Circulating adrenomedullin estimates survival and reversibility of organ failure in sepsis: the prospective observational multinational Adrenomedullin and Outcome in Sepsis and Septic Shock-1 (AdrenOSS-1) study

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.

Navigating the Modern Landscape of Sepsis: Advances in Diagnosis and Treatment

Sepsis poses a significant threat to human health due to its high morbidity and mortality rates worldwide. Traditional diagnostic methods for identifying sepsis or its causative organisms are time-consuming and contribute to a high mortality rate. Biomarkers have been developed to overcome these limitations and are currently used for sepsis diagnosis, prognosis prediction, and treatment response assessment. Over the past few decades, more than 250 biomarkers have been identified, a few of which have been used in clinical decision-making. Consistent with the limitations of diagnosing sepsis, there is currently no specific treatment for sepsis. Currently, the general treatment for sepsis is conservative and includes timely antibiotic use and hemodynamic support. When planning sepsis-specific treatment, it is important to select the most suitable patient, considering the heterogeneous nature of sepsis. This comprehensive review summarizes current and evolving biomarkers and therapeutic approaches for sepsis.

Postoperative bioactive adrenomedullin is associated with the onset of ARDS and adverse outcomes in patients undergoing open thoracoabdominal aortic surgery

Cytokine-mediated systemic inflammation after open thoracoabdominal aortic aneurysm (TAAA) repairs plays a pivotal role in disrupting circulatory homeostasis, potentially leading to organ dysfunction. The bioactive form of adrenomedullin (bio-ADM) is a peptide hormone with immunomodulatory and vasomotor effects, making it a potential diagnostic agent in these cases. This retrospective, bicentric study, conducted between January 2019 and December 2022, recruited 36 elective open TAAA repair patients in two German centres. Serum and plasma samples were collected at multiple time points to measure bio-ADM levels. The primary objective was to evaluate the association of bio-ADM levels with the onset of acute respiratory distress syndrome (ARDS), with secondary endpoints focusing on mortality and SIRS-related morbidity. Results showed a significant association between postoperative bio-ADM levels (12-48 h after surgery) and the onset of ARDS (p < .001), prolonged ventilation (p = .015 at 12h after surgery), atrial fibrillation (p < .001), and mortality (p = .05 at 24h). The biomarker was also strongly associated with sepsis (p = .01 at 12 h) and multi-organ dysfunction syndrome (MODS) (p = .02 at 24 h after surgery). The study underscores the potential utility of bio-ADM as a diagnostic tool for identifying patients at risk of postoperative complications following open TAAA repairs.

Biomarkers Improve Diagnostics of Sepsis in Adult Patients With Suspected Organ Dysfunction Based on the Quick Sepsis-Related Organ Failure Assessment (qSOFA) Score in the Emergency Department

OBJECTIVES

Consensus regarding biomarkers for detection of infection-related organ dysfunction in the emergency department is lacking. We aimed to identify and validate biomarkers that could improve risk prediction for overt or incipient organ dysfunction when added to quick Sepsis-related Organ Failure Assessment (qSOFA) as a screening tool.

DESIGN

In a large prospective multicenter cohort of adult patients presenting to the emergency department with a qSOFA score greater than or equal to 1, admission plasma levels of C-reactive protein, procalcitonin, adrenomedullin (either bioavailable adrenomedullin or midregional fragment of proadrenomedullin), proenkephalin, and dipeptidyl peptidase 3 were assessed. Least absolute shrinkage and selection operator regression was applied to assess the impact of these biomarkers alone or in combination to detect the primary endpoint of prediction of sepsis within 96 hours of admission.

SETTING

Three tertiary emergency departments at German University Hospitals (Jena University Hospital and two sites of the Charité University Hospital, Berlin).

PATIENTS

One thousand four hundred seventy-seven adult patients presenting with suspected organ dysfunction based on qSOFA score greater than or equal to 1.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The cohort was of moderate severity with 81% presenting with qSOFA = 1; 29.2% of these patients developed sepsis. Procalcitonin outperformed all other biomarkers regarding the primary endpoint (area under the curve for receiver operating characteristic [AUC-ROC], 0.86 [0.79-0.93]). Adding other biomarkers failed to further improve the AUC-ROC for the primary endpoint; however, they improved the model regarding several secondary endpoints, such as mortality, need for vasopressors, or dialysis. Addition of procalcitonin with a cutoff level of 0.25 ng/mL improved net (re)classification by 35.2% compared with qSOFA alone, with positive and negative predictive values of 60.7% and 88.7%, respectively.

CONCLUSIONS

Biomarkers of infection and organ dysfunction, most notably procalcitonin, substantially improve early prediction of sepsis with added value to qSOFA alone as a simple screening tool on emergency department admission.

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.

Bioactive adrenomedullin (bio-ADM) is associated with endothelial dysfunction in infants and children with complex congenital heart disease undergoing open-heart surgery on cardiopulmonary bypass

OBJECTIVES

Children with congenital heart disease (CHD) undergoing cardiac surgery on cardiopulmonary bypass (CPB) are at risk for systemic inflammation leading to endothelial dysfunction associated with increased morbidity. Bioactive adrenomedullin (bio-ADM) is a peptide regulating vascular tone and endothelial permeability. The aim of this study was to evaluate the dynamics of plasma bio-ADM in this patient cohort and its role in capillary leak.

METHODS

Plasma samples from 73 pediatric CHD patients were collected for bio-ADM measurement at five different timepoints (TP) in the pre-, intra-, and post-operative period. The primary endpoint was a net increase in bio-ADM levels after surgery on CPB. Secondary endpoints included association of bio-ADM levels with clinical signs for endothelial dysfunction.

RESULTS

Bio-ADM levels increased after surgery on CPB from pre-operative median of 12 pg/mL (IQR [interquartile range] 12.0-14.8 pg/mL) to a maximum post-operative median of 48.8 pg/mL (IQR 34.5-69.6 pg/mL, p<0.001). Bio-ADM concentrations correlated positively with post-operative volume balance, (r=0.341; p=0.005), increased demand for vasoactive medication (duration: r=0.415; p<0.001; quantity: TP3: r=0.415, p<0.001; TP4: r=0.414, p<0.001), and hydrocortisone treatment for vasoplegia (bio-ADM median [IQR]:129.1 [55.4-139.2] pg/mL vs. 37.9 [25.2-64.6] pg/mL; p=0.034). Patients who required pleural effusion drainage revealed higher bio-ADM levels compared to those who did not (median [IQR]: 66.4 [55.4-90.9] pg/mL vs. 40.2 [28.2-57.0] pg/mL; p<0.001).

CONCLUSIONS

Bio-ADM is elevated in children after cardiac surgery and higher levels correlate with clinical signs of capillary leakage. The peptide should be considered as biomarker for endothelial dysfunction and as potential therapeutic target in this indication.

Bioactive adrenomedullin and interleukin-6 in COVID-19: potential biomarkers of acute kidney injury and critical illness

BACKGROUND

The aim of this study was to investigate whether bioactive adrenomedullin (bio-ADM) and interleukin-6 (IL-6) are related to acute kidney injury (AKI) and severe illness in COVID-19 patients.

METHODS

153 patients with COVID-19 admitted to the emergency department (ED) were included. Blood samples were collected from each patient at admission. Bio-ADM and IL-6, as well as DPP3 and routinely measured markers were evaluated regarding the endpoints AKI (22/128 hospitalized patients) and a composite endpoint of admission to intensive care unit and/or in-hospital death (n = 26/153 patients).

RESULTS

Bio-ADM and IL-6 were significantly elevated in COVID-19 patients with AKI compared to COVID-19 patients without AKI (each p < 0.001). According to ROC analyses IL-6 and bio-ADM had the largest AUC (0.84 and 0.81) regarding the detection of AKI. Furthermore, bio-ADM and IL-6 were significantly elevated in COVID-19 patients reaching the composite endpoint (each p < 0.001). Regarding the composite endpoint ROC analysis showed an AUC of 0.89 for IL-6 and 0.83 for bio-ADM in COVID-19 patients. In the multivariable logistic model bio-ADM and IL-6 presented as independent significant predictors regarding both endpoints AKI and the composite endpoint in COVID-19 patients (as well as creatinine regarding the composite endpoint; each p < 0.05), opposite to leukocytes, C-reactive protein (CRP) and dipeptidyl peptidase 3 (DPP3; each p = n.s.).

CONCLUSION

Elevated levels of bio-ADM and IL-6 are associated with AKI and critical illness in patients with COVID-19. Therefore, both biomarkers may be potential tools in risk stratification in COVID-19 patients at presentation in the ED.

Mid-Regional Pro-Adrenomedullin Can Predict Organ Failure and Prognosis in Sepsis?

