Increased plasma levels of adrenomedullin in patients with systemic inflammatory response syndrome

Usefulness of mid-regional proadrenomedullin levels in the resuscitation phase of severely burned patients and its utility in early sepsis detection

INTRODUCTION

Mid-regional proadrenomedullin (MR-proADM) reflects the adrenomedullin level, which has vasodilatory activity, decreases endothelial permeability, and downregulates proinflammatory cytokines. Sepsis diagnosis in these patients is difficult, and MR-proADM is a widely studied sepsis biomarker. This study evaluates MR-proADM levels during the resuscitation phase, considering the potential influence of haemodynamic changes and its usefulness for the early sepsis detection in burn patients.

METHODS

A prospective observational study performed in the Critical Burn Unit. Demographic data, burn characteristics, comorbidities, prognostic/severity scales, and haemodynamic parameters were collected. The resuscitation protocol guided by diuresis, transpulmonary thermodilution, and lactate levels was followed. Blood samples were collected at various time points for biomarker measurement. Biomarker levels, including MR-proADM, C-reactive protein, and procalcitonin were measured during the resuscitation phase and septic episodes.

RESULTS

Twenty-seven patients were included, with a mean age of 51 years, a mean total body surface area burn of 41.8%, a mean Abbreviated Burn Severity Index of 9.7, and a mean Baux score of 92. MR-proADM levels were elevated on admission (0.9 ± 0.5 nmol/l) and continued to increase slightly during the resuscitation phase (2.4 ± 2.2 nmol/l). Haemodynamic changes during resuscitation did not significantly affect MR-proADM levels. Twelve of the 27 patients developed sepsis, whose MR-proADM levels were significantly elevated on the day of clinical diagnosis (3.91 ± 2.99 nmol/l) and even the day before (2.57 ± 3.37). Higher MR-proADM levels were associated with greater severity as measured by the Sequential Organ Failure Assessment score. The mean MR-proadrenomedullin values during resuscitation in the patients who died was 3.51 ± 2.30 nmol/l, whereas in the survivors it was 1.28 ± 1.10 nmol/l (p = 0.0001).

CONCLUSION

MR-proadrenomedullin values are elevated after thermal injury but are not affected by haemodynamic changes. During septic episodes in burn patients, MR-proADM rises early (the day before sepsis diagnosis). Higher levels of MR-proADM are associated with greater organ dysfunction and mortality.

A Focus on the Pathophysiology of Adrenomedullin Expression: Endothelitis and Organ Damage in Severe Viral and Bacterial Infections

Adrenomedullin (ADM) is a peptide hormone produced primarily in the adrenal glands, playing a crucial role in various physiological processes. As well as improving vascular integrity and decreasing vascular permeability, ADM acts as a vasodilator, positive inotrope, diuretic, natriuretic and bronchodilator, antagonizing angiotensin II by inhibiting aldosterone secretion. ADM also has antihypertrophic, anti-apoptotic, antifibrotic, antioxidant, angiogenic and immunoregulatory effects and antimicrobial properties. ADM expression is upregulated by hypoxia, inflammation-inducing cytokines, viral or bacterial substances, strength of shear stress, and leakage of blood vessels. These pathological conditions are established during systemic inflammation that can result from infections, surgery, trauma/accidents or burns. The ability to rapidly identify infections and the prognostic, predictive power makes it a valuable tool in severe viral and bacterial infections burdened by high incidence and mortality. This review sheds light on the pathophysiological processes that in severe viral or bacterial infections cause endothelitis up to the development of organ damage, the resulting increase in ADM levels dosed through its more stable peptide mid-regional proadrenomedullin (MR-proADM), the most significant studies that attest to its diagnostic and prognostic accuracy in highlighting the severity of viral or bacterial infections and appropriate therapeutic insights.

Systematic review with meta-analysis of mid-regional pro-adrenomedullin (MR-proadm) as a prognostic marker in Covid-19-hospitalized patients

BACKGROUND

Mid-regional pro-adrenomedullin (MR-proADM) is useful for risk stratification in patients with sepsis and respiratory infections. The study's purpose was to assess the available data and determine the association between MR-proADM levels and mortality in COVID-19 participants.

METHODS

A comprehensive literature search of medical electronic databases was performed including PubMed, Web of Science, Scopus, Cochrane, and grey literature for relevant data published from 1 January 2020, to 20 November 2022. Mean differences (MD) with 95% confidence intervals (CI) were calculated.

RESULTS

Fourteen studies reported MR-proADM levels in survivors vs. non-survivors of COVID-19 patients. Pooled analysis showed that MR-proADM level in the survivor group was 0.841 ± 0.295 nmol/L for patients who survive COVID-19, compared to 1.692 ± 0.761 nmol/L for non-survivors (MD = -0.78; 95%CI: -0.92 to -0.64; p < 0.001).

CONCLUSIONS

The main finding of this study is that mortality of COVID-19 is linked to MR-proADM levels, according to this meta-analysis. The use of MR-proADM might be extremely beneficial in triaging, assessing probable therapy escalation, predicting potential complications during therapy or significant clinical deterioration of patients, and avoiding admission which may not be necessary. Nevertheless, in order to confirm the obtained data, it is necessary to conduct large prospective studies that will address the potential diagnostic role of MR-proADM as a marker of COVID-19 severity.KEY MESSAGESSeverity of COVID-19 seems to be linked to MR-proADM levels and can be used as a potential marker for predicting a patient's clinical course.The use of MR-proADM might be beneficial in triaging, assessing probable therapy escalation, predicting potential complications during therapy or significant clinical deterioration of patients, and avoiding admission which may not be necessary.For patients with COVID-19, MR-proADM may be an excellent prognostic indicator because it is a marker of endothelial function that may predict the precise impact on the equilibrium between vascular relaxation and contraction and lowers platelet aggregation inhibitors, coagulation inhibitors, and fibrinolysis activators in favor of clotting factors.

Mid-Regional Proadrenomedullin in COVID-19-May It Act as a Predictor of Prolonged Cardiovascular Complications?

The rising prevalence of cardiovascular disease (CVD) and the impact of the SARS-CoV-2 pandemic have both led to increased mortality rates, affecting public health and the global economy. Therefore, it is essential to find accessible, non-invasive prognostic markers capable of identifying patients at high risk. One encouraging avenue of exploration is the potential of mid-regional proadrenomedullin (MR-proADM) as a biomarker in various health conditions, especially in the context of CVD and COVID-19. MR-proADM presents the ability to predict mortality, heart failure, and adverse outcomes in CVD, offering promise for improved risk assessment and treatment strategies. On the other hand, an elevated MR-proADM level is associated with disease severity and cytokine storms in patients with COVID-19, making it a predictive indicator for intensive care unit admissions and mortality rates. Moreover, MR-proADM may have relevance in long COVID, aiding in the risk assessment, triage, and monitoring of individuals at increased risk of developing prolonged cardiac issues. Our review explores the potential of MR-proADM as a predictor of enduring cardiovascular complications following COVID-19 infection.

Clinical Potential of Adrenomedullin Signaling in the Cardiovascular System

Numerous clinical studies have revealed the utility of circulating AM (adrenomedullin) or MR-proAM (mid-regional proAM 45-92) as an effective prognostic and diagnostic biomarker for a variety of cardiovascular-related pathophysiologies. Thus, there is strong supporting evidence encouraging the exploration of the AM-CLR (calcitonin receptor-like receptor) signaling pathway as a therapeutic target. This is further bolstered because several drugs targeting the shared CGRP (calcitonin gene-related peptide)-CLR pathway are already Food and Drug Administration-approved and on the market for the treatment of migraine. In this review, we summarize the AM-CLR signaling pathway and its modulatory mechanisms and provide an overview of the current understanding of the physiological and pathological roles of AM-CLR signaling and the yet untapped potentials of AM as a biomarker or therapeutic target in cardiac and vascular diseases and provide an outlook on the recently emerged strategies that may provide further boost to the possible clinical applications of AM signaling.

