Changes In Interleukin-6 Concentrations Research Articles

Acute inflammation elicits decreased blood pressure but similar arterial stiffness in young African American adults.

African Americans (AA) have a higher risk for cardiovascular disease (CVD) as compared to their White (W) counterparts. CVD is characterized by increased blood pressure (BP), arterial stiffness and systemic inflammation. An acute inflammatory stimulus may explain physiological manifestations responsible for amplified CVD in AA that are not apparent at rest. The purpose of this study was to evaluate central and peripheral BP, central and local arterial stiffness, and indices of pulse wave morphology in young healthy AA and W participants in response to acute inflammation. Concentrations of the inflammatory cytokine interleukin-6 (IL-6) and measures of central and peripheral BP, central arterial stiffness (carotid-femoral pulse wave velocity (cfPWV)), local carotid arterial stiffness (β-stiffness, elastic modulus (Ep)), and indices of pulse wave morphology were assessed in 28 participants (21±2years, AA: n = 11) at baseline (BL), 24h and 48h post-inflammation. Changes in IL-6 concentrations (ΔIL-6) were significantly greater at 24h as compared to 48h post-inflammation (0.652±0.644 vs. -0.146±0.532pg/μl, P≤0.0001). Among AA participants, central and peripheral diastolic BP were significantly decreased at 24h post-inflammation as compared to BL (aortic diastolic BP: -4±4mmHg, P=0.016; brachial diastolic BP: -4±4mmHg, P=0.014). AA participants also experienced a significant decrease in central and peripheral mean arterial BP at 48h post-inflammation as compared to BL (aortic mean arterial pressure: -4±4mmHg, P=0.009; brachial mean arterial pressure: -4±4mmHg, P=0.012). Despite haemodynamic changes, there were no differences in central or local carotid arterial stiffness or indices of pulse wave morphology.

Psychological care reflecting the specifics of the course of viral infection in SARS-CoV-2 oncological patients with oxygenation disorder - a case series.

During the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, patients treated with acute coronavirus disease 2019 (COVID-19) in intensive care units (ICU) have suffered from neuropsychiatric complications such as anxiety, depression, and confusion. Conditions related to the environment have the potential to worsen these symptoms. In combination with virus-dependent neuroinflammation, they form a "toxic" mixture. Discussion and planning strategies for providing psychological care in the ICU during the pandemic have revealed a great current challenge. We share our experience concerning psychological interventions for oncological patients with oxygen saturation depletion. Our observation of two SARS-CoV-2 patients suggests a close time-related association between the increase in inflammatory markers interleukin 6 (IL-6) and C-reactive protein (CRP) and intensive anxiety in the fast development of breath shortening in acute COVID-19 infection due to brain hypoxia and potential neuroinflammation. As cytokine IL-6 regulates induction of CRP gene expression, the changes in IL-6 concentrations associated with anxiety symptoms and breath shortening in the observed cluster can be detected hours earlier than changes in CRP levels, with a diagnostic implication for the clinicians. The SARS-CoV-2 patients with oncological diseases treated in our ICU asked for personal bedside contact with clinical psychologists, considered it irreplaceable and reported this psychological care as beneficial.

Two Biosensors for the Determination of Interleukin-6 in Blood Plasma by Array SPRi.

Interleukin-6 (IL-6) is a biomarker of inflammation, the advanced stage of COVID-19, and several cancers, including ovarian cancer. Two biosensors for the determination of IL-6 in blood plasma by array SPRi have been developed. One of these biosensors consists of the mouse monoclonal anti-IL-6 antibody as the receptor immobilized via the cysteamine linker. The second contains galiellalactone as the receptor, being an inhibitor specific for IL-6, immobilized via octadecanethiol (ODM) as the linker. Both biosensors are specific for IL-6. The biosensor with the antibody as the receptor gives a linear analytical response between 3 (LOQ) and 20 pg mL−1 and has a precision between 8% and 9.8% and recovery between 97% and 107%, depending on the IL-6 concentration. The biosensor with galiellalactone as the receptor gives a linear analytical response between 1.1 (LOQ) and 20 pg mL−1, and has a precision between 3.5% and 9.3% and recovery between 101% and 105%, depending on IL-6 concentration. Both biosensors were validated. Changes in IL-6 concentration in blood plasma before and after resection of ovarian tumor and endometrial cyst, as determined by the two developed biosensors, are given as an example of a real clinical application.