Sepsis causes immune dysregulation and endotheliitis, with an increase in mid-regional pro-adrenomedullin (MR-proADM). The aim of the study is to determine an MR-proADM value that, in addition to clinical diagnosis, can identify patients with localized infection or those with sepsis/septic shock, with specific organ damage or with the need for intensive care unit (ICU) transfer and prognosis. The secondary aim is to correlate the MR-proADM value with the length of stay (LOS). In total, 301 subjects with sepsis (124/301 with septic shock) and 126 with localized infection were retrospectively included. In sepsis, MR-proADM ≥ 3.39 ng/mL identified acute kidney injury (AKI); ≥2.99 ng/mL acute respiratory distress syndrome (ARDS); ≥2.28 ng/mL acute heart failure (AHF); ≥2.55 ng/mL Glascow Coma Scale (GCS) < 15; ≥3.38 multi-organ involvement; ≥3.33 need for ICU transfer; ≥2.0 Sequential Organ Failure Assessment (SOFA) score ≥ 2; and ≥3.15 ng/mL non-survivors. The multivariate analysis showed that MR-proADM ≥ 2 ng/mL correlates with AKI, anemia and SOFA score ≥ 2, and MR-proADM ≥ 3 ng/mL correlates with AKI, GCS < 15 and SOFA score ≥ 2. A correlation between mortality and AKI, GCS < 15, ICU transfer and cathecolamine administration was found. In localized infection, MR-proADM at admission ≥ 1.44 ng/mL identified patients with AKI; ≥1.0 ng/mL with AHF; and ≥1.44 ng/mL with anemia and SOFA score ≥ 2. In the multivariate analysis, MR-proADM ≥ 1.44 ng/mL correlated with AKI, anemia, SOFA score ≥ 2 and AHF. MR-proADM is a marker of oxidative stress due to an infection, reflecting severity proportionally to organ damage.

Inflammatory biomarkers to predict the prognosis of acute bacterial and viral infections

Mortality in acute infections is mostly associated with sepsis, defined as 'life-threatening organ dysfunction caused by a dysregulated host response to infection'. It remains challenging to identify the patients with increased mortality risk due to the high heterogeneity in the dysregulated host immune response and disease progression. Biomarkers reflecting different pathways involved in the inflammatory response might improve prediction of mortality risk (prognostic enrichment) among patients with acute infections by reducing heterogeneity of the host response, as well as suggest novel strategies for patient stratification and treatment (predictive enrichment) through precision medicine approaches. The predictive value of inflammatory biomarkers has been extensively investigated in bacterial infections and the recent COVID-19 pandemic caused an increased interest in inflammatory biomarkers in this viral infection. However, limited research investigated whether the prognostic potential of these biomarkers differs between bacterial and viral infections. In this narrative review, we provide an overview of the value of various inflammatory biomarkers for the prediction of mortality in bacterial and viral infections.

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.

Biomarker Enrichment in Sepsis-Associated Acute Kidney Injury: Finding High-Risk Patients in the Intensive Care Unit

BACKGROUND

Sepsis-associated acute kidney injury (AKI) is a leading comorbidity in admissions to the intensive care unit. While a gold standard definition exists, it remains imperfect and does not allow for the timely identification of patients in the setting of critical illness. This review will discuss the use of biochemical and electronic biomarkers to allow for prognostic and predictive enrichment of patients with sepsis-associated AKI over and above the use of serum creatinine and urine output.

SUMMARY

Current data suggest that several biomarkers are capable of identifying patients with sepsis at risk for the development of severe AKI and other associated morbidity. This review discusses these data and these biomarkers in the setting of sub-phenotyping and endotyping sepsis-associated AKI. While not all these tests are widely available and some require further validation, in the near future we anticipate several new tools to help nephrologists and other providers better care for patients with sepsis-associated AKI.

KEY MESSAGES

Predictive and prognostic enrichment using both traditional biomarkers and novel biomarkers in the setting of sepsis can identify subsets of patients with either similar outcomes or similar pathophysiology, respectively. Novel biomarkers can identify kidney injury in patients without consensus definition AKI (e.g., changes in creatinine or urine output) and can predict other adverse outcomes (e.g., severe consensus definition AKI, inpatient mortality). Finally, emerging artificial intelligence and machine learning-derived risk models are able to predict sepsis-associated AKI in critically ill patients using advanced learning techniques and several laboratory and vital sign measurements.

Prospective evaluation of the efficacy, safety, and optimal biomarker enrichment strategy for nangibotide, a TREM-1 inhibitor, in patients with septic shock (ASTONISH): a double-blind, randomised, controlled, phase 2b trial

BACKGROUND

Activation of the triggering receptor expressed on myeloid cells-1 (TREM-1) pathway is associated with septic shock outcomes. Data suggest that modulation of this pathway in patients with activated TREM-1 might improve survival. Soluble TREM-1 (sTREM-1), a potential mechanism-based biomarker, might facilitate enrichment of patient selection in clinical trials of nangibotide, a TREM-1 modulator. In this phase 2b trial, we aimed to confirm the hypothesis that TREM1 inhibition might improve outcomes in patients with septic shock.

METHODS

This double-blind, randomised, placebo-controlled, phase 2b trial assessed the efficacy and safety of two different doses of nangibotide compared with placebo, and aimed to identify the optimum treatment population, in patients across 42 hospitals with medical, surgical, or mixed intensive care units (ICUs) in seven countries. Non-COVID-19 patients (18-85 years) meeting the standard definition of septic shock, with documented or suspected infection (lung, abdominal, or urinary [in patients ≥65 years]), were eligible within 24 h of vasopressor initiation for the treatment of septic shock. Patients were randomly assigned in a 1:1:1 ratio to intravenous nangibotide 0·3 mg/kg per h (low-dose group), nangibotide 1·0 mg/kg per h (high-dose group), or matched placebo, using a computer-generated block randomisation scheme (block size 3). Patients and investigators were masked to treatment allocation. Patients were grouped according to sTREM-1 concentrations at baseline (established from sepsis observational studies and from phase 2a change to data) into high sTREM-1 (≥ 400 pg/mL). The primary outcome was the mean difference in total Sequential Organ Failure Assessment (SOFA) score from baseline to day 5 in the low-dose and high-dose groups compared with placebo, measured in the predefined high sTREM-1 (≥ 400 pg/mL) population and in the overall modified intention-to-treat population. Secondary endpoints included all-cause 28-day mortality, safety, pharmacokinetics, and evaluation of the relationship between TREM-1 activation and treatment response. This study is registered with EudraCT, 2018-004827-36, and Clinicaltrials.gov, NCT04055909.

FINDINGS

Between Nov 14, 2019, and April 11, 2022, of 402 patients screened, 355 were included in the main analysis (116 in the placebo group, 118 in the low-dose group, and 121 in the high-dose group). In the preliminary high sTREM-1 population (total 253 [71%] of 355; placebo 75 [65%] of 116; low-dose 90 [76%] of 118; high-dose 88 [73%] of 121), the mean difference in SOFA score from baseline to day 5 was 0·21 (95% CI -1·45 to 1·87, p=0·80) in the low-dose group and 1·39 (-0·28 to 3·06, p=0·104) in the high-dose group versus placebo. In the overall population, the difference in SOFA score from baseline to day 5 between the placebo group and low-dose group was 0·20 (-1·09 to 1·50; p=0·76),and between the placebo group and the high-dose group was 1·06 (-0·23 to 2·35, p=0·108). In the predefined high sTREM-1 cutoff population, 23 (31%) patients in the placebo group, 35 (39%) in the low-dose group, and 25 (28%) in the high-dose group had died by day 28. In the overall population, 29 (25%) patients in the placebo, 38 (32%) in the low-dose, and 30 (25%) in the high-dose group had died by day 28. The number of treatment-emergent adverse events (111 [96%] patients in the placebo group, 113 [96%] in the low-dose group, and 115 [95%] in the high-dose group) and serious treatment-emergent adverse events (28 [24%], 26 [22%], and 31 [26%]) was similar between all three groups. High-dose nangibotide led to a clinically relevant improvement in SOFA score (of two points or more) from baseline to day 5 over placebo in those with higher cutoff concentrations (≥532 pg/mL) of sTREM-1 at baseline. Low dose nangibotide displayed a similar pattern with lower magnitude of effect across all cutoff values.

INTERPRETATION

This trial did not achieve the primary outcome of improvement in SOFA score at the predefined sTREM-1 value. Future studies are needed to confirm the benefit of nangibotide at higher concentrations of TREM-1 activation.

FUNDING

Inotrem.

Distinct host-response signatures in circulatory shock: a narrative review

Circulatory shock is defined syndromically as hypotension associated with tissue hypoperfusion and often subcategorized according to hemodynamic profile (e.g., distributive, cardiogenic, hypovolemic) and etiology (e.g., infection, myocardial infarction, trauma, among others). These shock subgroups are generally considered homogeneous entities in research and clinical practice. This current definition fails to consider the complex pathophysiology of shock and the influence of patient heterogeneity. Recent translational evidence highlights previously under-appreciated heterogeneity regarding the underlying pathways with distinct host-response patterns in circulatory shock syndromes. This heterogeneity may confound the interpretation of trial results as a given treatment may preferentially impact distinct subgroups. Re-analyzing results of major 'neutral' treatment trials from the perspective of biological mechanisms (i.e., host-response signatures) may reveal treatment effects in subgroups of patients that share treatable traits (i.e., specific biological signatures that portend a predictable response to a given treatment). In this review, we discuss the emerging literature suggesting the existence of distinct biomarker-based host-response patterns of circulatory shock syndrome independent of etiology or hemodynamic profile. We further review responses to newly prescribed treatments in the intensive care unit designed to personalize treatments (biomarker-driven or endotype-driven patient selection in support of future clinical trials).

