Acute lymphoblastic leukemia (ALL) is the most frequent pediatric malignancy. The chemotherapy for ALL is associated with a profound secondary immune deficiency.We evaluated the number and phenotype of natural killer (NK) cells at diagnosis, after the intensive chemotherapy and following the completion of the entire treatment for patients with ALL. The fraction, absolute number, and percentage of NK cells expressing interferon-γ were determined in full blood samples. The fraction of NK cells expressing CD158a, CD158b, perforin, A, B, and K granzymes was examined in isolated NK cells.We have shown that patients assessed at ALL diagnosis showed significantly lower values of the fraction of NK cells and percentage of NK cells with the granzyme A expression. Additionally, the absolute number of NK cells, the expression of CD158a, CD158b, perforin, and granzyme A were significantly lower in patients who completed intensive chemotherapy. Also, there was a significantly higher fraction of NK cells expressing granzyme K in patients who completed the therapy.Abnormalities of NK cells were found at all stages of the treatment; however, the most pronounced changes were found at the end of intensive chemotherapy.

Background: A retrospective analysis was performed to investigate the survival outcomes in pediatric acute lymphoblastic leukemia (ALL) based on time period. We hypothesized that improvement has been obtained with the time-dependent therapeutic era and rise in the gross domestic product (GDP) and Human Development Index (HDI). Materials and Methods: Data from 710 children who were treated for ALL between 1958 and 2018 at a single pediatric center were analyzed for probability of 5-year overall survival (pOS), event-free survival (pEFS) and relapse risk (pRR). Time periods were defined by the treatment protocols used in seven consecutive therapeutic eras. Results: Over the 60-year period analyzed, pOS increased from 1.2% to 90.7%, pEFS from 1.2% to 86.6%, and pRR decreased from 98.8% to 9.9% for patients treated in the past decade. Risk of mortality for patients who received chemotherapy and hematopoietic cell transplant was reduced to 9.9% in the recent era, however, no statistically significant survival difference was found between patients treated with stem cell transplant and those not. Conclusion: The therapeutic era, related to improved GDP and HDI, was a statistically significant predictor of increased OS from ALL.

Objective: Iron overload (IO) is a common and life-threatening complication resulting from the therapy of AL and HCT patients. This study aimed to evaluate the prognostic value of 12 serum biomarkers of iron metabolism in pediatric patients treated for AL or undergoing HCT. Patients: Overall, 50 patients with AL after intensive treatment and 32 patients after HCT were prospectively included in the study. AL patients at diagnosis and healthy controls served as reference groups. Methods: The impact of the following 12 serum iron metabolism parameters on the outcome of AL/HCT patients was analyzed: iron, transferrin (Tf), total iron-binding capacity (TIBC), ferritin, ferritin heavy chains (FTH1), ferritin light chains (FTL), hepcidin, soluble hemojuvelin (sHJV), soluble ferroportin-1 (sFPN1), erythroferrone (ERFE), erythropoietin (EPO), and soluble transferrin receptor (sTfR). Results: With a median follow-up of 2.2 years, high levels of ferritin and low levels of sHJV had an adverse prognostic impact on OS and EFS in children after HCT. If these patients were combined with those with AL after intensive chemotherapy, the results were confirmed for OS and EFS both for ferritin and sHJV. Conclusions: Among the 12 analyzed serum parameters of iron metabolism, increased levels of ferritin and decreased levels of sHJV had an adverse prognostic impact on survival in children after HCT. More data are needed to clarify the relationship between ferritin, sHJV, and mortality of AL children after intensive chemotherapy, and more extensive prospective studies are required to prove sHJV predictivity.

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Background/Aim: Neurofibromatosis type 1 (NF1) is characterized by the occurrence of multisystem tumors, among which the most characteristic are optic pathway gliomas (OPGs) and plexiform neurofibromas (PNFs). With the development of new anticancer drugs targeting the immune system, it is important to examine the immunological status of patients with NF1. Furthermore, the immune system has been suggested as a probable modulator of NF1associated phenotypes. The objective of this study was the analysis of lymphocyte subset populations with respect to the presence of PNFs and OPGs. Patients and Methods: Fiftythree patients with NF1 diagnosed with OPG/PNF were analyzed for lymphocyte subpopulations. Results: Significantly lower levels of B-cells, T-cells and natural killer (NK) cells were observed in the group of patients with PNFs compared to those with OPG. Conclusion: Our observation may indicate a correlation between weakened functioning of the immune system and the formation of PNFs.

A total number of 817 children with acute lymphoblastic leukemia (ALL) and 181 with acute myeloblastic leukemia (AML) were assessed for individualized tumor response testing (ITRT) profile as a prognostic factor in long-term follow-up. For each patient, ITRT, initial response to therapy and long-term outcome were assessed. In initial ALL, an impact on long-term response was shown in ITRT for 13 drugs, while in initial AML only for cytarabine. For patients with ALL, a combined five-drug ITRT profile for prednisolone, l-asparaginase, vincristine, cytarabine and daunorubicin or doxorubicin had predictive value for probability of disease-free survival (pDFS) in univariate analysis, whereas in multivariate analysis, bone marrow response by day 33 was the only prognostic factor. For patients with AML, no factor had prognostic value for pDFS in univariate analysis, while ITRT to cytarabine almost reached significance. In conclusion, ITRT can possibly be regarded as a risk factor in childhood acute leukemias.

Aim of the studyResistance to imatinib is one of the most important issues in treatment of chronic myeloid leukemia (CML) patients. The objective of the study was to analyze the ex vivo drug resistance profile to bortezomib and 22 other antileukemic drugs, including three tyrosine kinase inhibitors (TKIs), in CML in comparison to acute myeloid leukemia (AML).Material and methodsA total of 82 patients entered the study, including 36 CML and 46 AML adults. Among CML patients, 19 had advanced disease, 16 were resistant to imatinib, and 6 had ABL-kinase domain mutations. The ex vivo drug resistance profile was studied by the MTT assay.ResultsCML cells were more resistant than AML blasts to the following drugs: prednisolone, vincristine, doxorubicin, etoposide, melphalan, cytarabine, fludarabine, thiotepa, 4-HOO-cyclophosphamide, thioguanine, bortezomib, topotecan, and clofarabine. CML cells were 2-fold more sensitive to busulfan than AML cells. CML patients with clinical imatinib resistance had higher ex vivo resistance to vincristine, daunorubicin, etoposide, and busulfan. No significant differences to all tested drugs, including TKIs, were observed between CML patients with non-advanced and advanced disease. CML patients with mutation had higher ex vivo resistance to vincristine, idarubicin, thiotepa, and busulfan.ConclusionsCML cells are ex vivo more resistant to most drugs than acute myeloid leukemia blasts. Busulfan is more active in CML than AML cells. In comparison to AML cells, bortezomib has little ex vivo activity in CML cells. No differences between CML subgroups in sensitivity to 3 tested TKIs were detected.

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