Semantics, inflammation, cytokines and common sense

Discovery of dibenzylbutane lignan LCA derivatives as potent anti-inflammatory agents

Inflammation is the body's response to defence against infection or injury, and is associated with the progression of many diseases, such as inflammatory bowel disease (IBD) and rheumatoid arthritis (RA). LCA, a dibenzylbutane lignan extracted from the roots of traditional medicinal plant Litsea cubeba (Lour.) Pers., has demonstrated promising anti-inflammatory activity. In this study, a series of novel LCA derivatives were designed, synthesized, and evaluated for anti-inflammatory activity. Lipopolysaccharide (LPS)-induced RAW 264.7 cell model experiments showed that compound 10h (at 20 μM of concentration) had the strongest inhibitory effect on NO release, and inhibited the secretion and gene expression levels of interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α in vitro. In addition, western blot, immunofluorescence, and molecular docking showed that the anti-inflammatory mechanism of compound 10h may be related to the nuclear factor (NF)-κB signalling pathway. In vivo studies based on a carrageenan-induced mouse paw edema model have shown significant anti-inflammatory activity of compound 10h at 20 mg kg-1. Preliminary in vitro and in vivo studies indicate that compound 10h has the potential to be developed as a novel anti-inflammatory agent.

Anakinra authorized to treat severe coronavirus disease 2019; Sepsis breakthrough or time to reflect?

Introduction

The European Medicines Agency (EMA) and the United States Food and Drug Administration (FDA) announced conditions for using recombinant human interleukin-1 receptor antagonist (rhIL-1ra) to treat hospitalized patients with Coronavirus disease 2019 (COVID-19) and risk for progression. These decisions followed publication of the suPAR-guided Anakinra treatment for Validation of the risk and early Management OF seveRE respiratory failure by COVID-19 (SAVE- MORE) phase 3 clinical trial that yielded positive results.

Methods

We conducted a literature review and theoretical analysis of IL-1 blockade as a therapy to treat COVID-19. Using a stepwise analysis, we assessed clinical applicability of the SAVE-MORE results and evaluated conceptual support for interleukin-1 suppression as a suitable approach to COVID-19 treatment. This therapeutic approach was then examined as an example of inflammation-suppressing measures used to treat sepsis.

Results

Anakinra use as a COVID-19 therapy seems to rely on a view of pathogenesis that incorrectly reflects human disease. Since COVID-19 is an example of sepsis, COVID-19 benefit due to anti-inflammatory therapy contradicts an extensive history of unsuccessful clinical study. Repurposing rhIL-1ra to treat COVID-19 appears to exemplify a cycle followed by inflammation-suppressing sepsis treatments. A landscape of treatment failures is interrupted by a successful clinical trial. However, subsequent confirmatory study fails to replicate the positive data.

Discussion

We suggest further experimentation is not a promising pathway to discover game-changing sepsis therapies. A different kind of approach may be necessary.

The predictive value of perioperative circulating markers on surgical complications in patients undergoing robotic-assisted radical prostatectomy

BACKGROUND

The occurrence of postoperative complications was associated with poor outcomes for patients undergoing robotic-assisted radical prostatectomy. A prediction model with easily accessible indices could provide valuable information for surgeons. This study aims to identify novel predictive circulating biomarkers significantly associated with surgical complications.

METHODS

We consecutively assessed all multiport robotic-assisted radical prostatectomies performed between 2021 and 2022. The clinicopathological factors and perioperative levels of multiple circulating markers were retrospectively obtained from the included patients. The associations of these indices with Clavien-Dindo grade II or greater complications, and surgical site infection were assessed using univariable and multivariable logistic regression models. Further, the models were validated for the overall performance, discrimination, and calibration.

RESULTS

In total, 229 patients with prostate cancer were enrolled in this study. Prolonged operative time could independently predict surgical site infection (OR, 3.39; 95% CI, 1.09-10.54). Higher RBC (day 1-pre) implied lower risks of grade II or greater complications (OR, 0.24; 95% CI, 0.07-0.76) and surgical site infection (OR, 0.23; 95% CI, 0.07-0.78). Additionally, RBC (day 1-pre) independently predicted grade II or greater complications of obese patients (P value = 0.005) as well as those in higher NCCN risk groups (P value = 0.012). Regarding the inflammatory markers, NLR (day 1-pre) (OR, 3.56; 95% CI, 1.37-9.21) and CRP (day 1-pre) (OR, 4.16; 95% CI, 1.69-10.23) were significantly associated with the risk of grade II or greater complications, and both the indices were independent predictors in those with higher Gleason score, or in higher NCCN risk groups (P value < 0.05). The NLR (day 0-pre) could also predict the occurrence of surgical site infection (OR, 5.04; 95% CI, 1.07-23.74).

CONCLUSIONS

The study successfully identified novel circulating markers to assess the risk of surgical complications. Postoperative increase of NLR and CRP were independent predictors for grade II or greater complications, especially in those with higher Gleason score, or in higher NCCN risk groups. Additionally, a marked decrease of RBC after the surgery also indicated a higher possibility of surgical complications, especially for the relatively difficult procedures.