Peptidylglycine α-amidating monooxygenase and adrenomedullin measurement in patients with hepatic cirrhosis

Background: Peptidylglycine α-amidating monooxygenase (PAM) is an enzyme involved in the maturation of regulatory peptides. Here we examined PAM activity and adrenomedullin (bio-ADM) concentrations in patients with hepatic cirrhosis and determined net changes across the liver, kidneys and leg. Materials & methods: A total of 48 patients with hepatic cirrhosis and 16 control subjects were included. All patients and controls underwent an invasive procedure with blood collected across organs. Results: PAM activity was increased in cirrhotic patients but without a net change across the liver, leg or kidney. In contrast, bio-ADM concentrations were associated with severity of disease and found to be higher in venous blood from the liver. Conclusion: Increased PAM activity in patients with hepatic cirrhosis may reflect other organs involved in cirrhotic disease.

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.

Plasma bioactive adrenomedullin predicts outcome after acute stroke in early rehabilitation

An early and reliable prediction of outcomes after stroke is important for early effective stroke management and the adequate optimal planning of post-stroke rehabilitation and long-term care. Bioactive adrenomedullin (bio-ADM) is a 52-amino acid peptide that is an important peptide hormone in nervous system diseases. The aim of this study was to investigate the prognostic value of bio-ADM on outcomes after rehabilitation in patients with stroke. A total of 557 consecutive patients with a primary diagnosis of ischemic or hemorrhagic stroke (age 69.6-12.9 years, male 51.3%, ischemic stroke 72.5%), who were admitted to an in-patient early rehabilitation center directly after discharge from acute stroke hospital care, were enrolled in this prospective observational study. Plasma concentrations of bio-ADM were determined by using a chemiluminescence immunoassay (functional assay sensitivity 8 pg/ml). The early rehabilitation barthel index (ERBI) was used for the neurological assessment of the patients. The plasma bio-ADM level was analyzed in association with 6-month all-cause mortality as well as a composite outcome of all-cause mortality, unscheduled re-hospitalization, or transfer to a long-term care facility in a vegetative or minimally conscious state. Bio-ADM levels significantly increased in patients with ischemic stroke who died compared to surviving patients (40.4 pg/ml vs. 23.8 pg/ml, p < 0.001) or in those with composite outcomes compared to those with no events (36.9 pg/ml vs. 23.5 pg/ml, p < 0.001). Six-month all-cause mortality was higher in all patients with bio-ADM levels > 70 pg/ml (HR 4.83 [CI 2.28-10.2]). Patients with bio-ADM levels > 70 pg/ml also had higher rates of 6-month composite outcomes (HR 3.82 [CI 2.08-7.01]). Bio-ADM was an independent predictor of all-cause mortality and 6-month composite outcomes after adjusting for age, gender, and ERBI (adjusted OR 1.5; 95% CI 1.0-2.1; p = 0.047 and adjusted OR 1.48; 95% CI 1.1-2.0; p = 0.01, respectively). Bio-ADM may be a suitable novel biomarker to assess the outcomes of patients in rehabilitation after acute stroke. Elevated bio-ADM concentrations may have prognostic value for fatal and nonfatal events in patients with ischemic stroke during early rehabilitation.

Plasma bioactive adrenomedullin on intensive care unit admission is associated with acute respiratory distress syndrome: an observational study

BACKGROUND

Bioactive adrenomedullin (bio-ADM) is a vasoactive peptide with a key role in reducing vascular hyperpermeability and improving endothelial stability during infection, but it also has vasodilatory properties. Bioactive ADM has not been studied in conjunction with acute respiratory distress syndrome (ARDS), but it has recently been shown to correlate with outcomes after severe COVID-19. Therefore, this study investigated the association between circulating bio-ADM on intensive care unit (ICU) admission and ARDS. The secondary aim was the association between bio-ADM and ARDS mortality.

METHODS

We analysed bio-ADM levels and assessed the presence of ARDS in adult patients admitted to two general intensive care units in southern Sweden. Medical records were manually screened for the ARDS Berlin criteria. The association between bio-ADM levels and ARDS and mortality in ARDS patients was analysed using logistic regression and receiver-operating characteristics analysis. The primary outcome was an ARDS diagnosis within 72 h of ICU admission, and the secondary outcome was 30-day mortality.

RESULTS

Out of 1224 admissions, 11% (n = 132) developed ARDS within 72 h. We found that elevated admission bio-ADM level was associated with ARDS independently of sepsis status and of organ dysfunction as measured by the Sequential organ failure assessment (SOFA) score. Both lower levels (< 38 pg/L) and high (> 90 pg/L) levels of bio-ADM were independently (of the Simplified acute physiology score, SAPS-3) predictive of mortality. Patients with indirect mechanisms of lung injury had higher bio-ADM levels than those with a direct mechanism of injury, and bio-ADM increased with increasing ARDS severity.

CONCLUSIONS

High levels of bio-ADM on admission are associated with ARDS, and bio-ADM levels significantly differ depending on the injury mechanism. In contrast, both high and low levels of bio-ADM are associated with mortality, possibly due to the dual action of bio-ADM in stabilising the endothelial barrier and causing vasodilation. These findings could lead to improved diagnostic accuracy of ARDS and potentially lead to new therapeutic strategies.

Biomarkers as Prognostic Predictors and Therapeutic Guide in Critically Ill Patients: Clinical Evidence

A biomarker is a molecule that can be measured in a biological sample in an objective, systematic, and precise way, whose levels indicate whether a process is normal or pathological. Knowing the most important biomarkers and their characteristics is the key to precision medicine in intensive and perioperative care. Biomarkers can be used to diagnose, in assessment of disease severity, to stratify risk, to predict and guide clinical decisions, and to guide treatments and response to them. In this review, we will analyze what characteristics a biomarker should have and how to ensure its usefulness, and we will review the biomarkers that in our opinion can make their knowledge more useful to the reader in their clinical practice, with a future perspective. These biomarkers, in our opinion, are lactate, C-Reactive Protein, Troponins T and I, Brain Natriuretic Peptides, Procalcitonin, MR-ProAdrenomedullin and BioAdrenomedullin, Neutrophil/lymphocyte ratio and lymphopenia, Proenkephalin, NefroCheck, Neutrophil gelatinase-associated lipocalin (NGAL), Interleukin 6, Urokinase-type soluble plasminogen activator receptor (suPAR), Presepsin, Pancreatic Stone Protein (PSP), and Dipeptidyl peptidase 3 (DPP3). Finally, we propose an approach to the perioperative evaluation of high-risk patients and critically ill patients in the Intensive Care Unit (ICU) based on biomarkers.

Biomarker-Based Prediction of Survival and Recovery of Kidney Function in Acute Kidney Injury

BACKGROUND

Acute kidney injury (AKI) affects increasing numbers of hospitalized patients; the prognosis remains poor. The diagnosis is still based on the 2012 published KDIGO criteria. Numerous new AKI biomarkers have been identified in recent years; they either reflect impaired excretory function or structural damage. The majority of markers are useful for AKI recognition under certain circumstances. Fewer data are available on the role of biomarkers in the prediction of in-hospital survival and renal recovery post-AKI. The current article is intended to provide information about these two aspects.

SUMMARY

The following databases were screened: PubMed, Web of Science, Cochrane Library, Scopus. The period lasted from 2000 until 2022. The following terms were applied: "AKI" AND "biomarker" AND "survival" OR "mortality" OR "recovery of kidney function" OR "renal recovery" OR "kidney recovery". The following terms were used for additional literature search: "TIMP-2" AND "IGFBP7" and "RNA biomarker" AND "hematology". Regarding mortality, exclusively those studies were selected that addressed the in-hospital mortality. Nine (9) studies were identified that evaluated biomarker-based prediction of in-hospital mortality and/or of recovery of kidney function (ROKF). A homogenous definition of ROKF is however missing yet. Currently, some biomarkers, measured early during the course of the disease, are associated with increased mortality risk and/or with a higher chance of renal recovery.

KEY MESSAGES

The literature provides only a few biomarker-related studies that address the issues of mortality and recovery. The definition of ROKF needs to be homogenized.

