Soluble tumour necrosis factor receptors, tumour necrosis factor and interleukin-6 in serum in granulocytopenic patients with fever

Predictive value of interleukin-5 and monocyte chemotactic protein-1 for bacteremia in children with febrile neutropenia

A variety of clinical and laboratory parameters have been used to predict bacteremia. We hypothesize that the generation of a cytokine profile could be used to identify patients at higher risk of bacteremia at the time of presentation with febrile neutropenia. We prospectively evaluated children with cancer who presented with an episode of febrile neutropenia. A multiplexed flow cytometric assay was performed which measured 15 cytokines and chemokines obtained before the initiation of antibiotics. Fifty-eight episodes of chemotherapy-induced febrile neutropenia were included in this study during which 4 patients (7%) had bacteremia. An interleukin-5 level of >8 pg/dL had a sensitivity of 67% and a specificity of 96% to predict bacteremia. An monocyte chemotactic protein-1 level >1650 pg/dL had a sensitivity of 80% and a specificity of 82% to predict bacteremia. Erythrocyte sedimentation rate, C-reactive protein, protein C, and other cytokines/chemokines were not predictive of bacteremia. Elevations of interleukin-5 and monocyte chemotactic protein-1 are predictive of bacteremia in children with cancer who have febrile neutropenia. Prospective studies should be undertaken to determine whether these parameters retain predictive value in a larger series of patients and can select children for outpatient management or early discharge.

Procalcitonin-a sensitive inflammation marker of febrile episodes in neutropenic children with cancer

OBJECTIVE

Sensitive parameters of inflammations, are rare or of limited validity in neutropenic patients. Procalcitonin (PCT) proven to be a sensitive inflammatory marker in nonneutropenic patients was evaluated for its diagnostic relevance in febrile episodes of neutropenic patients with cancer

METHODS

Plasma levels of PCT were determined by an immunoluminometric assay in children with febrile neutropenic episodes (n=376) starting at the date of admission until the resolution of fever and were correlated with serum levels of the C-reactive protein (CrP). Febrile episodes were classified as fever of unknown origin (FUO), microbiologically or clinically documented infections and were also differentiated according to the site of the infection (unknown, bacteremia, respiratory, soft tissue, gastrointestinal and urinary tract infection).

RESULTS

Independently from the aetiology and the site of infection the PCT peak value occurred mostly on the second hospital day and decreased rapidly in cases of successful antibiotic therapy and with the resolution of fever to the normal range (0.1+/-0.5 microg/l). The highest PCT peak levels at the onset of fever and during the febrile course were observed in patients with gramnegative bacteremia (n = 22, median 12.1 microg/l, range 0.4+/-568.2 microg/l). There was a positive correlation between PCT peak levels and CrP peak levels (r = 0.48, p = 0.001) which mostly were observed 24 h later than for PCT.

CONCLUSIONS

PCT is a sensitive and specific parameter in the diagnostic and in the sequential assessment of febrile neutropenic episodes, especially in gramnegative infections. Its diagnostic accuracy in neutropenic patients is clearly higher than that of CrP.

Soluble tumor necrosis factor (TNF) receptor-1 induces apoptosis via reverse TNF signaling and autocrine transforming growth factor-beta1

The pro-inflammatory cytokine tumor necrosis factor-alpha (TNF-alpha) plays a central role in inflammatory disorders. Transmembrane TNF-alpha and its two receptors are cleaved by the proteinase TNF-alpha converting enzyme (TACE), resulting in appreciable serum levels of soluble TNF-alpha and soluble TNF-alpha receptors (sTNFR1 and -2). The only known functions of sTNFR1 are to antagonize and buffer circulating TNF-alpha. Here, we present evidence that sTNFR1 exerts immunoregulatory functions by induction of apoptosis in monocytes through reverse signaling via transmembrane TNF-alpha. sTNFR1-induced apoptosis is independent of death receptor pathways but depends on autocrine transforming growth factor (TGF)-beta1 signaling through the mitogen-activated protein kinase p38alpha. This novel mechanism has implications for understanding the physiological role of sTNFR1 and for TNF-alpha-blocking therapies of autoimmune diseases.