Chasing the Ghost: Hyperinflammation Does Not Cause Sepsis

Sepsis is infection sufficient to cause illness in the infected host, and more severe forms of sepsis can result in organ malfunction or death. Severe forms of Coronavirus disease-2019 (COVID-19), or disease following infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are examples of sepsis. Following infection, sepsis is thought to result from excessive inflammation generated in the infected host, also referred to as a cytokine storm. Sepsis can result in organ malfunction or death. Since COVID-19 is an example of sepsis, the hyperinflammation concept has influenced scientific investigation and treatment approaches to COVID-19. However, decades of laboratory study and more than 100 clinical trials designed to quell inflammation have failed to reduce sepsis mortality. We examine theoretical support underlying widespread belief that hyperinflammation or cytokine storm causes sepsis. Our analysis shows substantial weakness of the hyperinflammation approach to sepsis that includes conceptual confusion and failure to establish a cause-and-effect relationship between hyperinflammation and sepsis. We conclude that anti-inflammation approaches to sepsis therapy have little chance of future success. Therefore, anti-inflammation approaches to treat COVID-19 are likewise at high risk for failure. We find persistence of the cytokine storm concept in sepsis perplexing. Although treatment approaches based on the hyperinflammation concept of pathogenesis have failed, the concept has shown remarkable resilience and appears to be unfalsifiable. An approach to understanding this resilience is to consider the hyperinflammation or cytokine storm concept an example of a scientific paradigm. Thomas Kuhn developed the idea that paradigms generate rules of investigation that both shape and restrict scientific progress. Intrinsic features of scientific paradigms include resistance to falsification in the face of contradictory data and inability of experimentation to generate alternatives to a failing paradigm. We call for rejection of the concept that hyperinflammation or cytokine storm causes sepsis. Using the hyperinflammation or cytokine storm paradigm to guide COVID-19 treatments is likewise unlikely to provide progress. Resources should be redirected to more promising avenues of investigation and treatment.

Interplay between hereditary and environmental factors to establish an in vitro disease model of keratoconus

Keratoconus (KC) is a bilateral corneal dystrophy and a multifactorial, multigenic disorder with an etiology involving a strong environmental component and complex inheritance patterns. The underlying pathophysiology of KC is poorly understood because of potential crosstalk between genetic-epigenetic variants possibly triggered by the environmental factors. Here, we decode the etiopathological basis of KC using genomic, transcriptomic, proteomic and metabolic approaches. The lack of relevant models that accurately imitate this condition has been particularly limiting in terms of the effective management of KC. Tissue-engineered in vitro models of KC could address this need and generate valuable insights into its etiopathology for the establishment of disease models to accelerate drug discovery.

Altered tear inflammatory profile in Indian keratoconus patients - The 2015 Col Rangachari Award paper

Purpose:

Conventionally, keratoconus (KC) has been considered a noninflammatory corneal ectatic disorder. Recent evidence suggests a possible role of inflammation in the pathogenesis of KC. Hence, we analyzed the levels of inflammatory factors in the tear fluid of Indian KC patients.

Methods:

Tear fluid samples were collected from age- and sex-matched healthy controls and KC patients (with different grades). The levels of the inflammatory factors in tears were analyzed using cytometric bead array (Human Soluble Protein Flex Set System, BD Biosciences) for levels of interleukin-1α (IL-1α), IL-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-9, IL-10, IL-12p70, IL-23p40, IL-13, IL-17A, IL-17F, IL-21, interferon-α (IFNα), IFNγ, tumor necrosis factor-α, CCL2/monocyte chemotactic protein-1, CCL4/macrophage inflammatory protein-1β (MIP-1β), MIP-1α, CCL5/RANTES, CXCL10/IP10, ICAM1, CD62E, vascular endothelial growth factor and transforming growth factor β.

Results:

An increase in Kmax and Kmean, and a decrease in central corneal thickness was observed with increasing grades of KC. Tear analysis showed that most of the tear soluble factors, including cytokines, chemokines, growth factors and cell adhesion molecules were significantly elevated in the KC patients compared to the controls.

Conclusion:

Our findings suggest that inflammatory factors associated with KC may play a role in its pathogenesis. This opens the potential to explore anti-inflammatory strategies to either halt or delay the progression of KC.

Inflammatory Biomarkers Predict Heart Failure Severity and Prognosis in Patients With Heart Failure With Preserved Ejection Fraction: A Holistic Proteomic Approach

BACKGROUND

Underlying mechanisms in heart failure (HF) with preserved ejection fraction remain unknown. We investigated cardiovascular plasma biomarkers in HF with preserved ejection fraction and their correlation to diastolic dysfunction, functional class, pathophysiological processes, and prognosis.

