Management of oncology patients admitted to the paediatric intensive care unit of a general children's hospital - a single center analysis

BACKGROUND

The improving prognosis of children with cancer has partially been attributed to the increasing importance of pediatric intensive care units (PICU). We analyze whether outcome of these patients on a PICU improved during the last decade and which factors may influence the outcome in our hospital.

PATIENTS AND METHODS

The charts of all oncology patients admitted to the PICU between 1998 and 2009 have been reviewed retrospectively. The survival of patients admitted for life threatening complications has been correlated with basic data, organ failure and the PRISM score. The results of 2 consecutive treatment periods (1998-2003 and 2004-2009) were compared.

RESULTS

644 admissions of 226 patients were recorded. 79 admissions were performed because of potentially life threatening complications (Group A), 236 for monitoring (B) and 329 admissions for interventions (C). 62% of Group A patients and all Group B and C patients were discharged alive. Poor outcome was associated with admission >28 days after initial diagnosis, PRISM >10, organ failure >2 organs, sepsis, allogeneic stem cell transplantation, need for mechanical ventilation or for catecholamines. The PICU survival rate of Group A patients admitted between 2004 and 2009 (78%) was higher than in the period between 1998 and 2003 (48%).

CONCLUSIONS

PICU provides essential services to support the pediatric oncology ward. Although children with cancer may have had benefit from advances in pediatric intensive care over the past decade, specific scoring systems for early identification of children with cancer needing PICU treatment are required. These systems might further improve PICU outcome in critical ill pediatric cancer patients.

[Immune tolerance induction with high-dose FVIII and pulsed intravenous immunoglobulin]

The development of neutralizing allo-antibodies against factor VIII (FVIII) or FVIII inhibitors is a severe complication in the treatment of haemophilia A. About 25% of the children with severe haemophilia A develop FVIII inhibitors. Here we report on a boy with severe haemophilia A and intron 22 inversion of the FVIII gene who was diagnosed at ten months of age. After 16 exposure days to FVIII (81 days after initial exposure) he developed a FVIII inhibitor (maximum: 9.76 BU/ml).

THERAPY

We started immune tolerance induction (ITI) according to the Bonn protocol with high dose plasma derived FVIII concentrate (100 IU per kg body weight) twice daily. For additional inhibitor elimination treatment the patient received intravenous immunoglobulin (ivIg) at a dose of 1-2 g/kg body weight every 4 to 6 weeks. After start of treatment a rapid decline of the inhibitor level was observed, nevertheless low FVIII inhibitor levels persisted (<5 BU/ml). Furthermore, the FVIII half-life was still accelerated. However, after every course of ivIg the inhibitor level declined and FVIII half-life was prolonged. Currently, the FVIII half-life is approaching normal values after more than seven months of ITI duration.

CONCLUSION

Additional application of immunoglobulin is beneficial for immune tolerance induction.

Molecular mechanisms and gene regulation of melphalan- and hyperthermia-induced apoptosis in Ewing sarcoma cells

The prognosis of high-risk Ewing tumours (HR-ET) remains poor. Melphalan-containing chemotherapy regimens are commonly applied for HR-ET patients. Moreover, melphalan (Mel) is a promising agent in thermochemotherapy. Therefore, we investigated the single effects, the synergism and the gene regulation of Mel and hyperthermia (HT) in an ET cell line (RD-ES). Dose-dependent cytotoxicity by Mel was demonstrated, which was enhanced by the concomitant application of HT (42 degrees C for 2 h). Mel, HT and their combination caused a significant activation of caspase-3. Using the pan-caspase inhibitor z-VAD-fmk, we demonstrated that both stimuli mediated predominantly caspase-dependent cytotoxicity. With cDNA array analysis, 20 out of 198 apoptosis-related genes were identified to be differentially expressed by Mel and/or HT. Although a significant enhancement of three selected genes could not be proven at the protein level in subsequent experiments, this study gives insight into the complex molecular and genetic response of tumour cells to cytotoxic stimulation.