Young Healthy Men and Women Have Similar Arterial Stiffness at Rest and Post‐Acute Inflammation

The cardioprotective effects of estrogen on arterial function and inflammation are well‐documented; however, it is unclear whether arterial stiffness and compliance vary between healthy premenopausal women and age‐matched men following an acute inflammation. The objective of the current study was to evaluate central and local arterial stiffness and compliance at rest and in response to an acute inflammatory stimulus, specifically, when estrogen levels are thought to be similar between young healthy women and men. It was hypothesized that sustained effects of estrogen throughout the lower‐hormone phase of a natural menstrual or oral contraceptive pill cycle would induce lower central and local stiffness and higher compliance in women as compared to men at rest and in response to an acute inflammatory stimulus. Concentrations of interleukin‐6 (IL‐6) and assessments of central and local arterial stiffness and compliance were obtained from 29 young healthy adults (21±3 y; female, n=15) at baseline (BL), and 24‐ (24H) and 48‐hours (48H) following administration of a seasonal influenza vaccine. To capture the lower‐hormone phases of female participants, women were assessed within the early follicular phase if naturally menstruating or the placebo pill phase if using oral contraceptives. Central stiffness was assessed via carotid‐to‐femoral pulse wave velocity (cfPWV) and local stiffness was measured using ultrasonography at the carotid artery to obtain β‐stiffness, elastic modulus (Ep) and arterial compliance (AC). IL‐6 concentrations were expressed as change‐values from BL and were compared between sexes and timepoints (24H‐BL vs. 48H‐BL). Indices of central and local stiffness and AC were compared between sexes and individual timepoints (BL vs. 24H vs. 48H). Men and women exhibited similar changes in concentrations of IL‐6 (effect of sex: P=0.60), with significant elevations at 24H‐BL as compared to 48H‐BL (effect of time: P=0.0002), indicating that the influenza vaccine successfully induced an acute inflammatory response in both groups. However, there were no effects of sex or time on cfPWV, β‐stiffness or Ep (P>0.05 for all). While men displayed greater AC as compared to women at BL (1.09±0.25 vs. 0.88±0.17 mm2/kPa, P=0.01), there were no sex‐differences at 24H and 48H (P=0.10 and 0.70, respectfully), suggesting that the women were able to compensate for their lower resting AC values when exposed to an acute inflammatory stimulus. In conclusion, when estrogen levels are similar between young healthy women and men, there are no sex‐differences in central or local arterial stiffness at rest nor in response to an acute inflammatory stimulus.

Intraoperative Peritoneal Interleukin-6 Concentration Changes in Relation to the High-Mobility Group Protein B1 and Heat Shock Protein 70 Levels in Children Undergoing Cholecystectomy.

The aim was the evaluation of IL-6 concentration in peritoneal lavage fluid of children which underwent cholecystectomy to ascertain if there is a difference in early inflammatory response depending on the type of surgical approach (open vs. laparoscopy). The analysis of high-mobility group protein B1 (HMGB1) and heat shock protein 70 (HSP70) was performed to find out if the source of IL-6 was related to tissue damage. IL-6 concentration in peritoneal lavage fluid samples, obtained at the beginning and at the end of the laparoscopic (N = 23) and open cholecystectomy (N = 14), was tested with a routinely used electrochemiluminescence assay. The concentrations of HMGB1 and HSP70 were analyzed with the use of an ELISA method. Statistical analysis was performed using the STATISTICA PL release 12.5 Program. The differences were assessed using the Mann-Whitney U test and Wilcoxon matched pairs test. Correlations were studied by using the Spearman correlation test. Our results demonstrated significant peritoneal lavage fluid IL-6 concentration growth measured at the end of the cholecystectomy as compared to the beginning, regardless of the type of the procedure. IL-6 growth during open cholecystectomy was greater compared to laparoscopic cholecystectomy (62.51-fold vs. 3.19-fold). IL-6 concentration did not correlate with HMGB1 and HSP70, which indicate that the significant growth of this cytokine was not related to mechanical tissue damage due to surgical procedure. A clinical significance of the study could be related to the fact that the evaluation of IL-6 concentration in peritoneal lavage fluid may be useful to assess an early local inflammatory response.