Procalcitonin and Adrenomedullin in Infectious Diseases

Calcitonin (CT) and adrenomedullin (ADM) are members of the CT family. Procalcitonin (PCT) is a prohormone of CT. Elevations in serum PCT and ADM levels are associated with severe sepsis and coronavirus disease 2019 (COVID-19). PCT enhances sepsis mortality and it binds to the CGRP receptor, which is a heterodimer of CT receptor-like receptor and receptor activity-modifying protein 1. The N-terminal truncated form of PCT, PCT3-116, is produced by the cleavage of PCT by dipeptidyl peptidase 4 (DPP-4) and is the main form of PCT in serum during sepsis, inducing microvascular permeability. Mid-regional pro-adrenomedullin (MR-proADM) is used instead of ADM as a biological indicator because ADM is rapidly degraded, and MR-proADM is released at the same rate as ADM. ADM reduces endothelial permeability and promotes endothelial stability. Endothelial dysfunction is responsible for multiple organ failure in sepsis and COVID-19 patients. Therefore, ADM may be an important molecule for improving the severity associated with sepsis and COVID-19. This review focuses on the current knowledge of PCT and ADM in sepsis and COVID-19.

Proenkephalin A and bioactive adrenomedullin are useful for risk prognostication in cardiac surgery

Introduction

Various clinical scores have been developed to predict organ dysfunction and mortality in patients undergoing cardiac surgery, but outcome prediction may be inaccurate for some patient groups. Proenkephalin A (penKid) and bioactive adrenomedullin (bio-ADM) have emerged as promising biomarkers correlating with shock and organ dysfunction. This imposes the question of whether they can be used as prognostic biomarkers for risk stratification in the perioperative setting of cardiac surgery.

Methods

Patients undergoing cardiac surgery were prospectively enrolled in this observational study. PenKid and bio-ADM plasma levels, as well as markers evaluating inflammation and organ dysfunction, were measured at five perioperative time points from before the induction of anesthesia to up to 48 h postoperatively. Clinical data regarding organ dysfunction and patient outcomes were recorded during the intensive care unit (ICU)-stay with a special focus on acute kidney injury (AKI).

Results

In 136 patients undergoing cardiac surgery, the bio-ADM levels increased and the penKid levels decreased significantly over time. PenKid was associated with chronic kidney disease (CKD), the incidence of AKI, and renal replacement therapy (RRT). Bio-ADM was associated with lactate and the need for vasopressors. PenKid was useful to predict an ICU-length of stay (LOS)>1 day and added prognostic value to the European System for Cardiac Operative Risk Evaluation Score (EuroSCORE) II when measured after the end of cardiopulmonary bypass and 24 h after cardiac surgery. For bio-ADM, the same was true when measured 24 h after surgery. PenKid also added prognostic value to the EuroSCORE II for the combined outcome "ICU length of stay >1 day and in-hospital mortality."

Conclusion

The combination of preoperative EuroSCORE II and intraoperative measurement of penKid may be more useful to predict a prolonged ICU LOS and increased mortality than EuroSCORE II alone. Bio-ADM correlates with markers of shock. More research is encouraged for early risk stratification and validation of penKid and bio-ADM as a tool involved in clinical decisions, which may enable the early initiation of organ protective strategies.

Circulating dipeptidyl peptidase 3 and bio-adrenomedullin levels are associated with impaired outcomes in critically ill COVID-19 patients: a prospective international multicentre study

Introduction

Dipeptidyl peptidase-3 (DPP3) is a protease involved in the degradation of several cardiovascular mediators. Adrenomedullin (bio-ADM) is a peptide essential for regulation of endothelial barrier function. In different shock-pathologies, both biomarkers are associated with disease severity, organ dysfunction and mortality. Associations with outcome in critically ill COVID-19 patients are unknown. The objectives of the present study were to investigate associations of bio-ADM and "circulating DPP3" (cDPP3) with short-term outcome in critically ill COVID-19 patients (n=80).

Methods

A multicentre prospective cohort study was performed. The primary end-point was 28-day mortality. Secondary end-points included different severities of acute kidney injury (AKI).

Results

cDPP3 levels were mainly associated with 28-day mortality; Area under the receiver operating characteristics (AUROCs) of 0.69 (0.56-0.82, p=0.023), 0.77 (0.64-0.90, p<0.001) and 0.81 (0.65-0.96, p<0.001) at admission, day 3 and day 7, respectively. In contrast, bio-ADM levels were mainly associated with AKI, with AUROCs of 0.64 (0.51-0.77, p=0.048), 0.75 (0.64-0.86, p<0.001) and 0.83 (0.74-0.93, p<0.001) for day 1, 3 and 7, respectively. Interestingly, patients with high levels of both cDPP3 and bio-ADM at day 7 had an additionally increased risk of 28-day mortality (hazard ratio 11.8; 95% CI 2.5-55.3, p<0.001).

Conclusions

cDPP3 and bio-ADM responses were associated with short-term mortality and AKI in critically ill COVID-19 patients, respectively. These findings suggest that treatment with specific antibodies modulating cDPP3 or bio-ADM-related pathways may improve outcome of COVID-19.

Utility of Measuring Circulating Bio-Adrenomedullin and Proenkephalin for 30-Day Mortality Risk Prediction in Patients with COVID-19 and Non-COVID-19 Interstitial Pneumonia in the Emergency Department

Background and Objectives: In order to accelerate the risk stratification of patients referred to the Emergency Department (ED) with interstitial pneumonia, it could be useful to provide new and effective laboratory tests for use. The aim of our study was to evaluate the prognostic role of two biomarkers, bio-adrenomedullin (Bio-ADM) and proenkephalin (penKid), in patients with interstitial pneumonia (IP) at ED admission. Materials and Methods: In 153 consecutive patients with IP, both from COVID-19 or non-COVID-19 etiology, we measured, in a prospective observational manner, penKid and Bio-ADM at ED admission and after 24 h. In order to evaluate patient outcomes, 30-day follow-ups were also performed. The endpoints were 24 h, 10-day, and 30-day mortality. Results: Both biomarkers were shown to be good predictors of adverse events at 30 days, with Bio-ADM outperforming penKid. Bio-ADM was linked with 24 h and 10-day patient mortality. Moreover, PenKid was related to parameters defining worsening kidney function. Conclusions: Both in patients with COVID-19 or non-COVID-19 interstitial pneumonia at ED admission, Bio-ADM and penKid were good predictors of patient mortality. To evaluate these two biomarkers could be considered to be useful during the first evaluation in the ED when integrated with clinical scores.

30 Days Mortality Prognostic Value of POCT Bio-Adrenomedullin and Proenkephalin in Patients with Sepsis in the Emergency Department

Background and Objective: Sepsis is a worldwide severe disease with a high incidence and mortality rate. Sepsis is a frequent cause of admission to the emergency department (ED). Although prognostic scores (Sequential Organ Failure Assessment, SOFA; New Early Warning Score, NEWS; Rapid Emergency Medicine Score, REMS) are commonly used for risk stratification in septic patients, many of these scores are of poor utility in the ED. In this setting, biomarkers are promising alternatives, easier to perform and potentially more specific. Bio-adrenomedullin (Bio-ADM) and Proenkephalin (PenKid) seem to have a key role in the development of organ dysfunctions induced by sepsis and, therefore, could help in the risk stratification of patients with sepsis at ED admission. The aim of this study was to evaluate the utility of Bio-ADM and PenKid, obtained through a point of care (POCT) device, in predicting 30 days mortality for patients presenting to the ED with sepsis. Methods and Results: In total, 177 consecutive adult patients with a diagnosis of sepsis presenting to the ED of San Giovanni Addolorata Hospital in Rome, Italy, between May 2021 and April 2022 were enrolled in this prospective observational study. For each patient, Bio-ADM and PenKid were obtained at ED admission together with SOFA, NEWS and REMS scores. Next, 30 days follow-up data were collected to evaluate patient mortality. Both biomarkers (Bio-ADM and PenKid) and clinical scores (SOFA, NEWS and REMS) were good predictors of mortality at 30 days, with Bio-ADM and REMS outperforming the others. Moreover, PenKid resulted in being linked with the worsening of kidney function. Conclusions: In patients presenting with sepsis in the ED, Bio-ADM and PenKid, evaluated with a POCT device, predicted 30-day mortality. These two biomarkers seem even more useful when integrated with clinical risk scores at ED admission.

Sepsis biomarkers and diagnostic tools with a focus on machine learning

Over the last years, there have been advances in the use of data-driven techniques to improve the definition, early recognition, subtypes characterisation, prognostication and treatment personalisation of sepsis. Some of those involve the discovery or evaluation of biomarkers or digital signatures of sepsis or sepsis sub-phenotypes. It is hoped that their identification may improve timeliness and accuracy of diagnosis, suggest physiological pathways and therapeutic targets, inform targeted recruitment into clinical trials, and optimise clinical management. Given the complexities of the sepsis response, panels of biomarkers or models combining biomarkers and clinical data are necessary, as well as specific data analysis methods, which broadly fall under the scope of machine learning. This narrative review gives a brief overview of the main machine learning techniques (mainly in the realms of supervised and unsupervised methods) and published applications that have been used to create sepsis diagnostic tools and identify biomarkers.