Prognostic Role of Serum Adrenomedullin in Patients with Ventilator Associated Pneumonia

Objective: Ventilator associated pneumonia is a common type of sepsis that occurs to about 9–27% of all mechanically ventilated patients and 20–50% of them develop septic shock. Several clinical, laboratory, and radiological methods have been used for diagnosing VAP. Adrenomedullin (ADM) has been found to be elevated in the plasma of septic patients. The study aim was to explore the prognostic role of ADM in the VAP patients. Design: A prospective observational study. Setting: Intensive Care Department of Alexandria University Hospitals. Patients: A total of 140 patients with proven VAP after medical ICU admission were consecutively enrolled. Methods: APACHE II score, SOFA score, CRP, lactate, and serum ADM were measured at day 0 of VAP diagnosis and 5 days later. The results were correlated with the outcomes of patients. Results: APACHE II, lactate, and serum ADM on day 0 could predict an unfavorable outcome. ADM prediction power was significantly higher than APACHE II and lactate. Day 5 readings of all tested parameters could predict occurrence of the unfavorable outcome. ADM on day 0 showed the highest sensitivity (96.25%). Conclusions: Serum adrenomedullin when measured at days 0 and 5 of VAP diagnosis may serve as an early predictor of unfavorable outcome.

Diagnostic value of mid-regional pro-Adrenomedullin as a biomarker of invasive bacterial infection in children: a systematic review

Background

Invasive bacterial infections (IBI) in children present a difficult clinical challenge. They are often life-threatening, however in the early stages they can be hard to differentiate from benign viral infections. This leaves clinicians with the risk of missing a serious IBI diagnosis or inappropriately using antimicrobials in a child with a viral infection- contributing to the ongoing development of increased antimicrobial resistance. Hence, biomarkers which could aid in early detection of IBI and differentiation from viral infections are desirable. Mid-Regional pro-Adrenomedullin (MR-proADM) is a biomarker which has been associated with IBI. The aim of this systematic review was to determine its diagnostic accuracy in identifying children with IBI.

Methods

A strategy was devised to search online databases MEDLINE, Embase, Web of Science and Scopus for human clinical trials reporting the accuracy of MR-proADM in children. Against predesigned inclusion and exclusion criteria full texts were selected for inclusion and data extraction. True positives, false positives, true negatives and false negatives were extracted from each included study to fill 2 × 2 tables. Using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool methodological quality of each study was assessed.

Results

A total of 501 articles were initially identified. After the removal of duplicates and abstract screening 11 texts were fully reviewed and four texts (totaling 1404 patients) were included in the systematic analysis. Only one study was of a high quality and that study accounted for the vast majority of patients. A single study reported the diagnostic accuracy of MR-proADM for invasive bacterial infection reporting an Area under the Curve of 0.69. The paucity of available studies made meta-analysis and studies of heterogeneity impossible.

Conclusion

There is a paucity of research regarding the diagnostic accuracy of MR-proADM in the diagnosis of invasive bacterial infections in children. Initial results would suggest that MR-proADM testing alone is poor at identifying IBI in young children. It remains unclear if MR-proADM performs differently in older children or in children with signs and symptoms of IBI.

Trial registration

PROSPERO CRD42018096295.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03255-9.

Translational studies of adrenomedullin and related peptides regarding cardiovascular diseases

Adrenomedullin (AM) is a vasodilative peptide with various physiological functions, including the maintenance of vascular tone and endothelial barrier function. AM levels are markedly increased during severe inflammation, such as that associated with sepsis; thus, AM is expected to be a useful clinical marker and therapeutic agent for inflammation. However, as the increase in AM levels in cardiovascular diseases (CVDs) is relatively low compared to that in infectious diseases, the value of AM as a marker of CVDs seems to be less important. Limitations pertaining to the administrative route and short half-life of AM in the bloodstream (<30 min) restrict the therapeutic applications of AM for CVDs. In early human studies, various applications of AM for CVDs were attempted, including for heart failure, myocardial infarction, pulmonary hypertension, and peripheral artery disease; however, none achieved success. We have developed AM as a therapeutic agent for inflammatory bowel disease in which the vasodilatory effect of AM is minimized. A clinical trial evaluating this AM formulation for acute cerebral infarction is ongoing. We have also developed AM derivatives that exhibit a longer half-life and less vasodilative activity. These AM derivatives can be administered by subcutaneous injection at long-term intervals. Accordingly, these derivatives will reduce the inconvenience in use compared to that for native AM and expand the possible applications of AM for treating CVDs. In this review, we present the latest translational status of AM and its derivatives.

Beyond CGRP: The calcitonin peptide family as targets for migraine and pain

The CGRP system has emerged as a key pharmacological target for the treatment of migraine. However, some individuals who suffer from migraine have low or no response to anti-CGRP or other treatments, suggesting the need for additional clinical targets. CGRP belongs to the calcitonin family of peptides, which includes calcitonin, amylin, adrenomedullin and adrenomedullin 2. These peptides display a range of pro-nociceptive and anti-nociceptive actions, in primary headache conditions such as migraine. Calcitonin family peptides also show expression at sites relevant to migraine and pain. This suggests that calcitonin family peptides and their receptors, beyond CGRP, may be therapeutically useful in the treatment of migraine and other pain disorders. This review considers the localisation of the calcitonin family in peripheral pain pathways and discusses how they may contribute to migraine and pain. LINKED ARTICLES: This article is part of a themed issue on Advances in Migraine and Headache Therapy (BJP 75th Anniversary). To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v179.3/issuetoc.

Mid-Regional Proadrenomedullin (MR-proADM) and Microcirculation in Monitoring Organ Dysfunction of Critical Care Patients With Infection: A Prospective Observational Pilot Study

Introduction: Microvascular alterations are involved in the development of organ injury in critical care patients. Mid-regional proadrenomedullin (MR-proADM) may predict organ damage and its evolution. The main objective of this study was to assess the correlation between MR-proADM and microvascular flow index (MFI) in a small cohort of 20 adult critical care patients diagnosed with infection, sepsis, or septic shock. Further objectives were to evaluate the correlation between the clearance of MR-proADM and the variables of microcirculation and between MR-proADM and the Sequential Organ Failure Assessment (SOFA) score.

Materials and Methods: This is a prospective observational pilot study. Inclusion criteria: consecutive adult patients admitted to intensive care unit (ICU) for or with infection-related illness. Daily measurement of MR-proADM and calculation of the SOFA score from admission in ICU to day 5. Repeated evaluations of sublingual microcirculation, collection of clinical data, and laboratory tests.

Results: Primary outcome: MR-proADM was not significantly correlated to the MFI at admission in ICU. A clearance of MR-proADM of 20% or more in the first 24 h was related to the improvement of the MFIs and MFIt [percentual variation of the MFIs + 12.35 (6.01–14.59)% vs. +2.23 (−4.45–6.01)%, p = 0.005; MFIt +9.09 (4.53–16.26)% vs. −1.43 (−4.36–3.12)%, p = 0.002].

Conclusion: This study did not support a direct correlation of MR-proADM with the MFI at admission in ICU; however, it showed a good correlation between the clearance of MR-proADM, MFI, and other microvascular variables. This study also supported the prognostic value of the marker. Adequately powered studies should be performed to confirm the findings.

Adrenomedullin: A Novel Therapeutic for the Treatment of Inflammatory Bowel Disease

Adrenomedullin (AM) is a bioactive peptide with various physiological functions, including vasodilation, angiogenesis, anti-inflammation, organ protection, and tissue repair. AM suppresses inflammatory cytokine production in the intestinal mucosa, improves vascular and lymphatic regeneration and function, mucosal epithelial repair, and immune function in the intestinal bacteria of animal models with intestinal inflammation. We have been promoting translational research to develop novel therapeutic agents for inflammatory bowel disease (IBD) using AM and have started clinical research for IBD patients since 2010. A multicenter clinical trial is currently underway in Japan for patients with refractory ulcerative colitis and Crohn’s disease. Moreover, since current AM administration is limited to continuous intravenous infusion, the development of a subcutaneous formulation using long-acting AM is underway for outpatient treatment.

Promotion of vascular integrity in sepsis through modulation of bioactive adrenomedullin and dipeptidyl peptidase 3

Sepsis represents one of the major medical challenges of the 21st century. Despite substantial improvements in the knowledge on pathophysiological mechanisms, this has so far not translated into novel adjuvant treatment strategies for sepsis. In sepsis, both vascular tone and vascular integrity are compromised, and contribute to the development of shock, which is strongly related to the development of organ dysfunction and mortality. In this review, we focus on dipeptidyl peptidase 3 (DPP3) and adrenomedullin (ADM), two molecules that act on the vasculature and are involved in the pathophysiology of sepsis and septic shock. DPP3 is an ubiquitous cytosolic enzyme involved in the degradation of several important signalling molecules essential for regulation of vascular tone, including angiotensin II. ADM is a key hormone involved in the regulation of vascular tone and endothelial barrier function. Previous studies have shown that circulating concentrations of both DPP3 and ADM are independently associated with the development of organ failure and adverse outcome in sepsis. We now discuss new evidence illustrating that these molecules indeed represent two distinct pathways involved in the development of septic shock. Recently, both ADM-enhancing therapies aimed at improving endothelial barrier function and vascular tone and DPP3-blocking therapies aimed at restoring systemic angiotensin responses have been shown to improve outcome in various preclinical sepsis models. Given the current lack of effective adjuvant therapies in sepsis, additional research on the therapeutic application of these peptides in humans is highly warranted.

Circulating biomarkers to assess cardiovascular function in critically ill

PURPOSE OF REVIEW

Circulatory shock is one of the most common reasons for ICU admission. Mortality rates in excess of 40% necessitate the rapid identification of high-risk patients, as well as the early assessment of effects of initiated treatments. There is an unmet medical need for circulating biomarkers that may improve patient stratification, predict responses to treatment interventions and may even be a target for novel therapies, enabling a better biological rationale to personalize therapy.

RECENT FINDINGS

Apart from established biomarkers such as lactate, ScvO2 or NT-pro-BNP, novel biomarkers, including adrenomedullin, angiopoietins, angiotensin I/II ratios, renin and DPP3 show promise, as they are all associated with well defined, therapeutically addressable molecular pathways that are dysregulated during circulatory shock. Although some of the therapies related to these biomarkers are still in preclinical stages of development, they may represent personalized treatment opportunities for patients in circulatory shock.

SUMMARY

From a molecular perspective, shock represents a highly heterologous syndrome, in which multiple unique pathways are dysregulated. Assessment of the status of these pathways with circulating biomarkers may provide a unique opportunity to detect specific phenotypes and implement personalized medicine in the treatment of circulatory shock.

Usage of Plasma Presepsin, C-Reactive Protein, Procalcitonin and Proadrenomedullin to Predict Bacteremia in Febril Neutropenia of Pediatric Hematological Malignancy Patients

OBJECTIVE

To investigate the value of presepsin and proadrenomedullin (proADM) as new markers for febrile neutropenia, by comparing them with conventional markers.

METHODS

Plasma specimens for presepsin, proADM, C-reactive protein (CRP), and procalcitonin (PCT) were collected every 3 days during each episode of febrile neutropenia.

RESULTS

A total of 39 patients experiencing a collective 47 episodes of febrile neutropenia with hematological malignant neoplasms, as well as 40 healthy control patients without infectious disease, were enrolled in this study. Levels of the studied analytes in the presepsin 1 group (with baseline values taken at admission), presepsin 2 group (values recorded on the 3rd day of febrile neutropenia), and presepsin 3 group (values recorded on the 6th day of hospitalization) were all higher in the subgroups with bacteremia. C-reactive protein 1 (baseline value taken at admission), procalcitonin 1 (as recorded at admission), and procalcitonin 2 (recorded on the 3rd day of febrile neutropenia) were higher in the subroups with bacteremia (P =.03, P = .04, and P = .04, respectively). In multivariate logistic regression analysis, presepsin 1 and/or PCT 1/CRP 1 combined analysis was superior in predicting bacteremia.

CONCLUSION

Presepsin could be used in combination with other biomarkers to detect bacteremia.

Effect of Adrenomedullin on Migraine-Like Attacks in Patients With Migraine: A Randomized Crossover Study

OBJECTIVE

To determine whether the IV infusion of adrenomedullin, a potent vasodilator belonging to calcitonin family of peptides, provokes attacks of migraine in patients.

METHODS

Twenty patients with migraine without aura participated in a placebo-controlled and double-blind clinical study. In a randomized crossover design, the patients received an IV infusion of human adrenomedullin (19.9 pmol/kg/min) or placebo (saline) administrated via an automated IV pump (20 minutes). The patients participated in 2 study days with a washout period of minimum of 7 days. The primary outcome of the study was predefined as a difference in migraine incidence (0-12 hours), and the secondary outcomes were the area under curve (AUC_0-12 hours) for the headache intensity score and AUC_{0-90 minutes} for mean arterial blood pressure (MAP), flushing, and heart rate (HR).

RESULTS

Eleven patients with migraine without aura (55%) fulfilled migraine attacks criteria after adrenomedullin infusion compared to only 3 patients who reported attack (15%) after placebo (p = 0.039). We found that patients reported in a period of 0 to 12 hours stronger headache intensity after adrenomedullin compared to placebo infusion (p = 0.035). AUC_{0-90 minutes} value for HR and flushing (p < 0.05) was significant and for MAP (p = 0.502) remained unchanged. Common reported adverse events were facial flushing, heat sensation, and palpitation (p < 0.001).

CONCLUSION

Our data implicate adrenomedullin in migraine pathogenesis. This suggests that adrenomedullin or its receptors are novel therapeutic targets for the treatment of migraine. However, we cannot discount the possibility that adrenomedullin may be acting through the canonical calcitonin gene-related peptide receptor.

TRIAL REGISTRATION INFORMATION

ClinicalTrials.gov Identifier: NCT04111484.

Diagnostic and prognostic blood biomarkers in vascular dementia: From the viewpoint of ischemic stroke

Reliable quantitative blood biomarkers are important in vascular dementia (VaD) because early diagnosis and therapeutic intervention are effective in preventing progression of dementia. Although many blood biomarkers for acute ischemic stroke (AIS) or VaD have been reported, there are few reliable blood biomarkers. VaD and AIS have similar pathological conditions that are associated with small vessel disease (SVD) such as oxidative stress, inflammation, endothelial dysfunction, and neuronal injury. Therefore, it may be possible to find superior blood biomarkers of VaD among AIS blood biomarkers. Owing to recent developments, noncoding RNAs such as microRNA and long noncoding RNA, which can be analyzed using a single drop of blood, are also particularly reliable VaD markers because they stably reflect brain tissue damage. A multimarker combining several blood biomarkers or artificial intelligence technology may also be beneficial to compensate for insufficiencies of a single blood biomarker. This review describes the blood biomarkers of VaD and how they are related to blood biomarkers of AIS.

Adrecizumab: an investigational agent for the biomarker-guided treatment of sepsis

Introduction: Sepsis is a major health problem with a high incidence and mortality. ADM, a free-circulating peptide mainly expressed and secreted by vascular endothelial cells, shows vasodilatory properties and causes hypotension when present in higher concentrations during sepsis. Areas covered: Adrecizumab (ADZ) (HAM 8101) is a humanized targeted therapy directed against the N-terminus of adrenomedullin (ADM). ADZ inhibits excessive circulating sepsis-induced ADM and stimulates protective effects on the endothelial barrier, and decreases interstitial vasodilatory effects. ADZ demonstrated a promising safety profile in healthy subjects in phase I studies. According to these results, a phase II proof of concept study enrolling 300 septic patients is currently in course (NCT03085758). Expert opinion: ADZ is the first humanized antibody directed against ADM. The main interest of ADZ is its potential use as a 'biomarker-guided therapy' in septic patients with high circulating ADM. ADZ is increasingly seen as a potential adjunct therapy to restore endothelial function in septic shock. A positive pivotal phase III trial is indeed needed to convince the intensive care community to prescribe ADZ in septic shock patients. Further, it would be of interest to see whether ADZ might also benefit other critical diseases such as cardiogenic shock where endothelial dysfunction has also been described.

Effects of the Non-Neutralizing Humanized Monoclonal Anti-Adrenomedullin Antibody Adrecizumab on Hemodynamic and Renal Injury in a Porcine Two-Hit Model

Adrenomedullin is a vasoactive peptide that improves endothelial barrier function in sepsis, but may also cause hypotension and organ failure. Treatment with a non-neutralizing monoclonal anti-adrenomedullin antibody showed improvement in murine sepsis models. We tested the effects of the humanized monoclonal anti-adrenomedullin antibody Adrecizumab in a porcine two-hit model of hemorrhagic and septic shock.In this randomized, blinded study 12 German Landrace pigs were bled to half of baseline mean arterial pressure for 45 min. Sepsis was induced using an Escherichia coli clot placed into the abdominal cavity 6 h after hemorrhagic shock. Animals received either 2 mg/kg BW anti-adrenomedullin antibody or vehicle solution immediately after sepsis induction. After 4 h, resuscitation was initiated using balanced crystalloids and noradrenalin to maintain a central venous pressure of 8 to 12 mm Hg, a mean arterial pressure ≥ 65 mm Hg, and a ScvO2 ≥70% for another 8 h. Hemodynamic parameters, laboratory parameters, and kidney histology were assessed.The amount of volume resuscitation was significantly lower and significantly less animals developed a septic shock in the antibody-treated group, compared with the vehicle group. Kidney histology showed significantly lower granulocytes in both cortex and medulla in antibody-treated animals, while the remaining four kidney measures (serum creatinine and urine output and cortical and medullary injury in histopathology) did not reach the significance levels. After induction of sepsis, plasma adrenomedullin increased immediately in both the groups, but increased quicker and more pronounced in the antibody group.In this two-hit shock model, treatment with an anti-adrenomedullin antibody significantly increased plasma adrenomedullin levels, while significantly less animals developed septic shock and renal granulocyte extravasation was significantly reduced. Thus, therapy with Adrecizumab may provide benefit in sepsis, and clinical investigation of this drug candidate is warranted.

Pro-atrial natriuretic peptide and pro-adrenomedullin before cardiac surgery in children. Can we predict the future?

INTRODUCTION AND OBJECTIVE

Pro-atrial natriuretic peptide (proANP) and pro-adrenomedullin (proADM) levels increase in acute heart failure and sepsis. After cardiac surgery, children may require increased support in the intensive care unit and may develop complications. The aim of this study was to evaluate the utility of proANP and proADM values, determined prior to cardiac surgery, for predicting the need for increased respiratory or inotropic support during the post-operative period.

METHODS

This was a prospective study in children. Biomarkers were analyzed before surgery using a single blood test. The primary endpoints were the need for greater respiratory and/or inotropic support during the post-operative period. Secondary endpoints were the relationship between these biomarkers and complications after surgery.

RESULTS

One hundred thirteen patients were included. ProANP and proADM were higher in children who required greater respiratory and inotropic support, especially proANP; for increased respiratory support, 578.9 vs. 106.6 pmol/L (p = 0.004), and for increased inotropic support, 1938 vs. 110.4 pmol/L (p = 0.002). ProANP had a greater AUC than proADM for predicting increased respiratory support after surgery: 0.791 vs. 0.724. A possible cut-off point for proANP could be ≥ 325 pmol/L (sensitivity = 66.7% and specificity = 88.8%). In the multivariate analysis, the logarithmic transformation of proANP was independently associated with the need for increased respiratory support (OR = 3.575). Patients who presented a poor outcome after cardiac surgery also had higher biomarker values (proADM, p = 0.013; proANP, p = 0.001).

CONCLUSIONS

Elevated proANP before cardiac surgery may identify which children will need more respiratory and inotropic support during the post-operative period.

A protocol for a systematic review and meta-analysis of the diagnostic accuracy of mid-regional pro-adrenomedullin in predicting invasive bacterial infection in children

BACKGROUND

The early recognition of invasive bacterial infections (IBI) in children can be difficult. Clinically it is often challenging to differentiate between the early stages of an IBI and a benign self-limiting viral infection. These challenges mandate a cautious approach resulting in the overuse of antimicrobial drugs with resultant antimicrobial resistance. Due to these challenges, there is growing research into the role of biomarkers for the early identification of children with IBI. Earlier and more accurate diagnoses may lead to improved clinical outcomes for children and reduced antimicrobial resistance. Mid-regional pro-adrenomedullin (MR-proADM) is a biomarker that has been shown to be elevated in patients with IBI. The aim of this systematic review is to determine the diagnostic accuracy of MR-proADM at identifying children with IBI.

METHODS

To identify relevant studies we will search MEDLINE, Embase, Web of Science and Scopus from 1980 to the present day for all human clinical trials involving children that report the test accuracy of MR-proADM. We will include case-control studies, cohort studies and randomised control trials reported in any language. In addition, we will hand-search reference lists and grey literature including conference abstracts and web searches. Two reviewers will independently screen study titles and abstracts for eligibility followed by full-text assessment and data extraction including population, setting, timing and use of index test and reference standard used. Methodological quality will be assessed, by two authors, according to the revised tool for the quality assessment of diagnostic accuracy studies (QUADAS-2), any discrepancies will be resolved by a third author. The following test characteristics will be extracted into 2 × 2 tables for all included studies: true positives, false positives, true negatives and false negatives. Study-specific estimates of sensitivity and specificity with 95% confidence intervals will be displayed in forest plots.

DISCUSSION

This review will report the normal ranges for MR-proADM in health and the diagnostic accuracy of MR-proADM at identifying children with IBI. The review will help to define where in the diagnostic pathway MR-proADM could be useful including potential as a point-of-care test for children at first presentation with IBI.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018096295.

PAMP protects intestine from Enterohemorrhagic Escherichia coli infection through destroying cell membrane and inhibiting inflammatory response

Proadrenomedullin N-terminal 20 peptide (PAMP) is elevated in sepsis, but the function and possible mechanism of PAMP in bacterial infection is elusive. This study is aim to evaluate the role of PAMP in the interaction between the Enterohemorrhagic E. coli (EHEC) and the host barrier. Our results showed that PAMP alleviated the EHEC-induced disruption of goblet cells and mucosal damage in the intestine, increased the expression of occludin in the colon of EHEC-infected mice, and reduced the proinflammatory cytokines level in serum significantly compared with the control group. Meanwhile, lipopolysaccharide (LPS) stimulation could dose-dependently induce the expression of preproADM, the precursor of PAMP, in human intestinal epithelial cell (HIEC) and human umbilical vein endothelial cell (HUVEC). In addition, PAMP inhibited the growth of EHEC O157:H7 and destroyed the inner and outer membrane. At low concentration, PAMP attenuated the EHEC virulence genes including hlyA and eaeA, which was also confirmed from reduced hemolysis to red cells and adhesion to HIEC. These results indicated that EHEC infection would modulate the expression of PAMP in intestinal epithelium or vascular endothelium, and in turn exerted a protective effect in EHEC induced infection by rupturing the bacterial cell membrane and attenuating the bacterial virulence.

Vascular Effects of Adrenomedullin and the Anti-Adrenomedullin Antibody Adrecizumab in Sepsis

Sepsis remains a major scientific and medical challenge, for which, apart from significant refinements in supportive therapy, treatment has barely changed over the last few decades. During sepsis, both vascular tone and vascular integrity are compromised, and contribute to the development of shock. The free circulating peptide adrenomedullin (ADM) is involved in the regulation of the endothelial barrier function and tone of blood vessels. Several animal studies have shown that ADM administration improves outcome of sepsis. However, in higher dosages, ADM administration may cause hypotension, limiting its clinical applicability. Moreover, ADM has a very short half-life and easily adheres to surfaces, further hampering its clinical use. The non-neutralizing anti-ADM antibody Adrecizumab (HAM8101) which causes a long-lasting increase of plasma ADM has shown promising results in animal models of systemic inflammation and sepsis; it reduced inflammation, attenuated vascular leakage, and improved hemodynamics, kidney function, and survival. Combined with an excellent safety profile derived from animal and phase I human studies, Adrecizumab represents a promising candidate drug for the adjunctive treatment of sepsis. In this review, we first provide a brief overview of the currently available data on the role of adrenomedullin in sepsis and describe its effects on endothelial barrier function and vasodilation. Furthermore, we provide a novel hypothesis concerning the mechanisms of action through which Adrecizumab may exert its beneficial effects in sepsis.