METHODS AND RESULTS

In 86 stable patients with HF and EF ≥45% in the Karolinska Rennes (KaRen) biomarker substudy, biomarkers were quantified by a multiplex immunoassay. Orthogonal projection to latent structures by partial least square analysis was performed on 87 biomarkers and 240 clinical variables, ranking biomarkers associated with New York Heart Association (NYHA) Functional class and the composite outcome (all-cause mortality and HF hospitalization). Biomarkers significantly correlated with outcome were analyzed by multivariable Cox regression and correlations with echocardiographic measurements performed. The orthogonal partial least square outcome-predicting biomarker pattern was run against the Ingenuity Pathway Analysis (IPA) database, containing annotated data from the public domain. The orthogonal partial least square analyses identified 32 biomarkers correlated with NYHA class and 28 predicting outcomes. Among outcome-predicting biomarkers, growth/differentiation factor-15 was the strongest and an additional 7 were also significant in Cox regression analyses when adjusted for age, sex, and N-terminal probrain natriuretic peptide: adrenomedullin (hazard ratio per log increase 2.53), agouti-related protein; (1.48), chitinase-3-like protein 1 (1.35), C-C motif chemokine 20 (1.35), fatty acid-binding protein (1.33), tumor necrosis factor receptor 1 (2.29), and TNF-related apoptosis-inducing ligand (0.34). Twenty-three of them correlated with diastolic dysfunction (E/e') and 5 with left atrial volume index. The IPA suggested that increased inflammation, immune activation with decreased necrosis and apoptosis preceded poor outcome.

CONCLUSIONS

In HF with preserved ejection fraction, novel biomarkers of inflammation predict HF severity and prognosis that may complement or even outperform traditional markers, such as N-terminal probrain natriuretic peptide. These findings lend support to a hypothesis implicating global systemic inflammation in HF with preserved ejection fraction.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov; Unique identifier: NCT00774709.

Research, policy, and programmatic considerations from the Biomarkers Reflecting Inflammation and Nutritional Determinants of Anemia (BRINDA) project

The Biomarkers Reflecting Inflammation and Nutritional Determinants of Anemia (BRINDA) project sought to inform the interpretation of iron and vitamin A biomarkers (ferritin, serum transferrin receptor, and retinol binding protein) in settings of prevalent inflammation as well as the prevention of and control strategies to address anemia. Our purpose is to comment on the contributions of the BRINDA to advance global knowledge with regard to iron and vitamin A status assessment in women and preschool children and to analyze the findings in terms of their rigor and usefulness for global nutrition research and programs. BRINDA investigators found that the acute-phase response is so prevalent that it must be assessed in surveys of iron and vitamin A status for valid interpretation of micronutrient biomarkers. Furthermore, they found that C-reactive protein and α-1-acid glycoprotein provide important and different information about these responses and that common survey variables cannot replace the information they provide. Developing a method for adjusting micronutrient biomarkers for the independent influence of inflammation is challenging and complex, and BRINDA has brought greater clarity to this challenge through the use of large and diverse data sets. When comparing approaches, the regression methods appear to perform best when sample sizes are sufficient and adequate statistical capacity is available. Further correction for malaria does not appear to materially alter regression-adjusted prevalence estimates. We suggest that researchers present both adjusted and unadjusted values for the micronutrient biomarkers. BRINDA findings confirm that iron deficiency is a common and consistent risk factor for anemia globally and that anemia control must combine iron interventions with control of infection and inflammation. Anemia control strategies must be informed by local data. By applying the knowledge in these studies, researchers, program planners, and evaluators working in populations with prevalent inflammation can use and interpret biomarkers with more confidence, tempered with necessary caution.

It's time to redefine inflammation

Inflammation has been defined for many years as the response to tissue injury and infection. We are now forced to reconsider this definition by the avalanche of reports that molecules and cells associated with inflammation are activated or expressed in high concentration in a large variety of states in the absence of tissue injury or infection. Modest increases in concentration of C-reactive protein, a circulating marker of inflammation, have been reported to be associated with an astounding number of conditions and lifestyles felt to be associated with poor health; these conditions represent or reflect minor metabolic stresses. In recent years we have learned that inflammation is triggered by sentinel cells that monitor for tissue stress and malfunction-deviations from optimal homeostasis-and that molecules that participate in the inflammatory process play a role in restoring normal homeostasis. Accordingly, we suggest that inflammation be redefined as the innate immune response to potentially harmful stimuli such as pathogens, injury, and metabolic stress.-Antonelli, M., Kushner, I. It's time to redefine inflammation.

The crucial role of systemic responses in the innate (non-adaptive) host defense

We suggest that successful defense against microbial invasion requires both local inflammation and systemic anti-inflammation. The key systemic responses involve the hypothalamic-pituitary-adrenocortical axis, the sympathetic-adrenomedullary axis, acute phase protein production, thermoregulation and alterations in leukocyte responsiveness to agonists such as bacterial endotoxin. These integrated responses raise blood and tissue concentrations of several anti-infective molecules, mobilize leukocytes into the circulation, and increase blood flow to injured or infected sites. They also neutralize cytokines, proteases and oxidants that enter the bloodstream from inflamed local sites and forestall endothelial activation in distant vessels. Together, these forces help concentrate activated phagocytes at injured or infected local sites while preventing potentially damaging inflammation in uninvolved tissues.