Effects of enrichment strategies on outcome of adrecizumab treatment in septic shock: Post-hoc analyses of the phase II adrenomedullin and outcome in septic shock 2 trial

PURPOSE

Adrecizumab, a non-neutralizing antibody of adrenomedullin (ADM) was recently investigated regarding its potential to restore endothelial barrier function in septic shock patients with high plasma ADM levels. Circulating dipeptidyl peptidase 3 (cDPP3), a protease involved in the degradation of several cardiovascular mediators, represents another biological pathway strongly associated with outcome in septic shock, although unrelated to ADM. Therefore, the prognosis of patients with elevated cDPP3 may not be influenced by Adrecizumab. Also, time until initiation of treatment may influence efficacy.

OBJECTIVE

To evaluate effects of cDPP3-based enrichment on treatment efficacy of Adrecizumab.

MATERIALS AND METHODS

Post-hoc analysis of AdrenOSS-2, a phase-II, double-blind, randomized, placebo-controlled biomarker-guided trial of Adrecizumab.

RESULTS

Compared to the total study cohort [HR for 28-day mortality of 0.84 (95% CI 0.53;1.31), p = 0.439], therapeutic benefit of Adrecizumab tended to be more pronounced in the subgroup of 249 patients with low cDPP3 (<50 ng/mL); [HR of 0.61 (95% CI 0.34;1.08), p = 0.085]. Median duration to study drug infusion was 8.5 h. In the subgroup of 129 patients with cDPP3 <50 ng/mL and an early start of treatment (<8.5 h after septic shock diagnosis) HR for 28-day mortality vs. placebo was 0.49 (95% CI 0.21-1.18), p = 0.105. In multivariate interaction analyses corrected for baseline disease severity, both cDPP3, as well as the cDPP3 * treatment interaction term were associated with a reduced HR for 28-day mortality in the Adrecizumab treated group; p = 0.015 for cDPP3 in univariate analysis, p = 0.025 for the interaction term between cDPP3 and treatment group. In contrast, treatment timing was not significantly associated with 28-day mortality in multivariate interaction analyses.

DISCUSSION

In septic shock patients with high ADM levels, a further post-hoc enrichment strategy based on cDPP3 may indicate (with all the caveats to be considered for post-hoc subgroup analyses) that therapeutic efficacy is most pronounced in patients with lower cDPP3 levels.

Prognostic value of proadrenomedullin in patients with COVID-19 pneumonia

Objective

The aim of the study was to assess the role of mid-regional proadrenomedullin (MR-proADM) in comparison with routine laboratory tests in patients with COVID-19.

Materials and methods

140 hospitalized patients aged 18 and older with COVID-19 pneumonia were included in prospective single-center study. Routine analyses were performed, and MR-proADM level was measured within the first and the third hospital days using Human MR pro-ADM (Mid-regional pro-adrenomedullin) ELISA Kit with a sensitivity of 0.469 pmol/L (immunofluorescence assay). National Early Warning Score (NEWS) was used for primary assessment of the disease severity. According to disease outcome the patients were divided into two groups: discharged patients (n = 110, 78.6%) and deceased patients (n = 30, 21.4%). Results: The groups had no statistically significant difference in sex, comorbidity, body temperature, oxygen saturation level, heart rate, respiratory rate, and C-reactive protein (CRP) level and procalcitonin (PCT). The deceased patients had statistically significant difference in age (median, 76 years; interquartile range, 73.2–78.2 vs. median, 66 years; interquartile range, 62–67; p < 0.0001), NEWS value (median, 5; interquartile range, 3–8 vs. median, 2; interquartile range, 0–6; p <0.05), hospitalization period (median, 17; interquartile range, 7–35 vs. median, 6; interquartile range, 3–14), quantitative CT extent of lung damage > 50% [n = 26 (86.7%) vs. n = 9 (8.2%) p < 0.0001], level of leukocytes (median, 11.4 ×109/L; interquartile range, 6.2–15.5 vs. median, 5.3 ×109/L; interquartile range, 4.7–6.4; p = 0.003), level of neutrophils (median, 80.9%; interquartile range, 73.6–88.6 vs. median, 72.6%; interquartile range, 68.7–76.9; p = 0.027), level of MR-proADM at the first hospital day (median, 828.6 pmol/L; interquartile range, 586.4–1,184.6 vs. median, 492.6 pmol/L; interquartile range, 352.9–712.2; p = 0.02), and level of MR-proADM at the third hospital day (median, 1,855.2 pmol/L; interquartile range, 1,078.4–2,596.5 vs. median, 270.7 pmol/L; interquartile range, 155.06–427.1).

Conclusion

Mid-regional proadrenomedullin has a higher prognostic value in patients with COVID-19 in comparison with routine inflammatory markers (leukocyte and neutrophils levels, CRP, and PCT) and NEWS.

Biologically Active Adrenomedullin (bio-ADM) is of Potential Value in Identifying Congestion and Selecting Patients for Neurohormonal Blockade in Acute Dyspnea

PURPOSE

This study was designed to evaluate the role of biologically active adrenomedullin (bio-ADM) in congestion assessment and risk stratification in acute dyspnea.

METHODS

This is a sub-analysis of the Lithuanian Echocardiography Study of Dyspnea in Acute Settings. Congestion was assessed by means of clinical (peripheral edema, rales) and sonographic (estimated right atrial pressure) parameters. Ninety-day mortality was chosen for outcome analysis.

RESULTS

There were 1188 patients included. Bio-ADM concentration was higher in patients with peripheral edema at admission (48.2 [28.2-92.6] vs 35.4 [20.9-59.2] ng/L, P < .001). There was a stepwise increase in bio-ADM concentration with increasing prevalence of rales: 29.8 [18.8-51.1], 38.5 [27.5-67.1], and 51.1 [33.1-103.2] ng/L in patients with no rales, rales covering less than one-half, and greater than or equal to one-half of the pulmonary area, respectively (P < 0.001). Bio-ADM concentration demonstrated gradual elevation in patients with normal, moderately, and severely increased estimated right atrial pressure: 25.1 [17.6-42.4] ng/L, 36.1 [23.1-50.2], and 47.1 [30.7-86.7] ng/L, respectively (P < .05). Patients with bio-ADM concentration >35.5 ng/L were at more than twofold increased risk of dying (P < .001). Survival in those with high bio-ADM was significantly modified by neurohormonal blockade at admission (P < .05), especially if NT-proBNP levels were lower than the median (P = .002 for interaction).

CONCLUSION

Bio-ADM reflects the presence and the degree of pulmonary, peripheral, and intravascular volume overload and is strongly related to 90-day mortality in acute dyspnea. Patients with high bio-ADM levels demonstrated survival benefit from neurohormonal blockade.

Regulation and Dysregulation of Endothelial Permeability during Systemic Inflammation

Systemic inflammation can be triggered by infection, surgery, trauma or burns. During systemic inflammation, an overshooting immune response induces tissue damage resulting in organ dysfunction and mortality. Endothelial cells make up the inner lining of all blood vessels and are critically involved in maintaining organ integrity by regulating tissue perfusion. Permeability of the endothelial monolayer is strictly controlled and highly organ-specific, forming continuous, fenestrated and discontinuous capillaries that orchestrate the extravasation of fluids, proteins and solutes to maintain organ homeostasis. In the physiological state, the endothelial barrier is maintained by the glycocalyx, extracellular matrix and intercellular junctions including adherens and tight junctions. As endothelial cells are constantly sensing and responding to the extracellular environment, their activation by inflammatory stimuli promotes a loss of endothelial barrier function, which has been identified as a hallmark of systemic inflammation, leading to tissue edema formation and hypotension and thus, is a key contributor to lethal outcomes. In this review, we provide a comprehensive summary of the major players, such as the angiopoietin-Tie2 signaling axis, adrenomedullin and vascular endothelial (VE-) cadherin, that substantially contribute to the regulation and dysregulation of endothelial permeability during systemic inflammation and elucidate treatment strategies targeting the preservation of vascular integrity.

Bioactive adrenomedullin in sepsis patients in the emergency department is associated with mortality, organ failure and admission to intensive care

Background

Adrenomedullin is a vasoactive hormone with potentially prognostic and therapeutic value, which mainly has been investigated in intensive care unit (ICU) settings. The triaging in the emergency department (ED) of patients to the right level of care is crucial for patient outcome.

Objectives

The primary aim of this study was to investigate the association of bioactive adrenomedullin (bio-ADM) with mortality among sepsis patients in the ED. Secondary aims were to investigate the association of bio-ADM with multiple organ failure (MOF), ICU admission and ED discharge.

Methods

In this prospective observational cohort study, adult sepsis patients in the ED (2013–2015) had blood samples collected for later batch analysis of bio-ADM. Odds ratios (OR) with 95% confidence interval (CI) for bio-ADM were calculated.