Relationship between somatostatin and interleukin-6: A cross-sectional study in patients with acute pancreatitis

ObjectivesThe aim of the analysis is to determine dynamic changes in somatostatin (SS) and interleukin-6 (IL-6) concentrations during in acute pancreatitis (AP). MethodsThe influence of tobacco smoking on IL-6 and SS levels in the serum of non-smoking (n = 10) and smoking (n = 27) patients with diagnosed AP and control group: non-smoking (n = 44), smoking (n = 42) and passive smoking (n = 29) healthy persons was proved. The concentration of IL-6 and SS was determined by means of ELISA. Differences between the groups analyzed were tested using the U Mann Whitney test. The Spearman rank correlation analysis was used to evaluate the correlations. ResultsThe concentrations of IL-6 and SS were significantly higher in smoking patients with AP and healthy persons when compared with non-smoking population on every day (1 day: p = 0.0002, p = 0.015; 3 day: p = 0.005, p = 0.001 and 7 day: p = 0.025, p = 0.038). Dynamic changes in concentrations of IL-6 and SS in the serum of patients with AP were demonstrated in the ensuing days of the disease. In case of non-smoking and smoking patients, significant positive correlations between IL-6 and SS was observed. ConclusionsThese findings suggest that some of the antiinflammatory effects of SS against acute pancreatitis may be mediated by reducing the local proinflammatory cytokine secretion in the pancreas.

Change in serum interleukin-6 levels in patients after pancreatoduodenectomy for periampullary cancer

This study was undertaken to elucidate the changes in interleukin-6 concentrations in the systemic circulation of 20 patients following pancreatoduodenectomy and whether it had any predictive value for postoperative complications. Blood was drawn on the day before surgery, at fixed intervals immediately after closure of the abdomen, and on day 1, 3, 5 after surgery for the measurement of interleukin-6. Change in the serum interleukin-6 levels was observed before and after pancreatoduodenectomy and between patients with and without complications. There was no mortality, but morbidity occurred in 5 patients. Serum interleukin-6 levels peaked immediately after surgery and gradually declined to preoperative level on postoperative day 5, but it remained persistently higher in a patient who developed postoperative complication. The peak level of interleukin-6 was significantly correlated with body mass index, duration of jaundice, biliary decompression prior to surgery, operation time and hospital stay, but not with operative blood loss. In conclusion, interleukin-6 is an important stress marker for predicting the complications after pancreatoduodenectomy operation. Patient with good body mass index status, short duration of jaundice and without preoperative biliary decompression provides less operative stress, less chance of complications and shorter hospital stay.

Abstract # 1844 A high-sensitivity magnetic multiplex assay detects changes in plasma concentrations of interleukin-6 induced by the Trier Social Stress Test

Concern exists about whether or not multiplex assays are sensitive enough to detect subtle yet biologically relevant changes in circulating concentrations of inflammatory biomarkers such as interleukin (IL)-6 in healthy humans. We tested two different multiplex kits (human Magnetic Luminex Performance Assay, RD and human Cytokine/Chemokine Magnetic Bead Panel, Millipore [Billerica, MA]) to detect IL-6 concentration changes versus a high sensitivity (HS)-ELISA (R&D Systems) in plasma collected from eighteen healthy adults (mean age 35.3 [SD = 8.88]) (10 women) before and 90 and 210 min after the start of an acute laboratory psychosocial stressor, the Trier Social Stress Test (TSST). Multiplexes were completed per manufacturer instructions and analyzed using a MAGPIX (Luminex, Austin, TX). For the R&D multiplex, IL-6 was detected in all samples and values were associated with concentrations determined by HS-ELISA ( r = 0.81, p p = 0.46). To examine associations between IL-6 responses to the TSST we computed areas under the curve (AUCs) using the trapezoidal method. AUCs were positively correlated between the R&D multiplex and HS-ELISA ( r = 0.83, p = 0.001), but not between the Millipore multiplex and HS-ELISA. These results suggest that certain multiplex assays may be able to detect changes in plasma concentrations of IL-6 as a result of TSST challenge.

TEMPORAL LINKS BETWEEN ENDOTOXIN ACTIVITY LEVELS AND INTERLEUKIN 6 CONCENTRATIONS IN ABDOMINAL SEPSIS.