The role of C-reactive protein as a prognostic indicator in advanced cancer

C-reactive protein (CRP) is a nonspecific but sensitive marker of inflammation. Interleukin-6 (IL-6), IL-1, and tumor necrosis factor alpha induce the synthesis of CRP in hepatocytes. Increased CRP level is considered to be an important risk factor for atherosclerosis, myocardial infarction, peripheral vascular disease, and ischemic stroke. It is positively correlated with weight loss, anorexia-cachexia syndrome, extent of disease, and recurrence in advanced cancer. Its role as a predictor of survival has been shown in multiple myeloma, melanoma, lymphoma, ovarian, renal, pancreatic, and gastrointestinal tumors. Measurement of CRP is simple, cheap, and routine and provides valuable information in palliative care.

T-helper-1 and T-helper-2 responses in psychiatric disorders

The expanding field of psychoneuroimmunology has markedly increased knowledge about the interference of the central nervous system and the immune system. Immunological abnormalities in psychiatric patients have been repeatedly described in the last century. Modern concepts of immunology and the growing knowledge of psychoneuroimmunology may help in understanding the distinct immunological mechanisms in psychiatric disorders. One of these concepts regarding the adaptive immune system is the discrimination between Th1-like cell-mediated and Th2-like antibody-related immune responses. This article systematically describes alterations of Th1- or Th2-specific parameters in the major psychiatric disorders schizophrenia, major depression, and Alzheimer's disease. There are several hints of associations of these two distinct arms of immune response with subgroups of schizophrenia and major depression. The immunological research in Alzheimer's disease has already led to a preclinical model of immunotherapy. Categorization of immune parameters may also help to identify a possible immune-related pathophysiology in psychotic and affective disorders, resulting in specific treatment strategies.

Procalcitonin in paediatric cancer patients: its diagnostic relevance is superior to that of C-reactive protein, interleukin 6, interleukin 8, soluble interleukin 2 receptor and soluble tumour necrosis factor receptor II

Sensitive parameters of inflammation are rare in neutropenic cancer patients. In this study, procalcitonin (PCT), C-reactive protein (CRP), interleukin 6 (IL-6), IL-8, the soluble IL-2 receptor (sIL-2R) and the soluble tumour necrosis factor receptor II (sTNFRII) were evaluated for their diagnostic relevance in febrile episodes of cancer patients. Plasma or serum levels of these parameters were determined in neutropenic children with febrile episodes (n = 122) classified according to both the kind of infection [60 cases of fever of unknown origin (FUO), 28 cases of localized infection, 13 cases of pneumonia, 20 cases of bacteraemia, one case of fungaemia] and the World Health Organization (WHO) score of chemotherapy-induced mucositis. At baseline and during the febrile episodes, the highest levels of all parameters were observed in cases of gram-negative bacteraemia. However, in FUO and localized infections, low or only slightly elevated median levels of all parameters were documented. The degree of chemotherapy-induced mucositis did not influence the value of any parameter. In comparison with the other inflammatory parameters, PCT (optimum cut-off level 0.5 microg/l) was a more sensitive and more specific parameter in the diagnosis of high-risk (gram-negative bacteraemia) and low-risk (FUO) episodes, as well as in the sequential assessment of all febrile neutropenic episodes.

T-lymphocyte functions in acute leukaemia patients with severe chemotherapy-induced cytopenia: characterization of clonogenic T-cell proliferation

Intensive chemotherapy for acute leukaemia is followed by a period of severe chemotherapy-induced leukopenia. We used a limiting dilution assay to investigate whether remaining CD4+ and CD8+ T lymphocytes derived from such leukopenic patients could be activated and undergo clonogenic proliferation. The activation signal in our model was accessory cells (irradiated normal peripheral blood mononuclear cells) + phytohaemagglutinin (PHA) + interleukin-2 (IL-2). During severe leukopenia a majority of circulating lymphocytes were CD4+ T cells. Clonogenic proliferating T lymphocytes were detected for all patients. Higher frequencies of clonogenic cells were detected in the CD8+ subset as compared to the CD4+ subset. However, for both subsets frequencies of proliferating cells were decreased compared with healthy individuals. The CD4+ and CD8+ lymphocytes were also capable of proliferation in response to alloactivation, and accessory cells mainly containing acute myelogenous leukaemia blast were efficient as accessory cells for activation. For the CD4+ cells, increased proliferation was detected in the presence of acute myelogenous leukaemia (AML) blasts compared with normal accessory cells. Based on our results we conclude that: (1) although acute leukaemia patients with therapy-induced leukopenia have both a quantitative and a qualitative T-cell defect, (2) the remaining T-cell population includes a subset capable of clonogenic proliferation. However, (3) proliferation of the clonogenic CD4+ cells can be modulated by AML blasts.

Interleukin 4 responses in acute leukaemia patients with severe chemotherapy-induced leucopenia

T lymphocyte functions in acute leukaemia patients with severe chemotherapy-induced leucopenia were investigated using 3 different approaches: (i) analysis of serum concentrations of the T cell cytokine interleukin 4 (IL4) demonstrated that serum IL4 levels increased during complicating bacterial infections. However, this response was modulated by a concomitant increase in serum levels of the potential IL4 antagonist soluble IL4 receptor alpha chain (sIL4R alpha). (ii) Even during leucopenia a subset of T lymphocytes derived from leucopenic patients expressed the activation markers CD25 (IL2 receptor), CD71 (transferrin receptor) and HLA-DR. (iii) Subsets of circulating CD4+ and CD8+ T lymphocytes could undergo clonogenic proliferation in vitro, and a majority of these clones secreted IL4. CD4+ clones showed higher IL4 levels than CD8+ clones. Our results indicate that T lymphocytes can be activated and contribute to cytokine responses in acute leukaemia patients with severe chemotherapy-induced cytopenia.

A recombinant tumor necrosis factor-alpha p80 receptor:Fc fusion protein decreases circulating bioactive tumor necrosis factor-alpha but not lung injury or mortality during immunosuppression-related gram-negative bacteremia

PURPOSE

During gram-negative bacteremia (GNB), tumor necrosis factor-alpha (TNF-alpha) is a critical early mediator of host defense, whose overexpression can initiate acute lung injury, multiple organ failure, and death. In this study we evaluated the ability of a chimeric fusion protein containing two extracellular domains of the human p80 TNF-alpha receptor and the Fc region of human IgG1 (TNFR:Fc) to reduce circulating TNF-alpha, and to ameliorate organ injury and improve survival in a rodent model of GNB during immunosuppression-related neutropenia.

MATERIALS AND METHODS

Conscious catheterized male rats (n = 37) with stable cyclophosphamide-induced neutropenia were infected intravenously (i.v.) with 5 x 10(9) live Escherichia coli (EC, serotype O55:B5) ending at t = 0. All animals received antibiotics (penicillin/ amikacin sulfate) at t = 0.5 and t = 8 hours, and 0.9% sodium chloride (normal saline solution (NS), 1 mL/h) from t = 0 to 8 hours. Subgroups were post-treated at t = 0.5 hours with a 1.0 mL i.v. dose of TNFR:Fc (60, 600, or 1,200 micrograms; Immunex), 600 micrograms of human IgG1-kappa or IgG1-lambda (Sigma), or NS alone (controls). A separate TNFR:Fc pretreatment subgroup received 600 micrograms/rat of the fusion protein 5 minutes before starting EC infusion. Hemodynamics were monitored continuously through t = 24 hours, and arterial samples were collected at baseline and at t = 1.5, 4.5, 8, and 24 hours after EC were analyzed for blood gases, quantitative culture, serum endotoxin, bioactive and antigenic TNF-alpha, and formed elements. Postmortem tissues were examined for histopathologic changes.