Chronic Inflammation and Breast Pathology: A Theoretical Model

Breast cell pathology results from biochemical and molecular changes that culminate in the cell’s loss of functional responsiveness. The epithelial cell compartment in the breast ductal system is the site of approximately 98% of malignant proliferations, and it is from within these cells that the first biochemical signal of change may be expressed as an inflammatory response. Inflammation may be represented by biomarkers of early pathologic changes in breast cells and be associated with risk for the development of breast cancer. A theoretical model of the inflammatory process is proposed showing predictive linkages among stimuli in the breast microenvironment and the development of breast pathology, in particular, breast cancer. This model fuels intervention concepts that may prevent malignant breast health outcomes.

Possible biomarkers modulating haloperidol efficacy and/or tolerability

Haloperidol (HP) is widely used in the treatment of several forms of psychosis. Despite of its efficacy, HP use is a cause of concern for the elevated risk of adverse drug reactions. adverse drug reactions risk and HP efficacy greatly vary across subjects, indicating the involvement of several factors in HP mechanism of action. The use of biomarkers that could monitor or even predict HP treatment impact would be of extreme importance. We reviewed the elements that could potentially be used as peripheral biomarkers of HP effectiveness. Although a validated biomarker still does not exist, we underlined the several potential findings (e.g., about cytokines, HP metabolites and genotypic biomarkers) which could pave the way for future research on HP biomarkers.

Acute inflammatory biomarker profiles predict depression risk following moderate to severe traumatic brain injury

OBJECTIVE

To examine whether acute inflammation profiles predict posttraumatic depression (PTD) risk 6 and 12 months after traumatic brain injury.

SETTING

University-affiliated level 1 trauma center and community.

PARTICIPANTS

Adults with moderate to severe traumatic brain injury (acute serum levels: n = 50; acute cerebrospinal fluid (CSF) levels: n = 41).

DESIGN

Prospective cohort study.

MAIN MEASURES

Patient Health Questionnaire; inflammatory biomarkers (interleukin [IL]-1β, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12, tumor necrosis factor α, soluble vascular adhesion molecule [sVCAM-1], soluble intracellular adhesion molecule [sICAM-1], soluble Fas [sFAS]).

RESULTS

Higher levels of acute CSF cytokine surface markers (sVCAM-1, sICAM-1, and sFAS) in an inflammatory biomarker risk (IBR) score were associated with a 3.920-fold increase in the odds of developing PTD at 6 months (95% confidence interval: 1.163-8.672). Having sICAM-1, sVCAM-1, or sFAS above the 75th percentile had a positive predictive value of 85.7% for PTD risk at 6 months. An IBR score including inflammatory biomarkers IL-7 and IL-8 showed a trending association with 12-month PTD risk (odds ratio = 3.166, 95% confidence interval: 0.936-10.708).

CONCLUSION

Acute CSF IBR scores show promise for identifying individuals at risk for PTD. Further research should assess acute CSF inflammatory biomarkers' relationships to chronic inflammation as a mechanism of PTD and should explore anti-inflammatory treatments for PTD, as well as prevention and screening protocols, and link inflammatory biomarkers to symptom tracking.

Flavonoids inhibit COX-1 and COX-2 enzymes and cytokine/chemokine production in human whole blood

Cyclooxygenase 2 (COX-2) and the production of cytokines/chemokines are important targets for the modulation of the inflammatory response. Although a large variety of inhibitors of these pathways have been commercialized, some of those inhibitors present severe side effects, governing the search for new molecules, as alternative anti-inflammatory agents. This study was undertaken to study an hitherto not evaluated group of flavonoids, concerning its capacity to inhibit COX-1 and COX-2 enzymes, as well as to inhibit the production of the cytokines and a chemokine, in a complex matrix involved in the systemic inflammatory process, the blood, aiming the establishment of a structure-activity relationship. The results obtained reveal promising flavonoids for the modulation of the inflammatory process, namely the ones presenting a catechol group in B ring, as some flavonoids were able to simultaneously inhibit the production of inflammatory prostaglandin E2 and pro-inflammatory cytokines.

The wnt pathway: a macrophage effector molecule that triggers inflammation

Wnt proteins are members of the highly conserved wingless family of proteins responsible for cell differentiation and development and for neoplastic and degenerative processes. Recently, Toll-like receptor-mediated Wnt signaling was found to be associated with innate immunity in Drosophila. Upregulation of Wnt5A in human macrophages upon microbial challenge indicated a similar mechanism. Toll-like receptor-mediated Wnt5A expression is a key process for sustained inflammatory macrophage activation through autocrine and paracrine signaling. Downregulation of Wnt5A expression and subsequent attenuation of inflammatory macrophage responses by activated protein C supports the link between inflammation and coagulation, another highly conserved biologic system. Direct evidence for the relevance of Wnt5A in severe systemic inflammation is provided by the finding of higher Wnt5A levels in patients with sepsis than in healthy individuals. The fact that Wnt5A signaling can be modulated by anti-inflammatory mediators makes this effector molecule an attractive target for therapeutic intervention in inflammatory diseases.