Results

Bio-ADM in 594 sepsis patients was analyzed of whom 51 died within 28 days (8.6%), 34 developed severe MOF, 27 were ICU admitted and 67 were discharged from the ED. The median (interquartile range) bio-ADM was 36 (26–56) and 63 (42–132) pg/mL among survivors and non-survivors, respectively, 81 (56–156) pg/mL for patients with severe MOF and 77 (42–133) pg/mL for ICU admitted patients. Each log-2 increment of bio-ADM conferred an OR of 2.30 (95% CI 1.74–3.04) for mortality, the adjusted OR was 2.39 (95% CI 1.69–3.39). The area under the receiver operating characteristic curve of a prognostic mortality model based on demographics and biomarkers increased from 0.80 to 0.86 (p = 0.02) when bio-ADM was added. Increasing bio-ADM was associated with severe MOF, ICU admission and ED discharge with adjusted ORs of 3.30 (95% CI 2.13–5.11), 1.75 (95% CI 1.11–2.77) and 0.46 (95% CI 0.32–0.68), respectively.

Conclusion

Bio-ADM in sepsis patients in the ED is associated with mortality, severe MOF, ICU admission and ED discharge, and may be of clinical importance for triage of sepsis patients in the ED.

The value of bioactive adrenomedullin and dipeptidyl peptidase 3 to predict short-term unfavourable outcomes after cardiac surgery: A prospective cohort study

BACKGROUND

Adrenomedullin (ADM) is a key regulator of endothelial barrier function and vascular tone. Dipeptidyl peptidase 3 (DPP3) is a protease involved in the degradation of several cardiovascular mediators. Increased levels of bioactive ADM (bio-ADM) and circulating DPP3 (cDPP3) were found to predict short-term outcome in cardiogenic shock patients.

OBJECTIVES

To investigate the unknown temporal profiles of bio-ADM and cDPP3 and their association with short-term outcome following cardiac surgery.

DESIGN

Prospective observational study of 203 adult cardiac surgery patients admitted to the intensive care unit (ICU) postoperatively. Plasma bio-ADM and cDPP3 levels were measured at ICU admission (day 1) and on days 2 and 3.

MAIN OUTCOME MEASURES

Biomarker prediction of prolonged vasopressor dependency (>3 days), acute kidney injury (AKI) and prolonged ICU length of stay (ICU-LOS) (>3 days).

RESULTS

bio-ADM and cDPP3 levels displayed distinct temporal profiles following cardiac surgery. cDPP3 levels were highest on day 1 and strongly correlated with surgical complexity and duration but subsequently normalised on day 2 in most patients. In contrast, bio-ADM levels on day 1 were within the normal range but subsequently increased. Day 2 bio-ADM levels were strongly associated with study outcomes: the area under the receiver-operating curves (AUROC) were 0.82 (95% CI, 0.72 to 0.92) for prolonged vasopressor dependency, 0.87 (0.81 to 0.92) for AKI and 0.82 (0.75 to 0.90) for prolonged ICU-LOS (all P < 0.0001). cDPP3 levels on day 2 also predicted these outcomes, albeit to a lesser extent, with AUROCs of 0.73 (95% CI, 0.64 to 0.81) for prolonged vasopressor dependency, 0.69 (0.61 to 0.77) for AKI and 0.70 (0.62 to 0.79) for prolonged ICU-LOS (all P < 0.0001).

CONCLUSION

Following cardiac surgery, increased bio-ADM levels are strongly associated with unfavourable short-term outcomes, whereas cDPP3 levels are mainly related to surgery complexity and duration. On the basis of these findings, ADM-modulating therapies may have beneficial effects in cardiac surgery patients whereas DPP3-targeted therapies should be reserved for patient categories with higher baseline disease severity.

Bioactive adrenomedullin a prognostic biomarker in patients with mild to moderate dyspnea at the emergency department: an observational study

Acute dyspnea with underlying congestion is a leading cause of emergency department (ED) visits with high rates of hospitalization. Adrenomedullin is a vasoactive neuropeptide hormone secreted by the endothelium that mediates vasodilation and maintains vascular integrity. Plasma levels of biologically active adrenomedullin (bio-ADM) predict septic shock and vasopressor need in critically ill patients and are associated with congestion in patients with acute heart failure (HF) but the prognostic value in unselected dyspneic patients at the ED is unknown. The purpose of this study is to test if bio-ADM predicts adverse outcomes when sampled in patients with acute dyspnea at presentation to the ED. In this single-center prospective observational study, we included 1402 patients from the ADYS (Acute DYSpnea at the Emergency Department) cohort in Malmö, Sweden. We fitted logistic regression models adjusted for sex, age, N-terminal pro-B-type natriuretic peptide (NT-proBNP), creatinine, and C-reactive protein (CRP) to associate bio-ADM plasma levels to mortality, hospitalization, intravenous (IV) diuretic treatment and HF diagnosis. Using receiver operating characteristic (ROC) curve analysis we evaluated bio-ADM discrimination for these outcomes compared to a reference model (sex, age, NT-proBNP, creatinine, and CRP). Model performance was compared by performing a likelihood ratio test on the deviances of the models. Bio-ADM (per interquartile range from median) predicts both 90-day mortality [odds ratio (OR): 1.5, 95% confidence interval (CI) 1.2-2.0, p < 0.002] and hospitalization (OR: 1.5, 95% CI 1.2-1.8, p < 0.001) independently of sex, age, NT-proBNP, creatinine, and CRP. Bio-ADM statistically significantly improves the reference model in predicting mortality (added χ² 9.8, p = 0.002) and hospitalization (added χ² 14.1, p = 0.0002), and is associated with IV diuretic treatment and HF diagnosis at discharge. Plasma levels of bio-ADM sampled at ED presentation in acutely dyspneic patients are independently associated with 90-day mortality, hospitalization and indicate the need for decongestive therapy.

Single-dose of adrecizumab versus placebo in acute cardiogenic shock (ACCOST-HH): an investigator-initiated, randomised, double-blinded, placebo-controlled, multicentre trial

BACKGROUND

Cardiogenic shock has a high mortality on optimal therapy. Adrenomedullin is released during cardiogenic shock and is involved in its pathophysiological processes. This study assessed treatment with the humanised, monoclonal, non-neutralising, adrenomedullin antibody adrecizumab, increasing circulating concentrations of adrenomedullin in cardiogenic shock.

METHODS

In this investigator-initiated, placebo-controlled, double-blind, multicentre, randomised trial (ACCOST-HH), patients were recruited from four university hospitals in Germany. Patients were eligible if they were 18 years old or older and hospitalised for cardiogenic shock within the last 48 h. Exclusion criteria were resuscitation for longer than 60 min and cardiogenic shock due to sustained ventricular tachycardia or bradycardia. Adult patients in cardiogenic shock were randomly assigned (1:1) to intravenous adrecizumab (8 mg/kg bodyweight) or placebo using an internet-based software. A block randomisation procedure was applied with stratification by age (older vs younger than 65 years), sex (male vs female), and type of underlying cardiogenic shock (acute myocardial infarction vs other entities). Investigators, patients, and medical staff involved in patient care were masked to group assignment. The primary endpoint was number of days up to day 30 without the need for cardiovascular organ support, defined as vasopressor therapy, inotropes, or mechanical circulatory support (or both) assessed in the intention-to-treat population. Safety outcomes included therapy-emergent serious adverse events, severe adverse events, adverse events, suspected unexpected serious adverse reactions, study drug-related mortality, and total mortality. The trial was registered at ClinicalTrials.gov, NCT03989531, and EudraCT, 2018-002824-17, and is now complete.

FINDINGS

Between April 5, 2019, and Jan 13, 2021, 150 patients were enrolled: 77 (51%) were randomly assigned to adrecizumab and 73 (49%) to placebo. All patients received the allocated treatment. The number of days without the need for cardiovascular organ support was not different between patients receiving adrecizumab or placebo (12·37 days [95% CI 9·80-14·94] vs 14·05 [11·41-16·69]; adjusted mean difference -1·69 days [-5·37 to 2·00]; p=0·37). Serious adverse events occurred in 59 patients receiving adrecizumab and in 57 receiving placebo (odds ratio 0·92 [95% CI 0·43-1·98]; p=0·83). Mortality was not different between groups at 30 days (hazard ratio 0·99 [95% CI 0·60-1·65]; p=0·98) or 90 days (1·10 [0·68-1·77]; p=0·71).

INTERPRETATION

Adrecizumab was well tolerated in patients with cardiogenic shock but did not reduce the need for cardiovascular organ support or improve survival at days 30 and 90.

FUNDING

Adrenomed AG and University Hospital of Hamburg.