In severe human peritonitis, the precise pathophysiological importance of endotoxin is controversial. Prognostic and therapeutic studies have yielded conflicting results. The current study wanted to investigate qualitative, quantitative, and temporal associations between blood endotoxin activity (EA) levels and acute inflammatory reactions. We conducted a prospective observational study in 30 patients with intra-abdominal infections who had undergone specific focus therapies (surgical/radiological/pharmaceutical interventions) and who required intensive care therapy. We performed sequential postinterventional measurements of blood EA levels and plasma interleukin 6 (IL-6) concentrations until recurrence or cure. There was no association between daily EA levels and IL-6 concentrations, or daily EA levels and changes in IL-6 concentrations on subsequent days. We found, however, a significant association between EA levels and IL-6 concentrations, when newly changing EA levels were referred to subsequent changes in IL-6 concentrations (P < 0.05). Increasing EA levels were followed by a 90% increase of subsequent IL-6 concentrations during the next 24 to 48 h, whereas decreasing/stable EA levels were associated with slightly decreasing IL-6 concentrations (P < 0.05). Our findings suggest an altered response of the innate immune system because postinterventional EA levels did not vary with concomitant or subsequent inflammatory reactions and because inflammatory responses to newly increasing EA levels were delayed and comparatively small. Still, our results support the concept that endotoxin is a trigger of inflammatory reactions in human peritonitis.

Temporal Profile of Cerebrospinal Fluid, Plasma, and Brain Interleukin-6 After Normothermic Fluid-Percussion Brain Injury: Effect of Secondary Hypoxia

Interleukin-6 (IL-6) is a proinflammatory cytokine that may play multiple roles in the pathogenesis of traumatic brain injury (TBI). The present study determined time-dependent changes in IL-6 concentrations in vulnerable brain regions, cerebrospinal fluid (CSF) samples, and plasma after normothermic TBI. Because secondary insults are common in head injured patients, we also assessed the consequences of a post-traumatic secondary hypoxic insult on this pleiotropic cytokine. Male Sprague-Dawley rats were intubated, anesthetized, and underwent a moderate parasagittal fluid-percussion brain injury (1.8-2.1 atm, 37°C) followed by either 30 minutes of normoxic or hypoxic (pO₂ = 30-40 mmHg) gas levels. Rats were sacrificed 3, 6, or 24 hours after TBI or shamoperated procedures. Brain samples, including the ipsilateral cerebral cortex and hippocampus were dissected and analyzed. Plasma and CSF samples were collected at similar times and stored at -80°C until analysis. IL-6 levels were significantly increased ( p < 0.05) at 3, 6, and 24 hours in the cerebral cortex and at 6 hours in the hippocampus after TBI. IL-6 levels in the TBI normoxic group for both structures returned to control levels by 24 hours. Plasma levels of IL-6 were elevated at all time points, while CSF levels were high at 3 and 6 hours, but normalized by 24 hours. Post-traumatic hypoxia led to significantly elevated ( p < 0.05) IL-6 protein levels in the cerebral cortex at 24 hours compared to sham-operated controls. These findings demonstrate that moderate TBI leads to an early increase in IL-6 brain, plasma, and CSF protein levels. Secondary post-traumatic hypoxia, a common secondary injury mechanism, led to prolonged elevations in plasma IL-6 levels that may participate in the pathophysiology of this complicated TBI model.

Impact of anesthesia method on cortisol and interleukin-6 concentration changes during and after laparoscopic colorectal surgery

Results and discussion. There were statistically significant differences be­ tween the groups in pain score after surgery (p

Evidence for cigarette smoke-induced oxidative stress in the rat pancreas

Background/aims: Recent findings with a rodent model of cigarette smoke inhalation revealed a causal relationship between chronic exposure to cigarette smoke and the development of pancreatitis. The present study was conducted to ascertain whether cigarette smoke induces oxidative stress in the rat pancreas concurrently with inflammation.Methodology: Rats (six per treatment group) were treated for 0, 3, 6, 9, or 12 weeks with cigarette smoke (0.7 mg/L). Pancreatic tissues were examined for histological and pathological alterations and serum for changes in interleukin-6 concentration. Pancreatic expression and localization of α-smooth muscle actin, transforming growth factor-β1, and collagen-1 were determined as measures of progressive inflammation/fibrosis. Pancreatic superoxide dismutase and glutathione peroxidase activities and malondialdehyde content were measured as indices of oxidative stress.Results: Inflammatory cell infiltration and ductal hyperplasia were detected in pancreata after 12 weeks of treatment with cigarette smoke. The serum interleukin-6 concentration increased significantly and pancreatic glutathione peroxidase activity declined significantly after 12 weeks of treatment. No other significant changes were observed.Conclusions: Pancreata of rats exposed chronically to cigarette smoke exhibit inflammation concurrently with suppression of glutathione peroxidase activity. These observations favor a role for oxidative stress in the induction of pancreatitis associated with chronic cigarette smoke inhalation.