Muscle endurance in elderly nursing home residents is related to fatigue perception, mobility, and circulating tumor necrosis factor-alpha, interleukin-6, and heat shock protein 70

OBJECTIVES

To explore the relationships between muscle endurance and circulating interleukin (IL)-6, tumor necrosis factor alpha (TNF-alpha), and heat shock protein (Hsp)70 in nursing home residents and to assess how muscle endurance relates to self-perceived fatigue and mobility.

DESIGN

Exploratory study.

SETTING

Three nursing homes of the Foundation for Psychogeriatrics (Brussels, Belgium).

PARTICIPANTS

Seventy-seven residents (53 female and 24 male, mean age 81 +/- 8).

MEASUREMENTS

Participants were assessed for muscle endurance (fatigue resistance and grip work); perceived fatigue (visual analogue scale for fatigue); fatigue during daily activities (Mobility-Tiredness Scale); effect of fatigue on quality of life (World Health Organization Quality Of Life questionnaire); mobility (Tinetti Test & Elderly Mobility Scale (EMS)); and circulating IL-6, TNF-alpha, and Hsp70.

RESULTS

Residents with better fatigue resistance reported less self-perceived tiredness (P<.05). Similar trends were observed for fatigue during daily activities and for the extent to which fatigue bothered subjects. Higher grip work was associated with less self-perceived fatigue on all fatigue scales (P<.01). Fatigue resistance and grip work were positively related to balance and basic mobility (all P<.01; trend for relationship between fatigue resistance and EMS). Subjects with high IL-6 and Hsp70 showed significantly worse fatigue resistance (P=.007) and muscle work (P=.045) than those with high IL-6 and low Hsp70. In male residents, higher TNF-alpha was related to worse fatigue resistance and grip work (P<.05).

CONCLUSION

Elderly nursing home residents complaining of fatigue need to be taken seriously, because they show worse muscle endurance, which is related to poorer mobility. Inflammatory processes involving TNF-alpha and the interaction between IL-6 and Hsp70 are related to poorer muscle endurance in these patients.

Severe sepsis and septic shock: the role of gram-negative bacteremia

Abstract Although Gram-negative bacteria have often been implicated in the pathogenesis of severe sepsis and septic shock, how they trigger these often lethal syndromes is uncertain. In particular, the role played by blood-borne bacteria is controversial. This review considers two alternatives. In the first, circulating Gram-negative bacteria induce toxic reactions directly within the vasculature; in the second, the major inflammatory stimulus occurs in local extravascular sites of infection and circulating bacteria contribute little to inducing toxic responses. Evidence for each alternative is found in the literature. Bacteremia and severe sepsis are not so closely linked that the most striking cases can be a model for the rest. Intravascular and extravascular triggers may warrant different approaches to prevention and therapy.

The influence of intramammary lipopolysaccharide infusion on serum Ca, P, vitamin D, cytokines and cortisol concentrations in lactating sows

Ten multiparous lactating sows were used to investigate whether intramammary infusion of lipopolysaccharides (LPS; Escherichia coli 0111:B4; 2.0 microg/kg of body weight) would affect the circulating concentrations of Ca, P, 25-hydroxyvitamin D (25-OHD), tumour necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) and cortisol. The sows were randomly allotted to either control group (control) or LPS-treated group with five individuals per group and were infused with either physiological saline solution or LPS solution. The rectal temperature and udder quarter appearance were recorded at 0 (just before infusion), 1, 3, 7, 12 or 24 h after infusion. Blood samples were taken at 0, 1, 3, 7, 12 or 24 h after infusion. Before infusion, the rectal temperatures of all sows were below 39.2 degrees C. At 3 and 7 h after infusion, the sows in the LPS group had a rectal temperature over 39.4 degrees C. At 24 h after infusion, the rectal temperatures returned to pre-infusion levels. Serum Ca and P concentrations in the LPS group decreased (P < 0.05) after LPS infusion compared with the control group at 1 h after infusion. No significant differences (P > 0.05) in the concentrations of 25-OHD were observed between groups control and LPS at any sampling time. Increased (P < 0.01) concentrations of serum TNF-alpha, IL-6 and cortisol were observed in the LPS group compared with the control group at 3 and 7 h after infusion respectively. In conclusion, the elevation of serum concentrations of TNF-alpha, IL-6 and cortisol and the alterations of circulating concentrations of Ca and P following LPS infusion indicate that the immune system has been activated and immune activation may affect macromineral homeostatic regulation, which might have important implications for metabolic health of lactating sows. Lowered serum Ca and P following immune activation also shows a causative mechanism whereby immune activation increases the risk of secondary disorders such as mastitis-metritis-agalactia syndrome. However, immune activation did not affect circulating concentrations of vitamin D metabolites.

What does minor elevation of C-reactive protein signify?

