BACKGROUND: Auer rods (AuRs) are prominent intracellular structures found almost exclusively in myeloid cell malignancies, such as acute myeloid leukemia (AML), chronic and juvenile myelomonocytic leukemia and myelodysplastic syndrome. Extremely rare AuRs have been reported in patients with acute lymphoblastic leukemia (ALL) or among ambiguous lineage leukemia patients with a dominantly lymphoblastic immunophenotype. PROCEDURE: We report diagnostic and follow-up data of an international cohort of 11 children suffering from leukemias with AuRs and with significant presence of T and myeloid markers, majority of whom categorized as early T-cell precursor (ETP, n = 7); or T-ALL (ETP status unknown, n = 2), ALAL (acute leukemia of ambiguous lineage, n = 1), and AML reclassified from ALAL (n = 1). We described other diagnostic details and treatment types and responses. Moreover, we summarize previously published data. RESULTS: Among the four patients who started and remained on ALL-type therapy, all were in the first complete remission, whereas both patients who started and remained on AML-type therapy relapsed and died. Of the patients who followed either a combined ALL/AML protocol (Interfant 06) or who switched from one of the two types of therapy to the other, one patient died, and the remaining four were in first complete remission at the most recent follow-up. We also searched for similar cases in the literature and found only three additional children with nonmyeloid leukemia and AuRs and 10 adults with this type of leukemia. CONCLUSIONS: Briefly, ALL- or combined ALL/AML-type therapy may be effective for treating AuR-positive leukemia patients with a lymphoid immunophenotype.

• MeSH
• akutní lymfatická leukemie patologie   terapie   imunologie   MeSH
• akutní myeloidní leukemie patologie   terapie   imunologie   MeSH
• dítě MeSH
• imunofenotypizace * MeSH
• kojenec MeSH
• lidé MeSH
• mladiství MeSH
• následné studie MeSH
• předškolní dítě MeSH
• Check Tag
• dítě MeSH
• kojenec MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Presence of minimal residual disease (MRD), detected by flow cytometry, is an important prognostic biomarker in the management of B-cell precursor acute lymphoblastic leukemia (BCP-ALL). However, data-analysis remains mainly expert-dependent. In this study, we designed and validated an Automated Gating & Identification (AGI) tool for MRD analysis in BCP-ALL patients using the two tubes of the EuroFlow 8-color MRD panel. The accuracy, repeatability, and reproducibility of the AGI tool was validated in a multicenter study using bone marrow follow-up samples from 174 BCP-ALL patients, stained with the EuroFlow BCP-ALL MRD panel. In these patients, MRD was assessed both by manual analysis and by AGI tool supported analysis. Comparison of MRD levels obtained between both approaches showed a concordance rate of 83%, with comparable concordances between MRD tubes (tube 1, 2 or both), treatment received (chemotherapy versus targeted therapy) and flow cytometers (FACSCanto versus FACSLyric). After review of discordant cases by additional experts, the concordance increased to 97%. Furthermore, the AGI tool showed excellent intra-expert concordance (100%) and good inter-expert concordance (90%). In addition to MRD levels, also percentages of normal cell populations showed excellent concordance between manual and AGI tool analysis. We conclude that the AGI tool may facilitate MRD analysis using the EuroFlow BCP-ALL MRD protocol and will contribute to a more standardized and objective MRD assessment. However, appropriate training is required for the correct analysis of MRD data.

• MeSH
• dítě MeSH
• dospělí MeSH
• imunofenotypizace metody   MeSH
• kojenec MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• pre-B-buněčná leukemie * patologie   diagnóza   MeSH
• předškolní dítě MeSH
• průtoková cytometrie * metody   MeSH
• reprodukovatelnost výsledků MeSH
• reziduální nádor * patologie   diagnóza   MeSH
• senioři MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• kojenec MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• multicentrická studie MeSH

Myeloid maturation in bone marrow (BM) is a complex process currently evaluated mainly by morphological examination. Although there are published data showing advantages of using flow cytometry (FC) in diagnostics of myelodysplastic syndrome in adults, age-specific reference values are missing and broader studies so far used only 4-5 fluorochromes simultaneously. Recent developments in FC bring great potential for discrimination of impaired hematopoiesis, such as BM failure or immunodeficiency, which has not been fully exploited. Our aim is to introduce a standardized analysis of myeloid maturation in pediatric BM samples. Important part is a description of specifics in patients on antileukemic therapy or after hematopoietic stem cell transplantation (HSCT). This knowledge will improve identification of malignant cells in a terrain of reactive changes. Character of myeloid maturation recovery after HSCT might reflect acute complications and graft function. Hence, establishment of FC examination could provide a basis for earlier clinical decisions and proper therapy.