The response of plasma interleukin-6 and its soluble receptors to exercise in the cold in humans

In this study, we wished to determine whether the changes in metabolism observed during exercise in the cold are associated with changes in interleukin-6 (IL-6) and/or its soluble receptors. Eight healthy male participants performed 1 h of cycling exercise at 70% [Vdot]O2max in a control (20°C) and cold (0°C) environment. Plasma concentrations of IL-6, soluble IL-6 receptor (sIL-6R), and sgp130 were measured before exercise, at 30 and 60 min of exercise, and 60 min after exercise. Substrate oxidation was estimated through measures of pulmonary gas exchange recorded between 50 and 55 min of cycling. Exercise in the cold resulted in an increase (P < 0.05) in carbohydrate oxidation (mean 2.58 g · min−1, s = 0.49 at 20°C vs. 2.85 g · min−1, s = 0.58 at 0°C) and a decrease (P < 0.05) in fat oxidation (0.55 g · min−1, s = 0.17 at 20°C vs. 0.38 g · min−1, s = 0.16 at 0°C) compared with the control trial. Interleukin-6 concentrations were elevated (P < 0.05) after 60 min of exercise in both the cold and control trials, with no differences between trials at any instant. Neither sIL-6R nor sgp130 was affected by exercise or the environment. The alterations in carbohydrate and fat utilization during 1 h of exercise in the cold are not paralleled by changes in plasma concentrations of IL-6 or its soluble receptors.

Omega‐3 fatty acids inhibit an increase of proinflammatory cytokines in patients with active Crohn's disease compared with omega‐6 fatty acids

Crohn's disease is a chronic inflammatory condition affecting the gastrointestinal tract. Polyunsaturated omega-3 fatty acids given orally may reduce the secretion of proinflammatory cytokines and hereby downregulate the inflammatory process. To assess the effects of enteral fatty acids, in the form of Impact Powder (Novartis, Switzerland), as adjuvant therapy to corticosteroid treatment on the proinflammatory and anti-inflammatory cytokine profiles in patients with active Crohn's disease. The proinflammatory and anti-inflammatory cytokines were measured in plasma from 31 patients with active Crohn's disease. Patients were randomized for oral intake of omega-3 fatty acid (3-Impact Powder) or omega-6 fatty acids (6-Impact Powder). Clinical and biochemical markers of inflammation were studied at baseline and after 5 and 9 weeks. Within the 3-Impact Powder group, no significant changes in concentrations of interleukin-6, interferon-gamma, monocyte chemoattractant protein-1, interleukin-2, interleukin-5 and interleukin-10, whereas a significant differences in concentration of interleukin-1beta and interleukin-4 were observed during therapy. Within the 6-Impact Powder group a significant changes in concentrations of interleukin-1beta, interleukin-6, interferon-gamma, monocyte chemoattractant protein-1, interleukin-2, interleukin-4, interleukin-5 and interleukin-10 were observed. The 3-Impact Powder showed immunomodulatory properties and might inhibit an increase of proinflammatory cytokines in contrast to the 6-Impact Powder.

Changes in Interleukin-6 Concentration in Peripheral Blood of Pre- and Post-Partum Dairy Cattle and Its Relationship to Postpartum Reproductive Diseases

Reproductive diseases after parturition are a serious problem in dairy cattle. It is important to predict postpartum reproductive diseases early and to develop prophylaxis. The objectives of this study were to demonstrate changes in the peripheral blood concentration of interleukin-6 (IL-6) before parturition, which was mainly produced by T helper 2 type (Th2) cells, and to investigate a correlation between the IL-6 concentration and the occurrence of the postpartum retained placenta, endometritis and/or follicular cyst in dairy cattle. Twenty-seven Holstein-Friesian cows were used for this study. Thirteen had no clinical disease, 8 had retained placenta, 4 were diagnosed with endometritis by vaginal inspection, and 2 were diagnosed with follicular cyst by rectal palpation at 1 and 2 months after parturition. Blood samples were collected 60 days pre- and post-partum. They used for IL-6, progesterone (P(4)) and estradiol-17beta (E(2)) concentration determination. This study showed that the IL-6 concentration prepartum was higher than postpartum. Low levels of IL-6 and P(4) in peripheral blood prepartum tended to affect retained placenta and a high level of IL-6 prepartum tended to affect endometritis. These results indicate that measurement of change in the IL-6 concentration during pregnancy is one useful tool for predicting crisis in postpartum reproductive diseases in dairy cattle.

