5-aminoimidazole-4-carboxamide ribonucleoside induces differentiation in a subset of primary acute myeloid leukemia blasts.

BACKGROUND: All-trans retinoic acid (ATRA)-based treatment of acute promyelocytic leukemia (APL) is the most successful pharmacological treatment of acute myeloid leukemia (AML). Recent development of inhibitors of mutated isocitrate dehydrogenase and dihydroorotate dehydrogenase (DHODH) has revived interest in differentiation therapy of non-APL AML. Our previous studies demonstrated that 5-aminoimidazole-4-carboxamide ribonucleoside (AICAr) induced differentiation of monocytic cell lines by activating the ATR/Chk1 via pyrimidine depletion. In the present study, the effects of AICAr on the viability and differentiation of primary AML blasts isolated from bone marrow of patients with non-APL AML were tested and compared with the effects of DHODH inhibitor brequinar and ATRA. METHODS: Bone marrow samples were obtained from 35 patients and leukemia blasts were cultured ex vivo. The cell viability was assessed by MTT assay and AML cell differentiation was determined by flow cytometry and morphological analyses. RNA sequencing and partial data analysis were conducted using ClusterProfiler package. Statistical analysis was performed using GraphPad Prism 6.0. RESULTS: AICAr is capable of triggering differentiation in samples of bone marrow blasts cultured ex vivo that were resistant to ATRA. AICAr-induced differentiation correlates with proliferation and sensitivity to DHODH inhibition. RNA-seq data obtained in primary AML blasts confirmed that AICAr treatment induced downregulation of pyrimidine metabolism pathways together with an upregulation of gene set involved in hematopoietic cell lineage. CONCLUSION: AICAr induces differentiation in a subset of primary non-APL AML blasts, and these effects correlate with sensitivity to a well-known, potent DHODH inhibitor.

Immunoglobulin heavy/light chain analysis enhances the detection of residual disease and monitoring of multiple myeloma patients.

AIM: To evaluate the clinical utility of incorporating a novel heavy/light chain immunoassay (HLC) into the existing methods for the assessment of multiple myeloma (MM) patients. METHODS: Convenience sera samples from 90 previously treated IgG and IgA MM patients in different disease stages were analyzed. The study was conducted in Clinical Hospital Center Zagreb between 2011 and 2013. The collected sera were analyzed by standard laboratory techniques (serum protein electrophoresis, quantification of total immunoglobulins, serum immunofixation, serum free light chain [FLC] assay) and HLC assay. RESULTS: HLC ratios outside the normal range were found in 58 of 90 patients, including 28 out of 61 patients with total immunoglobulin measurements within the normal range and 5 out of 23 patients in complete response. Both elevated HLC isotype level and abnormal HLC ratio correlated with the parameters of tumor burden, including percentage of plasma cells in the bone marrow (P<0.001 and P=0.002, respectively) and an abnormal serum FLC ratio (for both P<0.001). In addition, abnormal HLC isotype level correlated with serum beta-2-microglobulin level (P=0.038). In terms of prognosis, abnormal HLC isotype level and abnormal HLC ratio were significantly associated with shorter overall survival (P<0.001 and P=0.002, respectively). Interestingly, suppression of the uninvolved (polyclonal) isotype pair, but not other non-myeloma immunoglobulin isotypes, was also associated with a shorter overall survival (P=0.021). In a multivariate analysis, an abnormal HLC ratio and ß2-microglobulin level >3.5mg/L were independent risk factors for survival. CONCLUSION: The new HLC assay has greater sensitivity in detecting monoclonal protein, correlates with tumor burden markers, and affects patients' outcome.

[Extracorporeal photopheresis in treatment of chronic graft versus host disease]. / Ekstrakorporalna fotofereza u lijecenju kronicne reakcije transplantata protiv primatelja.