Determination of terephthalic acid isopropylamide in urine with a liquid chromatography/mass spectrometry (LC/MS) method

A sensitive and simple liquid chromatography/mass spectrometry (LC/MS) method was developed for the determination of terephthalic acid isopropylamide, the final metabolite of procarbazine in human urine. A solid-phase extraction with C(18) cartridges was used followed by LC/MS with a single mass spectrometer (SSQ 7000 from Finnigan). Terephthalic acid isobutylamide was the internal standard. The quantification limit was 30 ng/mL in urine (6 x noise). This assay was applied for drug monitoring of terephthalic acid isopropylamide in urine after oral administration of procarbazine in children and adolescents with Hodgkin lymphomas.

TRAIL-induced cytotoxicity in a melphalan-resistant rhabdomyosarcoma cell line via activation of caspase-2

The prognosis for patients with chemo-refractory rhabdomyosarcoma remains poor. The tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) is a hopeful candidate for new strategies in chemotherapy. The effects of TRAIL and melphalan (Mel) in the rhabdomyosarcoma cell line TE-671 were investigated by colorimetric caspase assays and flow cytometry. TRAIL induced the activation of caspases-2, -3 and -8, but not the activation of caspase-9, in the Mel-resistant TE-671 cells. Inhibition of caspase-2 with the caspase-2 inhibitor z-VDVAD-fmk significantly down-regulated the TRAIL-induced caspase-3 activation, as well as the TRAIL-induced cytotoxicity. When TE-671 cells were treated with a combination of Mel and TRAIL, a significant synergism of drug-induced cytotoxicity was obtained. The inhibition of caspase-2 could completely abolish caspase-3 activation, suggesting that TRAIL sensitises TE-671 cells for Mel-induced cytotoxicity via a caspase-2- and -3-dependent mechanism. In conclusion, it was shown, for the first time, that TRAIL could sensitise Mel-resistant tumour cells to melphalan.

Regulation of interleukin-2 induced soluble Fas ligand release from human peripheral blood mononuclear cells

Adjuvant interleukin (IL)-2 immunotherapy has been used in the treatment of different malignant dieseases. However, clinical results have been rather disappointing. Therefore, further investigations on IL-2-induced mediators of cytotoxicity seem to be necessary in order to possibly create cytokine cocktails which could enhance the IL-2-induced cytotoxicity. We therefore investigated the regulation of IL-2-induced release of soluble Fas Ligand (sFasL), since this factor is known to possess anti-tumor activities. In CD3-stimulated peripheral blood mononuclear cells IL-2 induced sFasL in a dose-dependent fashion. Maximum sFasL concentrations were obtained after stimulation of MNC for 120 hrs. Inhibition of endogenous IL-12 production significantly reduced IL-2-mediated sFasL release by about 25%. In contrast, addition of IL-12 enhanced the IL-2-induced sFasL about 1,5-fold. IL-10 and IL-4 reduced the IL-2-stimulated sFasL by about 30%. Interestingly, these suppressive effects could be antagonized by the addition of IL-12. Not only exogenous IL-10 but also endogenously produced IL-10 decreased the sFasL release to that extent which had been stimulated by IL-12. Since IL-12 and IL-10 only marginally influenced the IL-2-mediated cell proliferation as well as the IL-2-induced cell death, the IL-12- and IL-10-controlled sFasL release seems to be based on an enhanced production per cell. However, the increase in cell numbers as well as the decrease of viability during cell culture might additionally contribute to the IL-2-induced increase of sFasL release. This secondary effect might explain why IL-2-mediated sFasL production is only partially controlled by regulatory cytokines such as IL-4, IL-10 or IL-12. In conclusion, addition of IL-12 might increase the efficacy of IL-2 immunotherapy by inhibition of the IL-10-mediated negative feed-back loop on IL-2-mediated sFasL release.

