Peripheral blood cells from weight-losing cancer patients control the hepatic acute phase response by a primarily interleukin-6 dependent mechanism

Cancer cachexia is associated with an elevated hepatic acute phase protein response, poor outcome and elevated cytokine production from peripheral blood mononuclear cells (PBMC). This study investigates the mechanism by which PBMC can induce a hepatic acute phase response. Supernatants from the peripheral blood cells of cancer patients induced significantly higher C-reactive protein (CRP) from hepatocytes (198+/-21 ng ml-1) than did supernatants from healthy controls (64+/-20, p<0.005). CRP production in vitro correlated with IL-6 production by PBMC from patients with pancreatic cancer (r=0.76, p<0.0001). This C-reactive protein production was reduced by 84% using neutralising antibody to IL-6 (p<0.001). There was a significant negative correlation between PBMC-induced hepatocyte C-reactive protein production and survival (r=-0.45, p<0.01). PBMC from cancer patients induce the hepatic acute phase response via a primarily IL-6-dependent mechanism.

Pancreatic cancer as a model: inflammatory mediators, acute-phase response, and cancer cachexia

Patients with pancreatic cancer frequently develop the syndrome of cancer cachexia. Pro-inflammatory cytokines have been strongly implicated in the pathogenesis of this syndrome. In patients with pancreatic cancer an acute-phase response (an index of pro-inflammatory cytokine activity) is associated with accelerated weight loss, hypermetabolism, anorexia, and a shortened duration of survival. However, little is known about the primary significance of the acute-phase response in terms of altered hepatic export protein synthesis rates and its potential impact on the body's nitrogen economy. In a recent series of studies on weight-losing pancreatic cancer patients with hypoalbuminemia we have demonstrated albumin synthesis to be unaltered whereas fibrinogen synthesis is increased two- to threefold compared with healthy controls. Because of the mismatch in amino acid composition between the body's main labile amino acid reserve (skeletal muscle) and that of acute-phase proteins, these results lend support to the concept that in pancreatic cancer the reprioritization of body protein metabolism during an acute-phase response may well be a significant factor in the loss of lean tissue in these patients.

Fibrinogen synthesis is elevated in fasting cancer patients with an acute phase response

The unusual amino acid composition of acute phase proteins may be relevant to our understanding of the mechanism of tissue wasting in chronic inflammatory disease. During periods in which demand for amino acids outstrips dietary supply, skeletal muscle protein may be mobilized to meet this demand. An imbalance in the amino acid composition of these proteins may thus be detrimental to the body's nitrogen economy. To address this problem, we have measured the synthetic rate of fibrinogen (perhaps the major acute phase protein) and plasma amino acid profiles in a group of patients with adenocarcinoma of the pancreas and an ongoing inflammatory response (serum C-reactive protein >10 mg/L in the absence of any other obvious infective or inflammatory cause). These were also measured in a control group with no evidence of inflammation. Fibrinogen synthesis was measured after an overnight fast, using a flooding dose of 2H5-phenylalanine. The fractional rate of fibrinogen synthesis was significantly elevated in the cancer group compared with healthy controls [39.3 (20.0-49.9) and 21.9 (13.2-37.7) %/d, respectively; median (range), P < 0.05]. The absolute rate of fibrinogen synthesis was also elevated [84 (33-143) and 26 (15-43) mg/(kg.d), respectively; median (range), P < 0.01]. We calculated that, in cancer patients with anorexia-cachexia (i.e., documented ongoing weight loss in the absence of an obvious cause such as obstruction or malabsorption), aromatic amino acid supply (predominantly tryptophan) most limits fibrinogen synthesis from skeletal muscle reserves. Demand for the nonessential amino acids serine and glycine was elevated. Assuming that tryptophan is limiting, up to 2.6 g muscle protein ( approximately 12 g skeletal muscle tissue) may be wasted to synthesize 1 g fibrinogen. Interpretation of the observation that circulating free tryptophan concentrations were significantly reduced in the cancer patients will have to await flux measurements. The metabolic changes accompanying the inflammatory response suggest that down-regulation of this process may be beneficial.

Albumin synthesis rates are not decreased in hypoalbuminemic cachectic cancer patients with an ongoing acute-phase protein response

OBJECTIVE

To determine whether suppression of albumin synthesis contributes to the hypoalbuminemia observed in weight-losing cancer patients with evidence of an ongoing acute-phase protein response (APPR).