Vyzrávání myeloidní řady v kostní dřeni (KD) je komplexní proces v současné době hodnocený především pomocí morfologie. Ačkoli existují přístupy pro využití průtokové cytometrie především v odlišení myelodysplastického syndromu, chybí věkově specifické normy pro zastoupení jednotlivých vývojových forem a rozsáhlejší studie využívající více než 4-5 fluorochromů současně. Rozvoj průtokové cytometrie přináší velký potenciál pro odlišení poruch krvetvorby, např. selhání kostní dřeně či imunodeficitu, který doposud nebyl plně využit. Naším cílem je zavést standardizovanou analýzu vývoje myeloidní řady v KD u dětí. Důležitou součástí je i identifikace změn při antileukemické terapii a po transplantaci kostní dřeně. Tato znalost umožní lépe odlišit maligní buňky v terénu reaktivních změn a zlepšit tak stanovení minimální reziduální nemoci pomocí průtokové cytometrie. Charakter obnovy krvetvorby po transplantaci kmenových buněk může odrážet akutní komplikace i následnou funkci štěpu a zavedení cytometrického hodnocení tak může přispět k časnějšímu klinickému rozhodování a optimální léčbě.

• Klíčová slova
• transplantace kmenových buněk, akutní myeloidní leukémie, acute myeloid leukemia, Hematopoietic stem cell transplantation, průtoková cytometrie, minimální reziduální nemoc, minimal residual disease, flow cytometry, vyzrávání myeloidní řady, myeloid maturation,

• NLK Publikační typ
• závěrečné zprávy o řešení grantu AZV MZ ČR

Detailed knowledge of human B-cell development is crucial for the proper interpretation of inborn errors of immunity and malignant diseases. It is of interest to understand the kinetics of protein expression changes during development, but also to properly interpret the major and possibly alternative developmental trajectories. We have investigated human samples from healthy individuals with the aim of describing all B-cell developmental trajectories. We validated a 30-parameter mass cytometry panel and demonstrated the utility of "vaevictis" visualization of B-cell developmental stages. We used the trajectory inference tool "tviblindi" to exhaustively describe all trajectories leading to all developmental ends discovered in the data. Focusing on Natural Effector B cells, we demonstrated the dynamics of expression of nuclear factors (PAX-5, TdT, Ki-67, Bcl-2), cytokine and chemokine receptors (CD127, CXCR4, CXCR5) in relation to the canonical B-cell developmental stage markers. We observed branching of the memory development, where follicular memory formation was marked by CD73 expression. Lastly, we performed an analysis of two example cases of abnormal B-cell development caused by mutations in RAG-1 and Wiskott-Aldrich syndrome gene in patients with primary immunodeficiency. In conclusion, we developed, validated, and presented a comprehensive set of tools for the investigation of B-cell development in the bone marrow compartment.

• MeSH
• algoritmy * MeSH
• B-lymfocyty * imunologie   MeSH
• buněčná diferenciace * imunologie   genetika   MeSH
• homeodoménové proteiny * genetika   metabolismus   MeSH
• lidé MeSH
• mutace MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Resistance to glucocorticoids (GC), the common agents for remission induction in pediatric B-cell precursor acute lymphoblastic leukemia (BCP-ALL), poses a significant therapeutic hurdle. Therefore, dissecting the mechanisms shaping GC resistance could lead to new treatment modalities. Here, we showed that CD9- BCP-ALL cells were preferentially resistant to prednisone and dexamethasone over other standard cytotoxic agents. Concordantly, we identified significantly more poor responders to the prednisone prephase among BCP-ALL patients with a CD9- phenotype, especially for those with adverse presenting features including older age, higher white cell count and BCR-ABL1. Furthermore, gain- and loss-offunction experiments dictated a definitive functional linkage between CD9 expression and GC susceptibility, as demonstrated by the reversal and acquisition of relative GC resistance in CD9low and CD9high BCP-ALL cells, respectively. Despite physical binding to the GC receptor NR3C1, CD9 did not alter its expression, phosphorylation or nuclear translocation but potentiated the induction of GC-responsive genes in GC-resistant cells. Importantly, the MEK inhibitor trametinib exhibited higher synergy with GC against CD9- than CD9+ lymphoblasts to reverse drug resistance in vitro and in vivo. Collectively, our results elucidate a previously unrecognized regulatory function of CD9 in GC sensitivity, and inform new strategies for management of children with resistant BCP-ALL.

