An approach for cure: PEI-chemotherapy and regional deep hyperthermia in children and adolescents with unresectable malignant tumors.

BACKGROUND: Elevated temperatures of 40 - 44 degrees C increase the actions of various anticancer drugs including N-lost derivatives, cytotoxic antibiotics and platinum analoga. In clinical usage thermochemotherapy (TCH) should facilitate surgical resection and ameliorate local tumor control. PATIENTS AND METHODS: From 07/1993 to 12/2002 a total of 39 patients have been enrolled onto a phase-II study (female = 24, male = 15, age 1 - 37.5 years, median 5.2). Among these, 24 patients had extracranial non-testicular germ cell tumors and 15 patients soft tissue or chondrosarcomas. INDICATION: locoregional relapse (n = 29) or unresectable tumor after neoadjuvant chemotherapy (n = 10). Among these two groups, there were ten patients with poor response or progressive disease under primary or relapse chemotherapy. Ten out of the 29 relapse patients had more than one relapse. Tumor site: pelvis (30), abdomen (4), head and neck (2), proximal leg (2) and lumbar spine (1). Thermochemotherapy (TCH): 1800 - 2000 mg ifosfamide/m (2) and 100 mg etoposide/m (2) on days 1 - 4 and 40 mg cisplatin/m (2) on days 1 + 4 combined with regional deep hyperthermia (42 - 44 degrees C, 1 h) on days 1 + 4. RESULTS: In 39 protocol patients a total of 166 TCH courses (332 heat sessions) were applied. 20 patients achieved complete response, and 10 patients achieved partial response. TCH was followed by surgical tumor resection in 28/39 patients and/or radiotherapy in 13/39 patients. At a median follow-up of 27 months, outcome in this high-risk patient population was 22 NED, 3 AWD, 12 DOD, 2 DOC. Five year event free (EFS) and overall survival (OS) for the whole study cohort was 0.39 +/- 0.11 (20/39 patients) and 0.52 +/- 0.11 (25/39 patients), respectively. CONCLUSION: TCH shows substantial therapeutic efficacy and facilitates complete tumor resection in 14 out of 28 operated patients. Multimodal treatment including TCH, surgical resection and/or radiotherapy leads to sustained remission in the majority of patients with locoregional tumor recurrence. The therapeutic effect is most pronounced, if TCH is administered at first relapse. Due to the clinical and histologic heterogeneity the number of patients eligible for TCH is limited. Therefore, a more valid assessment of treatment efficacy can only be made by a matched-pair comparison in cooperation with the clinical registers.

In vivo cytokine responses to interleukin-2 immunotherapy after autologous stem cell transplantation in children with solid tumors.

The potent immunostimulatory cytokine interleukin-2 (IL-2) has been extensively investigated for its potential to induce anti-tumor immunity in a number of tumor models. Only recently the complex interplay of mutually suppressive or supportive cytokines of the IL-2-induced network of cytokines has been better characterized. The aim of this study was to assess which of these in vitro findings are reproducible in vivo in recipients of stem cell transplants (SCT), since in these patients long- lasting impairments in cytokine inducibility have been described. We have therefore studied the kinetics of putative modulators and mediators of IL-2-induced immune activation, namely IL-1beta, IL-4, IL-5, IL-10, IL-12, soluble Fas ligand (sFasL), and GM-CSF during IL-2 therapy. All patients were children or adolescents suffering from solid tumors with poor prognosis who received three 5-day courses of high-dose intravenous IL-2 as an adjuvant to their radio-chemotherapy and autologous SCT. While IL-1beta, IL-4 and IL-12 were not, and sFasL was only mildly affected by the IL-2 therapy, we observed a consistent and early rise of IL-10, IL-5, and GM-CSF. These increases were rapidly reversible after discontinuation of IL-2 therapy. The inducibility of IL-10, IL-5 and GM-CSF was more pronounced with increasing time from the SCT, and in the third cycle reached an order of magnitude as in high-dose IL-2 patients without SCT. Together with the abundant in vitro data, these findings may help devise a combination immunotherapy permitting stronger anti-tumor effects, but lesser adverse effects.

Rapid progressive subacute sclerosing panencephalitis in a 2-year-old child with congenital athyreosis.

We present the unique case of a 2-year-old girl with congenital athyreosis who acquired primary measles virus infection at the age of 18 months, coincidentally with an Epstein-Barr virus infection. First neurologic symptoms of subacute sclerosing panencephalitis appeared 5 months later, and the girl died within 6 months after a rapid progressive illness. Factors possibly predisposing to this extraordinary disease course-primary measles virus infection at an early age and lack of evidence for immunodeficiency-are discussed.

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.

Cytokine-mediated regulation of granulocyte colony-stimulating factor production.

