The feasibility of the CD271+ and CD271– mesenchymal stromal cell enrichment toward nucleus pulposus-like cells

Introduction. Factors promoting nerve cell ingrowth are considered responsible for chronic back pain resulting from the intervertebral disc degeneration (IDD). One of the recent exploratory IDD treatments is stem cell transplantation therapy. The CD271 (low-affinity nerve growth factor receptor) has been identified as a mark­er of the most homogeneous mesenchymal stem cell (MSC) subset. It is capable of promoting differentiation along adipogenic, osteogenic and chondrogenic lineages and producing significantly higher levels of cytokines as compared to the total population of plastic adherence-mesenchymal stem cells (PA-MSCs). We investigated the ability of CD271+ MSCs to differentiate into chondrocyte-like cells of the nucleus pulposus (NP) of intervertebral disc. We also examined CD271– MSCs, using PA-MSCs as a control cell population. Material and methods. Bone marrow derived PA-MSCs and its two subsets, CD271– MSCs and CD271+ MSCs, were seeded in collagen scaffolds. After two weeks of growth in NP-differentiation medium, RNA was isolated from cells-scaffold constructs and was analyzed by q-PCR for expression of NP markers. Glycosaminoglycans were analyzed biochemically directly in cells-scaffold constructs. Results. Expression of NP markers — extracellular matrix components such as aggrecan, collagen type II and glycosaminoglycans on both RNA and the protein levels — was significantly higher in CD271– MSCs compared to the CD271+ MSCs and PA-MSCs cell populations. Conclusions. CD271– MSCs may be superior candidates for NP restorative treatment compared to CD271+ MSCs and PA-MSCs due to their ability of expressing NP-supporting extracellular matrix components at levels higher than the other two studied MSC subsets

Prognostic impact of combined fludarabine, treosulfan and mitoxantrone resistance profile in childhood acute myeloid leukemia

Background: The role of cellular drug resistance in childhood acute myeloid leukemia (AML) has not yet been established. The aim of the study was the analysis of the clinical value of ex vivo drug resistance in pediatric AML. Patients and Methods: A cohort of 90 children with de novo AML were assayed for drug resistance profile by the 3-4,5- dimethylthiazol-2-yl-2,5-difenyl tetrazolium bromide (MTT) assay and prognostic model of in vitro drug sensitivity was analyzed. Results: Children who relapsed during follow-up showed higher in vitro resistance of leukemic blasts to most of the drugs tested, except for cytarabine, cladribine, vincristine, mercaptopurine and thioguanine. A combined in vitro drug resistance profile to fludarabine, treosulfan and mitoxantrone (FTM score) was defined and it had an independent prognostic significance for disease free survival in pediatric AML. Conclusion: The combined fludarabine, treosulfan and mitoxantrone resistance profile to possibly may be used for better stratification of children with AML or indicate the necessity for additional therapy

Outcome of refractory and relapsed acute myeloid leukemia in children treated during 2005-2011 : experience of the Polish Pediatric Leukemia/Lymphoma Study Group (PPLLSG)

AIM OF THE STUDY: Recent studies showed relatively better outcome for children with refractory (refAML) and relapsed acute myeloid leukemia (relAML). Treatment of these patients has not been unified within Polish Pediatric Leukemia/Lymphoma Study Group (PPLLSG) so far. The goal of this study is to analyze the results of this therapy performed between 2005–2011. MATERIAL AND METHODS: The outcome data of 16 patients with refAML and 62 with relAML were analyzed retrospectively. Reinduction was usually based on idarubicine, fludarabine and cytarabine with allogenic hematopoietic stem cell transplant (alloHSCT) in 5 refAML and 30 relAML children. RESULTS: Seventy seven percent relAML patients entered second complete remission (CR2). Five-year OS and disease-free survival (DFS) were estimated at 16% and 30%. The outcome for patients after alloHSCT in CR2 (63%) was better than that of those not transplanted (36%) with 5-year OS of 34% vs. 2-year of 7% and 5-year DFS of 40% vs. 12.5%. Second complete remission achievement and alloHSCT were the most significant predictors of better prognosis (p = 0.000 and p = 0.024). The outcome of refAML children was significantly worse than relAML with first remission (CR1) rate of 33%, OS and DFS of 25% at 3 years and 53% at 2 years, respectively. All survivors of refAML were treated with alloHSCT after CR1. CONCLUSIONS: The uniform reinduction regimen of the documented efficacy and subsequent alloHSCT in remission is needed to improve the outcome for ref/relAML children treated within PPLLSG. The focus should be on the future risk-directed both front and second line AML therapy

Epidemiology and prevention strategies of SARS-CoV-2 infection in pediatric hematology and oncology centers in Poland

IntroductionEpidemiological analysis of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infections in pediatric hematology and oncology (PHO) and hematopoietic cell transplant (HCT) centers in a Polish nationwide study, as well as analysis of the preventive strategies in these centers. MethodsAll of the 18 PHO/HCT centers participated in eight surveys and questionnaires conducted over the first 5 months of the SARS-CoV-2/coronavirus disease 2019 (COVID-19) pandemic in Poland. Epidemiological data were collected at eight regular time points, and the strategy of preventive management was done once after 4 months of the pandemic. ResultsDuring this analyzed period, eight patients were positive for SARS-CoV-2. The estimated incidence of SARS-CoV-2 positivity in Polish PHO/HCT centers was 0.5%. After exclusion of HCT patients (with one patient being infected), the estimated incidence of SARSCoV-2 positivity was between 0.5 and 0.6%. In all but one case, the course of COVID-19 was asymptomatic or mild, and it was moderate in one case. None of them developed SARS or respiratory insufficiency, none of them required treatment in the intensive care unit (ICU), and no patient died due to SARS-CoV-2 infection. As of July 1, parents staying in the hospital together with their children were regularly tested for the virus in 13 centers. Asymptomatic healthcare personnel were regularly tested for the virus in seven centers. ConclusionsThe estimated incidence of SARS-CoV-2 infection among PHO/HCT patients is lower than in Western Europe; however, these patients cannot be regarded as a low-risk group. The low COVID-19 incidence should be interpreted as a result of strictly and continuously implemented detailed preventive measures in the PHO/HCT wards and in hospitals