MIF reflects tissue damage rather than inflammation in post-cardiac arrest syndrome in a real life cohort

Elevated Plasma Soluble PD-L1 Levels in Out-of-Hospital Cardiac Arrest Patients

Background: A deregulated immune system has been implicated in the pathogenesis of post-cardiac arrest syndrome (PCAS). A soluble form of programmed cell death-1 (PD-1) ligand (sPD-L1) has been found at increased levels in cancer and sustained inflammation, thereby deregulating immune functions. Here, we aim to study the possible involvement of sPD-L1 in PCAS. Methods: Thirty out-of-hospital cardiac arrest (OHCA) patients consecutively admitted to the ER of Mie University Hospital were prospectively enrolled. Plasma concentrations of sPD-L1 were measured by an enzyme-linked immunosorbent assay in blood samples of all 30 OHCA patients obtained during cardiopulmonary resuscitation (CPR). In 13 patients who achieved return-of-spontaneous-circulation (ROSC), sPD-L1 levels were also measured daily in the ICU. Results: The plasma concentrations of sPD-L1 in OHCA were significantly increased; in fact, to levels as high as those observed in sepsis. sPD-L1 levels during CPR correlated with reduced peripheral lymphocyte counts and increased C-reactive protein levels. Of 13 ROSC patients, 7 cases survived in the ICU for more than 4 days. A longitudinal analysis of sPD-L1 levels in the 7 ROSC cases revealed that sPD-L1 levels occurred in parallel with organ failure. Conclusions: This study suggests that ischemia- reperfusion during CPR may aberrantly activate immune and endothelial cells to release sPD-L1 into circulation, which may play a role in the pathogenesis of immune exhaustion and organ failures associated with PCAS.

Immune modulation by the macrophage migration inhibitory factor (MIF) family: D-dopachrome tautomerase (DDT) is not (always) a backup system

Human macrophage migration inhibition factor (MIF) is a protein with cytokine and chemokine properties that regulates a diverse range of physiological functions related to innate immunity and inflammation. Most research has focused on the role of MIF in different inflammatory diseases. D-dopachrome tautomerase (DDT), a different molecule with structural similarities to MIF, which shares receptors and biological functions, has recently been reported, but little is known about its roles and mechanisms. In this review, we sought to understand the similarities and differences between these molecules by summarizing what is known about their different structures, receptors and mechanisms regulating their expression and biological activities with an emphasis on immunological aspects.

The Association Between Intra-abdominal View and Systemic Cytokine Response in Complicated Intra-abdominal Infections

BACKGROUND

There is a wide variety of disease severity in patients with complicated intraabdominal infection (cIAI). The prognostic role of intraabdominal view (IAV) was recently studied, and an IAV score was introduced. The aim of this study was to analyze the associations between the preoperative levels of eight relevant circulating cytokines and IAV components, the IAV score, as well as outcome.

MATERIALS AND METHODS

This was a single-center prospective study. The study cohort consisted of operatively managed adult patients with a cIAI. Preoperative plasma levels of eight cytokines were determined. The operating surgeon filled a form describing IAV. Outcomes analyzed were 30-day mortality and the development of organ dysfunctions requiring intensive care unit admission.

RESULTS

A total of 131 patients with cIAI were analyzed, 30-day mortality was 9.9% (n = 13), and 28 (21.4%) patients had postoperative organ dysfunctions. All components of IAV, the IAV score, and outcomes were associated with various cytokine levels. Interleukin-8 was the most competent marker associating with all the variables assessed in this study: diffuse peritonitis (P < 0.001), substantial diffuse redness (P = 0.012), substantial diffuse fibrin (P = 0.003), fecal or bile as exudate (P = 0.001), nonappendiceal source of infection (P < 0.001), IAV Score groups (P < 0.001), organ dysfunctions (P < 0.001), and 30-day mortality (P = 0.035).

CONCLUSIONS

Various cytokines associate with the IAV and outcome. IL-8 showed the best overall performance. The results emphasize the role of the surgeons' perception of the IAV. IAV provides an approximation of the magnitude of the systemic inflammatory response.

Circulating MIF Levels Predict Clinical Outcomes in Patients With ST-Elevation Myocardial Infarction After Percutaneous Coronary Intervention

BACKGROUND

The purpose of the study was to assess the value of admission macrophage migration inhibitory factor (MIF) levels in predicting clinical outcomes in ST-elevation myocardial infarction (STEMI) patients.

METHODS

For this study we recruited 498 STEMI patients after they received percutaneous coronary intervention (PCI), 40 with stable angina pectoris and 137 healthy participants. Plasma MIF levels were measured at admission and after PCI. The primary end points were in-hospital mortality and major adverse cardio-and/or cerebrovascular events (MACCE) during hospitalization and 3.2-year follow-up period.

RESULTS

Admission MIF levels were elevated in 88.4% of STEMI patients over the upper reference limit of healthy controls and it was 3- to 7-fold higher than that in stable angina pectoris and control groups (122 ± 61 vs 39 ± 19 vs 17 ± 8 ng/mL; P < 0.001). Admission MIF levels were significantly higher in patients who died after myocardial infarction vs survivors. For predicting in-hospital mortality using the optimal cutoff value (127.8 ng/mL) of MIF, the area under the receiver operating characteristic curve for MIF was 0.820, similar area under the receiver operating characteristic curve values for predicting short-term outcomes were observed for high-sensitivity troponin T, CK-MB, N-terminal probrain natriuretic peptide, and Global Registry of Acute Coronary Events (GRACE) score. Although peak high-sensitivity troponin T and N-terminal probrain natriuretic peptide also predicted MACCE during the follow-up period, only higher admission MIF levels predicted in-hospital mortality and MACCE during the 3.2-year follow-up. Multivariate regression analysis showed the independent predictive value of a higher admission MIF level (≥ 127.8 ng/mL) on in-hospital mortality (odds ratio, 9.1; 95% confidence interval, 1.7-47.2) and 3.2-year MACCE (hazard ratio, 2.8; 95% confidence interval, 1.5-5.6).

CONCLUSIONS

A higher admission MIF level is an independent predictor for in-hospital mortality and long-term MACCE in STEMI patients who underwent PCI.

Assessing clinical implications and perspectives of the pathophysiological effects of erythrocytes and plasma free hemoglobin in autologous biologics for use in musculoskeletal regenerative medicine therapies. A review

Autologous biologics, defined as platelet-rich plasma (PRP) and bone marrow aspirate concentrate (BMC), are cell-based therapy treatment options in regenerative medicine practices, and have been increasingly used in orthopedics, sports medicine, and spinal disorders. These biological products are produced at point-of-care; thereby, avoiding expensive and cumbersome culturing and expansion techniques.

Numerous commercial PRP and BMC systems are available but reports and knowledge of bio-cellular formulations produced by these systems are limited. This limited information hinders evaluating clinical and research outcomes and thus making conclusions about their biological effectiveness. Some of their important cellular and protein properties have not been characterized, which is critical for understanding the mechanisms of actions involved in tissue regenerative processes. The presence and role of red blood cells (RBCs) in any biologic has not been addressed extensively. Furthermore, some of the pathophysiological effects and phenomena related to RBCs have not been studied. A lack of a complete understanding of all of the biological components and their functional consequences hampers the development of clinical standards for any biological preparation.

This paper aims to review the clinical implications and pathophysiological effects of RBCs in PRP and BMC; emphasizes hemolysis, eryptosis, and the release of macrophage inhibitory factor; and explains several effects on the microenvironment, such as inflammation, oxidative stress, vasoconstriction, and impaired cell metabolism.

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Different biological formulations optimize disease specific regenerative treatment protocols.

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Disintegrated RBC's release harmful components to regenerative therapy treatment vials.

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The effectiveness of MSC injection depends on the quality of the bone marrow aspiration procedure.

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PRP and BMC should contain minimal to no erythrocytes.

Admission macrophage migration inhibitory factor predicts long-term prognosis in patients with ST-elevation myocardial infarction

Aims

We previously showed in patients with ST-segment elevated myocardial infarction (STEMI) that admission levels of macrophage migration inhibitory factor (MIF) predict infarct size. We studied whether admission MIF alone or in combination with other biomarkers is useful for risk assessment of acute and chronic clinical outcomes in STEMI patients.

Methods and results

A total of 658 STEMI patients treated with primary percutaneous coronary intervention (PCI) were consecutively recruited. MIF level was determined at admission and echocardiography performed on day-3 and then 12 months post-MI. Patients were followed for a median period of 64 months. Major endpoints included ST-segment resolution, all-cause mortality, and major adverse cardiovascular events (MACE). High MIF level was associated with larger enzymatic infarct size, incomplete resolution of ST-segment elevation post-PCI, impaired left ventricular ejection fraction (LVEF), and poorer improvement of LVEF (all P < 0.001). After adjustment for classical risk factors standard biomarkers and day-3 LVEF, admission MIF remained independently prognostic for all-cause mortality [hazard ratio (HR) 2.27, 95% confidence interval (CI) 1.43-3.22], and MACE (HR 1.39, 95% CI 1.12-1.71, both P < 0.05). MIF was a significant additive predictor of all-cause mortality with a net reclassification improvement of 0.34 (P = 0.02). Furthermore, patients in high tertile of both admission MIF and day-3 Nt-proBNP had the highest mortality risk relative to other tertile groups (HR 11.28, 95% CI 4.82-26.94; P < 0.001).

Conclusion

STEMI patients with high admission MIF level experienced a poorer recovery of cardiac function and worse long-term adverse outcomes. Combination of Nt-proBNP with MIF further improves prognostic capability.

Circulating macrophage migration inhibitory factor (MIF) in patients with heart failure

BACKGROUND

Heart failure (HF) is characterized by impaired systolic ejection capacity and/or diastolic filling of the heart, leading to a multisystem disorder. Remote organ failure, systemic inflammation or pulmonary hypertension (PH) are hallmarks of the pathophysiological changes in HF. The Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine that is involved in a variety of cardiovascular and inflammatory diseases. Circulating MIF levels and their potential role as a disease marker in the different subgroups of HF have not been investigated yet. We here aimed to unravel a potential role of MIF in HF.

METHODS AND RESULTS

MIF plasma levels were assessed in 249 consecutive patients with HF. MIF was detectable in all investigated subjects and showed no difference with regard to the nature of HF (preserved or reduced ejection fraction). Spearman correlation revealed an association with inflammatory biomarkers (white blood cell count r = 0.18, p = 0.005; c-reactive protein r = 0.20, p = 0.003). MIF was associated with higher pulmonary artery systolic pressure (PASP) as assessed by echocardiography (r = 0.23, p < 0.001). Log-transformed PASP was also independently associated with MIF in a multivariable linear regression model (p = 0.02). Follow-up (FU) data after 180 days revealed that patients with increased MIF values (in ng/ml) were more likely to reach the endpoint all-cause mortality (HR 1.01, 95% CI 1.004-1.02, p = 0.005, per unit change).

CONCLUSION

MIF is detectable in the circulation of patients with HF and might be associated with clinical endpoints in HF, markers of inflammation and PH. These promising results should stimulate further research to elucidate the role of MIF in the multisystem disorder of HF.

Predictive potential of macrophage migration inhibitory factor (MIF) in patients with heart failure with preserved ejection fraction (HFpEF)

Background

Prognostication in heart failure with preserved ejection fraction (HFpEF) is challenging and novel biomarkers are urgently needed. Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine that plays a crucial role in cardiovascular and various inflammatory diseases. Whether MIF is involved in HFpEF is unknown.

Methods and results

Sixty-two patients with HFpEF were enrolled and followed up for 180 days. MIF plasma levels as well as natriuretic peptide (NP) levels were assessed. High MIF levels significantly predicted the combined end-point of all-cause death or hospitalization at 180 days in the univariate analysis (HR 2.41, 95% CI 1.12–5.19, p = 0.025) and after adjustment for relevant covariates in a Cox proportional hazard regression model (HR 2.35, 95% CI 1.05–5.27, p = 0.0374). Furthermore, MIF levels above the median were associated with higher pulmonary artery systolic pressure (PASP) as assessed by echocardiography (PASP 31 mmHg vs 48 mmHg in the low- and high-MIF group, respectively, p = 0.017). NPs significantly correlated with MIF in HFpEF patients (BNP p = 0.011; r = 0.32; NT-proBNP p = 0.027; r = 0.28).

Conclusion

MIF was associated with clinical outcomes and might be involved in the pathophysiology of pulmonary hypertension in patients with HFpEF. These first data on MIF in HFpEF should stimulate further research to elucidate the role of this cytokine in heart failure.

Trial registration NCT03232671

Methods for Defining the Neuroprotective Properties of Xenon

Xenon has features that make it an ideal general anesthetic agent; cost and scarcity mitigate xenon's widespread use in the operating room. Discovery of xenon's cytoprotective properties resulted in its application to thwart ongoing acute neurologic injury, an unmet clinical need. The discovery that xenon's neuroprotective effect interacts synergistically with targeted temperature management (TTM) led to its investigation in clinical settings, including in the management of the postcardiac arrest syndrome, in which TTM is indicated. Following successful demonstration of xenon's efficacy in combination with TTM in a preclinical model of porcine cardiac arrest, xenon plus TTM was shown to significantly decrease an imaging biomarker of brain injury for out of hospital cardiac arrest victims that had been successfully resuscitated. With the development of an efficient delivery system the stage is now set to investigate whether xenon improves survival, with good clinical outcome, for successfully resuscitated victims of a cardiac arrest.

Red blood cells: The primary reservoir of macrophage migration inhibitory factor in whole blood

Red blood cells are widely accepted to be inert carriers of oxygen and haemoglobin, but there is growing evidence that they play a much more critical role in immune function. Macrophage migration inhibitory factor (MIF) is a key cytokine in disease with additional oxido-reductase activity, which aids in managing oxidative stress. Although two studies have reported the presence of MIF in red blood cells, no study has quantified the levels of this protein. In this study, freshly isolated plasma, platelets, leukocytes, and red blood cells from healthy individuals were collected and the concentration of MIF was determined using an enzyme linked immunosorbent assay. This analysis demonstrated that MIF in red blood cells was present at 25 µg per millilitre of whole blood, which is greater than99% of the total MIF and 1000-fold higher concentration than plasma. This result was supported by electrophoresis and Western blot analysis, which identified MIF in its monomer structural form following sample processing. Furthermore, by assessing the level of tautomerase activity in red blood cell fractions in the presence of a MIF inhibitor, it was determined that the red blood cell-derived MIF was also functionally active. Together, these findings have implications on the effect of haemolysis during sample preparation and provide some clue into the inflammatory processes that occur following haemolysis in vivo. These results support the hypothesis that red blood cells are a major reservoir of this inflammatory protein and may play a role in inflammation.

Myocardial Expression of Macrophage Migration Inhibitory Factor in Patients with Heart Failure

Macrophage migration inhibitory factor (MIF) is a pleiotropic inflammatory protein and contributes to several different inflammatory and ischemic/hypoxic diseases. MIF was shown to be cardioprotective in experimental myocardial ischemia/reperfusion injury and its expression is regulated by the transcription factor hypoxia-inducible factor (HIF)-1α. We here report on MIF expression in the failing human heart and assess myocardial MIF in different types of cardiomyopathy. Myocardial tissue samples from n = 30 patients were analyzed by quantitative Real-Time PCR. MIF and HIF-1α mRNA expression was analyzed in myocardial samples from patients with ischemic (ICM) and non-ischemic cardiomyopathy (NICM) and from patients after heart transplantation (HTX). MIF expression was elevated in myocardial samples from patients with ICM compared to NICM. Transplanted hearts showed lower MIF levels compared to hearts from patients with ICM. Expression of HIF-1α was analyzed and was shown to be significantly increased in ICM patients compared to patients with NICM. MIF and HIF-1α mRNA is expressed in the human heart. MIF and HIF-1α expression depends on the underlying type of cardiomyopathy. Patients with ICM show increased myocardial MIF and HIF-1α expression.

