Low interleukin-10 release after ex vivo stimulation of whole blood is associated with persistent organ dysfunction in sepsis: A prospective observational study

Predicting Organ Dysfunction in Septic and Critically Ill Patients: A Prospective Cohort Study Using Rapid Ex Vivo Immune Profiling

OBJECTIVES

While cytokine response patterns are pivotal in mediating immune responses, they are also often dysregulated in sepsis and critical illness. We hypothesized that these immunological deficits, quantifiable through ex vivo whole blood stimulation assays, may be indicative of subsequent organ dysfunction.

DESIGN

In a prospective observational study, adult septic patients and critically ill but nonseptic controls were identified within 48 hours of critical illness onset. Using a rapid, ex vivo assay based on responses to lipopolysaccharide (LPS), anti-CD3/anti-CD28 antibodies, and phorbol 12-myristate 13-acetate with ionomycin, cytokine responses to immune stimulants were quantified. The primary outcome was the relationship between early cytokine production and subsequent organ dysfunction, as measured by the Sequential Organ Failure Assessment score on day 3 of illness (SOFAd3).

SETTING

Patients were recruited in an academic medical center and data processing and analysis were done in an academic laboratory setting.

PATIENTS

Ninety-six adult septic and critically ill nonseptic patients were enrolled.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Elevated levels of tumor necrosis factor and interleukin-6 post-endotoxin challenge were inversely correlated with SOFAd3. Interferon-gamma production per lymphocyte was inversely related to organ dysfunction at day 3 and differed between septic and nonseptic patients. Clustering analysis revealed two distinct immune phenotypes, represented by differential responses to 18 hours of LPS stimulation and 4 hours of anti-CD3/anti-CD28 stimulation.

CONCLUSIONS

Our rapid immune profiling technique offers a promising tool for early prediction and management of organ dysfunction in critically ill patients. This information could be pivotal for early intervention and for preventing irreversible organ damage during the acute phase of critical illness.

Whey protein hydrolysate mitigates both inflammation and endotoxin tolerance in THP-1 human monocytic leukemia cells

INTRODUCTION

It is important to control both inflammation and immunosuppression after severe insults, such as sepsis, trauma, and surgery. Endotoxin tolerance is one of the immunosuppressive conditions and it has been known that endotoxin tolerance relates to poorer clinical outcomes in patients with severe insults. This study investigated whether whey protein hydrolysate (WPH) mitigates inflammation and endotoxin tolerance in THP-1 human monocytic leukemia cells.

METHODS

Endotoxin tolerance can be experimentally reproduced by two consecutive stimulations with lipopolysaccharide (LPS). THP-1 cells were incubated with LPS and WPH (first stimulation). After collecting the culture supernatant to evaluate the effect on inflammation, the cells were washed and restimulated by 100 ng/ml LPS (second stimulation). The culture supernatant was again collected to evaluate the effect on endotoxin tolerance. Concentrations of LPS and WPH in the first stimulation were adjusted to evaluate their dose dependency. Cytokine levels in the supernatant were determined by enzyme-linked immunosorbent assay. Statistical analysis was performed using the student's t-test or Dunnett's test.

RESULTS

Five mg/ml WPH significantly decreased interleukin (IL)-6 (p = .006) and IL-10 (p < .001) levels after the first LPS stimulation (1000 ng/ml). WPH significantly increased tumor necrosis factor-alpha (p < .001) and IL-10 (p = .014) levels after the second LPS stimulation. The suppressive effect of WPH on inflammation and endotoxin tolerance was dependent on the concentrations of LPS and WPH. The effective dose of WPH for endotoxin tolerance was lower than its effective dose for inflammation.

CONCLUSION

WPH mitigated both inflammation and endotoxin tolerance. Therefore, WPH might be a candidate for valuable food ingredients to control both inflammation and immunosuppression after severe insults.

Toona sinensis modulates autophagy and cytokines in lipopolysaccharide-induced RAW 264.7 macrophages

Toona sinensis (TS) is a medicinal herb possessing anti-apoptotic, anti-oxidant, and anti-inflammatory properties and is used to treat diabetes, cancer, and inflammatory diseases. In traditional Chinese medicine theory, TS clears dampness and heat, strengthens the stomach function, and regulates vital energy flow. TS is also used as an astringent and a pesticide. In this study, we aimed to evaluate how TS influences autophagy and cytokines during the inflammatory process in RAW 264.7 macrophages. The treatment groups were pre-supplemented with TS leaf extract; rapamycin was used to enhance autophagy and lipopolysaccharide (LPS) was used to induce inflammation. The expression of autophagy-related proteins was analyzed by western blotting. The survival rate of, and chemokine expression and oxidative stress in the cells were also assessed. TS leaf extract inhibited mammalian target of rapamycin (mTOR) phosphorylation at site S2448 in the macrophages. At relatively higher concentrations (50 and 75 μg/mL), TS elevated the expression of light chain 3 II (LC3-II), which further modulated autophagy. Pre-supplementation with TS leaf extract elevated the total glutathione (GSH) level and GSH/oxidized GSH (GSSG) ratio, but it decreased the GSSG, total nitric oxide, nitrate, nitrite, malondialdehyde, and superoxide anion levels. TS reversed the effects of LPS-induced cytokines, including interleukin (IL)-6 and IL-10. TS did not induce significant toxicity at the studied concentrations. In conclusion, TS leaf extract may modulate autophagy during inflammation. Furthermore, it may prevent cell damage via anti-inflammation and anti-oxidation. Thus, this study supports the ethnomedical use of TS in the prevention of inflammation-related diseases.

Concurrent Immune Suppression and Hyperinflammation in Patients With Community-Acquired Pneumonia

Background

The nature and timing of the host immune response during infections remain uncertain and most knowledge is derived from critically ill sepsis patients. We aimed to test the hypothesis that community-acquired pneumonia (CAP) is associated with concurrent immune suppression and systemic inflammation.

Methods

Blood was collected from 79 CAP patients within 24 h after hospitalization and 1 month after discharge; 42 age- and sex-matched subjects without acute infection served as controls. Blood leukocytes were stimulated with lipopolysaccharide (LPS) or Klebsiella pneumoniae, and cytokines were measured in supernatants. Fifteen plasma biomarkers reflective of key host response pathways were compared between CAP patients with the strongest immune suppression (lowest 25% blood leukocyte tumor necrosis factor (TNF)-α production in response to LPS) and those with the least immune suppression (highest 25% of LPS-induced TNF-α production).

Results

Blood leukocytes of CAP patients (relative to control subjects) showed a reduced capacity to release TNF-α, interleukin (IL)-1β, IL-6 and IL-10 upon stimulation with LPS or K. pneumoniae, with a concurrently enhanced ability to release the anti-inflammatory mediator IL-1 receptor antagonist, irrespective of the presence of sepsis (18.9% of cases). Low (relative to high) TNF-α producers displayed higher plasma levels of biomarkers reflecting systemic inflammation, neutrophil degranulation, endothelial cell activation, a disturbed vascular barrier function and coagulation activation.

Conclusion

CAP replicates a common feature of immune suppression in sepsis. The coexistence of immune suppression and hyperinflammation in CAP argues against the theory of two distinct phases during the host response to sepsis.