BACKGROUND DATA

Proinflammatory cytokines such as tumor necrosis factor (TNF) and interleukin 6 (IL-6) are known to downregulate albumin synthesis and increase acute-phase protein production in isolated hepatocytes. However, whether albumin synthesis is suppressed in hypoalbuminemic cancer patients with evidence of an ongoing acute-phase response is unknown.

METHODS

Albumin synthesis rates were determined in six healthy controls and in six weight-losing pancreatic cancer patients with an ongoing APPR using a flooding dose technique with [2H5]-phenylalanine. The presence of an APPR was defined as a serum C-reactive protein concentration >10 mg/L. Serum cytokines (TNF, IL-6) and soluble TNF receptors (sTNF-R 55 and 75), along with serum cortisol and insulin, were also measured in both groups.

RESULTS

Cancer patients had reduced serum albumin (median 32 [range, 23-36] vs. 42 g/L [40-45]; p < 0.01) and increased serum C-reactive protein concentrations (72 [23-126] vs. <5 mg/L; p < 0.01) when compared with controls. TNF was not detected in either group. sTNF-R 55 levels were significantly elevated in the cancer patients (3.8 [1.9-8.1] vs. 1.2 pg/mL [0.9-2.2]; p < 0.01). Circulating IL-6, insulin, and cortisol concentrations were not significantly different between the groups. The intravascular albumin mass was lower (88 [56-93] vs. 133 g [105-177]; p < 0.01), but the intravascular albumin fractional synthetic rate was higher (13.9 [13.5-18.5] vs. 10.3%/d [71-11.3]; p < 0.01) in the cancer patients compared with the controls. The total intravascular albumin synthetic rate was, however, similar between the two groups (12.7 [7.7-15.7] vs. 11.7 g/d [8.5-18.7]; p NS).

CONCLUSIONS

In weight-losing pancreatic cancer patients with evidence of an ongoing APPR, hypoalbuminemia is not caused by a decreased rate of albumin synthesis.

Simultaneous measurement of albumin and fibrinogen synthetic rates in normal fasted subjects

Albumin and fibrinogen synthesis appear to account for the majority of protein exported by the liver and therefore make a substantial contribution to that of whole-body protein synthesis. However, data on the protein synthetic rates of albumin and fibrinogen in normal subjects are limited. Albumin and fibrinogen synthetic rates were measured simultaneously over a 120-min period in normal subjects (n = 6) by using a flooding dose of 2H5-phenylalanine. Tracer incorporation into proteins was measured by gas chromatography/mass spectrometry. Body mass index, circulating concentrations of insulin, albumin, fibrinogen, C-reactive protein, and plasma volumes of the subjects were all within the normal reference range. There was a small and transient rise in circulating insulin concentrations following the flooding dose of phenylalanine. The median fractional synthetic rate and absolute synthetic rate for albumin was 10.3%/d and 208 mg.kg-1.d-1, respectively. The median fractional synthetic rate and absolute synthetic rate for fibrinogen was 19.5%/d and 28 mg.kg-1.d-1. In the context of the current interest in manipulating the inflammatory response of patients with various disease states, we introduce the concept of an acute phase protein quotient (APPQ). The APPQ is defined as the absolute rate of fibrinogen synthesis divided by that of albumin. In this group of normal subjects, the median APPQ was 0.14.

An open-label phase I/II dose escalation study of the treatment of pancreatic cancer using lithium gammalinolenate

There are currently no satisfactory treatments for inoperable pancreatic cancer. Median survivals for untreated patients are of the order of 100 days and, with one exception, no chemotherapy or radiotherapy regime has been found to produce a worthwhile extension of life with reasonably tolerable side effects. Gamma-linolenic acid (GLA) has been found to kill about 40 different human cancer cell lines in vitro without harming normal cells. The lithium salt of GLA (LiGLA) can be administered intravenously and a dose escalation study of a 10 day infusion followed by oral therapy in patients with inoperable pancreatic cancer was carried out in 48 patients in two centres. Peripheral venous infusion caused thrombophlebitis but this could be avoided by infusing via a central vein with appropriate heparinisation. Too rapid infusion caused haemolysis which could be avoided by slow dose escalation in the first few days and maintenance of plasma lithium below 0.8 mmol/l. Doses ranged from 7 to 77g/patient cumulatively delivered over 2-12 days. Other than the above described events there were no important side effects and patients felt well during the infusions. A Kaplan-Meier analysis showed that survival was not significantly influenced by which centre the patients were treated in, the sex of the patients or the presence or absence of histological confirmation. The presence or absence of liver metastases, the patients' Karnofsky scores and the-dose of LiGLA had significant effects on survival from treatment. A Cox proportional hazards model revealed similar results: in both centres, in both sexes, and in patients with and without liver metastases according to the model the highest doses of LiGLA were associated with longer survival times as compared with the lowest doses. LiGLA deserves investigation in a randomised prospective study.