Personalized medicine with IgGAM compared with standard of care for treatment of peritonitis after infectious source control (the PEPPER trial): study protocol for a randomized controlled trial

Background

Peritonitis is responsible for thousands of deaths annually in Germany alone. Even source control (SC) and antibiotic treatment often fail to prevent severe sepsis or septic shock, and this situation has hardly improved in the past two decades. Most experimental immunomodulatory therapeutics for sepsis have been aimed at blocking or dampening a specific pro-inflammatory immunological mediator. However, the patient collective is large and heterogeneous. There are therefore grounds for investigating the possibility of developing personalized therapies by classifying patients into groups according to biomarkers. This study aims to combine an assessment of the efficacy of treatment with a preparation of human immunoglobulins G, A, and M (IgGAM) with individual status of various biomarkers (immunoglobulin level, procalcitonin, interleukin 6, antigen D-related human leucocyte antigen (HLA-DR), transcription factor NF-κB1, adrenomedullin, and pathogen spectrum).

Methods/design

A total of 200 patients with sepsis or septic shock will receive standard-of-care treatment (SoC). Of these, 133 patients (selected by 1:2 randomization) will in addition receive infusions of IgGAM for 5 days. All patients will be followed for approximately 90 days and assessed by the multiple-organ failure (MOF) score, by the EQ QLQ 5D quality-of-life scale, and by measurement of vital signs, biomarkers (as above), and survival.

Discussion

This study is intended to provide further information on the efficacy and safety of treatment with IgGAM and to offer the possibility of correlating these with the biomarkers to be studied. Specifically, it will test (at a descriptive level) the hypothesis that patients receiving IgGAM who have higher inflammation status (IL-6) and poorer immune status (low HLA-DR, low immunoglobulin levels) have a better outcome than patients who do not receive IgGAM. It is expected to provide information that will help to close the knowledge gap concerning the association between the effect of IgGAM and the presence of various biomarkers, thus possibly opening the way to a personalized medicine.

Trial registration

EudraCT, 2016–001788-34; ClinicalTrials.gov, NCT03334006. Registered on 17 Nov 2017.

Trial sponsor: RWTH Aachen University, represented by the Center for Translational & Clinical Research Aachen (contact Dr. S. Isfort).

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3244-4) contains supplementary material, which is available to authorized users.

Adrenomedullin mediates pro-angiogenic and pro-inflammatory cytokines in asthma and COPD

PURPOSE

Adrenomedullin (AM) is a pluripotent peptide hormone with contradictory effects in human health and disease. In chronic inflammatory lung diseases, such as asthma and COPD, AM has been shown to inhibit inflammation and cell proliferation. In the present study, we aimed to investigate the effect of AM on pro-angiogenic and pro-inflammatory cytokines in asthma and COPD.

PATIENTS AND METHODS

Serum levels of pro-AM were measured in patients with asthma, COPD and matched controls. The effect of AM on intracellular signaling proteins and cytokine secretion was assessed in primary cultures of epithelial cells (EC) and airway smooth muscle cells (ASMC) established from endo-bronchial biopsies of patients with asthma, COPD and controls.

RESULTS

Serum pro-AM was higher in patients with asthma and COPD, compared to controls. AM stimulated cAMP in ASMC but not in EC. In EC, AM decreased Erk1/2 MAPK expression and activation but in ASMC, AM activated Erk1/2. This effect was similar in asthma, COPD and controls. AM stimulated the secretion of pro-angiogenic CXCL1 by EC of controls and CXCL5 by EC of asthma patients. AM did not affect the secretion of IL-6 or IL-8 by EC but stimulated the secretion of IL-6 by ASMC. In EC, AM inhibited the stimulatory effect of TGF-β and IL-4 on the secretion of IL-6 and IL-8 but had an additive stimulatory effect with TGF-β in ASMC.

CONCLUSIONS

These data suggest that AM mediates the secretion of pro-angiogenic and pro-inflammatory cytokines in a cell-type and/or a disease-specific way, explaining its association with clinical outcomes in COPD.

MR-proADM: A New Biomarker for Early Diagnosis of Sepsis in Burned Patients

Mid regional pro-adrenomedullin (MR-proADM) has been used as a marker of sepsis, but its dynamics and role in a burn injury setting has not been tested. In a prospective observational study, we included 42 consecutive patients with >15% TBSA. Daily blood specimens collected over the initial 20 days of treatment were submitted for laboratory analysis of MR-proADM and procalcitonin (PCT) via immunoluminometric sandwich assay (Kryptor, BRAHMS, Berlin, Germany). In patients with an absence of sepsis, an initial increase in MR-proADM and PCT levels was noted post-burn injury, peaking on the second day postadmission and thereafter demonstrated a continued decline in MR-proADM and PCT levels. In those patients who went on to develop sepsis (n = 27, 64.3%), the levels of MR-proADM and PCT were significantly higher (P < .001) on days categorized as septic, than on days categorized as nonseptic. The increase in PCT levels was noted on the first day to be categorized as septic. In contrast, the MR-proADM levels demonstrated an increase one day earlier. The optimal relationship between the specificity and sensitivity of MR-proADM and PCT for the detection of sepsis was an increase of 31% and at least 0.015 nmol/L (area under curve 0.76) or of >39% and at least 0.15 µg/L (area under the curve 0.83), respectively. Burn injury is associated with increased levels of MR-proADM. Subsequent increases may be considered as diagnostic of sepsis onset. In this context, PCT displayed higher specificity and sensitivity, while MR-proADM may be more suitable for the early recognition of sepsis (ClinicalTrials.gov number, NCT01055587).

Adrenomedullin and Adrenomedullin-Targeted Therapy As Treatment Strategies Relevant for Sepsis

Sepsis remains a major medical challenge, for which, apart from improvements in supportive care, treatment has not relevantly changed over the last few decades. Vasodilation and vascular leakage play a pivotal role in the development of septic shock, with vascular leakage being caused by disrupted endothelial integrity. Adrenomedullin (ADM), a free circulating peptide involved in regulation of endothelial barrier function and vascular tone, is implicated in the pathophysiology of sepsis. ADM levels are increased during sepsis, and correlate with extent of vasodilation, as well as with disease severity and mortality. In vitro and preclinical in vivo data show that administration of ADM exerts anti-inflammatory, antimicrobial, and protective effects on endothelial barrier function during sepsis, but other work suggests that it may also decrease blood pressure, which could be detrimental for patients with septic shock. Work has been carried out to negate ADMs putative negative effects, while preserving or even potentiating its beneficial actions. Preclinical studies have demonstrated that the use of antibodies that bind to the N-terminus of ADM results in an overall increase of circulating ADM levels and improves sepsis outcome. Similar beneficial effects were obtained using coadministration of ADM and ADM-binding protein-1. It is hypothesized that the mechanism behind the beneficial effects of ADM binding involves prolongation of its half-life and a shift of ADM from the interstitium to the circulation. This in turn results in increased ADM activity in the blood compartment, where it exerts beneficial endothelial barrier-stabilizing effects, whereas its detrimental vasodilatory effects in the interstitium are reduced. Up till now, in vivo data on ADM-targeted treatments in humans are lacking; however, the first study in septic patients with an N-terminus antibody (Adrecizumab) is currently being conducted.

Assessment of adrenomedullin and proadrenomedullin as predictors of mortality in septic patients: A systematic review and meta-analysis

OBJECTIVE

To ascertain the ability of adrenomedullin (ADM) and proadrenomedullin (proADM) to predict mortality in sepsis patients.

DESIGN

A systematic literature search was made of the PubMed, EMBASE, Cochrane and China National Knowledge Infrastructure (CNKI) databases before May 2017, supplemented by manual searches of references. A meta-analysis of high-quality clinical studies was subsequently performed to assess the association between ADM/proADM and mortality risk among patients with sepsis.

PATIENTS

Thirteen studies involving 2556 patients were included in the study.

INTERVENTIONS

Two reviewers independently identified articles, extracted data, assessed quality and cross-checked the results. The predictive values of ADM and proADM referred to mortality were assessed by relative risk (RR). The overall diagnostic accuracy of ADM and proADM in application to sepsis was pooled according to a bivariate model. Publication bias was assessed using Deek's funnel plot asymmetry test.

RESULTS

Elevated ADM or proADM levels were associated with increased mortality (pooled RR=3.31; 95%CI 2.31-4.75). Subgroup analyses indicated the pooled RRs were 3.12 (95%CI 1.75-5.56) and 3.43 (95%CI 2.21-5.31) for ADM and proADM, respectively. The pooled sensitivity and specificity were 0.72 (95%CI 0.64-0.78) and 0.77 (95%CI 0.69-0.83), respectively. The overall area under the summary receiver operating characteristic (SROC) curve was 0.80 (95%CI 0.77-0.84). Publication bias was not statistically significant.

CONCLUSIONS

Both ADM and proADM might serve as useful markers for predicting the prognosis of sepsis.

Identification of key pathogenic genes of sepsis based on the Gene Expression Omnibus database

Sepsis is a life-threatening condition in which an uncontrolled inflammatory host response is triggered. The exact pathogenesis of sepsis remains unclear. The aim of the present study was to identify key genes that may aid in the diagnosis and treatment of sepsis. mRNA expression data from blood samples taken from patients with sepsis and healthy individuals was downloaded from the Gene Expression Omnibus database and differentially expressed genes (DEGs) between the two groups were identified. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, and protein-protein interaction (PPI) network construction, was performed to investigate the function of the identified DEGs. Furthermore, for validation of these results, the expression levels of several DEGs were analyzed by reverse transcription quantitative-polymerase chain reaction (RT-qPCR) in three patients with sepsis and three healthy blood samples to support the results obtained from the bioinformatics analysis. Receiver operating characteristic analyses were also used to analyze the diagnostic ability of the identified DEGs for sepsis. The results demonstrated that a total of 4,402 DEGs, including 1,960 upregulated and 2,442 downregulated genes, were identified between patients with sepsis and healthy individuals. KEGG pathway analysis revealed that 39 DEGs were significantly enriched in toll-like receptor signaling pathways. The top 20 upregulated and downregulated DEGs were used to construct the PPI network. Hub genes with high degrees, including interleukin 1 receptor-associated kinase 3 (IRAK3), S100 calcium-binding protein (S100)A8, angiotensin II receptor-associated protein (AGTRAP) and S100A9, were demonstrated to be associated sepsis. Furthermore, RT-qPCR results demonstrated that IRAK3, adrenomedullin (ADM), arachidonate 5-lipoxygenase (ALOX5), matrix metallopeptidase 9 (MMP9) and S100A8 were significantly upregulated, while ectonucleoside triphosphate diphosphohydrolase 1 (ENTPD1) was upregulated but not significantly, in blood samples from patients with sepsis compared with healthy individuals, which was consistent with bioinformatics analysis results. Therefore, AGTRAP, IRAK3, ADM, ALOX5, MMP9, S100A8 and ENTPD1 were identified to have potential diagnostic value in sepsis. In conclusion, dysregulated levels of the AGTRAP, IRAK3, ADM, ALOX5, MMP9, S100A8 and ENTPD1 genes may be involved in sepsis pathophysiology and may be utilized as potential diagnostic biomarkers or therapeutic targets.

Actin dynamics in the regulation of endothelial barrier functions and neutrophil recruitment during endotoxemia and sepsis

Sepsis is a leading cause of death worldwide. Increased vascular permeability is a major hallmark of sepsis. Dynamic alterations in actin fiber formation play an important role in the regulation of endothelial barrier functions and thus vascular permeability. Endothelial integrity requires a delicate balance between the formation of cortical actin filaments that maintain endothelial cell contact stability and the formation of actin stress fibers that generate pulling forces, and thus compromise endothelial cell contact stability. Current research has revealed multiple molecular pathways that regulate actin dynamics and endothelial barrier dysfunction during sepsis. These include intracellular signaling proteins of the small GTPases family (e.g., Rap1, RhoA and Rac1) as well as the molecules that are directly acting on the actomyosin cytoskeleton such as myosin light chain kinase and Rho kinases. Another hallmark of sepsis is an excessive recruitment of neutrophils that also involves changes in the actin cytoskeleton in both endothelial cells and neutrophils. This review focuses on the available evidence about molecules that control actin dynamics and regulate endothelial barrier functions and neutrophil recruitment. We also discuss treatment strategies using pharmaceutical enzyme inhibitors to target excessive vascular permeability and leukocyte recruitment in septic patients.

Adrenomedullin Regulates IL-1β Gene Expression in F4/80+ Macrophages during Synovial Inflammation

Adrenomedullin (AM) plays an important role in the regulation of inflammatory processes; however, the role and expression of AM in synovial inflammation have not been determined. To investigate the expression and role of AM in inflamed synovial tissue (ST), the gene expression profiles of AM in the ST, including synovial macrophages and fibroblasts, of a murine patellar surgical dislocation model were characterized. In addition, the effects of interleukin- (IL-) 1β and AM in cultured synovial cells were also examined. CD11c⁺ macrophages were found to be elevated in ST of the surgically dislocated patella. Higher gene expression of CD11c, IL-1β, AM, receptor activity-modifying proteins 2 (RAMP2), and 3 (RAMP3) was also observed in ST obtained from the dislocated side. AM expression was also significantly increased in synovial fibroblasts and macrophages in response to IL-1β treatment. Synovial macrophages also highly expressed RAMP3 compared to fibroblasts and this expression was further stimulated by exogenously added IL-1β. Further, the treatment of the F4/80-positive cell fraction obtained from ST with AM inhibited IL-1β expression. Taken together, these findings demonstrated that AM was produced by synovial fibroblasts and macrophages in inflamed ST and that increased levels of AM may exert anti-inflammatory effects on synovial macrophages.

Plasma adrenomedullin in critically ill patients with sepsis after major surgery: A pilot study

PURPOSE

Adrenomedullin is released by different tissues in hypoxia, oxidative stress, and inflammation and is found in general and medical patients and, recently, in sepsis patients in emergency departments. The aim of this study was to evaluate biologically active adrenomedullin that mirrors directly the active peptide levels in plasma of surgical intensive care unit (ICU) patients with sepsis.

MATERIALS AND METHODS

In this single-center observational pilot trial, 42 ICU patients with sepsis and 14 patients after major surgery were included after sepsis diagnosis or ICU admission.

RESULTS

Patients (66% male) were 70 (median) (interquartile range [IQR], 61-77]) years old and had a body mass index of 26.2 (24.2-29.4) kg/m². The ICU and hospital length of stay was 8 (1-22) and 17 (8-21) days, respectively. Eight patients had sepsis, 19 developed severe sepsis, and 15 suffered from septic shock. Adrenomedullin increased with severity (sepsis: 25.8 pg/mL [IQR 20.3-40.2], severe sepsis: 84.2 pg/mL [IQR 42.7-118.5], septic shock: 119.7 pg/mL [IQR 83.8-172.6]; P<.0001). Higher adrenomedullin was associated with poor 90-day outcomes (P=.019) and more frequent vasopressor use (P=.001).

CONCLUSIONS

This is the first study investigating adrenomedullin in patients with sepsis following major surgery. Higher adrenomedullin on admission is associated with increased vasopressor need and mortality after 90 days. Thus, adrenomedullin may be a useful additional parameter in surgical patients with sepsis.

Regulation of endothelial and epithelial barrier functions by peptide hormones of the adrenomedullin family

The correct regulation of tissue barriers is of utmost importance for health. Barrier dysfunction accompanies inflammatory disorders and, if not controlled properly, can contribute to the development of chronic diseases. Tissue barriers are formed by monolayers of epithelial cells that separate organs from their environment, and endothelial cells that cover the vasculature, thus separating the blood stream from underlying tissues. Cells within the monolayers are connected by intercellular junctions that are linked by adaptor molecules to the cytoskeleton, and the regulation of these interactions is critical for the maintenance of tissue barriers. Many endogenous and exogenous molecules are known to regulate barrier functions in both ways. Proinflammatory cytokines weaken the barrier, whereas anti-inflammatory mediators stabilize barriers. Adrenomedullin (ADM) and intermedin (IMD) are endogenous peptide hormones of the same family that are produced and secreted by many cell types during physiologic and pathologic conditions. They activate certain G-protein-coupled receptor complexes to regulate many cellular processes such as cytokine production, actin dynamics and junction stability. In this review, we summarize current knowledge about the barrier-stabilizing effects of ADM and IMD in health and disease.

Adrenomedullin and endothelin-1 are associated with myocardial injury and death in septic shock patients

Background

Adrenomedullin and endothelin-1 are hormones with opposing effects on the cardiovascular system. Adrenomedullin acts as a vasodilator and seems to be important for the initiation and continuation of the hyperdynamic circulatory response in sepsis. Endothelin-1 is a vasoconstrictor and has been linked to decreased cardiac performance. Few studies have studied the relationship between adrenomedullin and endothelin-1, and morbidity and mortality in septic shock patients. High-sensitivity troponin T (hsTNT) is normally used to diagnose acute cardiac injury but is also prognostic for outcome in intensive care. We investigated the relationship between mid-regional pro-adrenomedullin (MR-proADM), C-terminal pro-endothelin-1 (CT-proET-1), and myocardial injury, measured using transthoracic echocardiography and hsTNT in septic shock patients. We were also interested in the development of different biomarkers throughout the ICU stay, and how early measurements were related to mortality. Further, we assessed if a positive biomarker panel, consisting of MR-proADM, CT-proET-1, and hsTNT changed the odds for mortality.

Methods

A cohort of 53 consecutive patients with septic shock had their levels of MR-proADM, CT-proET-1, hsTNT, and left ventricular systolic functions prospectively measured over 7 days. The relationship between day 1 levels of MR-proADM/CT-proET-1 and myocardial injury was studied. We also investigated the relationship between biomarkers and early (7-day) and later (28-day) mortality. Likelihood ratios, and pretest and posttest odds for mortality were calculated.

Results

Levels of MR-proADM and CT-proET-1 were significantly higher among patients with myocardial injury and were correlated with left ventricular systolic dysfunction. MR-proADM and hsTNT were significantly higher among 7-day and 28-day non-survivors. CT-proET-1 was also significantly higher among 28-day but not 7-day non-survivors. A positive biomarker panel consisting of the three biomarkers increased the odds for mortality 13-fold to 20-fold.

Conclusions

MR-proADM and CT-proET-1 are associated with myocardial injury. A biomarker panel combining MR-proADM, CT-proET-1, and hsTNT increases the odds ratio for death, and may improve currently available scoring systems in critical care.

p53- and PAI-1-mediated induction of C-X-C chemokines and CXCR2: importance in pulmonary inflammation due to cigarette smoke exposure

We previously demonstrated that tumor suppressor protein p53 augments plasminogen activator inhibitor-1 (PAI-1) expression in alveolar epithelial cells (AECs) during chronic cigarette smoke (CS) exposure-induced lung injury. Chronic lung inflammation with elevated p53 and PAI-1 expression in AECs and increased susceptibility to and exacerbation of respiratory infections are all associated with chronic obstructive pulmonary disease (COPD). We recently demonstrated that preventing p53 from binding to the endogenous PAI-1 mRNA in AECs by either suppressing p53 expression or blockading p53 interactions with the PAI-1 mRNA mitigates apoptosis and lung injury. Within this context, we now show increased expression of the C-X-C chemokines (CXCL1 and CXCL2) and their receptor CXCR2, and the intercellular cellular adhesion molecule-1 (ICAM-1), in the lung tissues of patients with COPD. We also found a similar increase in lung tissues and AECs from wild-type (WT) mice exposed to passive CS for 20 wk and in primary AECs treated with CS extract in vitro. Interestingly, passive CS exposure of mice lacking either p53 or PAI-1 expression resisted an increase in CXCL1, CXCL2, CXCR2, and ICAM-1. Furthermore, inhibition of p53-mediated induction of PAI-1 expression by treatment of WT mice exposed to passive CS with caveolin-1 scaffolding domain peptide reduced CXCL1, CXCL2, and CXCR2 levels and lung inflammation. Our study reveals that p53-mediated induction of PAI-1 expression due to chronic CS exposure exacerbates lung inflammation through elaboration of CXCL1, CXCL2, and CXCR2. We further provide evidence that targeting this pathway mitigates lung injury associated with chronic CS exposure.

Bench-to-bedside pharmacology of adrenomedullin

The bioactive peptide adrenomedullin (AM) exerts pleiotropic actions in various organs and tissues. In the heart, AM has an inhibitory effect on ventricular remodeling, suppressing cardiomyocyte hypertrophy and the proliferation of cardiac fibroblasts. This pharmacological property was shown not only in rat models of acute myocardial infarction, but also clinically in patients with this cardiac disease. An originally characterized feature of AM was a potent vasodilatory effect, but this peptide was found to be important for vascular integrity and angiogenesis. AM-induced angiogenesis is involved in tumor growth, while AM inhibits apoptosis of some types of tumor cell. A unique pharmacological property is anti-inflammatory activity, which has been characterized in sepsis and inflammatory bowel diseases; thus, there is an ongoing clinical trial to test the efficacy of AM for patients with intractable ulcerative colitis. These activities are assumed to be mediated via the specific receptor formed by calcitonin receptor-like receptor and receptor activity-modifying protein 2 or 3, while some questions remain to be answered about the molecular mechanisms of this signal transduction system. Taking these findings together, AM is a bioactive peptide with pleiotropic effects, with potential as a therapeutic tool for a wide range of human diseases from myocardial infarction to malignant tumors or inflammatory bowel diseases.

Host response biomarkers in the diagnosis of sepsis: a general overview

Critically ill patients who display a systemic inflammatory response syndrome (SIRS) are prone to develop nosocomial infections. The challenge remains to distinguish as early as possible among SIRS patients those who are developing sepsis. Following a sterile insult, damage-associated molecular patterns (DAMPs) released by damaged tissues and necrotic cells initiate an inflammatory response close to that observed during sepsis. During sepsis, pathogen-associated molecular patterns (PAMPs) trigger the release of host mediators involved in innate immunity and inflammation through identical receptors as DAMPs. In both clinical settings, a compensatory anti-inflammatory response syndrome (CARS) is concomitantly initiated. The exacerbated production of pro- or anti-inflammatory mediators allows their detection in biological fluids and particularly within the bloodstream. Some of these mediators can be used as biomarkers to decipher among the patients those who developed sepsis, and eventually they can be used as prognosis markers. In addition to plasma biomarkers, the analysis of some surface markers on circulating leukocytes or the study of mRNA and miRNA can be helpful. While there is no magic marker, a combination of few biomarkers might offer a high accuracy for diagnosis.

Adrenomedullin improves intestinal epithelial barrier function by downregulating myosin light chain phosphorylation in ulcerative colitis rats

Adrenomedullin (AM) is a pivotal endogenous vasoactive peptide, which can maintain epithelial barrier function in inflammatory bowel disease. Myosin light chain kinase (MLCK)‑dependent phosphorylated myosin light chain kinase (p‑MLC) is a key regulator of intestinal barrier function. The aim of the present study was to investigate the effect and mechanism of AM on the intestinal epithelial barrier in a rat model of ulcerative colitis (UC) induced by 2,4,6‑trinitro‑benzene‑sulfonic acid (TNBS). A total of 21 male Sprague‑Dawley rats were randomly divided into the following three groups and administered different agents for 7 days: The normal group (water and saline), model group (TNBS and saline) and the AM group (TNBS and AM; 1.0 µg). The weight of rats was recorded every day. Serum tumor necrosis factor‑α (TNF‑α) and interleukin‑6 (IL‑6) levels were detected using ELISA kits. Colon tissue was collected for the assessment of histological alterations. The protein expression of MLCK, p‑MLC and zonula occludens‑1 (ZO‑1) was examined by western blot analysis. Intestinal epithelial tight junctions were examined using transmission electron microscopy. The results demonstrated that in colitis model rats, the expression of TNF‑α, IL‑6, MLCK and p‑MLC significantly increased compared with normal rats. In addition, the expression of ZO‑1 decreased (P<0.05) and intestinal epithelial cell permeability increased. Following AM administration, TNF‑α, IL‑6, MLCK and p‑MLC expression significantly decreased compared with the model rats, the expression of ZO‑1 increased (P<0.05) and intestinal epithelial cell permeability reduced. These data indicate a protective effect of AM on intestinal epithelial barrier dysfunction via suppression of inflammatory cytokines and downregulation of MLCK‑p‑MLC in TNBS‑induced UC. In conclusion, AM/MLCK‑p‑MLC may be an important signaling pathway in the occurrence and development of UC.

Are there new approaches for diagnosis, therapy guidance and outcome prediction of sepsis?

Beside many efforts to improve outcome, sepsis is still one of the most frequent causes of death in critically ill patients. It is the most common condition with high mortality in intensive care units. The complexity of the septic syndrome comprises immunological aspects - i.e., sepsis induced immunosuppression - but is not restricted to this fact in modern concepts. So far, exact mechanisms and variables determining outcome and mortality stay unclear. Since there is no typical risk profile, early diagnosis and risk stratification remain difficult, which hinders rapid and effective treatment initiation. Due to the heterogeneous nature of sepsis, potential therapy options should be adapted to the individual. Biomarkers like C-reactive protein and procalcitonin are routinely used as complementary tools in clinical decision-making. Beyond the acute phase proteins, a wide bunch of promising substances and non-laboratory tools with potential diagnostic and prognostic value is under intensive investigation. So far, clinical decision just based on biomarker assessment is not yet feasible. However, biomarkers should be considered as a complementary approach.

Use of early biomarkers in neonatal brain damage and sepsis: state of the art and future perspectives

The identification of early noninvasive biochemical markers of disease is a crucial issue of the current scientific research, particularly during the first period of life, since it could provide useful and precocious diagnostic information when clinical and radiological signs are still silent. The ideal biomarker should be practical and sensitive in the precocious identification of at risk patients. An earlier diagnosis may lead to a larger therapeutic window and improve neonatal outcome. Brain damage and sepsis are common causes of severe morbidity with poor outcome and mortality during the perinatal period. A large number of potential biomarkers, including neuroproteins, calcium binding proteins, enzymes, oxidative stress markers, vasoactive agents, and inflammatory mediators, have been so far investigated. The aim of the present review was to provide a brief overview of some of the more commonly investigated biomarkers used in case of neonatal brain damage and sepsis.

A review of equine sepsis

Sepsis is defined as an exaggerated, systemic inflammatory response to infection and is a common condition in horses. Systemic inflammatory response syndrome (SIRS) associated with bacterial infection is a hallmark of sepsis. Sepsis in neonatal foals is a common sequela of failure of passive transfer and, in addition to development of SIRS, may be characterised by bacteraemia, pneumonia, enterocolitis, omphalophlebitis, meningoencephalitis or arthritis. Sepsis in mature horses is most commonly observed secondary to gastrointestinal lesions that result in disrupted mucosa and bacterial translocation into circulation (endotoxaemia). Pleuropneumonia and metritis may also cause sepsis in mature horses. Diagnosis of sepsis is based on SIRS criteria as well as suspected or confirmed infection. Due to the relatively low sensitivity of microbial culture and the subjectivity of sepsis scoring, many sepsis biomarkers are being studied for their usefulness in diagnosis and prognostication of sepsis in horses. Treatment of sepsis requires an intensive care approach that includes antimicrobial drug administration, fluid resuscitation and pressure support, and treatment for inflammation, endotoxaemia and coagulopathy. Early recognition of sepsis and prompt antimicrobial drug treatment are critical for a successful outcome. Multiple organ dysfunction syndrome may occur in severe cases of sepsis, with common manifestations including laminitis and coagulopathies. Although prognosis for septic mature horses depends highly on the primary disease process, the overall survival rate in septic neonatal foals ranges from 26 to 86%, with most studies indicating a survival rate of 45-60%.

The influence of diabetes mellitus on midregional proadrenomedullin concentrations and prognostic value in heart failure outpatients

BACKGROUND

Diabetes mellitus (DM) is associated with an adverse outcome in heart failure (HF). Increased concentrations of midregional proadrenomedullin (MR-proADM) have been associated with DM and are predictors of mortality in HF patients. The aim of this study was to elucidate the impact of DM on MR-proADM concentrations and the prognostic value regarding all-cause mortality and hospitalization among HF patients.

METHODS AND RESULTS

We included 366 patients from an HF clinic; 69 (19%) had a history of DM and 40 (11%) had newly diagnosed DM (HbA1c ≥48 mmol/mol). The median MR-proADM concentration was unaffected by DM status (P = .20) but increased in HF patients with impaired renal function (P < .001). During a median follow-up of 55 months, 189 died, and 292 either died or were hospitalized. After adjustment for clinically relevant parameters, MR-proADM was associated with all-cause mortality (hazard ratio [HR] 1.3, 95% confidence interval [CI] 1.1-1.4; P = .01) and the combined end point of death and hospitalization (HR 1.2, 95% CI 1.1-1.4; P = .02) per 1 SD increment of ln-transformed variable. No interaction between DM and MR-proADM was found regarding mortality or hospitalization.

CONCLUSIONS

Diabetes status had no impact on MR-proADM concentrations or in the predictive ability of MR-proADM in HF patients.

Plasma adrenomedullin concentrations in critically ill neonatal foals

Background

Bacterial sepsis remains a leading cause of morbidity and mortality in neonatal foals, but accurate diagnostic and prognostic markers are lacking. Adrenomedullin (AM) is a polypeptide with diverse biologic effects on the cardiovascular system that increases in septic humans and laboratory animals.

Hypotheses

Plasma AM concentration (p[AM]) is increased in septic neonatal foals compared to sick nonseptic and healthy control foals, and p[AM] is predictive of survival in septic neonatal foals.

Animals

Ninety critically ill (42 septic, 48 sick nonseptic) and 61 healthy foals <1 week of age.

Methods

A prospective observational clinical study was performed. Venous blood was collected from critically ill foals at admission and from healthy foals at 24 hours of age. Critically ill foals were categorized as septic or sick nonseptic based on blood culture results and sepsis score. Plasma [AM] was measured by using a commercially available ELISA for horses. Data were analyzed by using the Mann‐Whitney U‐test and P < .05 was considered significant.

Results

Plasma [AM] was not significantly different between septic and sick nonseptic foals (P = .71), but critically ill foals had significantly increased p[AM] compared to healthy controls (P < .0001). In critically ill foals, p[AM] was not predictive of survival (P = .051). A p[AM] cutoff concentration of 0.041 ng/mL provided a test sensitivity of 91% and specificity of 54% to predict illness.

Conclusions and Clinical Relevance

Plasma [AM] shows promise as a marker of health in neonatal foals, but p[AM] increases nonspecifically during perinatal illnesses and is not necessarily associated with sepsis.

Laboratory detection of sepsis: biomarkers and molecular approaches

Sepsis, severe sepsis, and septic shock cause significant morbidity and mortality worldwide. Rapid diagnosis and therapeutic interventions are desirable to improve the overall mortality in patients with sepsis. However, gold standard laboratory diagnostic methods for sepsis, pose a significant challenge to rapid diagnosis of sepsis by physicians and laboratories. This article discusses the usefulness and potential of biomarkers and molecular test methods for a more rapid clinical and laboratory diagnosis of sepsis. Because new technologies are quickly emerging, physicians and laboratories must appreciate the key factors and characteristics that affect the clinical usefulness and diagnostic accuracy of these test methodologies.