Extracorporeal photopheresis (ECP) is an immunomodulatory therapy which has been used in the treatment of chronic GVHD (cGVHD). ECP involves separation of the mononuclear cells with leukapheresis, followed by ex vivo administration of 8-methoxypsoralen and UV-A radiation and reinfusion to the patient. Aim of the study was to evaluate clinical and immunomodulatory effect of ECP procedures in patients with cGVHD. We analyzed 341 ECP procedures performed in 7 patients with cGVHD; median ECP per patient was 37 (range 13-131). All patients suffered from skin changes in combination with impaired joint mobility and symptoms of oral disease. ECP procedures were performed for two consecutive days: in initial phase weekly, followed by every two weeks and than monthly according to clinical response. Median of ECP treatment duration was 10 months (range 2-58). The effect of ECP in patients with cGVHD with skin andjoint involvement was mostly beneficial: 6 patients experienced either improvement or stabilization in skin changes and joint mobility. In 2 patients who suffered from oral disease, the total recovery was observed. Clinical response was typically delayed until 2 to 3 months, and reduction in glucocorticoid dose was observed. Adverse reactions were observed in 4.9% procedures. In patients who responded to ECP treatment, CD4+/CD8+ ratio and number of NK cells were normalized. ECP proved to be an efficient and safe procedure that may be recommended for patients with cGVHD who do not respond to conventional therapy.

All-trans retinoic acid induces differentiation in primary acute myeloid leukemia blasts carrying an inversion of chromosome 16.

All-trans retinoic acid (ATRA)-based therapy for acute promyelocytic leukemia (APL), a subtype of acute myeloid leukemia (AML), is the most successful example of differentiation therapy. Although ATRA can induce differentiation in some non-APL AML cell lines and primary blasts, clinical results of adding ATRA to standard therapy in non-APL AML patients have been inconsistent, probably due to use of different regimens and lack of diagnostic tools for identifying which patients may be sensitive to ATRA. In this study, we exposed primary blasts obtained from non-APL AML patients to ATRA to test for differentiation potential in vitro. We observed increased expression of differentiation markers, indicating a response to ATRA, in four out of fifteen primary AML samples. Three samples in which CD11b increased in response to ATRA had an inversion of chromosome 16 as well as the CBFB-MYH11 fusion gene, and the fourth sample was from a patient with KMT2A-rearranged, therapy-related AML. In conclusion, we identified a subgroup of non-APL AML patients with inv(16) and CBFB-MYH11 as the most sensitive to ATRA-mediated differentiation in vitro, and our results can help identify patients who may benefit from ATRA treatment.

Large volume leukapheresis: Efficacy and safety of processing patient's total blood volume six times.

Large-volume leukapheresis (LVL) differs from standard leukapheresis by increased blood flow and an altered anticoagulation regimen. An open issue is to what degree a further increase in processed blood volume is reasonable in terms of higher yields and safety. In 30 LVL performed in patients with hematologic malignancies, 6 total blood volumes were processed. LVL resulted in a higher CD34+ cell yield without a change in graft quality. Although a marked platelet decrease can be expected, LVL is safe and can be recommended as the standard procedure for patients who mobilize low numbers of CD34+ cells and when high number of CD34+ cells are required.

An Extensive Quality Control and Quality Assurance (QC/QA) Program Significantly Improves Inter-Laboratory Concordance Rates of Flow-Cytometric Minimal Residual Disease Assessment in Acute Lymphoblastic Leukemia: An I-BFM-FLOW-Network Report.

Monitoring of minimal residual disease (MRD) by flow cytometry (FCM) is a powerful prognostic tool for predicting outcomes in acute lymphoblastic leukemia (ALL). To apply FCM-MRD in large, collaborative trials, dedicated laboratory staff must be educated to concordantly high levels of expertise and their performance quality should be continuously monitored. We sought to install a unique and comprehensive training and quality control (QC) program involving a large number of reference laboratories within the international Berlin-Frankfurt-Münster (I-BFM) consortium, in order to complement the standardization of the methodology with an educational component and persistent quality control measures. Our QC and quality assurance (QA) program is based on four major cornerstones: (i) a twinning maturation program, (ii) obligatory participation in external QA programs (spiked sample send around, United Kingdom National External Quality Assessment Service (UK NEQAS)), (iii) regular participation in list-mode-data (LMD) file ring trials (FCM data file send arounds), and (iv) surveys of independent data derived from trial results. We demonstrate that the training of laboratories using experienced twinning partners, along with continuous educational feedback significantly improves the performance of laboratories in detecting and quantifying MRD in pediatric ALL patients. Overall, our extensive education and quality control program improved inter-laboratory concordance rates of FCM-MRD assessments and ultimately led to a very high conformity of risk estimates in independent patient cohorts.

Detection of residual B precursor lymphoblastic leukemia by uniform gating flow cytometry.

BACKGROUND: Residual disease (RD) is an important prognostic factor in acute lymphoblastic leukemia (ALL). Flow cytometry (FC)-based RD detection is easy to perform, but interpretation requires expert analysis due to individual differences among patients. PROCEDURE: We focused at the design of standardized and reproducible RD monitoring in ALL. RD was investigated by a uniform gating strategy, which was designed internationally and tested in one center by Ig/TCR rearrangements. RESULTS: For each gate, positivity cutoff value was assigned using quantification of non-leukemic background. Comparing to Ig/TCR at 0.1% level, 80 of 103 specimens were correctly diagnosed by FC. The predictive value of FC RD at day 15 was then analyzed. In B lineage ALL, day 15 FC significantly correlated with Ig/TCR results at day 33 and/or week 12 (P < 0.01). No significant correlation was found in T lineage ALL. CONCLUSIONS: Thus, FC with preset uniform gating at day 15 predicts PCR-detectable MRD in B precursor ALL. Presented data may be used to define new polychromatic cytometric diagnostics of MRD including semiautomatic assessment. Pediatr Blood Cancer 2010; 54:62-70. (c) 2009 Wiley-Liss, Inc.

CD20 positive childhood B-non Hodgkin lymphoma (B-NHL): morphology, immunophenotype and a novel treatment approach: a single center experience.

Lymphomas represent the third most common group of cancers in childhood and adolescence, mature B non Hodgkin's lymphoma (B-NHL) accounting for up to 60% of newly diagnosed patients. The diagnosis of specific entities of B-NHL is based on well-defined morphologic analysis, immunophenotyping, cytogenetics and molecular genetics, which determine the optimal treatment strategy. In adult population a major turning point in treatment of B-NHL has been achieved since rituximab, in combination with CHOP has improved the survival rate up to 19%. Rituximab is a chimeric monoclonal antibody that targets CD20, a transmembrane calcium channel expressed on normal and malignant B-cells that mediates cytotoxic, apoptotic and anti-proliferative effects. The effect of rituximab in pediatric population is still not well enough investigated. Based on morphology and immunophenotype of malignant cells, seven children with B-NHL in our institution were eligible for treatment with modified B-NHL-Berlin-Frankfurt-Münster (BFM)-95-based protocol with rituximab administered on day -5. The complete remission was achieved in all seven patients. Six patients are still in complete remission at least 12 months after having finished chemotherapy and one patient relapsed two months after the last cycle and subsequently died. Major adverse effects observed during treatment were prolonged B-cell depletion and myelosuppression. Rituximab in combination with B-NHL-BFM-95 protocol was otherwise well tolerated and proved to be effective in children and adolescents with B-NHL. The number of our patients is too small and the follow-up of a larger group of patients will help in defining the role of rituximab in the treatment of childhood B-NHL.

Subcutaneous panniculitis-like T-cell lymphoma in a 19 month-old boy: a case report.

Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare type of T-cell lymphoma of CD3+CD8+ phenotype characterized by deep-seated skin nodules or plaques mimicking panniculitis, a result of neoplastic lymphocytes infiltrating the subcutaneous fatty tissue. We present a case of a 19-month year old boy with SPTCL diagnosed and successfully treated in our institution. Disease first presented with symptoms of high fever and painful erythematous nodule located below the umbilicus. Later on the infiltrates appeared on the face, legs, arms and the back of the body. As the most decisive in obtaining the diagnosis, skin biopsy showed atypical, small to medium-sized lymphatic cells infiltrating the deeper dermal layers as well as the subcutaneous adipous tissue surrounding the adipocytes. Immunohystochemical analysis showed neoplastic lymphocytes positive for CD2, CD3, CD5, CD7, CD8, Tia-1, granzyme B and perforine, and negative for CD20, CD34, TDT and CD56. No infiltration of blood vessels or epidermis was evident. Specific T-cell lymphomas protocol (EURO-LB 02) was then initiated which resulted with rapid regression of all general and local symptoms. The treatment was completed according to schedule and the child is now, 24 months after the initiation of the treatment, in complete remission.

Collection and composition of autologous peripheral blood stem cells graft in patients with acute myeloid leukemia: influence on hematopoietic recovery and outcome.

Hematopoietic stem cell (HSC) transplantation is a standard approach in the treatment of hematological malignant diseases. For the last 15 years the main source of cells for transplantation have been peripheral blood stem cells (PBSC). With the availability of hematopoietic growth factors and understanding the advantages of treatment with PBSC, the application of bone marrow (BM) was supplanted. The aim of this survey was to explore the success of PBSC collection, the factors which influence the success of PBSC collection, the composition and the quality of graft and their influence on hematopoietic recovery and outcome after transplantation in patients with acute myeloid leukemia (AML). PBSC were collected by the method of leukapheresis after applying a combination of chemotherapy and growth factors or only growth factors. The quality of graft was determined with the clonogenic progenitor cell assay and with the flow cytometry analysis. Of the total 134 patients with AML, who were submitted to HSC mobilization, the collection was successful in 78 (58.2%) patients. The collection was more successful after the first than after the second attempt of HSC mobilization (49% vs. 11%). The criteria for effective mobilization were the number of leukocytes > 3 x 10(9)/L and the concentration of CD34+ cells > 20 x 10(3)/mL in the peripheral blood on the first day of leukapheresis. The number of CD34+ cells infused had the strongest impact on hematopoietic recovery. We noted significantly faster hematological recovery of neutrophils and platelets, fewer number of transfused units of red blood cells and platelets, shorter duration of the tranfusion support, shorter treatment with intravenous antibiotic therapy and shorter hospitalization after PBSC compared to BM transplantation. These advantages could provide their standard application in the treatment of patients with AML.

Lithium effect on glutamate induced damage in glioblastoma cells.

Lithium, besides mood stabilization, might be involved in neuroprotection. Previously we have found that the treatment with lithium increased the levels of p21(WAF/Cip1 and survivin in human glioblastoma A1235 cells. The aim of the present study was to examine the cytotoxic effect of glutamate on these cells, and to determine whether lithium can protect A1235 cells against toxic effects of glutamate. Cytotoxicity of glutamate was examined by spectrophotometric MTT assay, while the expression of apoptosis related genes was examined by Western blot method. Glutamate was excessively cytotoxic for A1235 cells only in concentrations higher than 100 mM. It did not induce apoptosis, but rather suppressed survivin expression and increased the level of p21(WAf/Cip1). Pretreatment with lithium (2 mM) partially reverted change in survivin expression induced by glutamate, suggesting that lithium may have beneficial effect on glutamate induced cell damage in glioblastoma cells.

[Biphenotypic and bilineal acute leukemias]. / Bifenotipske i bilinijske akutne leukemije.

Human acute leukemias (AL) are classified as myeloid or lymphoid according to cytomorphology and the expression of leukocyte differentiation antigens/CD-markers. However, in the minority of cases leukemic cells express markers of more than one lineage, which has led to the introduction of a new subgroup of acute leukemias termed mixed or biphenotypic acute leukemias (BAL). In an effort to distinguish between BAL and those AL with aberrant expression of markers of other lineage, the European Group for the Immunological Characterization of Acute Leukemias (EGIL) has proposed a scoring system in which CD-markers are assigned a score of 0.5, 1.0 or 2.0, depending on the specificity of a particular antigen for myeloid, B- and/or T-lymphoid lineage, respectively. The new WHO classification of hematologic tumors has adopted the EGIL criteria for BAL and introduced a new group of AL termed 'AL of ambiguous lineage'. In addition to BAL in which a single cell population expresses both myeloid and lymphoid differentiation markers, this new group of leukemias also comprises cases that present with two separate blast populations (acute bilineal leukemia, aBLL). In general, BAL accounts for less than 5% of all AL cases, whereas aBLL is a rare disease constituting 1%-2% of AL cases that contains B- or T-lymphoid along with myeloid blasts. Chromosome abnormalities are frequent in both entities with a relatively high incidence of Philadelphia chromosome and rearrangements involving 11q23, especially in cases with B- and myeloid involvement. Other biological features include CD34 expression and multi-drug resistance P-glycoprotein overexpression. The prognosis of BAL and aBLL is unfavorable, with poor prognostic factors being age, high WBC and the presence of Philadelphia chromosome. Unfortunately, optimal therapy is not known, although regimens designed for acute lymphoblastic leukemia may result in a better response rate. Collaborative studies are needed for better understanding of the biology of these entities and establishment of standard therapeutic protocols.

A search for a mutation of the Aiolos phosphorylation domain in lymphocytes from patients with leukemia.

We examined whether phosphorylation of Aiolos in primary human lymphocytes is part of the malignant transformation in leukemia. By analyzing mutations at a restriction site we show here that impairment of Aiolos activity in human leukemia is not based on deficient phosphorylation as had been demonstrated in experiments in vitro.

Interleukin-18 as a mediator of systemic juvenile idiopathic arthritis.

The objective of this report is to explore the balance between serum and synovial fluid levels of interleukin (IL)-18 in children with juvenile idiopathic arthritis (JIA). Blood samples were obtained from 81 children with JIA and 18 control children. Synovial fluid samples were collected from 16 children with oligoarticular JIA. Concentrations of IL-18 were determined using commercial kit. Patients with systemic JIA had higher serum levels of IL-18 than patients with other forms of JIA or control children, both during the active (median, range: 6,240, 1,600-78,750 pg/ml) and inactive (1,615, 513-3,270 pg/ml) phase of disease [analysis of variance (ANOVA), P<0.05). Levels of IL-18 in sera of children with oligoarticular JIA (255, 89-4,342 pg/ml) were similar to the respective synovial fluid levels (217, 89-1,245 pg/ml). Serum levels of IL-18 were proportional to the erythrocyte sedimentation rate and levels of C-reactive protein, but inversely proportional to the haemoglobin levels. IL-18 appears to be an important mediator of systemic JIA, while it seems of a lesser relevance in pathogenesis of other JIA forms. Therefore, inhibition of IL-18 might be a base for a successful biological therapy for systemic JIA.

[Treatment of hairy cell leukemia with cladribine]. / Lijecenje leukemije vlasastih stanica kladribinom.

Hairy cell leukemia is a chronic B-cell lymphoproliferative disorder characterized by clonal proliferation of hairy cells. Treatments of choice are purine analogues, particularly cladribine. We treated thirty patients with cladribine either by continuous 7-day infusion at a daily dose of 0.1 mg/kg or by 2-h infusion for 5 consecutive days at a daily dose of 0.14 mg/kg. Remission was achieved in 90% of the patients. After a median follow-up of 44 months overall survival is 93% and time to treatment failure more than 6 years. Two patients did not respond, one patient died of infection shortly after the treatment. Side-effects resulted mainly from hematological toxicity, 23% of the patients had neutropenic fever while 20% required platelets or packed red cell transfusions. Our results show that cladribine is safe and effective in the treatment of hairy cell leukemia. There were no significant differences in toxicity and response between 7-day continuous infusion and 5-day intermittent infusions of the drug.

CD95/Fas expression on peripheral blood T lymphocytes in patients with multiple sclerosis: effect of high-dose methylprednisolone therapy.

Recent data indicate that the apoptotic process, mediated by the CD95/Fas cell surface receptor, is impaired in activated lymphocytes of patients with relapsing-remitting multiple sclerosis. Using flow cytometric-immunophenotyping, we analyzed the expression of CD95/Fas on peripheral blood CD4+ and CD8+ T lymphocytes (PBL) in 10 MS patients in relapse, and the effect of pulse corticosteroid therapy on the apoptosis of autoreactive lymphocytes. The proportions of CD8+ and CD8+CD95+ T lymphocytes were significantly higher in MS patients in relapse before than after pulse corticosteroid therapy. Conversely, the proportions of CD4+ and CD4+CD95+ T cells were significantly lower before than after therapy, but not significantly different from healthy persons. The different expression of CD95/Fas on peripheral blood CD8+ T lymphocytes in relapsing RRMS and in healthy controls suggests a possible involvement of apoptosis in the pathogenesis of MS. Our results also show that pulse corticosteroid therapy influences the CD95/Fas expression on CD8+ and CD4+ T lymphocytes in patients with RRMS.

Carboplatin resistant human laryngeal carcinoma cells are cross resistant to curcumin due to reduced curcumin accumulation.

Curcumin is a natural compound that exhibits a wide range of beneficial effects, among them the anti-tumor activity. Recently it was shown that curcumin may be efficient against drug resistant tumor cells. The goal of our investigation was to examine if human laryngeal carcinoma cells resistant to carboplatin display sensitivity to curcumin, as compared to parental cells, and if this sensitivity is altered, to determine the molecular mechanisms that are responsible for it. We found that carboplatin resistant 7T cells were also cross resistant to curcumin. After the treatment with equimolar concentration of curcumin, 7T cells exhibited lower intracellular accumulation of curcumin which coincided with reduced formation of reactive oxygen species (ROS), diminished lipid and DNA damage followed by reduced induction of apoptosis and expression of heat shock protein 70 (Hsp70), as compared to parental HEp-2 cells. However, after the treatment with equitoxic concentration of curcumin, intracellular accumulation and all the explored downstream effects were similar in both cell lines suggesting that resistance of 7T cells to curcumin was based on its reduced intracellular accumulation. Since curcumin accumulates mostly in the membranes, we explored the fatty acid composition of both cell lines, but we did not find any difference between them.