Heat- and 4-hydroperoxy-ifosfamide-induced apoptosis in B cell precursor leukaemias.

In the group of high risk childhood acute lymphoblastic leukaemia (ALL), very early and early relapses have a very poor prognosis with conventional chemotherapy alone. Remission induction in these patients is often hindered by drug resistance. Thus, intensifying chemotherapy strategies are required. Application of hyperthermia enhances efficacy of certain anti-neoplastic drugs such as ifosfamide. In this study, effects and molecular mechanisms of ifosfamide - and hyperthermia-induced apoptosis are investigated in a B cell precursor leukaemia cell line (REH) and in primary patient-derived B cell progenitor leukaemic blasts. Both 4OOH-IFA and hyperthermia are able to induce cell death in leukaemic cells, mainly by induction of caspase-dependent apoptosis. However, completely different kinetics of caspase-3, -8 and -9 activation are found for both stimuli. In addition, activation of caspase-1 is only observed following stimulation with hyperthermia. Combined application of ifosfamide and hyperthermia reveals increased cytotoxicity in both the leukaemia cell line and in 5/8 of the patient-derived leukaemic blast samples. In conclusion, hyperthermia and ifosfamide mediate cytotoxicity in B precursor leukaemic blasts by different kinetics of caspase activation. This might explain the additive effects of 4OOH-IFA and heat on leukaemic cell death. Therefore, whole body thermochemotherapy could be considered as a treatment option in relapsed leukaemic patients.     

Differentiation between rebound thymic hyperplasia and thymic relapse after chemotherapy in pediatric Hodgkin lymphoma

Background

Rebound thymic hyperplasia (RTH) is a common phenomenon caused by stress factors such as chemotherapy (CTX) or radiotherapy, with an incidence between 44% and 67.7% in pediatric lymphoma. Misinterpretation of RTH and thymic lymphoma relapse (LR) may lead to unnecessary diagnostic procedures including invasive biopsies or treatment intensification. The aim of this study was to identify parameters that differentiate between RTH and thymic LR in the anterior mediastinum.

Methods

After completion of CTX, we analyzed computed tomographies (CTs) and magnetic resonance images (MRIs) of 291 patients with classical Hodgkin lymphoma (CHL) and adequate imaging available from the European Network for Pediatric Hodgkin lymphoma C1 trial. In all patients with biopsy-proven LR, an additional fluorodeoxyglucose (FDG)-positron emission tomography (PET)-CT was assessed. Structure and morphologic configuration in addition to calcifications and presence of multiple masses in the thymic region and signs of extrathymic LR were evaluated.

Results

After CTX, a significant volume increase of new or growing masses in the thymic space occurred in 133 of 291 patients. Without biopsy, only 98 patients could be identified as RTH or LR. No single finding related to thymic regrowth allowed differentiation between RTH and LR. However, the vast majority of cases with thymic LR presented with additional increasing tumor masses (33/34). All RTH patients (64/64) presented with isolated thymic growth.

Conclusion

Isolated thymic LR is very uncommon. CHL relapse should be suspected when increasing tumor masses are present in distant sites outside of the thymic area. Conversely, if regrowth of lymphoma in other sites can be excluded, isolated thymic mass after CTX likely represents RTH.     

The concept of the GPOH-HD 2003 therapy study for pediatric Hodgkin's disease: evolution in the tradition of the DAL/GPOH studies

Today it is possible to cure more than 90 % of children and adolescents with Hodgkin's disease with a combination of radiotherapy and chemotherapy. Since the DAL-HD 82 study, the main scientific focus has been on avoiding late effects such as the OPSI syndrome, late complications involving the heart, lungs, thyroid and/or gonads particularly sterility in men and premature onset of menopause in women, and the prevention of secondary malignancies. The GPOH-HD 2003 study will introduce FDG-PET to the initial diagnostic program and the assessment of response to therapy in order to evaluate further possibilities for reducing therapy. In this context, the central review of all clinical and radiological findings, systematically done since the DAL-HD 90 study, will be increasingly relevant in maintaining standardised stage classification and therapy group assignment which was established by the preceding studies. Continuing in the direction of the earlier studies, the indications for radiotherapy will be restricted even further. In the early stages (treatment group 1) patients with CR or a negative FDG-PET at the end of chemotherapy will receive no radiotherapy in order to reduce the risk of a secondary malignancy. In a randomized comparison, procarbazine will be replaced by dacarbazine in the COPP cycles to determine whether sterility in men and premature onset of menopause in women can be avoided by elimination of procarbazine while retaining the same clinical efficacy. Finally, relapse therapy is to be tailored according to the time of relapse, the initial therapy group, and the patient's response to the relapse therapy with more patients receiving autologous transplantation in order to further improve the results of relapse treatment.     