• MeSH
• antigeny CD9 * metabolismus   genetika   MeSH
• chemorezistence * genetika   MeSH
• dexamethason farmakologie   MeSH
• dítě MeSH
• glukokortikoidy * farmakologie   terapeutické užití   MeSH
• lidé MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• pre-B-buněčná leukemie * farmakoterapie   metabolismus   genetika   patologie   MeSH
• předškolní dítě MeSH
• receptory glukokortikoidů metabolismus   genetika   MeSH
• zvířata MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: T-cell acute lymphoblastic leukemia (T-ALL) represents a rare and clinically and genetically heterogeneous disease that constitutes 10-15% of newly diagnosed pediatric ALL cases. Despite improved outcomes of these children, the survival rate after relapse is extremely poor. Moreover, the survivors must also endure the acute and long-term effects of intensive therapy. Although recent studies have identified a number of recurrent genomic aberrations in pediatric T-ALL, none of the changes is known to have prognostic significance. The aim of our study was to analyze the cytogenomic changes and their various combinations in bone marrow cells of children with T-ALL and to correlate our findings with the clinical features of the subjects and their treatment responses. RESULTS: We performed a retrospective and prospective comprehensive cytogenomic analysis of consecutive cohort of 66 children (46 boys and 20 girls) with T-ALL treated according to BFM-based protocols and centrally investigated cytogenetics and immunophenotypes. Using combinations of cytogenomic methods (conventional cytogenetics, FISH, mFISH/mBAND, arrayCGH/SNP and MLPA), we identified chromosomal aberrations in vast majority of patients (91%). The most frequent findings involved the deletion of CDKN2A/CDKN2B genes (71%), T-cell receptor (TCR) loci translocations (27%), and TLX3 gene rearrangements (23%). All chromosomal changes occurred in various combinations and were rarely found as a single abnormality. Children with aberrations of TCR loci had a significantly better event free (p = 0.0034) and overall survival (p = 0.0074), all these patients are living in the first complete remission. None of the abnormalities was an independent predictor of an increased risk of relapse. CONCLUSIONS: We identified a subgroup of patients with TCR aberrations (both TRA/TRD and TRB), who had an excellent prognosis in our cohort with 5-year EFS and OS of 100%, regardless of the presence of other abnormality or the translocation partner. Our data suggest that escalation of treatment intensity, which may be considered in subsets of T-ALL is not needed for nonHR (non-high risk) patients with TCR aberrations.

• Publikační typ
• časopisecké články MeSH

In the effort to improve immunophenotyping and minimal residual disease (MRD) assessment in acute lymphoblastic leukemia (ALL), the international Berlin-Frankfurt-Münster (iBFM) Flow Network introduced the myelomonocytic marker CD371 for a large prospective characterization with a long follow-up. In the present study, we aimed to investigate the clinical and biological features of CD371-positive (CD371pos) pediatric B-cell precursor ALL (BCP-ALL). From June 2014 to February 2017, 1812 pediatric patients with newly diagnosed BCP-ALLs enrolled in trial AIEOP-BFM ALL 2009 were evaluated as part of either a screening (n = 843, Italian centers) or validation cohort (n = 969, other iBFM centers). Laboratory assessment at diagnosis consisted of morphological, immunophenotypic, and genetic analysis. Response assessment relied on morphology, multiparametric flow cytometry (MFC), and polymerase chain reaction (PCR)-MRD. At diagnosis, 160 of 1812 (8.8%) BCP-ALLs were CD371pos. This correlated with older age, lower ETV6::RUNX1 frequency, immunophenotypic immaturity (all P < .001), and strong expression of CD34 and of CD45 (P < .05). During induction therapy, CD371pos BCP-ALLs showed a transient myelomonocytic switch (mm-SW: up to 65.4% of samples at day 15) and an inferior response to chemotherapy (slow early response, P < .001). However, the 5-year event-free survival was 88.3%. Among 420 patients from the validation cohort, 27 of 28 (96.4%) cases positive for DUX4-fusions were CD371pos. In conclusion, in the largest pediatric cohort, CD371 is the most sensitive marker of transient mm-SW, whose recognition is essential for proper MFC MRD assessment. CD371pos is associated to poor early treatment response, although a good outcome can be reached after MRD-based ALL-related therapies.