Reports of the predictive value of minor elevation of serum C-reactive protein (CRP) levels (between 3 and 10 mg/L) for atherosclerotic events have generated considerable interest, as well as a degree of controversy and confusion. CRP concentrations in this range are found in about one third of the American population. To better understand the mechanisms underlying minor elevation of CRP, we have surveyed its reported associations with a variety of states and conditions. It has become clear that even minimal environmental irritants and inflammatory stimuli elicit a minor CRP response. Minor CRP elevation has been found associated with a number of genetic polymorphisms, with membership in different demographic and socioeconomic groups, with a variety of dietary patterns and with many medical conditions that are not apparently inflammatory. Finally, minor CRP elevation bears negative prognostic implications for many conditions, particularly age-related diseases, and predicts mortality in both diseased and apparently healthy individuals. In sum, minor CRP elevation is associated with a great many diverse conditions, some of which are, or may prove to be, causal. Many of these reported associations imply a mild degree of tissue stress or injury, suggesting the hypothesis that the presence of distressed cells, rather than a resulting inflammatory response, is commonly the stimulus for CRP production.

Anemia of chronic disease: pathophysiology and laboratory diagnosis

Classic iron deficiency (ID) does not represent a challenge for the laboratory and physicians. The anemia that accompanies infection, inflammation, and cancer, commonly termed anemia of chronic disease (ACD), features apparently normal or increased iron stores. However, 20% of these patients have iron-restricted erythropoiesis (functional ID), an imbalance between the iron requirements of the erythroid marrow and the actual iron supply. Functional ID leads to a reduction in red cell hemoglobiniza-tion, causing hypochromic microcytic anemia. The diagnosis of functional ID in real time is based on measuring the hemoglobin content of reticulocytes. An examination of the biochemical markers of iron metabolism demonstrates weaknesses in the diagnosis of functional ID. We developed a diagnostic plot for the assessment of iron status in ACD and the detection of advancing ID in patients with ID, ACD, and the combined state of functional ID and ACD. The plot indicates the correlation between a marker of the iron supply for erythropoiesis (ie, the ratio of the soluble transferrin receptor value to the logarithm of the ferritin value) and the reticulocyte hemoglobin content and functions as a marker of iron demand. The diagnostic plot shows good selectivity for assessing the iron status of disease-specific anemias such as classic ID, end-stage renal failure, cancer-related anemia, and the anemia of infection and inflammation. The therapeutic implications of the diagnostic plot are to differentiate patients who should be administered oral iron supplements, recombinant human erythropoietin (r-HuEPO), or a combination of r-HuEPO and iron. The response of erythropoiesis to r-HuEPO depends on the iron supply and the proliferation of erythropoiesis. The lack of an increase or a decrease in reticulocyte hemoglobin levels indicates a nonresponder to r-HuEPO or functional ID.

A review of the role of proinflammatory cytokines in labor and noninfectious preterm labor

The prevention of preterm labor has the potential to reduce newborn morbidity and mortality by decreasing the incidence of preterm birth. Half of all preterm births occur in women with no known clinical risk factors. Labor onset and progress is multifactorial, and we are just beginning to understand the role of cytokines in uterine activity. The purpose of this article is to review the role of cytokines in labor and preterm labor not associated with infection and to provide implications for research and practice.

Inflammatory C-reactive protein and cytokine levels in asymptomatic people with chronic spinal cord injury

OBJECTIVE

To determine the relation between serologic markers of information and clinical characteristics of people with chronic spinal cord injury (SCI).

DESIGN

Cross-sectional study.

SETTING

Academic medical center SCI outpatient clinic.

PARTICIPANTS

Convenience sample of 37 men with chronic SCI and 10 healthy control subjects.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Serum levels of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), and C-reactive protein (CRP).

RESULTS

The following results achieved statistical significance at P less than .05. Asymptomatic chronic SCI patients differed from referent controls with respect to serum CRP levels but not IL-6 or TNF-alpha. In SCI patients, higher levels of CRP correlated negatively with hemoglobin and albumin levels. A longer time since injury correlated with lower TNF-alpha values, whereas higher TNF-alpha levels correlated with higher serum albumin. Pressure ulcers and indwelling urinary catheters were associated with higher mean levels of CRP but not of the cytokines TNF-alpha and IL-6. Intermittent urinary catheterization was associated with lower levels of CRP when compared with other methods of bladder management.

CONCLUSIONS

Asymptomatic people with long-term SCI, especially those with indwelling urinary catheters, showed serologic evidence of a systemic inflammatory state. There was no evidence of an elevation in proinflammatory cytokines. Detection of an ongoing systemic inflammatory response in apparently healthy people with indwelling urinary catheters and small skin ulcers further supports the aggressive pursuit of catheter-free voiding options and pressure ulcer healing.

Tumor necrosis factor-, interleukin-6, serum amyloid A, haptoglobin, and cortisol concentrations in sows following intramammary inoculation of Escherichia coli

OBJECTIVE

To determine whether concentrations of proinflammatory cytokines, acute-phase proteins, and cortisol differ at parturition among 3 categories of sows (noninoculated, clinically affected and nonaffected following intramammary inoculation with Escherichia coll).

ANIMALS

16 sows.