Molecular biology and clinical manifestation of hereditary factor VII deficiency

Inherited factor VII (FVII) deficiency is a rare autosomal recessive disorder. Mutations and polymorphisms of the FVII gene were characterized in more than 40 unrelated patients with FVII deficiency. Among the 29 different mutations, the most frequent were Ala294 Val, Ala294Val;404delC, IVS7+7, and Val281 Phe. Four novel mutations (IVS2+1G>C, Arg247 Cys, Glu265 Lys, Asp343 His) were detected. The relationships between genotypes of mutations and polymorphisms of the FVII gene, FVII deficiency, and clinical phenotype were investigated. Homozygosity of the Phe4 Leu, IVS4+1G>A, Cys135 Arg, Ala244 Val, and Ala294 Val;404delC and the double heterozygosity of Tyr68 Cys / IVS3-1G>A, Val252 Met / IVS2+5G>T, Val281 Phe / Cys135 Arg, Ala294 Val / Val281 Phe, Ala294 Val;404delC / Val281Phe, Ala294 Val;404delC / Arg152 stop, Ala294Val;404delC / Gln(-35) stop, Ala294 Val / Val252 Met, Ala294 Val / Gly156 Asp, and Thr359 Met / Asp242 His were related to clinical symptoms. Double heterozygotes for Arg247 Cys / IVS2+1G>C, Ala206 Thr / Pro303 Arg, Leu(-20) Pro / Val252 Met as well as IVS7+7 /Ala294 Val, IVS7+7 /Ala206 Thr, and IVS7+7 / Met298 Ile were asymptomatic. The clinical symptomatology is rather poor in correlation with the FVII activity. Concerning the clinical phanotype, a correlation seems to exist between specific mutations and clinical symptoms.     

Low rate of severe venous thromboses in children with ALL treatment according to COALL-92 and -97 protocol.

Venous thromboses (VT) in children with ALL who were treated according to the COALL-89 protocol were reported to occur with a frequency of 2.1% (6/286). 4/6 of the reported VT were catheter related. However, in other cohorts of ALL patients treated according to American protocols the incidence of severe thromboses was 2-11%. Most of the VT were not catheter related, but were atypical thromboses like sinus venous thromboses. In these patients hereditary thrombophilia risk factors seemed to play a major role. In a 6 year period including the COALL protocols -92 and -97 only 10/684 (1.5%) children presented with symptomatic VT, and 7/10 thromboses were catheter related. Every thrombotic event could be successfully treated either by heparin administration or fibrinolytic agents. 2/10 VT were secondary due to a septic event. 5 out of 8 primary VT occurred after asparaginase/dexamethasone application during the reinduction therapy. In conclusion, symptomatic thrombotic events are very rare in the COALL studies. Important risk factors for development of VT appeared to be central lines, asparaginase application and infectious/septic complications. However, the role of genetic risk factors of thrombosis in these patients has still to be determined.     

FDG PET/CT in children and adolescents with lymphoma

The aim of this review is to give an overview of FDG PET/CT applications in children and adolescents with lymphoma. Today, FDG PET is used for tailoring treatment intensity in children with Hodgkin lymphoma within the framework of international treatment optimisation protocols. In contrast, the role of this method in children with Non-Hodgkin lymphoma is not well defined. This paper overviews clinical appearance and metabolic behaviour of the most frequent lymphoma subtypes in childhood. The main focus of the review is to summarise knowledge about the role of FDG PET/CT for initial staging and early response assessment.     

Co-operation of IL-1 and IL-2 on T-cell activation in mononuclear cell cultures.

In search of an optimized anti-cancer immunotherapy, the combination of IL-2 and IL-1 has been tried. In an in-vitro LAK model, this cytokine cocktail seemed to be quite promising. In our in-vitro model of IL-2 induced T-cell activation we have therefore investigated the co-operation of these two potent immunostimulators. Mononuclear cells were stimulated with CD3 activating antibody in the presence of different cytokines and blocking or neutralizing antibodies. Cytokine concentrations were detected in the supernatants with ELISA. Intracellular IFN-gamma and IL-4 in the different T-cell subsets was measured by flow cytometry. IL-1 and IL-1 receptor antagonist (IL-1Ra) were up-regulated by IL-2, this was achieved independently of IL-12 or CD40/CD40L interaction. As a negative feedback mechanism, IL-1beta induced its natural antagonist, IL-1Ra. Both endogenous and exogenous IL-10 suppressed IL-1beta and induced IL-1Ra, thus markedly decreased the amount of functional IL-1. The combination of IL-2 and IL-1beta lead to a mildly increased Interferon-gamma (IFN-gamma) secretion (+20%, p < 0.05), however, this appeared to be the result of an increased IFN-gamma production per secreting cell, rather than of an increased recruitment of non-secreting cells. Similarly, IL-6 was also induced in an additive fashion (+30%, p < 0.05). For both cytokines, this effect could be significantly augmented by neutralizing IL-1Ra. Concentrations of IL-2 induced IL-10 and soluble Fas ligand (sFasL) were not affected by IL-1beta. We were thus able to demonstrate that IL-1 relays its activity through different pathways than IL-2. Furthermore, we could show that the potentially synergistic action of IL-2 and IL-1 was hindered by the simultaneous induction of signficant amounts of IL-1Ra. From the latter findings we conclude that the combination of IL-2 and IL-1 for cytokine-induced anti-tumor activity may not, but a combination of IL-2 and anti-IL-1Ra might prove beneficial.