Granulocyte colony-stimulating factor (G-CSF) is an important regulator of granulopoiesis and an inducer of T helper 2 (Th2)-related cytokines. In this study we investigated the mechanism of cytokine-modulated G-CSF production in lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cells (PBMC) and bone marrow stromal cells (BMSC). In PBMC, LPS significantly induced G-CSF and interleukin (IL)-1, an inducer of G-CSF. Both were partly inhibited by IL-4, IL-6 and IL-10. None of these effects were the result of altered monocyte activation or proliferation. The effects of IL-4 and IL-10 appeared to be independent of IL-1 suppression or IL-1 receptor antagonist (IL-1ra) induction, but rather seemed to involve a blockade of IL-1 function, in addition to a blockade of IL-1-independent stimulatory effects on G-CSF production. The effect of the IL-6-induced suppression of G-CSF production differed from that of IL-4 and IL-10 in that it was much less pronounced and could be partially overridden by addition of functional IL-1, yet it also appeared to involve the interference with IL-1 function and the suppression of IL-1-independent mechanisms. In BMSC, G-CSF synthesis was regulated differently. Here, IL-1 was the main stimulator of G-CSF release, and the effect of IL-1 was neither affected by IL-10 nor IL-6, while IL-4 had a stimulatory effect. Thus, G-CSF production was found to be differently regulated in distinct cellular compartments, and a cross-regulation between these might be facilitated by IL-4-, IL-6- and IL-10-induced inhibition of IL-1. These results could be important for the understanding of G-CSF production in neutropenic patients during severe infection.

Interleukin 10 inhibits TNF-alpha production in human monocytes independently of interleukin 12 and interleukin 1 beta.

Previously we demonstrated that endogenously produced Interleukin (IL-)10 suppressed the production of tumor necrosis factor-alpha (TNF-alpha) in CD3 activated T-cells via down-regulation of paracrine IL-12 secretion from APC. Here we investigated the effect of endogenous IL-10 on TNF-alpha production in purified lipopolysaccharide (LPS) stimulated monocytes and its mechanism. Similarly to its effects on T-cells, IL-10 inhibited monocyte TNF-alpha production by about half. Unlike in T-cells, however, this effect was not mediated via IL-12. While blockade of endogenous IL-10 binding to the IL-10 receptor enhanced the autocrine production of TNF-alpha, IL-12 and IL-1 beta, the neutralization of IL-12 or IL-1 beta did not affect the IL-10 effects on TNF-alpha production. This suggests that despite its inhibitory effects on IL-12 and IL-1 beta, which is quite similarly observed in T-cells, in purified monocytes IL-10 does not effect its TNF-alpha suppression by this mechanism. These findings indicate that IL-10 regulates production of pro-inflammatory cytokines by distinct mechanisms in different cells and tissues. Our study thus adds to the appreciation of the complex cytokine regulation of the immune system.

Additive effects of infection and neutropenia on the induction of granulocytopoietic activity in vivo.

BACKGROUND: Granulocyte-colony stimulating factor (G-CSF) is a potent stimulator of granulocytopoiesis and granulocyte function. It has been used in the treatment of children with neutropenic infection; in this context, it was expected to shorten aplasia and limit the severity of infection. Clinical trials, however, have demonstrated conflicting results as to whether these aims can be met. Recently, the use of other, less lineage specific growth factors, such as interleukin (IL)-11 and stem cell factor (SCF), has also been discussed. The dynamics of growth factors and growth factor-regulating proteins during neutropenic infection, particularly in youngsters, are not well understood. METHODS: Serial blood samples from children and adolescents with infection during chemotherapy-induced neutropenia were assayed for C-reactive protein, white blood cell count, IL-11, SCF, G-CSF, IL-10, IL-4, IL-lalpha, and IL-1beta. RESULTS: Although no correlation could be demonstrated between endogenous IL-11 or SCF levels, infection, and leukocyte counts, endogenous G-CSF levels were increased during both aplasia and infection. However, only the additive effects of infection and neutropenia led to maximally stimulated endogenous G-CSF levels. CONCLUSIONS: The elevated G-CSF levels in a majority of patients during severe neutropenic infection may explain why a therapeutic benefit of G-CSF treatment cannot be demonstrated in all cases. There remains, however, a subgroup of patients in whom infection and cytopenia do not yield a good G-CSF response. This latter group should be identified, because they might derive some benefit from adjuvant growth factor therapy. The authors predict that the efficacy of G-CSF in the treatment of patients with neutropenic fever might depend on each individual's ability to initiate the necessary cytokine production.

Interaction between interleukin 10 and interleukin 6 in human B-cell differentiation.

Contrary to their opposing action on human T-lymphocytes and monocytes, both Interleukin (IL-)10 and IL-6 are potent differentiation factors of human B-cells. Both are known to induce immunoglobulin (Ig) production. The precise mechanism of this converging effect of IL-6 and IL-10 remains elusive, however. Here we investigated the role of IL-6 in the IL-10 dependent B-cell differentiation into Ig secreting cells. We found that co-stimulation of SAC-stimulated human peripheral B-lymphocytes with IL-10 and IL-6 exhibited no additive effect on Ig production over stimulation with IL-10 alone, and that IL-6 receptor blockade only mildly inhibited IL-10 induced Ig synthesis. In fact, we could show that stimulation of B-cells with IL-10 somewhat suppressed SAC induced autocrine IL-6 production. Despite this suppression IL-6 levels remained sufficiently high to stimulate its receptor, and IL-6 binding to the B-cell surface was not affected. The failure of IL-6 to exert an additional effect on SAC+IL-10 induced Ig production suggests that IL-10 may recruit components of the IL-6 intracellular pathway for Ig induction. In conclusion we could demonstrate that IL-10 acts on B-cell differentiation independently of autocrine IL-6 and that it had a considerably mild effect on B lymphocytic autocrine IL-6 secretion. This still allows an IL-6 effect in the presence of IL-10 which appears adaptive with a view to the converging effects of these two cytokines on human B lymphocytes. Our study thus adds to the appreciation of the complex cytokine regulation of the immune system.