PROCEDURE

Sows were allocated to inoculated (n = 12) or noninoculated (4) groups. Inoculated sows received intramammary administration of E coli (serotype O127) during the 24-hour period preceding parturition. Blood samples were collected from noninoculated and inoculated sows for 3 consecutive days within 3 to 11 days before farrowing and inoculation. Samples were also collected 0, 24, 48, 72, and 96 hours after farrowing and inoculation. Inoculated sows were further categorized as affected (4 sows) or nonaffected (8 sows) based on clinical signs of disease. Serum tumor necrosis factor (TNF)-alpha, plasma interleukin (IL)-6, and serum amyloid A (SAA) concentrations were measured by use of ELISA; serum haptoglobin concentration was assayed by use of a hemoglobin-binding method; and plasma cortisol concentration was determined by use of radioimmunoassay.

RESULTS

Plasma or serum concentrations of TNF-alpha, IL-6, and SAA of both categories of inoculated sows were significantly increased by 24 hours after intramammary inoculation of E coli, compared with concentrations in noninoculated sows. Concentrations of serum TNF-alpha and plasma IL-6 were significantly higher in inoculated sows that developed clinical mastitis than in nonaffected inoculated sows.

CONCLUSIONS AND CLINICAL RELEVANCE

Concentrations of TNF-alpha and IL-6 are promising markers for the identification of periparturient sows with subclinical coliform mastitis. Identification of such sows should help improve the health and survival of piglets.

Modulation of interleukin-6 in cardiac myoblasts during endotoxemia

INTRODUCTION

Interleukin (IL)-6 is induced in the heart during endotoxemia. We investigated endotoxin-induced IL-6 in vitro and its modulation by IL-1beta and tumor necrosis factor (TNF)-alpha. Whether lipopolysaccharide (LPS) would stimulate nuclear factor (NF)-kappaB intranuclear translocation was also examined. We hypothesized that IL-6 production is enhanced with LPS and cytokine challenge and that LPS stimulates NF-kappaB intranuclear translocation in a myogenic cell line.

METHODS

Rat H9c2 cardiac myoblasts were grown in culture. IL-6 protein was determined by enzyme-linked immunosorbent assay after LPS (10 microg/ml) and in the presence of TNF-alpha or IL-1beta. IL-6 mRNA was amplified using reverse-transcription polymerase chain reaction. Myoblasts were treated with LPS and stained for the p65 subunit of NF-kappaB.

RESULTS

LPS stimulated IL-6 protein and mRNA expression (P < 0.05). IL-1beta increased IL-6 when combined with TNF-alpha (P < 0.05). In the presence of LPS, TNF-alpha lowered IL-6 production, which was further reduced upon addition of IL-1beta. LPS activated NF-kappaB showing p65 subunit cellular localization within 30 min.

CONCLUSIONS

In cardiac myoblasts, IL-6 is either enhanced or reduced depending on interactions between LPS and cytokine challenge. Enhanced nuclear translocation of NF-kappaB in response to LPS was evident in a myogenic cell line.

IL-1beta and IL-6 act synergistically with TNF-alpha to alter cardiac contractile function after burn trauma

Although numerous studies have provided evidence that the inflammatory cytokines TNF-alpha and IL-1beta have significant negative inotropic effects, the role of the interleukins in burn-mediated cardiac dysfunction has not been defined. Furthermore, most studies examining the cardiotoxic effects of inflammatory cytokines have ignored the complex inflammatory milieu that occurs in the intact subject with trauma, sepsis, or ischemic heart disease. Therefore, this study examined the time course of IL-1beta and IL-6 secretion by cardiomyocytes after burn trauma, and additional studies examined the effects of these cytokines alone or in combination with TNF-alpha on cardiac contractile performance (Langendorff). Sprague-Dawley rats were given a full thickness burn injury over 40% of the total body surface area; fluid resuscitation was lactated Ringers solution, 4 mL/kg per burn percentage of burn area. Sham burn animals received identical anesthesia and handling, but no burn injury. Rats were sacrificed at several different times postburn, and isolated hearts (n = 4-5 rats/group/time period) were perfused with collagenase-containing buffer to prepare cardiomyocytes or were perfused in vitro to examine cardiac contractile function (n = 5-6 rats/group/time period). Additional naive control rats (n = 10) were included to prepare cardiomyocytes that, in turn, were challenged with different concentrations of either IL-1beta, IL-6, or TNF-alpha alone or in combination for several time periods (CO2 incubator at 37 degrees C for 1-3 h). Finally, inflammatory cytokines alone or in combination were added to the perfusate of hearts isolated from additional control rats (n = 6-7/group) to assess the cardiac contraction and relaxation effects of cytokine challenge. Despite aggressive fluid resuscitation, burn trauma produced a time-related increase in cardiomyocyte secretion of IL-1beta, IL-6, and TNF-alpha. Exposure of naive cardiomyocytes prepared from control rats to each cytokine alone or combined cytokine challenge produced a time-dependent and concentration-dependent decrease in cell viability and an increase in supernatant creatine kinase levels. Either IL-1beta or TNF-alpha produced greater cardiac defects than IL-6 when added separately to Langendorff-perfused hearts; dysfunction was maximal with combined cytokine challenge (IL-1beta plus TNF-alpha plus IL-6). The data confirm that burn trauma upregulates inflammatory cytokine secretion by cardiomyocytes and suggest that these inflammatory cytokines act in concert to produce burn-mediated cardiac contractile dysfunction.