The effect of polyunsaturated fatty acids on the progress of cachexia in patients with pancreatic cancer

Cachexia is common in patients with pancreatic cancer and has been associated with persistent activation of the hepatic acute phase response and increased energy expenditure. Fatty acids have been shown to have anticachectic effects in animal models and to reduce inflammatory mediators in healthy subjects and patients with chronic inflammatory disease. Eighteen patients with unresectable pancreatic cancer received dietary supplementation orally with fish oil capsules (1 g each) containing eicosapentaenoic acid 18% and docosahexaenoic acid 12%. Anthropometric measurement, body composition analysis, and measurement of resting energy expenditure and serum C-reactive protein were performed before and after supplementation with a median of 12 g/day of fish oil. Patients had a median weight loss of 2.9 kg/month (IQR 2-4.6) prior to supplementation. At a median of 3 months after commencement of fish oil supplementation, patients had a median weight gain of 0.3 kg/month (IQR 0-0.5) (p < 0.002). Changes in weight were accompanied by a temporary but significant reduction in acute phase protein production (p < 0.002) and by stabilisation of resting energy expenditure. This study suggests a component fish oil, perhaps EPA, merits further investigation in the treatment of cancer cachexia.

Ibuprofen reduces energy expenditure and acute-phase protein production compared with placebo in pancreatic cancer patients

The aim of this study was to investigate the effect of the cyclo-oxygenase inhibitor ibuprofen on the acute-phase protein response and resting energy expenditure (REE) of weight-losing patients with pancreatic cancer. Patients with irresectable pancreatic cancer (n = 16) were treated with either ibuprofen (1200 mg day-1 for 7 days (n = 10) or placebo (n = 6). A group of 17 age-related non-cancer subjects were also studied. Indirect calorimetry, anthropometry, multifrequency bioelectrical impedence analysis and serum C-reactive protein (CRP) estimation were performed immediately before and after treatment. Before treatment, total REE was significantly elevated in the pancreatic cancer patients compared with healthy controls (1499 +/- 71 vs 1377 +/- 58 kcal) (P < 0.02). Following treatment the mean REE of the ibuprofen group fell significantly (1386 +/- 89 kcal) compared with pretreatment values (1468 +/- 99 kcal) (P < 0.02), whereas no change was observed in the placebo group. Serum CRP concentration was also reduced in the ibuprofen-treated group (pre-ibuprofen, 51 mg l-1; post-ibuprofen, 29 mg l-1; P < 0.05). These results suggest that ibuprofen may have a role in abrogating the catabolic processes which contribute to weight loss in patients with pancreatic cancer.

Acute-phase protein response and survival duration of patients with pancreatic cancer

BACKGROUND

Current methods to predict survival duration of patients with pancreatic cancer are limited. The aim of this study was to determine whether certain nutritional indices and the acute-phase protein response are prognostic factors independent of disease stage for patients with unresectable pancreatic cancer.

METHODS

Variables at the time of diagnosis of 102 patients with unresectable pancreatic cancer were entered into a Cox's proportional hazards model. Included in the analysis were the serum concentration of C-reactive protein (CRP) and albumin, the extent of weight loss, age, sex, and disease stage (International Union Against Cancer criteria).

RESULTS

A multivariate analysis in which each factor was adjusted for the influence of the other factors revealed the patient age, disease stage, serum albumin, and serum CRP to be independent predictors of survival. The presence of an acute-phase protein response was the most significant independent predictors of survival duration. The median survival of those with an acute-phase protein response (CRP > 10 mg/L, n = 45) was 66 days compared with 222 days for those with no acute-phase protein response (n = 57, P = 0.001, Mann-Whitney U test).

CONCLUSION

The acute-phase protein response is a useful prognostic indicator for patients with unresectable pancreatic cancer. Moreover, the metabolic disturbances associated with an acute-phase protein response of patients with pancreatic cancer may be a worthwhile therapeutic target.

Acute-phase protein response and survival duration of patients with pancreatic cancer

BACKGROUND

Current methods to predict survival duration of patients with pancreatic cancer are limited. The aim of this study was to determine whether certain nutritional indices and the acute-phase protein response are prognostic factors independent of disease stage for patients with unresectable pancreatic cancer.

