit the accuracy in calculating the size of polyps by various specialists. Materials and Methods: Eighteen pathologists and four surgeons measured, with a conventional millimetre ruler, the largest diameter of 12 polyp phantoms. The results of two independent measurements (two weeks apart) were compared with the gold standard-size assessed at The Royal Institute of Technology, Sweden. Results: Thirty-one percent (83/264-trial 1) and 33% (88/264-trial 2) of the measurements underestimated or overestimated the gold standard size by > 1 mm. Of the 22 experienced participants, 95% (21/22-trial 1) and 91% (20/22-trial 2) misjudged by > 1 mm the size of one or more polyps. Values given by 13 participants (4.9%) in trial I and by 15 participants (5.7%) in trial 2, differed by ! 4 mm from the gold standard size. In addition, a big difference between the highest and the lowest values was recorded in some polyps (up to 11.4 mm). Those disparate values were regarded as a human error in reading the scale on the ruler. Conclusion: Using a conventional ruler (the tool of pathologists worldwide) unacceptably high intra-observer and inter-observer variations in assessing the size of polyp-phantoms was found. The volume and the shape of devices, as well as human error in reading the scale of the ruler were confounding factors in size assessment. In praxis, the size is crucial in the management of colorectal polyps. Considering the clinical implications of the results obtained, the possibility of developing a method that will allow assessment of the true size of removed clinical polyps is being explored.
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| 9. |
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| 10. |
- Saft, Leonie, et al.
(författare)
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Enumeration of CD34+ blasts by immunohistochemistry in bone marrow biopsies from MDS patients may have significant impact on final WHO classification
- 2020
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Ingår i: Journal of Hematopathology. - : Springer Science and Business Media LLC. - 1868-9256 .- 1865-5785. ; 13:2, s. 79-88
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Tidskriftsartikel (refereegranskat)abstract
- The percentage of blasts cells in the bone marrow (BM) of MDS patients is one of the key parameters for MDS classification and for the differential diagnosis with acute myeloid leukemia (AML). Currently, the gold standard to determine the blast percentage is conventional cytomorphology. To assess the possible impact of blast cell enumeration in BM biopsies from MDS patients on the final WHO classification using CD34 immunohistochemistry (IHC) a total of 156 BM samples from MDS and MDS-AML patients were studied and compared to blast counts by cytomorphology (CM). Eighty-nine BM aspirates were also studied by flow cytometry (FCM). Percentages of CD34+ blasts by IHC were determined blindly by two hematopathologists. Automated CD34-cell count was performed in 25 cases. Good overall agreement was found for CM and FCM with respect to critical blast thresholds (5%, 10%, 20%) (p < 0.05). However, in 17% of patients, CD34+ blast counts by IHC were higher as compared to CM with possible impact on MDS subclassification. In 7 of 21 AML patients, diagnosis was established on BM histology, while the blast percentage by CM was below the AML threshold. The assessment of CD34+ cells by IHC showed high interobserver agreement (Spearman R 0.95, p < 0.01), while automated CD34 counts were not optimal due to interference with other cellular and stromal elements. BM histology including CD34 IHC improves the diagnostic accuracy in MDS and AML. The quantification of blast cells should be based on the integration of all three methods for reliable disease classification and risk assessment.
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| 11. |
- Saft, Leonie, et al.