Graft-derived macrophage migration inhibitory factor correlates with hepatocellular injury in patients undergoing liver transplantation

Experimental studies suggest that macrophage migration inhibitory factor (MIF) mediates ischemia/reperfusion injury during liver transplantation. This study assessed whether human liver grafts release MIF during preservation, and whether the release of MIF is proportional to the extent of hepatocellular injury. Additionally, the association between MIF and early allograft dysfunction (EAD) after liver transplantation was evaluated. Concentrations of MIF, aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), and creatine kinase (CK) were measured in effluents of 38 liver grafts, and in serum of recipients. Concentrations of MIF in the effluent were greater than those in the recipients' serum before and after reperfusion (58 [interquartile range, IQR:23-79] μg/mL vs 0.06 [IQR:0.03-0.07] μg/mL and 1.3 [IQR:0.7-1.8] μg/mL, respectively; both P<.001). Effluent MIF concentrations correlated with effluent concentrations of the cell injury markers ALT (R=.51, P<.01), AST (R=.51, P<.01), CK (R=.45, P=.01), and LDH (R=.56, P<.01). Patients who developed EAD had greater MIF concentrations in effluent and serum 10 minutes after reperfusion than patients without EAD (Effluent: 80 [IQR:63-118] μg/mL vs 36 [IQR:20-70] μg/mL, P=.02; Serum: 1.7 [IQR:1.2-2.5] μg/mL vs 1.1 [IQR:0.6-1.7] μg/mL, P<.001).

CONCLUSION

Human liver grafts release MIF in proportion to hepatocellular injury. Greater MIF concentrations in effluent and recipient's serum are associated with EAD after liver transplantation.

Elevated MIF-2 levels predict mortality in critically ill patients

PURPOSE

D-dopachrome tautomerase (MIF-2 or DDT) is a member of the macrophage migration inhibitory factor (MIF) superfamily and a close structural homolog to MIF. Circulating MIF-2 has been described to be elevated in patients suffering from sepsis, severe burn injury and after surgery. We sought to evaluate the prognostic value of MIF-2 in critically ill patients.

METHODS

A total of 72 patients were studied upon admission to the medical intensive care unit (ICU). MIF and MIF-2 levels were assessed and compared to healthy controls. Clinical data, various laboratory parameters and mortality were assessed.

RESULTS

We found significantly elevated levels of MIF-2 and MIF at admission to the ICU in critically ill patients compared to healthy controls. MIF-2 levels were associated with disease severity as measured by APACHE II scores. MIF-2 levels in ICU patients correlated with biomarkers reflecting organ damage, but were not influenced by acute or chronic kidney disease. Kaplan-Meier analysis revealed distinctly elevated mortality in patients with high plasma MIF-2 levels.

CONCLUSIONS

MIF-2 levels are elevated in critically ill patients and linked to parameters of organ damage, supporting its value as a potential tool for the assessment of prognosis in critical illness.

Renal replacement therapy neutralizes elevated MIF levels in septic shock

BACKGROUND

Macrophage migration inhibitory factor (MIF) is known to amplify the immune response in septic animal models. Few clinical data support this pro-inflammatory role in septic patients. Renal replacement therapy (RRT) as adjuvants in the complex therapy of sepsis has been proposed as a possible approach to eliminate elevated circulating cytokines. Since recent data suggest that MIF can be effectively removed from the circulating blood pool in patients with chronic kidney disease, we here aimed to investigate whether RRT in septic shock can lower plasma levels of this pro-inflammatory cytokine in septic shock patients.

METHODS

An observational single-center study on an internist intensive care unit (ICU) was conducted. MIF plasma levels and mortality of n = 25 patients with septic shock were assessed with a previously validated method for reliable MIF values. The effect of continuous renal replacement therapy (CRRT) on daily MIF levels and mortality was assessed by comparing patients with and without need for CRRT due to acute kidney injury (AKI).

RESULTS

MIF plasma levels in patients undergoing CRRT due to septic AKI were steadily decreased compared to those from patients without CRRT hinting at a MIF removal by hemodialysis. MIF release during ICU stay as assessed by MIFAUC was lower in patients undergoing CRRT, and Kaplan-Meier analysis revealed a distinctly lower mortality in patients undergoing CRRT. Analysis of daily MIF levels showed that patients who did not survive septic shock exhibited steadily higher MIF plasma levels and higher MIFAUC compared to those surviving sepsis. Low MIF levels were closely associated with improved survival.

CONCLUSIONS

This is the first study investigating the effect of efficient MIF removal from the plasma pool of patients with septic shock. Reduction of high circulating MIF by CRRT therapy was accompanied by improved survival. Thus, targeted removal of MIF from the circulating blood pool might be a promising approach to reduce mortality in severe sepsis.