Prognostic value of T-1 cell numbers prior to allogeneic stem cell transplantation in patients with severe graft-versus-host disease

Assessment of risk factors for acute graft-versus-host disease (aGvHD) might help in tailoring the intensity of prophylactic immunosuppression after allogeneic stem cell transplantation (SCT), thereby decreasing the relapse rate in leukaemia patients. In this study, we analysed whether the number of recipient blood T cells and plasma levels of different cytokines were correlated with the risk of aGvHD after allogeneic SCT. Analyses were performed in 23 patients receiving pSCT immediately before or during the first 2 days of the conditioning regimen. In all, 40 or more Tc-1 cells/microl pretransplant were associated with a significantly increased risk of aGvHD (10/10 patients with GvHD>/=II; 4/13 patients without aGvHD with a Tc-1 number >40/microl, P<0.002, Fisher's exact test). In addition, 40 or more Th-1 cells/microl pretransplant were also associated with a significantly increased risk of aGvHD (P<0.04, Fisher's exact test). Furthermore, the number of Th-2 cells was significantly higher in patients with severe aGvHD even though the median absolute cell counts were very low. However, all other investigated parameters did not reveal predictive value. In conclusion, determination of T-1 cells prior to SCT might determine patients with high/low risk of aGvHD and could thus be used to control immunosuppression after SCT.

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.

Methylenetetrahydrofolate Reductase Gene Polymorphism and Glucocorticoid Intake in Children with ALL and Aseptic Osteonecrosis

BACKGROUND

Methotrexate is an essential part of the treatment of acute lymphoblastic leukaemia (ALL). Due to an increased survival of ALL patients, complications like BME (bone marrow edema) and AON (aseptic osteonecrosis) have become a matter of increasing importance. The aim of the study was to find out if a polymorphism of the methylenetetrahydrofolate reductase (MTHFR) gene predisposes to the development of BME and/or AON. Furthermore the cumulative prednisone equivalent dose per kilogram body weight was compared in a matched-pairs analysis.

PATIENTS AND METHODS

A retrospective analysis of the MTHFR polymorphism of 87 patients was performed (48 male, 43 female). 14/87 patients were diagnosed with BME and/or AON (16 %).

RESULTS

42/73 patients without BME and/or AON (43 male, 34 female, median age 5.3 yrs) and 10/14 patients with BME/AON (5 male, 9 female, median age 10.2 years) presented with a MTHFR-polymorphism (p = 0.28). 14,3 % of the patients with MTHFR-polymorphism but without BME and/or AON (6/42) and 70 % of the patients with MTHFR-polymorphism and with BME and/or AON (7/10) were over 10 years of age at ALL diagnosis (p = 0.002). The mean cumulative prednisone equivalent dose per kilogram body weight was 98.0 mg, compared with 100.0 mg in the matched pairs group.

CONCLUSIONS

The age of the patients at diagnosis seems to be a risk factor for the development of BME and/or AON as also seen in previous studies. If MTHFR polymorphism is an additional risk factor it was not borne out by this study, possible due to the small number of patients analyzed. This aspect is worth to be proven with a large group of patients considering the MTX pharmacokinetic and leucovorine rescue.

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.

Molecular mechanisms of hyperthermia- and cisplatin-induced cytotoxicity in T cell leukemia

BACKGROUND

The prognosis of early and very early relapse in acute lymphoblastic leukemia of childhood is still very poor unless a hematopoietic stem cell transplant is performed if a second remission can be achieved by induction chemotherapy. Therefore an intensification of chemotherapy is required.

MATERIALS AND METHODS

In the present study the molecular mechanisms of cisplatin- and/or hyperthermia-mediated cytotoxicity in CEM cells, a human T leukemia cell line, were investigated.

RESULTS

Both hyperthermia and cisplatin induced the activation of the effector caspases-3 and -6. However, caspase activation followed different time kinetics. While hyperthermia exerted maximum caspase activation immediately after application, cisplatin activated caspase-3 and -6 after 24 hours. At both time-points significant caspase-3 and -6 activation was observed when the cells were stimulated by a combination of heat and cisplatin. The application of z-VAD-fmk, a general caspase inhibitor, showed that hyperthermia mediated cytotoxicity mainly via caspase-dependent mechanisms, while cisplatin induced both caspase-dependent and -independent cytotoxicity. Time kinetic experiments revealed that hyperthermia induced cell death immediately after the heating pulse. In contrast, cisplatin-induced cell death had its maximum between 6 hours and 12 hours after the heating pulse. The combined application of heat and cisplatin induced two peaks of cytotoxicity, one immediately after the heating pulse and the other between 6 hours and 12 hours.