• MeSH
• buněčný rodokmen MeSH
• dítě MeSH
• imunofenotypizace MeSH
• kojenec MeSH
• lidé MeSH
• mladiství MeSH
• pre-B-buněčná leukemie * genetika   mortalita   farmakoterapie   patologie   diagnóza   terapie   metabolismus   MeSH
• předškolní dítě MeSH
• protokoly antitumorózní kombinované chemoterapie terapeutické užití   MeSH
• reziduální nádor * diagnóza   MeSH
• tetraspaniny genetika   metabolismus   MeSH
• Check Tag
• dítě MeSH
• kojenec MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• multicentrická studie MeSH
• práce podpořená grantem MeSH

Diagnostic criteria for juvenile myelomonocytic leukemia (JMML) are currently well defined, however in some patients diagnosis still remains a challenge. Flow cytometry is a well established tool for diagnosis and follow-up of hematological malignancies, nevertheless it is not routinely used for JMML diagnosis. Herewith, we characterized the CD34+ hematopoietic precursor cells collected from 31 children with JMML using a combination of standardized EuroFlow antibody panels to assess the ability to discriminate JMML cells from normal/reactive bone marrow cell as controls (n=29) or from cells of children with other hematological diseases mimicking JMML (n=9). CD34+ precursors in JMML showed markedly reduced B-cell and erythroid-committed precursors compared to controls, whereas monocytic and CD7+ lymphoid precursors were significantly expanded. Moreover, aberrant immunophenotypes were consistently present in CD34+ precursors in JMML, while they were virtually absent in controls. Multivariate logistic regression analysis showed that combined assessment of the number of CD34+CD7+ lymphoid precursors and CD34+ aberrant precursors or erythroid precursors had a great potential in discriminating JMMLs versus controls. Importantly our scoring model allowed highly efficient discrimination of truly JMML versus patients with JMML-like diseases. In conclusion, we show for the first time that CD34+ precursors from JMML patients display a unique immunophenotypic profile which might contribute to a fast and accurate diagnosis of JMML worldwide by applying an easy to standardize single eight-color antibody combination.

• MeSH
• antigeny CD34 genetika   MeSH
• dítě MeSH
• juvenilní myelomonocytární leukemie * diagnóza   genetika   MeSH
• lidé MeSH
• monocyty patologie   MeSH
• průtoková cytometrie MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Průtoková cytometrie je zásadní diagnostickou metodou v imunologii a v hematologii u dětí. Výhodou cytometrie je rychlost, kdy v rámci hodin může tato metoda klinikům pomoci ve volbě terapie a indikaci dalších vyšetření.

Flow cytometry is an essential diagnostic method in immunology and haematology in children. The advantage of flow cytometry is its speed, where within hours this method can help clinicians in the choice of therapy and the indication of further investigations.

• MeSH
• dítě MeSH
• krevní nemoci diagnóza   MeSH
• lidé MeSH
• lymfoblastická leukemie-lymfom z prekurzorových T-buněk diagnóza   MeSH
• průtoková cytometrie * metody   MeSH
• reziduální nádor diagnóza   MeSH
• syndromy imunologické nedostatečnosti diagnóza   MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• Publikační typ
• práce podpořená grantem MeSH
• přehledy MeSH

The standardized EuroFlow protocol, including CD19 as primary B-cell marker, enables highly sensitive and reliable minimal residual disease (MRD) assessment in B-cell precursor acute lymphoblastic leukaemia (BCP-ALL) patients treated with chemotherapy. We developed and validated an alternative gating strategy allowing reliable MRD analysis in BCP-ALL patients treated with CD19-targeting therapies. Concordant data were obtained in 92% of targeted therapy patients who remained CD19-positive, whereas this was 81% in patients that became (partially) CD19-negative. Nevertheless, in both groups median MRD values showed excellent correlation with the original MRD data, indicating that, despite higher interlaboratory variation, the overall MRD analysis was correct.

• MeSH
• adaptorové proteiny signální transdukční MeSH
• akutní lymfatická leukemie * MeSH
• antigeny CD19 terapeutické užití   MeSH
• Burkittův lymfom * MeSH
• lidé MeSH
• pre-B-buněčná leukemie * diagnóza   farmakoterapie   MeSH
• průtoková cytometrie metody   MeSH
• reziduální nádor MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH