Induction of circulating tumor necrosis factor (TNF alpha) as the mechanism for the febrile response to interleukin-2 (IL-2) in cancer patients

Cytokine network imbalance in children with B-cell acute lymphoblastic leukemia at diagnosis

Immune imbalance has been proved to be involved in the pathogenesis of hematologic neoplasm. However, little research has been reported altered cytokine network in childhood B-cell acute lymphoblastic leukemia (B-ALL) at diagnosis. Our study aimed to evaluate the cytokine network in peripheral blood of newly diagnosed pediatric patients with B-ALL. Serum levels of interleukin (IL)-2, IL-4, IL-6, IL-10, tumor necrosis factor (TNF), interferon (IFN)-γ, and IL-17A in 45 children with B-ALL and 37 healthy control children were measured by cytometric bead array, while the level of transforming growth factor-β1 (TGF-β1) in the serum was measured by enzyme-linked immunosorbent assay. Patients showed a significant increase in IL-6 (p < 0.001), IL-10 (p < 0.001), IFN-γ (p = 0.023) and a significant reduction in TGF-β1 (p = 0.001). The levels of IL-2, IL-4, TNF and IL-17A were similar in the two groups. Higher concentrations of pro-inflammatory cytokines were associated with febrile in patients without apparent infection by using unsupervised machine learning algorithms. In conclusion, our results indicated a critical role for aberrant cytokine expression profiles in the progression of childhood B-ALL. Distinct cytokine subgroups with different clinical features and immune response have been identified in patients with B-ALL at the time of diagnosis.

Treatment of equine sarcoids using recombinant poxviruses expressing feline interleukin-2

BACKGROUND

Interleukin (IL)-2 stimulates antitumour immunity and is successfully used for the treatment of different neoplasias.

HYPOTHESIS/OBJECTIVES

Canarypox virus locally expressing feline IL-2 is safe and can be used to treat equine sarcoids.

ANIMALS

Twenty horses of different breeds with a median age of eight years (interquartile range 6.0-13.3 years) and a total number of 59 sarcoids were included in the study.

METHODS

In this prospective clinical trial, sarcoids were injected twice seven days apart, with a recombinant canarypox virus expressing feline IL-2. Complete blood counts (CBC) and fibrinogen levels were measured before treatment and on days 1, 2, 7 and 8.

RESULTS

Complete regression was achieved in eight horses (40%) and partial regression in two horses (10%). No change in sarcoid size was observed in two horses (10%) and the disease progressed in five horses (25%). Sarcoids of three horses (15%) showed initial response followed by tumour growth. There were no significant changes in CBC and fibrinogen levels after either injection. One horse developed a mild fever the day after each injection, which subsided without treatment the following day.

CONCLUSIONS

Treatment of equine sarcoids with recombinant canarypox virus expressing feline IL-2 seems to be a safe therapy option. Although the expression of IL-2 after vector injection and its biological activity in horses were not proven in this study, the treatment resulted in regression and partial regression in 50% of the cases. Further studies are necessary to verify these findings and to establish a treatment protocol.

Cytokines in Febrile Diseases

The human body has a perfect thermoregulatory system to meet the needs of normal life activities. The central regulation of body temperature is mainly explained by the theory of "setting point (setpoint, SP)". Fever is a positive but nonspecific response of the body to infections and other pyrogens, which causes immune cells to release cytokines, leading to a brain protein-mediated rise in body temperature. Cytokines can be roughly divided into 2 categories: proinflammatory cytokines and anti-inflammatory cytokines. IL-1, TNF-α, and IL-6 are proinflammatory cytokines, whereas IL-4 and IL-10 are anti-inflammatory cytokines. IL-2 is a cytokine that can both activate and inhibit immunity. IL-8 is a neutrophil chemotactic factor, and IFN is a cytokine that plays a key role in the proper induction and maintenance of innate and acquired immunity. This article reviews the pathophysiological characteristics of fever and the cytokines related to fever (IL-2, 4, 6, 8, 10, IFN, TNF, etc.).

Anticancer Drug-induced Thyroid Dysfunction

Cancer immunotherapy and targeted therapy, though less toxic than conventional chemotherapy, can increase the risk of thyroid dysfunction. Immune checkpoint inhibitors render the cancer cells susceptible to immune destruction, but also predispose to autoimmune disorders like primary hypothyroidism as well as central hypothyroidism secondary to hypophysitis. Tyrosine kinase inhibitors act by blocking vascular endothelial growth factor receptors and their downstream targets. Disruption of the vascular supply from the inhibition of endothelial proliferation damages not only cancer cells but also organs with high vascularity like the thyroid. Interferon-α, interleukin-2 and thalidomide analogues can cause thyroid dysfunction by immune modulation. Alemtuzumab, a monoclonal antibody directed against the cell surface glycoprotein CD52 causes Graves' disease during immune reconstitution. Metaiodobenzylguanidine, combined with 131-iodine, administered as a radiotherapeutic agent for tumours derived from neural crest cells, can cause primary hypothyroidism. Bexarotene can produce transient central hypothyroidism by altering the feedback effect of thyroid hormone on the pituitary gland. Thyroid dysfunction can be managed in the usual manner without a requirement for dose reduction or discontinuation of the implicated agent. This review aims to highlight the effect of various anticancer agents on thyroid function. Early recognition and appropriate management of thyroid disorders during cancer therapy will help to improve treatment outcomes.

Memory CD4 T cell-derived IL-2 synergizes with viral infection to exacerbate lung inflammation

Defining the most penetrating correlates of protective memory T cells is key for designing improved vaccines and T cell therapies. Here, we evaluate how interleukin (IL-2) production by memory CD4 T cells, a widely held indicator of their protective potential, impacts immune responses against murine influenza A virus (IAV). Unexpectedly, we show that IL-2-deficient memory CD4 T cells are more effective on a per cell basis at combating IAV than wild-type memory cells that produce IL-2. Improved outcomes orchestrated by IL-2-deficient cells include reduced weight loss and improved respiratory function that correlate with reduced levels of a broad array of inflammatory factors in the infected lung. Blocking CD70-CD27 signals to reduce CD4 T cell IL-2 production tempers the inflammation induced by wild-type memory CD4 T cells and improves the outcome of IAV infection in vaccinated mice. Finally, we show that IL-2 administration drives rapid and extremely potent lung inflammation involving NK cells, which can synergize with sublethal IAV infection to promote acute death. These results suggest that IL-2 production is not necessarily an indicator of protective CD4 T cells, and that the lung environment is particularly sensitive to IL-2-induced inflammation during viral infection.

Following Chemotherapy: Serum Cytokine (Tumor Necrosis Factor, Interleukin-2, Interleukin-11), Immunoglobulin, Complement, Vascular Endothelial Growth Factor Levels, and the Systemic Symptoms like Capillary Leak Syndrome

Several problems such as myalgia, arthralgia, fever, dyspnea, generalized edema, and pleural effusion can occur in cancer patients following the chemotherapy, especially at the first cycle of the first chemotherapy treatment. Although it is assumed that some cytokines are associated with the development of these symptoms and signs, their pathophysiology has not been discovered completely yet. They are usually mild, but they may rarely progress to the severe stage of "Systemic Capillary Leak Syndrome" with a high mortality rate. The objective of this study was to investigate the association between the serum levels of interleukin-2 (IL-2), interleukin-11 (IL-11), tumor necrosis factor alpha (TNF-α), vascular endothelial growth factor (VEGF), and these symptoms and signs. A total of 44 cancer patients who had neither heart, lung, liver, renal, or thyroid disease were recruited into this study. Their symptoms and signs were examined and questioned before the first cycle of the first chemotherapy treatment and the 24 h after this chemotherapy. All participant's serum samples were taken, and the VEGF, TNF, IL-2, and IL-11 levels were studied. There was no association between the chemotherapeutic drugs, and the symptoms and signs such as edema, dyspnea, coughing, and flu-like symptoms. There was a significant decrease in IL-11 levels in the other treatment group compared with the group receiving paclitaxel, docetaxel, gemcitabine, and vinorelbine in the first day following chemotherapy (P = .006). However, no relation was observed between the symptoms and signs, the response to the chemotherapy, and the serum levels of VEGF, TNF, IL-2, and IL-11. These symptoms and life-threatening syndrome have been a current topic between the clinicians. Although some drugs and mediators are accused, its pathophysiology has not been discovered completely yet. In this study, we could not detect any association between the symptoms, signs, and the cytokine levels following the chemotherapy.

A novel immunization strategy using cytokine/chemokines induces new effective systemic immune responses, and frequent complete regressions of human metastatic melanoma

Immune responses have been elicited by a variety of cancer vaccines, but seldom induce regressions of established cancers in humans. As a novel therapeutic immunization strategy, we tested the hypothesis that multiple cytokines/chemokines secreted early in secondary responses ex-vivo might mimic the secretory environment guiding new immune responses. The early development of immune responses is regulated by multiple cytokines/chemokines acting together, which at physiologic concentrations act locally in concert with antigen to have non-specific effects on adjacent cells, including the maturation of dendritic cells, homing and retention of T cells at the site of antigen, and the differentiation and expansion of T cell clones with appropriate receptors. We postulated that repeated injections into a metastasis of an exogenous chemokine/cytokine mixture might establish the environment of an immune response and allow circulating T cell clones to self- select for mutant neo-epitopes in the tumor and generate systemic immune responses. To test this idea we injected some metastases in patients with multiple cutaneous melanoma nodules while never injecting other control metastases in the same patient. New immune responses were identified by the development of dense lymphocytic infiltrates in never-injected metastases, and the frequent complete regression of never-injected metastases, a surprising observation. 70% of subjects developed dense infiltrates of cytotoxic CD8 cells in the center and margin of never-injected metastases; 38% of subjects had complete and often durable regressions of all metastases, without the use of check-point inhibitors, suggesting that, as a proof-of-principle, an immunization strategy can control advanced human metastatic melanoma.

Adverse Events in Cancer Immunotherapy

Cancer immunotherapy has resulted in durable responses in patients with metastatic disease, unseen with traditional chemotherapy. Several therapies have been approved by the Food and Drug Administration for the treatment of various cancers, including: immune checkpoint inhibitors, cytokines - interleukin 2 (IL-2) and interferon alpha (IFN), and the cancer vaccine sipuleucel-T. These therapies upregulate the immune system to enhance antitumor responses. As a consequence, they can cause inflammatory and immune-related adverse events that can affect one or more organs, can be serious, and on occasion lifethreatening. The management of these adverse events is complex, and requires a multidisciplinary approach involving not only oncologists, but also other internal medicine specialists, to ensure prompt diagnosis and optimal management of these complications.

Biofluid Proteomics and Biomarkers in Traumatic Brain Injury

Traumatic brain injury (TBI) is an injury to the brain caused by an external mechanical force, affecting millions of people worldwide. The disease course and prognosis are often unpredictable, and it can be challenging to determine an early diagnosis in case of mild injury as well as to accurately phenotype the injury. There is currently no cure for TBI-drugs having failed repeatedly in clinical trials-but an intense effort has been put to identify effective neuroprotective treatment. The detection of novel biomarkers, to understand more of the disease mechanism, facilitates early diagnosis, predicts disease progression, and develops molecularly targeted therapies that would be of high clinical interest. Over the last decade, there has been an increasing effort and initiative toward finding TBI-specific biomarker candidates. One promising strategy has been to use state-of-the-art neuroproteomics approaches to assess clinical biofluids and compare the cerebrospinal fluid (CSF) and blood proteome between TBI and control patients or between different subgroups of TBI. In this chapter, we summarize and discuss the status of biofluid proteomics in TBI, with a particular focus on the latest findings.

Review: Infection, fever, and exogenous and endogenous pyrogens: some concepts have changed

For many years, it was thought that bacterial products caused fever via the intermediate production of a host-derived, fever-producing molecule, called endogenous pyrogen (EP). Bacterial products and other fever-producing substances were termed exogenous pyrogens. It was considered highly unlikely that exogenous pyrogens caused fever by acting directly on the hypothalamic thermoregulatory center since there were countless fever-producing microbial products, mostly large molecules, with no common physical structure. In vivo and in vitro, lipopolysaccharides (LPSs) and other microbial products induced EP, subsequently shown to be interleukin-1 (IL-1). The concept of the `endogenous pyrogen' cause of fever gained considerable support when pure, recombinant IL-1 produced fever in humans and in animals at subnanomolar concentrations. Subsequently, recombinant tumor necrosis factor-α (TNF-α), IL-6 and other cytokines were also shown to cause fever and EPs are now termed pyrogenic cytokines. However, the concept was challenged when specific blockade of either IL-1 or TNF activity did not diminish the febrile response to LPS, to other microbial products or to natural infections in animals and in humans. During infection, fever could occur independently of IL-1 or TNF activity. The cytokine-like property of Toll-like receptor (TLR) signal transduction provides an explanation by which any microbial product can cause fever by engaging its specific TLR on the vascular network supplying the thermoregulatory center in the anterior hypothalamus. Since fever induced by IL-1, TNF-α, IL-6 or TLR ligands requires cyclooxygenase-2, production of prostaglandin E2 (PGE 2) and activation of hypothalamic PGE2 receptors provides a unifying mechanism for fever by endogenous and exogenous pyrogens. Thus, fever is the result of either cytokine receptor or TLR triggering; in autoimmune diseases, fever is mostly cytokine mediated whereas both cytokine and TLR account for fever during infection.

Biomarkers

Biomarkers are key tools and can provide crucial information on the complex cascade of events and molecular mechanisms underlying traumatic brain injury (TBI) pathophysiology. Obtaining a profile of distinct classes of biomarkers reflecting core pathologic mechanisms could enable us to identify and characterize the initial injury and the secondary pathologic cascades. Thus, they represent a logical adjunct to improve diagnosis, track progression and activity, guide molecularly targeted therapy, and monitor therapeutic response in TBI. Accordingly, great effort has been put into the identification of novel biomarkers in the past 25 years. However, the role of brain injury markers in clinical practice has been long debated, due to inconsistent regulatory standards and lack of reliable evidence of analytical validity and clinical utility. We present a comprehensive overview of the markers currently available while characterizing their potential role and applications in diagnosis, monitoring, drug discovery, and clinical trials in TBI. In reviewing these concepts, we discuss the recent inclusion of brain damage biomarkers in the diagnostic guidelines and provide perspectives on the validation of such markers for their use in the clinic.

Immunotherapy of advanced renal cell carcinoma: Current and future therapies

Previously a malignancy with few therapeutic options, metastatic renal cell carcinoma (mRCC) treatment is rapidly evolving. Although cytokine therapies (interferon-a, interleukin-2) have been used less frequently over the past decade, recent approval of an immune checkpoint inhibitor, nivolumab, has led to a resurgence in immune therapy for mRCC. With greater understanding of the complex and dynamic interaction between the tumor and the immune system, numerous new immunotherapies are being studied for mRCC. In this article, we review the mechanism of action, clinical outcomes and toxicity profiles of both clinically approved and selected investigational immunotherapies. Either alone or in combination, these novel agents are encouraging for the future of mRCC therapy.

Clinical chorioamnionitis at term IV: the maternal plasma cytokine profile

INTRODUCTION

Fever is a major criterion for clinical chorioamnionitis; yet, many patients with intrapartum fever do not have demonstrable intra-amniotic infection. Some cytokines, such as interleukin (IL)-1, IL-6, interferon-gamma (IFN-γ), and tumor necrosis factor alpha (TNF-α), can induce a fever. The objective of this study was to determine whether maternal plasma concentrations of cytokines could be of value in the identification of patients with the diagnosis of clinical chorioamnionitis at term who have microbial-associated intra-amniotic inflammation.

METHODS

A retrospective cross-sectional study was conducted, including patients with clinical chorioamnionitis at term (n=41; cases) and women in spontaneous labor at term without clinical chorioamnionitis (n=77; controls). Women with clinical chorioamnionitis were classified into three groups according to the results of amniotic fluid culture, broad-range polymerase chain reaction coupled with electrospray ionization mass spectrometry (PCR/ESI-MS), and amniotic fluid IL-6 concentration: 1) no intra-amniotic inflammation; 2) intra-amniotic inflammation without detectable microorganisms; or 3) microbial-associated intra-amniotic inflammation. The maternal plasma concentrations of 29 cytokines were determined with sensitive and specific V-PLEX immunoassays. Nonparametric statistical methods were used for analysis, adjusting for a false discovery rate of 5%.

RESULTS

1) The maternal plasma concentrations of pyrogenic cytokines (IL-1β, IL-2, IL-6, IFN-γ, and TNF-α) were significantly higher in patients with clinical chorioamnionitis at term than in those with spontaneous term labor without clinical chorioamnionitis; 2) the maternal plasma concentrations of cytokines were not significantly different among the three subgroups of patients with clinical chorioamnionitis (intra-amniotic inflammation with and without detectable bacteria and those without intra-amniotic inflammation); and 3) among women with the diagnosis of clinical chorioamnionitis, but without evidence of intra-amniotic inflammation, the maternal plasma concentrations of pyrogenic cytokines were significantly higher than in patients with spontaneous labor at term. These observations suggest that a fever can be mediated by increased circulating concentrations of these cytokines, despite the absence of a local intra-amniotic inflammatory response.

CONCLUSIONS

1) The maternal plasma concentrations of pyrogenic cytokines (e.g. IL-1β, IL-2, IL-6, IFN-γ, and TNF-α) are higher in patients with intra-partum fever and the diagnosis of clinical chorioamnionitis at term than in those in spontaneous labor at term without a fever; and 2) maternal plasma cytokine concentrations have limited value in the identification of patients with bacteria in the amniotic cavity. Accurate assessment of the presence of intra-amniotic infection requires amniotic fluid analysis.

Clinical chorioamnionitis at term V: umbilical cord plasma cytokine profile in the context of a systemic maternal inflammatory response

OBJECTIVE

Microbial invasion of the fetus due to intra-amniotic infection can lead to a systemic inflammatory response characterized by elevated concentrations of cytokines in the umbilical cord plasma/serum. Clinical chorioamnionitis represents the maternal syndrome often associated with intra-amniotic infection, although other causes of this syndrome have been recently described. The objective of this study was to characterize the umbilical cord plasma cytokine profile in neonates born to mothers with clinical chorioamnionitis at term, according to the presence or absence of bacteria and/or intra-amniotic inflammation.

MATERIALS AND METHODS

A cross-sectional study was conducted, including patients with clinical chorioamnionitis at term (n=38; cases) and those with spontaneous term labor without clinical chorioamnionitis (n=77; controls). Women with clinical chorioamnionitis were classified according to the results of amniotic fluid culture, broad-range polymerase chain reaction coupled with electrospray ionization mass spectrometry (PCR/ESI-MS) and amniotic fluid interleukin (IL)-6 concentration into three groups: 1) no intra-amniotic inflammation; 2) intra-amniotic inflammation without detectable microorganisms; or 3) microbial-associated intra-amniotic inflammation. A fetal inflammatory response syndrome (FIRS) was defined as an umbilical cord plasma IL-6 concentration >11 pg/mL. The umbilical cord plasma concentrations of 29 cytokines were determined with sensitive and specific V-PLEX immunoassays. Nonparametric statistical methods were used for analysis, adjusting for a false discovery rate of 5%.

RESULTS

1) Neonates born to mothers with clinical chorioamnionitis at term (considered in toto) had significantly higher median umbilical cord plasma concentrations of IL-6, IL-12p70, IL-16, IL-13, IL-4, IL-10 and IL-8, but significantly lower interferon gamma (IFN-γ) and tumor necrosis factor alpha (TNF)-α concentrations than neonates born to mothers with spontaneous term labor without clinical chorioamnionitis; 2) neonates born to mothers with clinical chorioamnionitis at term but without intra-amniotic inflammation had higher concentrations of IL-6, IL-12p70, IL-13, IL-4, IL-5, and IL-8, but lower IFN-γ, than neonates not exposed to clinical chorioamnionitis, suggesting that maternal fever in the absence of intra-amniotic inflammation leads to a change in the fetal cytokine network; 3) there were significant, positive correlations between maternal and umbilical cord plasma IL-6 and IL-8 concentrations (IL-6: Spearman correlation=0.53; P<0.001; IL-8: Spearman correlation=0.42; P<0.001), consistent with placental transfer of cytokines; 4) an elevated fetal plasma IL-6 (>11 pg/mL), the diagnostic criterion for FIRS, was present in 21% of cases (8/38), and all these neonates were born to mothers with proven intra-amniotic infection; and 5) FIRS was associated with a high concentration of umbilical cord plasma IL-8, IL-10 and monocyte chemoattractant protein (MCP)-1.

CONCLUSIONS

Neonates born to mothers with clinical chorioamnionitis at term had higher concentrations of umbilical cord plasma cytokines than those born to mothers without clinical chorioamnionitis. Even neonates exposed to clinical chorioamnionitis but not to intra-amniotic inflammation had elevated concentrations of multiple cytokines, suggesting that intrapartum fever alters the fetal immune response.

Fever and the use of paracetamol during IL-2-based immunotherapy in metastatic melanoma

Fever is frequently observed in conjunction with interleukin-2 (IL-2)-based immunotherapy. Traditionally, fever has been regarded as an undesirable side effect and treated with fever-lowering drugs. However, new insights in tumor immunology suggest that elevated temperature may facilitate a more effective antitumor immune response. The purpose of this retrospective study was to examine the potential role of the IL-2-induced fever in melanoma patients treated with or without paracetamol in two consecutive cohorts. One hundred and seventy-nine patients with metastatic melanoma treated with a modified decrescendo regimen of IL-2 and Interferon (IFN) between 2004 and 2010 were retrospectively studied. 87 patients treated before 2007 received paracetamol as part of the treatment schedule, and 92 patients treated after 2007 did not receive paracetamol routinely. Body temperature was analyzed as dichotomized and continuous variables and correlated to objective tumor response and overall survival using logistic regression and Cox proportional hazard analysis. Patients experiencing peak temperature of ≥ 39.5 °C had a median OS of 15.2 months compared to 8.7 months among patients with lower temperatures (P = 0.01). In the multivariate analysis, peak temperature of ≥ 39.5 °C (HR 0.53; P = 0.026) and high mean temperature (HR 0.56; P = 0.004) were independent prognostic factors for improved survival. We suggest high fever as a biomarker for improved survival in melanoma patients treated with IL-2/IFN. The routine use of fever-reducing drugs during immunotherapy can therefore be questioned. More studies are needed to evaluate the role of fever and the use of antipyretics during cytokine-based immunotherapy.

High dose interleukin-2 (Aldesleukin) - expert consensus on best management practices-2014

Interleukin-2 (IL-2) was historically one of the few treatments for adults with stage IV solid tumors that could produce complete responses (CRs) that were often durable for decades without further therapy. The majority of complete responders with metastatic renal cell carcinoma (mRCC) and metastatic melanoma (mM) could probably be classified as "cures". Recent publications have suggested improved efficacy, perhaps due to improved patient selection based on a better understanding of clinical features predicting outcomes. Guidelines for clinical management were established from experience at the National Cancer Institute (NCI) and an affiliation of institutions known as the Cytokine Working Group (CWG), who were among the first to utilize HD IL-2 treatment outside of the NCI. As new centers have opened, further management variations have emerged based upon center-specific experience, to optimize administration of IL-2 and provide high quality care for patients at each individual site. Twenty years of evolution in differing environments has led to a plethora of clinical experience and effective management approaches. The goal of this review is to summarize the spectrum of HD IL-2 treatment approaches, describing various effective strategies that incorporate newer adjunctive treatments for managing the side effects of IL-2 in patients with mRCC and mM. The goal for IL-2 therapy is typically to administer the maximum number of doses of IL-2 without putting the patient at unacceptable risk for severe, irreversible toxicity. This review is based upon a consensus meeting and includes guidelines on pre-treatment screening, criteria for administration and withholding doses, and defines consensus criteria for safe administration and toxicity management. The somewhat heterogeneous best practices of 2014 will be compared and contrasted with the guidelines provided in 2001 and the package inserts from 1992 and 1998.

Tumor-induced perturbations of cytokines and immune cell networks

Until recently, the intrinsically high level of cross-talk between immune cells, the complexity of immune cell development, and the pleiotropic nature of cytokine signaling have hampered progress in understanding the mechanisms of immunosuppression by which tumor cells circumvent native and adaptive immune responses. One technology that has helped to shed light on this complex signaling network is the cytokine antibody array, which facilitates simultaneous screening of dozens to hundreds of secreted signal proteins in complex biological samples. The combined applications of traditional methods of molecular and cell biology with the high-content, high-throughput screening capabilities of cytokine antibody arrays and other multiplexed immunoassays have revealed a complex mechanism that involves multiple cytokine signals contributed not just by tumor cells but by stromal cells and a wide spectrum of immune cell types. This review will summarize the interactions among cancerous and immune cell types, as well as the key cytokine signals that are required for tumors to survive immunoediting in a dormant state or to grow and spread by escaping it. Additionally, it will present examples of how probing secreted cell-cell signal networks in the tumor microenvironment (TME) with cytokine screens have contributed to our current understanding of these processes and discuss the implications of this understanding to antitumor therapies.

Thyroid dysfunction as an unintended side effect of anticancer drugs

BACKGROUND

Several of the currently used anticancer drugs may variably affect thyroid function, with impairment ranging from modified total but not free concentration of thyroid hormones to overt thyroid disease.

SUMMARY

Cytotoxic agents seem to alter thyroid function in a relatively small proportion of adult patients. Anticancer hormone drugs may mainly alter serum levels of thyroid hormone-binding proteins without clinically relevant thyroid dysfunction. Old immunomodulating drugs, such as interferon-α and interleukin-2, are known to induce variably high incidence of autoimmune thyroid dysfunction. Newer immune checkpoint inhibitors, such as anti-CTLA4 monoclonal antibodies, are responsible for a relatively low incidence of thyroiditis and may induce secondary hypothyroidism resulting from hypophysitis. Central hypothyroidism is a well-recognized side effect of bexarotene. Despite their inherent selectivity, tyrosine kinase inhibitors may cause high rates of thyroid dysfunction. Notably, thyroid toxicity seems to be restricted to tyrosine kinase inhibitors targeting key kinase-receptors in angiogenic pathways, but not other kinase-receptors (e.g., epidermal growth factor receptors family or c-KIT). In addition, a number of these agents may also increase the levothyroxine requirement in thyroidectomized patients.

CONCLUSIONS

The pathophysiology of thyroid toxicity induced by many anticancer agents is not fully clarified and for others it remains speculative. Thyroid dysfunction induced by anticancer agents is generally manageable and dose reduction or discontinuation of these agents is not required. The prognostic relevance of thyroid autoimmunity, overt and subclinical hypothyroidism induced by anticancer drugs, the value of thyroid hormone replacement in individuals with abnormal thyrotropin following anticancer systemic therapy, and the correct timing of replacement therapy in cancer patients need to be defined more accurately in well-powered prospective clinical trials.

Acute phase responses induced in dwarf goats by r.BolL(-1beta), r.BolL(-2) and r.BolFN(-gamma)

The contribution of each of the pro-inflammatory cytokines to specific components of the host response to infection remains unclear. Therefore, the effects of single doses of cytokines were studied in dwarf goats. The present study was carried out to investigate the effects of r.BoIL(-1beta), r.BoIL(-2) and r.BoIFN(-gamma) on plasma zinc and iron concentrations, white blood cell counts, and body temperature. The i.v. injection of r.BolL(-1beta) (1 mug kg(-1)) resulted in an immediate fever which reached peak values 45 and 180 min after injection. Compared with fever induced by r.BoIL(-1beta), that caused by r.BoIFN(-gamma) (2 mug kg(-1)) was delayed in onset. Although the biphasic fever after r.BoIFN(-gamma) was more pronounced than after r.BoIL(-1beta), the reduction in plasma trace metal concentrations was less than after r.BoIL(-1beta), r.BoIL(-2) (1 mug kg(-1) i.v.) did not induce changes in these parameters. The haematologic changes observed revealed a cell type and cytokine specific pattern. The delayed onset of the effects induced by IFN(-gamma) suggests that they may be mediated through the induction of other mediators of inflammation.

Spontaneous regression of hepatocellular carcinoma is most often associated with tumour hypoxia or a systemic inflammatory response

BACKGROUND

Spontaneous regression of hepatocellular carcinoma (HCC) is well documented, although the aetiology of this phenomenon remains unknown.

METHODS

A review of the English literature was performed for reports of spontaneous regression of HCC. Reports were classified by mechanism based on the available information.

RESULTS

Spontaneous regression of HCC has been identified in 75 patients. The most common mechanisms of regression identified were tumour hypoxia (n= 21, 28.0%), a systemic inflammatory response (n= 25, 33.3%) and unknown (n= 29, 38.7%). In patients where tumour hypoxia was described as the aetiology, mechanisms included spontaneous hepatic artery thrombosis and sustained systemic hypotension. In patients where a systemic inflammatory response was the aetiology, mechanisms included cholangitis, trauma and elevated cytokine levels.

DISCUSSION

Spontaneous regression of HCC is most commonly associated with tumour hypoxia or a systemic inflammatory response. Determining the aetiology of spontaneous regression may identify potential therapeutic pathways. Tumour hypoxia is already the basis of treatment modalities such as hepatic artery embolization and the anti-angiogenic agent sorafenib. However, treatment modalities for HCC do not currently include immune-directed therapies; this may prove to be a worthy target for future research.

Predictors of bacterial pneumonia in Evaluation of Subcutaneous Interleukin-2 in a Randomized International Trial (ESPRIT)

BACKGROUND AND OBJECTIVES

Bacterial pneumonia still contributes to morbidity/mortality in HIV infection despite effective combination antiretroviral therapy (cART). Evaluation of Subcutaneous Interleukin-2 in a Randomized International Trial (ESPRIT), a trial of intermittent recombinant interleukin-2 (rIL-2) with cART vs. cART alone (control arm) in HIV-infected adults with CD4 counts ≥300cells/μL, offered the opportunity to explore associations between bacterial pneumonia and rIL-2, a cytokine that increases the risk of some bacterial infections.

METHODS

Baseline and time-updated factors associated with first-episode pneumonia on study were analysed using multivariate proportional hazards regression models. Information on smoking/pneumococcal vaccination history was not collected.

RESULTS

IL-2 cycling was most intense in years 1-2. Over ≈7 years, 93 IL-2 [rate 0.67/100 person-years (PY)] and 86 control (rate 0.63/100 PY) patients experienced a pneumonia event [hazard ratio (HR) 1.06; 95% confidence interval (CI) 0.79, 1.42; P=0.68]. Median CD4 counts prior to pneumonia were 570cells/μL (IL-2 arm) and 463cells/μL (control arm). Baseline risks for bacterial pneumonia included older age, injecting drug use, detectable HIV viral load (VL) and previous recurrent pneumonia; Asian ethnicity was associated with decreased risk. Higher proximal VL (HR for 1 log(10) higher VL 1.28; 95% CI 1.11, 1.47; P<0.001) was associated with increased risk; higher CD4 count prior to the event (HR per 100 cells/μL higher 0.94; 95% CI 0.89, 1.0; P=0.04) decreased risk. Compared with controls, the hazard for a pneumonia event was higher if rIL-2 was received <180 days previously (HR 1.66; 95% CI 1.07, 2.60; P=0.02) vs.≥180 days previously (HR 0.98; 95% CI 0.70, 1.37; P=0.9). Compared with the control group, pneumonia risk in the IL-2 arm decreased over time, with HRs of 1.41, 1.71, 1.16, 0.62 and 0.84 in years 1, 2, 3-4, 5-6 and 7, respectively.

CONCLUSIONS

Bacterial pneumonia rates in cART-treated adults with moderate immunodeficiency are high. The mechanism of the association between bacterial pneumonia and recent IL-2 receipt and/or detectable HIV viraemia warrants further exploration.

Changes in the levels of some acute-phase proteins in human immunodeficiency virus-1 infected patients, following interleukin-2 treatment

Intermittent interleukin (IL)-2 administration to human immunodeficiency virus (HIV)-1 infected patients is well documented and generally used, but there is limited information about the changes of acute-phase protein (APP) levels in response to this treatment. Fifteen patients undergoing highly active anti-retroviral therapy (HAART) treatment, with undetectable viral load, but low CD4+ cell count (<300/microl), have been treated with 3.6 M IU Proleukine administered twice daily by subcutaneous injection over 5 days. C-reactive protein (CRP), D-dimer, C3, C9, C1-inh and alpha-2HS glycoprotein levels were measured immediately before IL-2 administration, as well as on day 5 and 2-3 weeks thereafter. After IL-2 administration, both mean D-dimer and CRP levels increased significantly (P<0.001), but returned (P<0.001) to baseline within the subsequent 2-3 weeks. Alpha-2HS glycoprotein decreased immediately after IL-2 administration. No significant differences were detected in the levels of C3, C9 and C1-inh. A significant, positive correlation (r=0.5178, P=0.0008) was ascertained between the changes of CRP level, measured immediately before as well as 5 days after IL-2 administration, and changes in CD4 T cell counts measured 2-3 weeks before and after treatment, respectively. IL-2 administration induces rapid elevation of two major APPs (CRP, D-dimer). The positive correlation observed between the changes of CRP levels and CD4+ cell counts after IL-2 administration may indicate that the abrupt, but transitory overproduction of CRP might contribute to the CD4+ cell count-increasing effect of the drug and/ or may be associated with serious side effects.

Biomarkers for the diagnosis, prognosis, and evaluation of treatment efficacy for traumatic brain injury

Traumatic brain injury (TBI) remains a serious health concern, and TBI is one of the leading causes of death and disability, especially among young adults. Although preventive education, increased usage of safety devices, and TBI management have dramatically increased the potential for surviving a brain injury, there is still a need to develop reliable methods to diagnose TBI, the secondary pathologies associated with TBI, and predicting the outcomes of TBI. Biomarkers (changes of amount or activity in a biomolecule that reflect injury or disease) have shown promise in the diagnosis of several conditions, including cancer, heart failure, infection, and genetic disorders. A variety of proteins, small molecules, and lipid products have been proposed as potential biomarkers of brain damage from TBI. Although some of these changes have been reported to correlate with mortality and outcome, further research is required to identify prognostic biomarkers. This need is punctuated in mild injuries that cannot be readily detected using current techniques, as well as in defining patient risk for developing TBI-associated secondary injuries.

The efficacy of catheters coated with minocycline and rifampin in the prevention of catheter-related bacteremia in cancer patients receiving high-dose interleukin-2

High-dose interleukin-2 (HDIL-2) has proven to be an effective treatment for metastatic renal cell carcinoma and melanoma. Previous studies have shown an increase in catheter-related bacteremia (CRB) in patients on HDIL-2. The primary objective of this study was to evaluate the effectiveness of minocycline and rifampin-coated catheters (M/R-C) in reducing CRB in cancer patients on HDIL-2. This was a retrospective study where non-coated catheters (NC-C) and M/R-C were used for the administration of HDIL-2 before and after December 2004, respectively. Data collected included demographics, cancer type, catheter type, antibiotic prophylaxis, and infection rates. A total of 107 episodes of catheter use for HDIL-2 were evaluated in 78 patients (30 episodes in patients with M/R-C vs. 77 with NC-C). A total of nine episodes of CRB were identified, all in patients with NC-C (M/R-C 0% vs. NC-C 12%; p=0.06). The median time to bacteremia was 11 days (range 1-315 days). A log-rank test showed a trend that the M/R-C group had lower probability of getting CRB than the NC-C group (p=0.06). The use of M/R-C in patients on HDIL-2 therapy for advanced melanoma and renal cell carcinoma may have reduced the risk of CRB to nil. CRB still occurred despite antibiotic prophylaxis in patients with NC-C.

Interleukin-2 cycling causes transient increases in high-sensitivity C-reactive protein and D-dimer that are not associated with plasma HIV-RNA levels

OBJECTIVE

To determine the effects of interleukin (IL)-2 treatment on inflammatory and thrombotic biomarkers in chronically HIV-infected adults receiving antiretroviral therapy.

METHODS

Cryopreserved plasma was evaluated retrospectively for C-reactive protein (CRP) and D-dimer at baseline, end of an IL-2 cycle, and long-term follow up from two randomized, controlled trials: 57 IL-2-naive adults receiving either three to six cycles of IL-2 as well as antiretroviral therapy (nucleoside analogues) or antiretroviral therapy alone for 12 months, and 40 IL-2-experienced adults on highly active antiretroviral therapy who either interrupted or continued therapy for 6 months after a baseline IL-2 cycle. High-sensitivity CRP (hsCRP) was measured by immunonephelometry (detection limit 0.175 mg/l) and D-dimer by latex agglutination (detection limit 0.20 mg/l). Median within-group differences and pre and post-IL-2 changes between groups were assessed via nonparametric Wilcoxon signed-rank and Mann-Whitney U-tests. Spearman's rank test was used to assess correlations between changes in hsCRP, D-dimer, and HIV-RNA viral load.

RESULTS

Significant increases in hsCRP (study 1: 138.6 mg/l; study 2: 58.9 mg/l) and D-dimer (study 1: 3.1 mg/l; study 2: 0.4 mg/l, all P < 0.0001) occurred by the end of the initial IL-2 cycle, returning to baseline by the end of study. No correlations were seen between changes in hsCRP or D-dimer and HIV-RNA, CD4 T-cell count, or proliferation (Ki67 expression). No thrombotic or cardiovascular serious adverse events occurred during these study periods.

CONCLUSION

IL-2 dosing caused transient increases in plasma hsCRP and D-dimer levels, regardless of HIV-RNA viral load, suggesting the possibility of increased risk for thrombotic events.

Quantitative analysis of cytokine-induced vascular toxicity and vascular leak in the mouse brain

A storm of inflammatory cytokines is released during treatment with pro-inflammatory cytokines, such as interleukin-2 (IL-2), closely approximating changes initially observed during sepsis. These signals induce profound changes in neurologic function and cognition. Little is known about the mechanisms involved. We evaluated a number of experimental methods to quantify changes in brain blood vessel integrity in a well-characterized IL-2 treatment mouse model. Measurement of wet versus dry weight and direct measurement of small molecule accumulation (e.g. [(3)H]-H(2)O, sodium fluorescein) were not sensitive or reliable enough to detect small changes in mouse brain vascular permeability. Estimation of brain water content using proton density magnetic resonance imaging (MRI) measurements using a 7T mouse MRI system was sensitive to 1-2% changes in brain water content, but was difficult to reproduce in replicate experiments. Successful techniques included use of immunohistochemistry using specific endothelial markers to identify vasodilation in carefully matched regions of brain parenchyma and dynamic contrast enhanced (DCE) MRI. Both techniques indicated that IL-2 treatment induced vasodilation of the brain blood vessels. DCE MRI further showed a 2-fold increase in the brain blood vessel permeability to gadolinium in IL-2 treated mice compared to controls. Both immunohistochemistry and DCE MRI data suggested that IL-2 induced toxicity in the brain results from vasodilation of the brain blood vessels and increased microvascular permeability, resulting in perivascular edema. These experimental techniques provide us with the tools to further characterize the mechanism responsible for cytokine-induced neuropsychiatric toxicity.

Hyperthermia during anaesthesia and intensive care unit stay

Nosocomial hyperthermia (fever) occurs in about 30% of all medical patients at some time during their hospital stay. In patients admitted to the intensive care unit with severe sepsis the incidence of hyperthermia is greater than 90%, while in a specialized neurological critical care unit the incidence is reported as 47%. In contrast, hyperthermia during anaesthesia is rare owing to the impairment of thermoregulation by anaesthetic agents. This article is designed to give an overview on the various causes of hyperthermia with special emphasis on fever during general and regional anaesthesia in general and neurological critical care patients.

Retrospective analysis of peripheral blood stem cell transplantation for the treatment of high-risk neuroblastoma

Disease relapse after autologous peripheral blood stem cell transplantation (APBSCT) is the main cause of treatment failure in high-risk neuroblastoma (NBL). To reduce relapse, various efforts have been made such as CD34+ selection and double APBSCT. Here the authors reviewed the clinical features and outcomes of highrisk NBL patients and analyzed their survival. The medical records of 36 patients with stage III or IV NBL who underwent APBSCT at Seoul National University Children's Hospital between May 1996 and May 2004 were reviewed. Total 46 APBSCTs were performed in 36 patients. Disease free survival (DFS) and overall survival of all patients were 47.7% and 68.8%, respectively. The patients were allocated to three groups according to the APBSCT type. The DFS of CD34+ non-selected single APBSCT patients (N=13), CD34+ selected single APBSCT patients (N=14), and CD34+ selected double APBSCT patients (N=9) were 55.6%, 40.6%, and 50.0%, respectively, which were not significantly different. Thus the survival was not found to be affected by CD34+ selection or transplantation number. To improve long-term survival, various efforts should be made such as chemotherapy dose intensification, more effective tumor purging, and control of minimal residual disease via the use of differentiating and immune-modulating agents.

Association of interleukin (IL)-4 intron-3 and IL-6 -174 G/C gene polymorphism with susceptibility to end-stage renal disease

Earlier studies suggest that end-stage renal disease (ESRD) is associated with inflammatory state and have become a major cause of morbidity and mortality worldwide. This study speculated the role of interleukins (IL)-2, -4, and -6 cytokines gene polymorphism with risk of susceptibility to ESRD. Polymorphism in IL-2 (-330 T/G, polymerase chain reaction [PCR]-restriction fragment length polymorphism), IL-4 (intron-3, variable number of tandem repeat, variable number tandem repeats analysis), and IL-6 (-174 G/C, amplification refractory mutation system, i.e. ARMS-PCR) were genotyped in 193 ESRD patients and 180 controls. Significant difference was observed in genotype frequencies of IL-4 and IL-6 between ESRD patients and control group (p<0.001 and p=0.032, respectively). Patients had higher frequency of homozygous B2B2 genotype (IL-4) than controls (62.7% vs 46.7) and GG genotype of IL-6 (73.1% vs 60.6%). The genotypic frequencies of IL-2 were comparable in patients and controls (p=0.102). Significant association of IL-4 was also observed in patients with glomerulonephritis (p=0.001). Combination of low IL-4 and high IL-6 genotypes were significantly associated with ESRD showing the highest risk, i.e. >threefolds risk (odds ratio=3.48, 95%CI=1.88-6.42; p < 0.001) among the four possible combinations taking high IL-4 and low IL-6 as reference. Our study suggests that polymorphism in IL-4 and IL-6 may be associated with susceptibility to ESRD. Further, combined analysis implicated a higher risk in ESRD patients with low IL-4 and high IL-6 producing genotypes. This study provided the basis for defined anti-inflammatory approaches to limit renal disease progression.

Feasibility of high-dose interleukin-2 in heavily pretreated pediatric cancer patients

BACKGROUND

The administration of high-dose interleukin-2 (IL-2) seems to be a therapeutic option for children with refractory and metastatic solid malignancies.

METHODS

We prospectively studied treatment-related toxicities, quality of life and laboratory parameters in 10 children with progressive or metastatic solid tumors (metastatic osteosarcoma, n=4; neuroblastoma stage IV, n=3; metastatic Ewing's sarcoma, n=2; metastatic Wilms' tumor, n=1) during IL-2 therapy. Patients were scheduled to receive five cycles of high-dose IL-2 by continuous infusion for 5 days every 3 weeks.

RESULTS

All patients developed fever >39 degrees C and influenza-like symptoms, with a significant decrease in Karnofsky score. In two patients treatment had to be stopped after three cycles because of severe side-effects. During IL-2 therapy a statistical significant increase in white blood cells (WBC), creatinine, gamma-glutamyltransferase, C-reactive protein, glucose and body weight was observed. In contrast, red blood cells, platelets, protein, albumin and cholinesterase significantly decreased. When results from day 1 of the first and of the fifth cycle were compared, an increase of WBC and a decrease of alkaline phosphatase was shown. No constant quantitative changes in total lymphocytes and subsets were observed during IL-2 therapy.

CONCLUSIONS

IL-2 treatment in children with refractory and relapsed solid malignancies is associated with severe, but reversible, side-effects. However, five of the 10 patients with diseases of worst prognosis could be rescued by this treatment.

The cytokine gene polymorphisms in patients with chronic kidney graft rejection

Chronic allograft rejection remains an important cause of morbidity after kidney transplantation. The aim of the study was to examine the association between IL-2, IL-6 and TNF-alpha promoter polymorphisms and chronic kidney allograft rejection. The study included 64 patients with long-term stable graft function and 62 with chronic allograft nephropathy. Among patients with chronic allograft nephropathy a statistically significant prevalence of the IL-6 CC genotype associated with low IL-6 expression was observed (p < 0.01, OR 3.18; 95% CI 1.27-8.15). There were no statistically significant differences in distribution of IL-2 and TNF-alpha genotypes between patients with stable graft function and chronic allograft rejection. The results of present study suggest that the genetically determined low IL-6 production may be the risk factor of chronic allograft nephropathy development.

Pathogenesis of malaria and clinically similar conditions

There is now wide acceptance of the concept that the similarity between many acute infectious diseases, be they viral, bacterial, or parasitic in origin, is caused by the overproduction of inflammatory cytokines initiated when the organism interacts with the innate immune system. This is also true of certain noninfectious states, such as the tissue injury syndromes. This review discusses the historical origins of these ideas, which began with tumor necrosis factor (TNF) and spread from their origins in malaria research to other fields. As well the more established proinflammatory mediators, such as TNF, interleukin-1, and lymphotoxin, the roles of nitric oxide and carbon monoxide, which are chiefly inhibitory, are discussed. The established and potential roles of two more recently recognized contributors, overactivity of the enzyme poly(ADP-ribose) polymerase 1 (PARP-1) and the escape of high-mobility-group box 1 (HMGB1) protein from its normal location into the circulation, are also put in context. The pathogenesis of the disease caused by falciparum malaria is then considered in the light of what has been learned about the roles of these mediators in these other diseases, as well as in malaria itself.

Therapeutic use of IL-2 to enhance antiviral T-cell responses in vivo

Interleukin (IL)-2 is currently used to enhance T-cell immunity but can have both positive and negative effects on T cells. To determine whether these opposing results are due to IL-2 acting differently on T cells depending on their stage of differentiation, we examined the effects of IL-2 therapy during the expansion, contraction and memory phases of the T-cell response in lymphocytic choriomeningitis virus (LCMV)-infected mice. IL-2 treatment during the expansion phase was detrimental to the survival of rapidly dividing effector T cells. In contrast, IL-2 therapy was highly beneficial during the death phase, resulting in increased proliferation and survival of virus-specific T cells. IL-2 treatment also increased proliferation of resting memory T cells in mice that controlled the infection. Virus-specific T cells in chronically infected mice also responded to IL-2 resulting in decreased viral burden. Thus, timing of IL-2 administration and differentiation status of the T cell are critical parameters in designing IL-2 therapies.

Interleukin-2 Based Therapy for Kidney Cancer

In summary, IL-2 based therapy remains the basis for treatment of metastatic renal cell cancer. Un-answered questions remain in the development of regimens that exceed a mean response rate of 20%. Additionally, there may be differences among the histologic subtypes of renal cell cancer that predispose to response or lack there of to immunotherapy, and this is being further explored. As can be noted from the studies presented in this paper, there are numerous variations on the regimens for IL-2 based therapy. Current recommendations are to use the simplest and most feasible in a given institution. Certainly high dose IL-2 remains the standard regimen to which all others are measured.

Interleukin 2 leads to dose-dependent expression of the alpha chain of the IL-2 receptor on CD25-negative T lymphocytes in the absence of exogenous antigenic stimulation

Expression of the alpha chain of the interleukin 2 receptor on T lymphocytes is restricted, increasing in the setting of activation, particularly after antigenic stimulation via the TCR. The effects of IL-2 in vitro on the expression of CD25 and proliferation as well as the cytokine induction in CD25-depleted T cells were studied. CD25-depleted and PBMC of healthy donors were cultured for 7 days with 0, 10, or 100 IU/ml of IL-2. Phenotypic analysis and measurement of cytokines in the culture supernatants were performed. IL-2 led to a dose-dependent induction of the IL-2R alpha chain on both CD4 and CD8 T lymphocytes. In the CD25-depleted cultures, IL-2 treatment (100 IU/ml) increased the percentage of CD4 T cells expressing CD25 by 30.6% (P = 0.05) and of CD8 T cells by 48.2% (P = 0.01) on day 7 compared to no treatment. In the PBMC cultures the increase on day 7 was 36.4% for CD4 (P = 0.01) and 50.8% (P = 0.025) for CD8 T lymphocytes. The patterns of cytokine induction in the CD25-depleted and control cultures were similar with increases of IFN-gamma, GM-CSF, IL-16, TNF alpha, and soluble IL-2 receptor in the IL-2-containing cultures. CFSE experiments demonstrated the proliferative capacity of both CD25-positive and -negative T cells. Interleukin 2 alone can lead to a dose-dependent induction of the alpha chain of its receptor on resting CD4 and CD8 T lymphocytes. IL-2 as a sole stimulant is also associated with generation of a cytokine milieu that includes IFN-gamma, GM-CSF, IL-16, and TNF alpha.

Circulating cytokines as mediators of fever

The febrile response is thought to be mediated by endogenous mediators, generically called "endogenous pyrogens." In the classical model of pathogenesis, induction of fever is mediated by the release of pyrogenic cytokines such as tumor necrosis factor (TNF), interleukin (IL)-1, IL-6, and interferons into the bloodstream in response to exogenous pyrogens. These mediators act at the level of the organum vasculosum of the lamina terminalis in the central nervous system (CNS), inducing synthesis of prostaglandins, which are the central mediators of the coordinated responses leading to fever. However, analysis of recent data suggests that multiple pathways may be involved in the induction of fever by cytokines, such as local cytokine production leading to signaling through vagal fibers, release of cytokine-induced circulating mediators at the tissue level, the use of membrane-bound cytokines as mediators, or the local release of cytokines in the hypothalamus by circulating activated monocytes. In addition, certain bacterial products can stimulate cytokine production directly at the level of hypothalamus, probably by activation of Toll-like receptors. A multipathway mechanism for the induction of fever is therefore suggested.

Cytokines secreted by lymphokine-activated killer cells induce endogenous nitric oxide synthesis and apoptosis in DLD-1 colon cancer cells

IL-2-activated killer lymphocytes (LAK cells) secrete inflammatory cytokines such as interferon-gamma (IFN-gamma) and tumor necrosis factor alpha (TNFalpha) that can induce nitric oxide (NO) synthesis. We evaluated whether LAK cells could activate NO synthesis in human cancer cells. LAK cells and their culture supernatants induced NO synthesis in DLD-1 colon cancer cells in a dose-dependent manner. NO synthesis was inhibited completely by blocking antibodies to IFN-gamma, demonstrating a key role for this LAK cell cytokine in regulating NO synthesis. The addition of TNFalpha antibodies resulted in partial inhibition. Induction of iNOS mRNA and protein expression in DLD-1 cells was detected. Endogenous NO production inhibited DLD-1 cell proliferation and induced apoptosis, processes that were inhibitable by the NO synthase inhibitor N(G)-monomethyl-l-arginine. Our study has identified a novel, non-contact-dependent LAK cell cytotoxic mechanism: induction of growth inhibition and programmed cell death due to endogenous NO synthesis in susceptible human cancer cells.

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.

Alfentanil reduces the febrile response to interleukin-2 in humans

OBJECTIVE

Manifestation of intraoperative fever is impaired by volatile anesthetics and muscle relaxants. Opioids are common anesthetic adjuvants and remain the dominant treatment for postoperative surgical pain and sedation of critically ill patients. The effect of opioids on normal thermoregulatory control is well established. However, the extent to which these drugs might inhibit fever remains unknown. Accordingly, we tested the hypothesis that relatively low plasma concentrations of the mu-receptor agonist alfentanil reduce fever magnitude.

DESIGN

Prospective, randomized, crossover study.

SETTING

Outcomes Research Laboratory, at the Department of Anesthesia and Perioperative Care, University of California, San Francisco.

PATIENTS

Eight healthy male volunteers, aged 25-31 yrs, each studied on three separate days.

INTERVENTION

Each volunteer was given an intravenous injection of 30 IU/g interleukin (IL)-2, followed 2 hrs later by 70 IU/g. One hour after the second dose, the volunteers were randomly assigned to three doses of alfentanil: a) none (control); b) a target plasma concentration of 100 ng/mL; and c) a target concentration of 200 ng/mL. Opioid administration continued for 5 hrs.

METHODS AND MAIN RESULTS

Alfentanil significantly reduced the febrile response to pyrogen, decreasing integrated tympanic membrane temperatures from 7.5+/-2.2 degrees C x hr on the control day, to 4.9+/-1.5 degrees C x hr with 100 ng/mL alfentanil, and to 5.1+/-1.7 degrees C x hr with 200 ng/mL alfentanil (p = .011). Peak temperatures were also significantly reduced from 38.5+/-0.4 degrees C on the control day, to 38.0+/-0.4 degrees C on the 100 ng/mL-alfentanil day and 38.0+/-0.6 degrees C on the 200-ng/mL day (p = .019). Plasma cytokine concentrations increased after IL-2 administration, roughly in proportion to the elevation in core temperature. However, cytokine concentrations did not differ significantly among the treatment groups.

CONCLUSION

Alfentanil significantly reduced the febrile response to IL-2 administration. However, the reduction was comparable at plasma concentrations near 100 and 200 ng/mL. These data indicate that concentrations of opioids commonly observed in critical care patients significantly inhibit the manifestation of fever.

Decreased tolerance to interleukin-2 with repeated courses of therapy in patients with metastatic melanoma or renal cell cancer

High-dose interleukin-2 (IL-2) therapy has a response rate of approximately 20% in patients with metastatic melanoma and renal cell cancer. Animal models have shown that the anti-tumor effects of IL-2 are dose and schedule dependent, and one report has shown that patients with melanoma who responded to IL-2 therapy received more doses of IL-2 than did those who did not respond. The current study evaluated patients' tolerance to IL-2 over multiple courses of therapy and the factors that affected the number of doses delivered. Patients with metastatic melanoma or renal cell cancer who received at least two consecutive courses of high-dose intravenous IL-2 alone from October 1, 1985 through December 31, 1996 were evaluated. Patients served as their own controls in paired analyses. The number of doses tolerated from one course to the next and the reasons for stopping therapy were analyzed. One hundred fifty-nine patients received two or more courses of therapy during the study. The median number of doses of high-dose IL-2 decreased from course 1 (15 doses) to course 2 (12 doses) (p2 = 0.0001). Pretreatment factors were not found to significantly influence the decrease in the number of doses delivered. Only 2 of 33 separate toxic effects resulting in discontinuation of IL-2 dosing were found to be significantly different between courses. After adjusting for multiple tests of statistical significance, serum aspartate aminotransferase elevations were more likely to stop course 1 (p2 = 0.0033) and creatinine elevations were more likely to stop course 2 (p2 = 0.00007). The influence of renal toxicity was further assessed by comparing the median creatinine value at the time IL-2 dosing was discontinued. This difference was found to be significant when cycle 1 of course 1 (1.5 mg/dL) was compared with cycle 1 of course 2 (1.8 mg/dL; p2 = 0.0001). When pretreatment factors were analyzed, male sex (p2 = 0.006), a diagnosis of renal cell cancer (p2 = 0.008), previous nephrectomy (p2 = 0.001), and older age (p2 = 0.0055) were significantly associated with the development of renal toxicity that resulted in discontinuation of IL-2 therapy. Furthermore, the same four patient subsets had higher baseline creatinine values in individual univariate analyses. This study identified subsets of patients who tolerated less IL-2 with repeated courses. The decreasing tolerance to IL-2 was associated primarily with elevations in creatinine. Finding ways to ameliorate the renal toxicity seen during IL-2 therapy in this patient population may allow an increase in the number of IL-2 doses administered and potentially an increase in clinical response.

Pharmacodynamic aspects of peptide administration biological response modifiers

Cytokines, growth factors and other recombinant proteins have been one of the most rapidly growing areas of pharmaceuticals. Further, the development of these bio-engineered drugs is occurring at an astonishing pace with rapid preclinical and clinical development and licensing by regulatory agencies. In addition, the availability of the gene sequences and rational drug design technologies have resulted in a rapid development of engineered genes, proteins and peptidomimetics. In contrast to traditional pharmacophores, which are developed based on the identification of the maximum tolerated dose (MTD), most recombinant proteins have abnormal biodistributions, and pharmacodynamic and pharmacokinetic attributes. Within this chapter, representative cytokines including interferon-alpha (IFN-alpha), IFN-gamma and interleukin-2 are used to discuss the pharmacodynamic aspects of protein/peptide administration that are important in the development of these drugs. This includes the conceptual need for chronic immunoaugmentation for optimal therapeutic activity; the need to consider the pharmacokinetics of administration to optimize drug delivery and the nonlinear dose response relationship, which can result in a bell shaped dose response. Furthermore, these therapeutics have maximal potential in an adjuvant protocol and their development in combination with high-dose chemotherapy and stem cell rescue is discussed. The strategies for combination chemotherapy and immunotherapy, while holding great promise, require close attention to the pharmacodynamics of protein administration in order to impact on failure free and overall survival.

Immunotherapy and experimental approaches for metastatic melanoma

This article reviews the clinical investigations involving recombinant cytokines (either alone or in combination with adoptive immunotherapy, toxicity reduction agents, or cytotoxic chemotherapy), vaccines, monoclonal antibodies or antibody conjugates, and gene therapy. These various approaches are reviewed for their current and potential roles in curing metastatic melanoma.

A prospective crossover randomized trial of novobiocin and rifampin prophylaxis for the prevention of intravascular catheter infections in cancer patients treated with interleukin-2

BACKGROUND

The aim of this study was to determine the efficacy of novobiocin and rifampin as oral antibiotic prophylaxis for the prevention of catheter-related infection in melanoma patients treated with interleukin-2 (IL-2) plus interferon-alpha and chemotherapy (biochemotherapy).

METHODS

Patients with advanced melanoma who were treated with biochemotherapy at the University of Texas M. D. Anderson Cancer Center were randomized in a crossover study to receive either oral antibiotic prophylaxis consisting of novobiocin and rifampin or observation alone over a 35-day course period. Patients were subsequently "crossed over" to the opposite arm of the study for an additional 35-day period, with each serving as his or her own control.

RESULTS

Twenty-six patients were enrolled. Nine patients (35%) failed to tolerate oral antibiotics because of severe nausea and vomiting; 17 patients (65%) were crossed over and considered evaluable. During the control patient courses, 71% of evaluable patients had infectious complications, 41% had a catheter-associated bacteremia, and 53% had a local catheter infection. In contrast, of the patients treated with antibiotic prophylaxis, only 12% had an infectious complication (P = 0.001), 12% had a local catheter infection (P = 0.008), and 6% had catheter-associated bacteremias (P = 0.04). Thirty-six episodes of catheter infections occurred during the 17 control courses, whereas only 3 episodes occurred during antibiotic prophylaxis (P < 0.001).

CONCLUSIONS

Although more than one-third of patients receiving IL-2 treatment with biochemotherapy failed to tolerate novobiocin and rifampin, this oral antibiotic regimen was efficacious in preventing the infectious complications, especially those associated with vascular catheters, in this high risk patient population.