CONCLUSION

Hyperthermia and cisplatin induced cell death in T leukemic cells by different molecular mechanisms, which might explain the enhanced cisplatin-induced cytotoxicity by hyperthermia.

Endogenous pro-inflammatory cytokines in children and adolescents during chemotherapy-induced neutropenia

Monocyte-derived pro-inflammatory cytokines such as GM-CSF, IL-12, and IP-10 might protect patients with chemotherapy-induced neutropenia against infections. In settings with abundant neutrophils, G-CSF has been described as a suppressor of IL-12, but also as an inducer of GM-CSF. In 25 pediatric patients with chemotherapy-induced neutropenia the authors measured plasma levels of these four cytokines. GM-CSF was detectable in only a minority of patients (6/25). It was, however, positively correlated with high plasma levels of IL-12 and IP-10. G-CSF levels, however, were in no way correlated with the levels of any of these three cytokines.

Mechanisms of hyperthermia- and 4-hydroperoxy-ifosfamide-induced cytotoxicity in T cell leukemia

The prognosis of patients with early ALL (acute lymphoblastic leukaemia) relapse is poor with conventional chemotherapy alone. Thus, intensified chemotherapy strategies are required. The application of hyperthermia enhances the efficacy of certain antineoplastic drugs such as ifosfamide. In this study, the effects and molecular mechanisms of ifosfamide (4hydroperoxy-ifosfamide = 4OOH-IFA)- and/or hyperthermia-induced cell death are investigated in CEM cells. Hyperthermia enhanced the efficacy of 4OOH-IFA in a subaddictive manner. Analysis of caspase activation revealed an early hyperthermia-induced stimulation of caspase-3 and -6 directly after the heating pulse, while maximum activation following stimulation with 4OOH-IFA was obtained after 24 hours of culture. The combination of 4OOH-IFA and hyperthermia mediated an overaddictive caspase stimulation directly following the heating phase. At this time also an overaddictive cytotoxic effect was noticed, being mainly responsible for the enhancing effects of hyperthermia on 4OOH-IFA cytotoxicity. In conclusion, hyperthermia enhanced the cytotoxic effect of 4OOH-IFA on CEM cells by stimulation of an early 4OOH-IFA effect. Thus, thermochemotherapy might be considered as an intensifying treatment option in relapsed T cell leukemias.

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.

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.

Prothrombotic risk factors in children with acute lymphoblastic leukemia treated with delayed E. coli asparaginase (COALL-92 and 97 protocols)

Hereditary prothrombotic risk factors have been shown to increase the risk of venous thrombosis in children treated with the combination of E. coli asparaginase and steroids. In the present study the role of prothrombotic risk factors in children with ALL treated according to the COALL study protocol was investigated in 108 consecutively recruited childhood patients. The prevalence rates of prothrombotic risk factors [factor V G1691A mutation, the prothrombin G20210A variant, the TT677 methylenetetrahydrofolate reductase genotype, deficiencies of protein C, protein S, antithrombin, elevated lipoprotein (a)] in this cohort were within the range reported for healthy Caucasians, and comparable to previously reported data for other leukemic patients. Venous thromboembolism occurred in 3 of the 108 children (induction n = 1; reinduction n = 2: 2.8%), and none of these children carried a prothrombotic risk factor. The results of the present study, suggest that the role of hereditary and acquired disturbances of coagulation in the development of thromboses might depend on the treatment regimen.

Primary chemotherapy and conservative surgery for vaginal yolk-sac tumour. Maligne Keimzelltumoren Study Group

Vaginal yolk-sec tumours are usually incurable unless radical surgery is done. We have shown, however, that, neoadjuvant cisplatin-based chemotherapy with conservative surgery is effective in the management of these tumours, and results in a good survival rate, unlike germ-cell tumours of other origin.

Regulation of interleukin-2 induced interleukin-5 and interleukin-13 production in human peripheral blood mononuclear cells

Adjuvant interleukin (IL)-2 immunotherapy has been used for many years for a variety of malignant and nonmalignant entities. In many cases, a dose escalation might have seemed desirable, but was prevented by the rather severe adverse effects of systemic IL-2 application. Only recently has the regulation of IL-2 induced cytotoxicity been understood better, so that now efforts can be aimed at the design of cytokine cocktails that would selectively induce cytotoxicity but result in as few adverse effects as possible. Previously, induction of IL-5 under systemic IL-2 therapy has been described, and a number of the side-effects have been attributed to this event. We therefore investigated the regulation of IL-2 induced production of IL-5 and IL-13 (which, similarly to IL-5, is a mediator of allergy-like symptoms). At the same time, the effects of regulatory cytokines, such as IL-4, IL-10 and IL-12, on interferon-gamma (IFN-gamma), the major cytotoxic mediator of IL-2 therapy, were studied. All three have been discussed as antitumour immunotherapeutics, either alone or in combination with IL-2. In anti-CD3-treated peripheral blood mononuclear cells, IL-2 induced IL-5 and IL-13 alongside IFN-gamma, IL-10 and IL-12. In the presence of IL-2, inhibition of endogenous IL-12 production further enhanced the IL-5 and IL-13 responses, while IFN-gamma and IL-10 were markedly suppressed. Co-incubation with IL-2 and IL-12 suppressed IL-5/IL-13 below, but enhanced IFN-gamma and IL-10 above, levels induced by IL-2 alone. IL-10 was suppressive on all the investigated cytokines, while IL-4 interfered with IL-2 induced IFN-gamma and IL-12 production, but was additive to IL-2 in its effect on IL-5 and IL-13. These data suggest that the combination of IL-12 with IL-2 would enhance the cytotoxic activity of this regimen, but might reduce its adverse effects.

DDAVP treatment in a child with von Willebrand disease type 2M

von Willebrand disease (vWD) type 2M is characterized by the decreased platelet-dependent function of the von Willebrand factor (vWF) that is not caused by the absence of HMW vWF multimers. We report here on a 4-year-old boy with vWD type 2M, who underwent adenotomy and paracentesis after correction of his hemostatic defect by stimulation with DDAVP. The decreased basal levels of vWF Antigen (Ag), ristocetin cofactor activity (RiCoF) and collagen binding activity (CBA) (32%, 14% and 9% respectively) could be stimulated to maximum levels of 69%, 70% and 95% 2 h post DDAVP administration. DDAVP was administered in a dosage of 0.4 microg/kg BW intravenously 30 min prior to surgery. No bleeding occurred intra- and perioperatively. vWF multimer analysis revealed supranormal multimers with an abnormal satellite banding pattern. The typical separation by gel electrophoresis into oligomers with a triplet structure was missing even after stimulation with DDAVP. Thus, the functional hemostatic defect was corrected in this patient after DDAVP administration, although the structural abnormalities of the vWF multimers were still persisting.

CONCLUSION

In conclusion, type 2M vWD might be effectively treated with DDAVP administration in cases of elective surgery, dispensing with vWF replacement by pooled blood products.

Transforming growth factor-beta1 suppresses interleukin-15-mediated interferon-gamma production in human T lymphocytes

One of the most remarkable means by which tumour cells manage to evade recognition and elimination by the immune system is the release of immunosuppressive mediators, such as interleukin (IL)-10 or transforming growth factor-beta (TGF-beta). For antitumour immunotherapies to reach their full potential, cytokine cocktails will have to be custom-tailored to the tumour's individual cytokine microenvironment. One of the components of such a cytokine cocktail may be interleukin (IL)-15, which has demonstrated an excellent stimulatory potential of antitumour immunity. In an in vitro model, we have previously been able to show that the negative effects of IL-10 on IL-15-mediated cytotoxic T-cell activation can be outweighed by the addition of interleukin (IL)-12. The mechanism by which TGF-beta may influence the effect of IL-15 remains poorly understood, however. We have therefore taken our T-cell model further and have studied the effect of TGF-beta on IL-15-mediated interferon-gamma (IFN-gamma) production. In activated, IL-15-stimulated peripheral blood T lymphocytes, TGF-beta suppressed IFN-gamma mRNA and protein levels by approximately 75%. This effect was likewise observed on both CD4+ and CD8+ T cells and, in contrast to the effect of IL-10 in this system, could not be neutralized by the addition of IL-12. Thus, immunotherapy for TGF-beta-producing tumours may benefit from the addition of TGF-neutralizing activity rather than IL-12.