Adrenomedullin Therapy in Moderate to Severe COVID-19

The 2019 coronavirus (COVID-19) pandemic is still in progress, and a significant number of patients have presented with severe illness. Recently introduced vaccines, antiviral medicines, and antibody formulations can suppress COVID-19 symptoms and decrease the number of patients exhibiting severe disease. However, complete avoidance of severe COVID-19 has not been achieved, and more importantly, there are insufficient methods to treat it. Adrenomedullin (AM) is an endogenous peptide that maintains vascular tone and endothelial barrier function. The AM plasma level is markedly increased during severe inflammatory disorders, such as sepsis, pneumonia, and COVID-19, and is associated with the severity of inflammation and its prognosis. In this study, exogenous AM administration reduced inflammation and related organ damage in rodent models. The results of this study strongly suggest that AM could be an alternative therapy in severe inflammation disorders, including COVID-19. We have previously developed an AM formulation to treat inflammatory bowel disease and are currently conducting an investigator-initiated phase 2a trial for moderate to severe COVID-19 using the same formulation. This review presents the basal AM information and the most recent translational AM/COVID-19 study.

Combination of Prehospital NT-proBNP with qSOFA and NEWS to Predict Sepsis and Sepsis-Related Mortality

Background. The aim of this study was to assess the role of prehospital point-of-care N-terminal probrain natriuretic peptide to predict sepsis, septic shock, or in-hospital sepsis-related mortality. Methods. A prospective, emergency medical service-delivered, prognostic, cohort study of adults evacuated by ambulance and admitted to emergency department between January 2020 and May 2021. The discriminative power of the predictive variable was assessed through a prediction model trained using the derivation cohort and evaluated by the area under the curve of the receiver operating characteristic on the validation cohort. Results. A total of 1,360 patients were enrolled with medical disease in the study. The occurrence of sepsis, septic shock, and in-hospital sepsis-related mortality was 6.4% (67 cases), 4.2% (44 cases), and 6.1% (64 cases). Prehospital National Early Warning Score 2 had superior predictive validity than quick Sequential Organ Failure Assessment and N-terminal probrain natriuretic peptide for detecting sepsis and septic shock, but N-terminal probrain natriuretic peptide outperformed both scores in in-hospital sepsis-related mortality estimation. Application of N-terminal probrain natriuretic peptide to subgroups of the other two scores improved the identification of sepsis, septic shock, and sepsis-related mortality in the group of patients with low-risk scoring. Conclusions. The incorporation of N-terminal probrain natriuretic peptide in prehospital care combined with already existing scores could improve the identification of sepsis, septic shock, and sepsis-related mortality.

The course of adrenomedullin and endothelin levels in patients with vasodilatory shock after cardiac surgery compared to patients after uncomplicated elective cardiac surgery

PURPOSE

The aim of this study was to analyse the course of adrenomedullin (ADM) and endothelin-1 (ET-1) levels in patients with vasodilatory shock after cardiac surgery and to explore differences compared to patients after uncomplicated coronary artery bypass graft (CABG) surgery. ADM and ET-1 are involved in the vasomotor response during vasodilatory shock.

MATERIALS AND METHODS

We included 32 patients with vasodilatory shock (study group) and 10 patients after uncomplicated CABG surgery (control group). Daily measurements of MR-proADM and CT-proET-1 (stable surrogate markers for ADM and ET-1) were collected during the first 7 postoperative days.

RESULTS

MR-proADM and CT-proET-1 levels were significantly elevated in the study group when compared to the control group. In addition, the course of both biomarkers was significantly different in the study versus control group. Higher levels of both biomarkers were associated with organ dysfunction (higher maximum multiple organ dysfunction score, acute kidney injury).

CONCLUSIONS

Significantly higher levels of MR-proADM and CT-proET-1 and a different course of both biomarkers were observed in patients with vasodilatory shock after cardiac surgery and seemed to be associated with organ dysfunction.

Are Baseline Levels of Gas6 and Soluble Mer Predictors of Mortality and Organ Damage in Patients with Sepsis? The Need-Speed Trial Database

Soluble tyrosine kinase receptor Mer (sMer) and its ligand Growth arrest-specific protein 6 (Gas6) are predictors of mortality in patients with sepsis. Our aim is to clarify whether their measurement at emergency department (ED) presentation is useful in risk stratification. We re-analyzed data from the Need-Speed trial, evaluating mortality and the presence of organ damage according to baseline levels of sMer and Gas6. 890 patients were eligible; no association with 7- and 30-day mortality was observed for both biomarkers (p > 0.05). sMer and Gas6 levels were significantly higher in acute kidney injury (AKI) patients compared to non-AKI ones (9.8 [4.1–17.8] vs. 7.9 [3.8–12.9] ng/mL and 34.8 [26.4–47.5] vs. 29.8 [22.1–41.6] ng/mL, respectively, for sMer and Gas6), and Gas6 also emerged as an independent AKI predictor (odds ratio (OR) 1.01 [1.00–1.02]). Both sMer and Gas6 independently predicted thrombocytopenia in sepsis patients not treated with anticoagulants (OR 1.01 [1.00–1.02] and 1.04 [1.02–1.06], respectively). Moreover, sMer was an independent predictor of both prothrombin time-international normalized ratio (PT-INR) > 1.4 (OR 1.03 [1.00–1.05]) and sepsis-induced coagulopathy (SIC) (OR 1.05 [1.02–1.07]). An early measurement of the sMer and Gas6 plasma concentration could not predict mortality. However, the biomarkers were associated with AKI, thrombocytopenia, PT-INR derangement and SIC, suggesting a role in predicting sepsis-related organ damage.

Soluble neprilysin and survival in critically ill patients

Background

Critically ill patients admitted to an intensive care unit (ICU) exhibit a high mortality rate irrespective of the initial cause of hospitalization. Neprilysin, a neutral endopeptidase degrading an array of vasoactive peptides became a drug target within the treatment of heart failure with reduced ejection fraction. The aim of this study was to analyse whether circulating levels of neprilysin at ICU admission are associated with 30 day mortality.

Methods and results

In this single‐centre prospective observational study, 222 consecutive patients admitted to a tertiary ICU at a university hospital were included. Blood was drawn at admission and soluble neprilysin levels were measured using ELISA. In the total cohort, soluble neprilysin levels did not differ according to survival status after 30 days as well as type of admission. However, in patients after surgery or heart valve intervention, 30 day survivors exhibited significantly lower circulating neprilysin levels as compared to those who died within 30 days (660.2, IQR: 156.4–2512.5 pg/mL vs. 6532.6, IQR: 1840.1–10 000.0 pg/mL; P = 0.02). Soluble neprilysin predicted mortality independently from age, gender, and commonly used scores of risk‐prediction (EuroSCORE II, STS‐score, and SAPS II score). Additionally, soluble neprilysin was markedly elevated in patients with sepsis and septic shock (P < 0.05).

Conclusion

At the time of ICU admission, circulating levels of neprilysin independently predicted 30 day mortality in patients following cardiac surgery or heart valve intervention, but not in critically ill medical patients. Furthermore, patients suffering from sepsis and septic shock displayed significantly increased circulating neprilysin levels.

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.

[Which biomarkers for diagnosis and guidance of anti-infection treatment in sepsis?]

To date no biomarker has been identified bringing together perfect sensitivity and specificity to discriminate between inflammation and infections. Since the 1930s new markers of tissue damage and endothelial damage have been identified but which are incapable of identifying infections in every clinical setting to enable initiation of early antibiotic treatment. In this review the most important classical biomarkers and upcoming new PCR-based approaches are addressed. These markers are highlighted with respect to special clinical settings and to control the success of antibiotic treatment. The issue of discrimination between inflammation and infection is not yet solved. Based on one single biomarker it is impossible to decide whether infection is the reason for the patient's worsening condition but the combination of biomarkers or the integration of new biomarkers may be a meaningful supplement. The measurement of different biomarkers of infection or inflammation is part of the routine in critical care and will be essential in the future.

Endothelial dysfunction: a therapeutic target in bacterial sepsis?

INTRODUCTION

Endothelial cells maintain vascular integrity, tone, and patency and have important roles in hemostasis and inflammatory responses. Although some degree of endothelial dysfunction with increased vascular permeability may be necessary to control local infection, excessive dysfunction plays a central role in the pathogenesis of sepsis-related organ dysfunction and failure as it results in dysregulated inflammation, vascular leakage, and abnormal coagulation. The vascular endothelium has thus been proposed as a potential target for therapeutic intervention in patients with sepsis.

AREAS COVERED

Different mechanisms underlying sepsis-related dysfunction of the vascular endothelium are discussed, including glycocalyx shedding, nitrosative stress, and coagulation factors. Potential therapeutic implications of each mechanism are mentioned.

EXPERT OPINION

Multiple targets to protect or restore endothelial function have been suggested, but endothelium-driven treatments remain a future potential at present. As some endothelial dysfunction and permeability may be necessary to remove infection and repair damaged tissue, targeting the endothelium may be a particular challenge. Ideally, therapies should be guided by biomarkers related to that specific pathway to ensure they are given only to patients most likely to respond. This enrichment based on biological plausibility and theragnostics will increase the likelihood of a beneficial response in individual patients and enable more personalized treatment.