METHODS

Variables at the time of diagnosis of 102 patients with unresectable pancreatic cancer were entered into a Cox's proportional hazards model. Included in the analysis were the serum concentration of C-reactive protein (CRP) and albumin, the extent of weight loss, age, sex, and disease stage (International Union Against Cancer criteria).

RESULTS

A multivariate analysis in which each factor was adjusted for the influence of the other factors revealed the patient age, disease stage, serum albumin, and serum CRP to be independent predictors of survival. The presence of an acute-phase protein response was the most significant independent predictors of survival duration. The median survival of those with an acute-phase protein response (CRP > 10 mg/L, n = 45) was 66 days compared with 222 days for those with no acute-phase protein response (n = 57, P = 0.001, Mann-Whitney U test).

CONCLUSION

The acute-phase protein response is a useful prognostic indicator for patients with unresectable pancreatic cancer. Moreover, the metabolic disturbances associated with an acute-phase protein response of patients with pancreatic cancer may be a worthwhile therapeutic target.

Glutamine-supplemented total parenteral nutrition enhances T-lymphocyte response in surgical patients undergoing colorectal resection

OBJECTIVE

The authors determined the effect of glutamine-supplementation of TPN on postoperative peripheral blood T-cell response and proinflammatory cytokine production in patients undergoing colorectal resection.

SUMMARY BACKGROUND DATA

Several vital tissues, including the immune system, are very dependent on glutamine; however, this amino acid, which may be essential in conditions of stress, only now is becoming formulated suitably for incorporation into TPN. The effects of such supplementation on the immune function of stressed surgical patients is unknown.

METHODS

Patients (n = 20) were randomized to receive conventional TPN (0.2 g nitrogen/kg/d) or an isonitrogenous/isocaloric regimen with 0.18 g of glutamine/kg/d from days 1 to 6 postoperatively. T-cell DNA synthesis and interleukin (IL)-2 production and peripheral blood mononuclear cell IL-6 and tumor necrosis factor (TNF) production were measured in vitro preoperatively and on days 1 and 6 postoperatively.

RESULTS

T-cell DNA synthesis after 5 days of TPN was increased compared with preoperative values in the glutamine-supplemented group (median preoperative tritiated thymidine uptake: 78.3 x 10(3) cpm, day 6: 95.0 x 10(3) cpm, p < 0.05). There was no such increase in the control TPN group (preoperative: 89.0 x 10(3) cpm, day 6: 69.4 x 10(3) cpm, p > 0.05). Glutamine supplementation did not influence IL-2 production or the production of TNF or IL-6.

CONCLUSIONS

Glutamine supplementation may be a method of enhancing T-cell function in the surgical patient receiving TPN.

Effect of eicosapentaenoic acid and other fatty acids on the growth in vitro of human pancreatic cancer cell lines

A number of polyunsaturated fatty acids have been shown to inhibit the growth of malignant cells in vitro. To investigate whether fatty acids modify the growth of human pancreatic cancer, lauric, stearic, palmitic, oleic, linoleic, alpha-linolenic, gamma-linolenic, arachidonic, docosahexaenoic and eicosapentaenoic (EPA) acids were each incubated with the cells lines MIA PaCa-2, PANC-1 and CFPAC at concentrations ranging from 1.25 microM to 50 microM and the effect of each fatty acid on cell growth was examined. All the polyunsaturated fatty acids tested had an inhibitory effect, with EPA being the most potent (ID50 2.5-5 microM). Monounsaturated or saturated fatty acids were not inhibitory. The action of EPA could be reversed with the anti-oxidant vitamin E acetate or with oleic acid. The cyclo-oxygenase inhibitors indomethacin and piroxicam had no effect on the action of EPA. The action of EPA appeared to be associated with the generation of lipid peroxides, although the level of lipid peroxidation did not always appear to correlate directly with the extent of cell death. The ability of certain fatty acids to inhibit significantly the growth of three human pancreatic cancer cell lines in vitro at concentrations which could be achieved in vivo suggests that administration of such fatty acids may be of therapeutic benefit in patients with pancreatic cancer.

Evaluation of multi-frequency bio-impedance analysis for the assessment of extracellular and total body water in surgical patients

1. Multi-frequency bio-impedance analysis has been used to estimate extracellular and total body water in a heterogeneous group of 43 surgical patients (23 males, 20 females). 2. Radioisotope-dilution methods were used for the measurement of extracellular and total body water. 3. Resistance and reactance were measured between wrist and ankle at frequencies from 5 kHz to 1 MHz. 4. Extracellular and total body water were estimated by multiple stepwise regression using the radioisotope values as the dependent variables. The parameters included in the regression were: resistance and reactance at each frequency, body habitus parameters, plasma albumin and plasma sodium. 5. The standard errors of the estimates between the measured and estimated values were 1.73 litres (coefficient of variation 9.6%) and 2.17 litres (coefficient of variation 6.0%) for extracellular and total body water, respectively. 6. These errors represent a useful improvement relative to those obtained from anthropometric estimates. However, the improvements relative to the use of a single frequency (50 kHz) are not clinically significant.