RESULTS

Compared with antibiotic-treated and fluid-supported controls, TNFR:Fc dose-dependently reduced bioactive but not antigenic TNF-alpha without altering bacterial clearance, serum endotoxin, or 24-hour survival. Of note, 600 micrograms of IgG1-kappa or IgG1-lambda attenuated peak bioactive TNF-alpha to a similar degree as 1,200 micrograms TNFR:Fc, and also significantly reduced serum endotoxin levels. Nevertheless, by t = 8 hours all bacteremic rats were hypothermic with tachypnea-related hypocarbia and hyperoxemia and were thrombocytopenic. At death, all subgroups showed similar hepatic glycogen depletion and pulmonary congestion with perivascular edema and alveolar hemorrhage.

CONCLUSIONS

Although TNFR:Fc and its idiotypic control IgG1 reduced circulating bioactive TNF-alpha, neither treatment prevented progression of lethal shock with attendant organ injury in this conscious, antibiotic-treated and fluid-resuscitated model of immunosuppression-related GNB.

Serum levels of adhesion molecules and cytokines in patients with acute leukaemia

The cytokine network and the adhesion molecule system are intercellular signal pathways. The cytokine effects are modulated in vivo by soluble cytokine antagonists, whereas the cell to cell contact mediated by adhesion molecules and their ligands may be blocked by the soluble forms of the adhesion molecules. The cytokine network is important for proliferation and cytokine secretion by acute leukaemia blasts, and membrane-bound adhesion molecules are important for blast interactions with neighbouring cells of the in vivo microenvironment. Both these signal systems are operative during the period of cytopenia following intensive chemotherapy for acute leukaemia. In the present review, we discuss the influence of disease status, chemotherapy and complicating infections on serum levels of cytokines and soluble adhesion molecules in acute leukaemia patients. We have demonstrated increased serum levels of both cytokines and cytokine antagonists in acute leukaemia patients with complicating bacterial infections during chemotherapy-induced cytopenia. Serum levels of the selectin adhesion molecules were decreased during bacterial infections in leukopenic patients compared to healthy individuals. In contrast, the intercellular adhesion molecule-1 response and the cytokine/cytokine antagonist responses were qualitatively similar to responses seen in previously healthy individuals with serious bacterial infections.

The potential biological and clinical significance of the soluble tumor necrosis factor receptors

The role of TNF receptors (TNF-Rs) is not limited to signal transduction but includes extracellular regulatory functions affecting systemic TNF bioavailability. This review summarizes the regulation of TNF-R shedding and its kinetics, the complex interaction between the soluble receptors and their ligand in vitro and in vivo, and the potential diagnostic, prognostic and therapeutic value of the soluble receptors in malignant, inflammatory, infectious and autoimmune disorders.

Interleukin 1 receptor antagonist (IL1RA) in acute leukaemia: IL1RA is both secreted spontaneously by myelogenous leukaemia blasts and is a part of the acute phase reaction in patients with chemotherapy-induced leucopenia

Blast cells derived from peripheral blood of patients with acute myelogenous leukaemia (AML) were cultured in vitro and interleukin 1 receptor antagonist (IL1RA) concentrations determined in culture supernatants. AML blasts derived from patients classified as AML-M4 and AML-M5 subtype showed an increased release of IL1RA. IL1 alpha and IL1 beta caused a similar increase in AML blast release of IL1RA, and addition of anti-IL1 antibodies decreased IL1RA release. IL1RA release from AML blasts was also increased by stem cell factor, tumour necrosis factor alpha (TNF alpha), granulocyte-macrophage colony-stimulating factor and macrophage colony-stimulating factor, whereas interleukin 3, interleukin 6, leukaemia inhibitory factor and granulocyte colony-stimulating factor did not significantly alter IL1RA release. When investigating IL1RA serum levels, serum concentrations were decreased in acute leukaemia patients with chemotherapy-induced cytopenia compared with healthy controls. Serum levels of both IL1RA as well as IL1 beta and soluble TNF alpha receptors increased when the leucopenic patients developed complicating bacterial infections.