Stress, inflammation and cardiovascular disease

Various psychosocial factors have been implicated in the etiology and pathogenesis of certain cardiovascular diseases such as atherosclerosis, now considered to be the result of a chronic inflammatory process. In this article, we review the evidence that repeated episodes of acute psychological stress, or chronic psychologic stress, may induce a chronic inflammatory process culminating in atherosclerosis. These inflammatory events, caused by stress, may account for the approximately 40% of atherosclerotic patients with no other known risk factors. Stress, by activating the sympathetic nervous system, the hypothalamic-pituitary axis, and the renin-angiotensin system, causes the release of various stress hormones such as catecholamines, corticosteroids, glucagon, growth hormone, and renin, and elevated levels of homocysteine, which induce a heightened state of cardiovascular activity, injured endothelium, and induction of adhesion molecules on endothelial cells to which recruited inflammatory cells adhere and translocate to the arterial wall. An acute phase response (APR), similar to that associated with inflammation, is also engendered, which is characterized by macrophage activation, the production of cytokines, other inflammatory mediators, acute phase proteins (APPs), and mast cell activation, all of which promote the inflammatory process. Stress also induces an atherosclerotic lipid profile with oxidation of lipids and, if chronic, a hypercoagulable state that may result in arterial thromboses. Shedding of adhesion molecules and the appearance of cytokines, and APPs in the blood are early indicators of a stress-induced APR, may appear in the blood of asymptomatic people, and be predictors of future cardiovascular disease. The inflammatory response is contained within the stress response, which evolved later and is adaptive in that an animal may be better able to react to an organism introduced during combat. The argument is made that humans reacting to stressors, which are not life-threatening but are "perceived" as such, mount similar stress/inflammatory responses in the arteries, and which, if repetitive or chronic, may culminate in atherosclerosis.

Acute phase proteins, body temperature and urinary melatonin under the influence of bright and dim light intensities during the daytime

Concentrations of five acute phase proteins: C-reactive protein (CRP), alpha 1-antichymotrypsin (ACT), transferin (Tf), alpha 2-macroglobulin (alpha 2-M) and haptoglobin (Hp) as well as glycosylation profiles of alpha 1-antichymotrypsin (ACT) were studied in sera samples with 7 healthy volunteers under the influence of two different light intensities during the daytime dim (100 lx) and bright (3000 lx) light. Concentration of transferin (negative proteins) under the influence of bright light during the daytime decreased significantly. Other proteins have the tendency to increase (positive proteins) under the influence of daytime bright light. The microheterogeneity of ACT did not change under the influence of different light intensities. Melatonin and rectal temperature were also measured simultaneously. Rectal temperature decreased to be lower during the first half of the night and urinary melatonin secretion rate increased to be higher during the night when the subjects spent time under the bright light during the day. Thus, it is concluded that the diurnal bright light exposure may activate some parameters of acute phase proteins, increase nocturnal melatonin secretion and accelerate a fall of rectal temperature during first half period of night sleep.

Dimensions of antigen recognition and levels of immunological specificity

Although recognition and specificity are among the most fundamental concepts in immunology, there is a common tendency to equate these notions with the fit, especially in terms of molecular shape, between interacting molecules. Even in the case of monovalent recognition, there are factors that contribute to the energetics of the interaction that are not readily accounted for by detailed structural analysis of the interacting (epitopic and paratopic) molecular surfaces. Consequently, recognition involves more than just the three spatial dimensions and time. Factors such as solute-solvent interactions, molecular crowding, and confinement, not directly related to the details of the intermolecular interface, can play crucial roles in determining both intrinsic affinity and differential intrinsic affinity. Furthermore, stating that a given structural subunit (e.g., amino acid) is recognized in a given noncovalent interaction does not clarify whether the structural subunit in question participates in the interaction through van der Waals contact, contribution to intrinsic affinity, or differential contribution to relative intrinsic affinities for two or more different ligands. Additional factors become relevant in considering the specificity exhibited in multivalent interactions, cell activation, and activation of the whole immune system. Therefore, specificity as defined for a monovalent binding event can diverge from specificity as it is defined for higher-order interactions. A corollary of this conclusion is that the composition of epitopes and paratopes, defined in terms of the structural elements for which substitutions have an effect on the specificity-defining measurement, can differ in different contexts despite complete conservation of the structures that physically make direct contact. An analysis of specificity at the organismal level suggests that the immune system does not recognize or respond to substances that correspond precisely to either nonself substances or to dangerous substances. An alternative notion for the molecular origins of immunological discrimination does not require that there be any single reason for immune responsiveness. This concept of what the immune system recognizes and responds to derives from the recognition that the ultimate function of the immune system is to contribute to survival and reproductive success through any available means.