Cytokines, the acute-phase response, and resting energy expenditure in cachectic patients with pancreatic cancer

OBJECTIVE

To determine whether resting energy expenditure (REE) is increased in cachectic patients with pancreatic cancer and to define the relation of tumor necrosis factor (TNF) and interleukin-6 (IL-6) production to the acute-phase response and to REE.

METHODS

Measurement of REE (indirect calorimetry) and assessment of body composition (bioelectrical impedance analysis) were done in 21 patients with unresectable pancreatic cancer and on 16 age-related controls. The systemic inflammatory response in peripheral blood of the cancer patients was assessed using the acute-phase protein, C-reactive protein, and the cytokines TNF and IL-6. Production of these cytokines by peripheral blood mononuclear cells in vitro was also measured.

RESULTS

Patients with pancreatic cancer had an elevated REE when compared with controls (73.4 +/- 5.0 vs. 53.5 +/- 1.6 kcal/kg body cell mass; p < 0.003). Resting energy expenditure was significantly greater in cancer patients with an acute-phase response (C-reactive protein > 10 mg/L) than in those who did not have such a response (85.5 +/- 10.0 [n = 9] vs. 64.3 +/- 3.0 [n = 12] kcal/kg body cell mass; p < 0.04). Tumor necrosis factor was not detected in the serum of any of the cancer patients. Serum IL-6 was detected but levels were not significantly different among cancer patients with or without an acute-phase response. In contrast, spontaneous production of TNF and IL-6 by isolated peripheral blood mononuclear cells was significantly greater in cancer patients with an acute-phase response that in those without (TNF: 1231 +/- 244 vs. 210 +/- 54 pg/ml/10(5) cells; p < 0.001; IL-6: 11.5 +/- 1.7 vs. 3.6 +/- 1.4 ng/mL/10(5) cells; p < 0.003).

CONCLUSIONS

In pancreatic cancer at least a component of weight loss is due to increased REE. Furthermore, the presence of an acute-phase response identifies a group of patients who are markedly hypermetabolic. The serum concentration of TNF of IL-6 does not correlate with the presence of an acute-phase response, whereas rates of cytokine production by peripheral blood mononuclear cells are significantly greater in patients with such a response. This suggests that local rather than systemic cytokine production may be important in regulating the acute-phase response.

Relative effect of surgery and radiotherapy on the internal jugular vein following functional neck dissection

We examined the internal jugular veins in three groups of patients who had undergone (1) a functional neck dissection and radiotherapy, (2) a functional neck dissection alone, or (3) radiotherapy alone, using a noninvasive color Doppler ultrasound scan. The internal jugular veins were ultrasonically bilaterally normal in 18% of patients who had undergone a functional neck dissection and radiotherapy, in 88% of patients who had undergone a functional neck dissection alone, and in 57% of patients who had undergone radiotherapy alone. The combination of a functional neck dissection and radiotherapy significantly affected the internal jugular vein when compared with a functional neck dissection alone.

The effect of C3 levels on yeast opsonization by normal and pathological sera: identification of a complement independent opsonin

The ability of 150 normal and pathological sera to opsonize yeast for uptake by isolated human polymorphonuclear leucocytes has been studied. Phagocytosis was measured by an assay depending on electronic particle counting to measure yeast uptake and by a new fluorometric assay which is able to distinguish particle adherence from true phagocytosis. The opsonic activity of normal human serum was heat labile and depended markedly on C3 levels. The sera of 6% of healthy young adults (three from 45) and 8% of healthy donors aged 65-88 (four from 57) showed defective opsonization in spite of normal C3 and CH50 levels. Thirty-eight pathological sera with low C3 levels showed defective opsonization. However, three sera with low C3 levels showed apparently normal opsonic activity. The opsonin from two of these sera was characterized. It was heat stable, had apparent mol.wt of 400,000 and was active in serum free media. The opsonin was absorbed by immobilized Staphylococcus aureus and by gelatin-Sepharose, suggesting that it is related to fibronectin. Fibronectin from normal human sera prepared by affinity chromatography on gelatin-Sepharose was not opsonic in this system.