(författare)
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Intracerebral manifestation of iatrogenic, immunodeficiency-associated polymorphic B-LPD with morphology mimicking Hodgkin lymphoma : a case report and literature review
- 2022
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Ingår i: Journal of Hematopathology. - : Springer Heidelberg. - 1868-9256 .- 1865-5785. ; 15:1, s. 13-19
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Forskningsöversikt (refereegranskat)abstract
- Iatrogenic immunodeficiency-associated lymphoproliferative disorders (IA-LPD) may arise in patients treated with immunosuppressive drugs for autoimmune disease or other conditions. Polymorphic EBV-positive B-lymphoproliferations often have features mimicking Hodgkin lymphoma and typically a self-limited, indolent course. We present an unusual case with isolated, intracerebral manifestation of polymorphic B-LPD with features of classic Hodgkin-lymphoma in an immunosuppressed patient treated with methotrexate and infliximab, including clinical-radiological features and a detailed description of morphological findings, together with a literature review on reported cases of primary CNS manifestation of cHL and IA-LPD with Hodgkin-like morphology. The patient achieved complete remission following neurosurgery with gross total tumor resection and drug withdrawal without any additional treatment. Post-operative staging revealed no evidence for focal relapse or systemic disease during the 18 months follow-up period. Among the previously reported 24 cases of primary, isolated Hodgkin lymphoma in the central nervous system, three similar cases of iatrogenic, IA-LPDs were identified and are discussed here. Polymorphic B-LPD are destructive lesions with a range of morphologic features and disease manifestations. It is clinically important to recognize the spectrum of proliferations with features of classic Hodgkin lymphoma in immunodeficiency, iatrogenic settings, because they are likely to impact the choice of treatment strategies.
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| 12. |
- Saft, Leonie
(författare)
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TP53 mutations in myelodysplastic syndromes with deletion of 5q
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The myelodysplastic syndromes (MDS) constitute a heterogeneous group of malignant bone marrow disorders characterized by peripheral cytopenia(s) and increased risk of progression to acute myeloid leukemia (AML). International Prognostic Scoring system (IPSS) Low- or Intermediate (INT)-1 risk MDS with a deletion of 5q (del5q) were considered to have an indolent course and a low risk for progression to AML as compared to other MDS subtypes. However, more recent studies have shown that overall survival (OS) and risk for AML progression vary greatly in del(5q) MDS patients indicating that factors beyond established risk scoring systems impact patient outcome. Molecular abnormalities have emerged as putative prognostic markers. We performed molecular studies in a patient with classical 5q-syndrome who unexpectedly evolved to high-risk MDS with complex karyotype (Paper I). Immunohistochemistry (IHC) of pre-treatment marrow biopsies revealed a small fraction of progenitors with strong p53 expression and sequencing confirmed a TP53 mutation. TP53 mutated subclones had not been described in MDS with isolated del(5q) and indicated a previously unknown heterogeneity. In a subsequent study of 55 patients with lower-risk del(5q) MDS, 18% of the patients were found to have TP53 mutated subclones at diagnosis which rendered them at higher risk for progression (Paper II). Interestingly, the association with outcome was even stronger for p53 IHC indicating a high sensitivity of this method for early identification of patients with adverse outcome. As a next step, we assessed p53 protein expression in a cohort of 85 lower-risk del(5q) MDS patients treated with lenalidomide within a clinical trial (Paper IV). P53 IHC positive patients showed significantly shorter overall survival, higher risk for leukemic transformation, and lower cytogenetic response rate to lenalidomide, hence validating the results from Paper II. Importantly, pyrosequencing analysis of microdissected IHC stained cells confirmed that cells with strong staining carried TP53 mutations, while moderate staining reflected wild-type TP53. Due to the apparently exquisite sensitivity of the del(5q) clone to len, we hypothesized that higher doses of lenalidomide may induce cytogenetic and clinical responses also in patients with high-risk MDS/AML with chromosome 5 abnormalities who were refractory or ineligible for standard treatment (Paper III). In this study, we demonstrated that treatment was able to inhibit the del(5q)tumor clone in a cohort of patients with extremely advanced disease, which suggests that the selective inhibitory effect of len in vitro may be translated into a therapeutic response in vivo. Importantly, TP53 mutations were common (62%) in this cohort, and uniformly associated with treatment failure. Altogether, our findings suggest an important role of the p53 pathway in both low- and high-risk del(5q) MDS, and in relation to treatment with lenalidomide. These findings will have major implications for risk stratification and the choice of therapy.
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| 13. |
- Svensson, Tobias, et al.