Rap1 Small GTPase Regulates Vascular Endothelial-Cadherin-Mediated Endothelial Cell-Cell Junctions and Vascular Permeability

The vascular permeability of the endothelium is finely controlled by vascular endothelial (VE)-cadherin-mediated endothelial cell-cell junctions. In the majority of normal adult tissues, endothelial cells in blood vessels maintain vascular permeability at a relatively low level, while in response to inflammation, they limit vascular barrier function to induce plasma leakage and extravasation of immune cells as a defense mechanism. Thus, the dynamic but also simultaneously tight regulation of vascular permeability by endothelial cells is responsible for maintaining homeostasis and, as such, impairments of its underlying mechanisms result in hyperpermeability, leading to the development and progression of various diseases including coronavirus disease 2019 (COVID-19), a newly emerging infectious disease. Recently, increasing numbers of studies have been unveiling the important role of Rap1, a small guanosine 5'-triphosphatase (GTPase) belonging to the Ras superfamily, in the regulation of vascular permeability. Rap1 enhances VE-cadherin-mediated endothelial cell-cell junctions to potentiate vascular barrier functions via dynamic reorganization of the actin cytoskeleton. Importantly, Rap1 signaling activation reportedly improves vascular barrier function in animal models of various diseases associated with vascular hyperpermeability, suggesting that Rap1 might be an ideal target for drugs intended to prevent vascular barrier dysfunction. Here, we describe recent progress in understanding the mechanisms by which Rap1 potentiates VE-cadherin-mediated endothelial cell-cell adhesions and vascular barrier function. We also discuss how alterations in Rap1 signaling are related to vascular barrier dysfunction in diseases such as acute pulmonary injury and malignancies. In addition, we examine the possibility of Rap1 signaling as a target of drugs for treating diseases associated with vascular hyperpermeability.

Safety and tolerability of non-neutralizing adrenomedullin antibody adrecizumab (HAM8101) in septic shock patients: the AdrenOSS-2 phase 2a biomarker-guided trial

Purpose

Investigate safety and tolerability of adrecizumab, a humanized monoclonal adrenomedullin antibody, in septic shock patients with high adrenomedullin.

Methods

Phase-2a, double-blind, randomized, placebo-controlled biomarker-guided trial with a single infusion of adrecizumab (2 or 4 mg/kg b.w.) compared to placebo. Patients with adrenomedullin above 70 pg/mL, < 12 h of vasopressor start for septic shock were eligible. Randomization was 1:1:2. Primary safety (90-day mortality, treatment emergent adverse events (TEAE)) and tolerability (drug interruption, hemodynamics) endpoints were recorded. Efficacy endpoints included the Sepsis Support Index (SSI, reflecting ventilator- and shock-free days alive), change in Sequential-related Organ Failure Assessment (SOFA) and 28-day mortality.

Results

301 patients were enrolled (median time of 8.5 h after vasopressor start). Adrecizumab was well tolerated (one interruption, no hemodynamic alteration) with no differences in frequency and severity in TEAEs between treatment arms (TEAE of grade 3 or higher: 70.5% in the adrecizumab group and 71.1% in the placebo group) nor in 90-day mortality. Difference in change in SSI between adrecizumab and placebo was 0.72 (CI −1.93–0.49, p = 0.24). Among various secondary endpoints, delta SOFA score (defined as maximum versus minimum SOFA) was more pronounced in the adrecizumab combined group compared to placebo [difference at 0.76 (95% CI 0.18–1.35); p = 0.007]. 28-day mortality in the adrecizumab group was 23.9% and 27.7% in placebo with a hazard ratio of 0.84 (95% confidence interval 0.53–1.31, log-rank p = 0.44).

Conclusions

Overall, we successfully completed a randomized trial evaluating selecting patients for enrolment who had a disease-related biomarker. There were no overt signals of harm with using two doses of the adrenomedullin antibody adrecizumab; however, further randomized controlled trials are required to confirm efficacy and safety of this agent in septic shock patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00134-021-06537-5.

Elevated Plasma Bioactive Adrenomedullin and Mortality in Cardiogenic Shock: Results from the OptimaCC Trial

AIMS

Bioactive adrenomedullin (bio-ADM) was recently shown to be a prognostic marker in patients with acute circulatory failure. We investigate the association of bio-ADM with organ injury, functional impairment, and survival in cardiogenic shock (CS).

METHODS

OptimaCC was a multicenter and randomized trial in 57 patients with CS. In this post-hoc analysis, the primary endpoint was to assess the association between bio-ADM and 30-day all-cause mortality. Secondary endpoints included adverse events and parameters of organ injury or functional impairment.

RESULTS

Bio-ADM values were higher in 30-day non-survivors than 30-day survivors at inclusion (median (interquartile range) 67.0 (54.6-142.9) pg/mL vs. 38.7 (23.8-63.6) pg/mL, p = 0.010), at 24 h (p = 0.012), and up to 48 h (p = 0.027). Using a bio-ADM cutoff of 53.8 pg/mL, patients with increased bio-ADM had a HR of 3.90 (95% confidence interval 1.43-10.68, p = 0.008) for 30-day all-cause mortality, and similar results were observed even after adjustment for severity scores. Patients with the occurrence of refractory CS had higher bio-ADM value at inclusion (90.7 (59.9-147.7) pg/mL vs. 40.7 (23.0-64.7) pg/mL p = 0.005). Bio-ADM values at inclusion were correlated with pulmonary vascular resistance index, estimated glomerular filtration rate, and N-terminal pro-B-type natriuretic peptide (r = 0.49, r = -0.47, and r = 0.64, respectively; p < 0.001).

CONCLUSIONS

In CS patients, the values of bio-ADM are associated with some parameters of organ injury and functional impairment and are prognostic for the occurrence of refractory CS and 30-day mortality.

Human adrenomedullin and its binding protein attenuate tissue injury and inflammation following hepatic ischemia reperfusion in rabbits

Background

Liver injury caused by ischemia reperfusion (I/R) during surgical procedures, such as liver resection or liver transplantation, is a major cause of liver damage and graft failure. The current method of treatment is mostly preventative (i.e., ischemic preconditioning). While a number of pharmacological modalities have been studied to reduce hepatic I/R injury, none have been entirely successful. It has been demonstrated that the administration of adrenomedullin (AM) in combination with AM-binding protein (AM/AMBP-1) exerts significant protective effects in various pathological conditions. In an effort to develop AM/AMBP-1 as a novel therapeutic for hepatic I/R injury, the present study examined the effect of a low dose of human AM, which does not induce hypotension, in combination with human AMBP-1 in a rabbit model of hepatic I/R (i.e., non-rodent species).

Methods

Ischemia of 70% of the liver was induced by placing a microvascular clip across the hilum of the left and median lobes for 60 min. The clip was then removed to commence reperfusion. At 15 min following clip removal (i.e., reperfusion), human AM/AMBP-1 was administered intravenously via the ear marginal vein continuously for 30 min. At 20 h, blood and tissue samples were collected for various measurements.

Results

The serum levels of liver enzymes (alanine aminotransferase and aspartate aminotransferase) and lactate dehydrogenase, were elevated following hepatic I/R. The administration of AM/AMBP-1 significantly decreased these levels by 58, 44, 41%, respectively. Hepatic I/R increased the direct and total bilirubin levels, whereas treatment with human AM/AMBP-1 decreased these levels by 60% and 69%, respectively. Treatment with AM/AMBP-1 also inhibited interleukin-6 gene expression by 95%. There were no changes in tumor necrosis factor-α (TNF-α) gene expression and myeloperoxidase activity (MPO), lactate and Suzuki scores after treatment. The treatment, however, reduced apoptosis post-hepatic I/R in the ischemic portion of the liver.

Conclusion

Additional experiments with AM and AMBP-1 alone are needed to completely interpret the experimental results in this non-rodent species of hepatic I/R injury. The present study suggests that human AM/AMBP-1 may be developed as a novel therapeutic to attenuate hepatic I/R associated inflammation and liver injury.

New Agents in Development for Sepsis: Any Reason for Hope?

Sepsis is a syndrome which is defined as a dysregulated host response to infection leading to organ failure. Since it remains one of the leading causes of mortality worldwide, numerous drug candidates have already been tested, and continue to be developed, as potential adjunct therapies. Despite convincing mechanisms of action and robust pre-clinical data, almost all drug candidates in the field of sepsis have failed to demonstrate clinical efficacy in the past two decades. Accordingly, the development of new sepsis drugs has markedly decreased in the past few years. Nevertheless, thanks to a better understanding of sepsis pathophysiology and pathways, new promising drug candidates are currently being developed. Instead of a unique sepsis profile as initially suspected, various phenotypes have been characterised. This has  resulted in the identification of multiple targets for new drugs together with relevant biomarkers, and a better understanding of the most appropriate time to intervention. Within the entire sepsis drugs portfolio, those targeting the immune response are probably the most promising. Monoclonal antibodies targeting either cytokines or infectious agents are undoubtedly part of the potential successful therapeutic classes to come.