Changes in serum interleukin-6 concentrations in obese children and adolescents during a weight reduction program.

To investigate the effect of short term energy restriction combined with physical activity on serum concentrations of Interleukin-6 (IL-6) in obese children and adolescents. Longitudinal intervention study of 3.8-5 MJ daily with exercise. Forty-nine white obese children and adolescents (31 girls, age 11.9+/-1.8 y; 18 boys, age 11.6+/-1.7 y). Indexes of obesity, IL-6, leptin, estradiol, systolic and diastolic blood pressure, heart rate at baseline and after 3 weeks. All determined parameters decreased significantly during the 3 week program (IL-6: 3.9+/-4.7 vs 2.0+/-2.2 pg/ml; P<0.05). Body mass index (BMI) fat mass, percentage fat mass (indexes of obesity), and leptin were not related to IL-6 before the program. In contrast, IL-6 concentrations correlated significantly with indexes of obesity and leptin after weight loss. IL-6 concentrations did not correlate with estradiol, systolic and diastolic blood pressure, and heart rate. Changes in IL-6 concentrations correlated significantly with changes in BMI (r=0.25, P<0.05). An improved body composition induced by restriction of energy intake and increase in physical activity is associated with more favorable serum concentrations of IL-6 in obese children and adolescents.

Interleukin-6 in relation to other proinflammatory cytokines, chemotactic activity and neutrophil activation in rheumatoid synovial fluid.

To evaluate the relation between synovial fluid (SF) concentrations of interleukin-6 (IL-6) and other mediators of inflammation which are responsible for joint degradation in rheumatoid arthritis (RA). We measured IL-6, IL-1 beta, tumour necrosis factor alpha (TNF alpha), granulocyte macrophage colony stimulating factor, IL-8, and polymorphonuclear leucocyte (PMNL) chemotaxis and degranulation in SF from patients with RA (n = 30) in the early phase of the disease. In a cross-sectional study IL-6 concentrations correlated with those of IL-1 beta, IL-8 and with PMNL activation as reflected by lactoferrin concentrations. In a longitudinal study, changes in IL-6 concentrations correlated with changes in TNF alpha, IL-8 and lactoferrin concentrations. IL-6 in SF appears to reflect the local proinflammatory, potentially erosive activity in RA. This supports the use of acute phase proteins, which are mainly induced by IL-6, as variables to monitor the course of RA.

Elevation of circulating interleukin 6 after surgery: Factors influencing the serum level

To investigate the effect of surgical trauma and other factors on the postoperative elevation of serum interleukin 6 (IL-6), we examined changes in IL-6 concentration after major thoracoabdominal surgery. Serum IL-6 levels reached the maximum concentration on the first postoperative day in all 38 patients, with peak ranging from 1400.8 ± 383.4 pg/ml (mean ± SEM) to 29.8 ± 3.8 among six groups who underwent surgery at different sites. The IL-6 peak was significantly correlated with surgical trauma as defined by the operation length and the volume of blood loss during surgery (r = 0.554, P < 0.01 and r = 0.427, P < 0.01, respectively). The peak concentration of serum IL-6 in patients undergoing esophagectomy was significantly higher than in those undergoing pancreaticoduodenectomy ( P < 0.05), despite a similar degree of surgical trauma defined by the operation length and volume of blood loss during surgery. Peak IL-6 concentration observed in a patient who underwent esophagectomy was about 100-fold greater in fluid drained from the thorax than in the peripheral blood. IL-6 mRNA was demonstrated in leukocytes from thoracic and abdominal exudate at 6, 24 and 48 h after surgery. In contrast, IL-6 mRNA could not be detected in leukocytes from the peripheral blood. Similar findings were also observed for interleukin 8 (IL-8). However, interleukin 1β (IL-1β) and tumour necrosis factor-α (TNF-α) were detected only once after surgery in the drainage fluid. These results indicate that IL-6 and IL-8 are induced and secreted in the operative field and subsequently enter the peripheral blood to induce cytokinemia. The operation length, volume of blood loss, and thoractomy are factors influencing the concentration of cytokines in the blood.