(författare)
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A pilot phase I dose finding safety study of the thrombopoietin-receptor agonist, eltrombopag, in patients with myelodysplastic syndrome treated with azacitidine
- 2014
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Ingår i: European Journal of Haematology. - : Wiley. - 0902-4441 .- 1600-0609. ; 93:5, s. 439-445
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Thrombocytopenia is an independent adverse prognostic factor in patients with Myelodysplastic syndromes (MDS). Azacitidine, first-line treatment for the majority of patients with higher-risk MDS, is associated with aggravated thrombocytopenia during the first cycles. Eltrombopag is a novel thrombopoietin receptor agonist, which also has been shown to inhibit proliferation of leukaemia cell lines in vitro. This phase I clinical trial was designed to explore the safety and tolerability of combining eltrombopag with azacitidine in patients with MDS. In addition, we assessed the potential effects of eltrombopag on hematopoietic stem and progenitor cells (HSPCs) from included patients.Patients and methods: Previously untreated patients with MDS eligible for treatment with azacitidine and with a platelet count <75x10(9)/L were included. Patients received eltrombopag in dose escalation cohorts during three cycles of azacitidine.Results: Twelve patients, with a median age of 74yr, were included. Severe adverse events included infectious complications, deep vein thrombosis and transient ischaemic attack. The maximal tolerated eltrombopag dose was 200mg qd. Complete remission or bone marrow remission was achieved in 4 of 12 patients. Platelet counts improved or remained stable in 9 of 12 patients despite azacitidine treatment. No increase in blast count, disease progression, or bone marrow fibrosis related to study medication was reported. Eltrombopag did not induce cycling of HSPCs.Conclusion: The combination of eltrombopag with azacitidine in high-risk MDS patients is feasible and well tolerated. Improvements in platelet counts and the potential antileukaemic effect of eltrombopag should be explored in a randomised study.
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| 14. |
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| 15. |
- van der Velden, Vincent H.J., et al.
(författare)
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Flow cytometric analysis of myelodysplasia : Pre-analytical and technical issues—Recommendations from the European LeukemiaNet
- 2023
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Ingår i: Cytometry Part B - Clinical Cytometry. - : Wiley. - 1552-4949 .- 1552-4957. ; 104:1, s. 15-26
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Tidskriftsartikel (refereegranskat)abstract
- Background: Flow cytometry (FCM) aids the diagnosis and prognostic stratification of patients with suspected or confirmed myelodysplastic syndrome (MDS). Over the past few years, significant progress has been made in the FCM field concerning technical issues (including software and hardware) and pre-analytical procedures. Methods: Recommendations are made based on the data and expert discussions generated from 13 yearly meetings of the European LeukemiaNet international MDS Flow working group. Results: We report here on the experiences and recommendations concerning (1) the optimal methods of sample processing and handling, (2) antibody panels and fluorochromes, and (3) current hardware technologies. Conclusions: These recommendations will support and facilitate the appropriate application of FCM assays in the diagnostic workup of MDS patients. Further standardization and harmonization will be required to integrate FCM in MDS diagnostic evaluations in daily practice.
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| 16. |
- Westers, Theresia M., et al.
(författare)
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A series of case studies illustrating the role of flow cytometry in the diagnostic work-up of myelodysplastic syndromes
- 2023
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Ingår i: Cytometry Part B - Clinical Cytometry. - : Wiley. - 1552-4949 .- 1552-4957. ; 104:1, s. 87-97
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Tidskriftsartikel (refereegranskat)abstract
- Current guidelines recommend flow cytometric analysis as part of the diagnostic assessment of patients with cytopenia suspected for myelodysplastic syndrome. Herein we describe the complete work-up of six cases using multimodal integrated diagnostics. Flow cytometry assessments are illustrated by plots from conventional and more recent analysis tools. The cases demonstrate the added value of flow cytometry in case of hypocellular, poor quality, or ambiguous bone marrow cytomorphology. Moreover, they demonstrate how immunophenotyping results support clinical decision-making in inconclusive and clinically ‘difficult’ cases.
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